@article{IngendohTsakmakidisMikolaiWinkeletal.2019,
  author    = {Ingendoh-Tsakmakidis, Alexandra and Mikolai, Carina and Winkel, Andreas and Szafrański, Szymon P. and Flak, Christine S. and Rossi, Angela and Walles, Heike and Stiesch, Meike},
  title     = {Commensal and pathogenic biofilms differently modulate peri-implant oral mucosa in an organotypic model},
  series = {Cellular Microbiology},
  volume    = {21},
  journal   = {Cellular Microbiology},
  doi       = {10.1111/cmi.13078},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323077},
  year      = {2019},
  abstract  = {The impact of oral commensal and pathogenic bacteria on peri-implant mucosa is not well understood, despite the high prevalence of peri-implant infections. Hence, we investigated responses of the peri-implant mucosa to Streptococcus oralis or Aggregatibacter actinomycetemcomitans biofilms using a novel in vitro peri-implant mucosa-biofilm model. Our 3D model combined three components, organotypic oral mucosa, implant material, and oral biofilm, with structural assembly close to native situation. S. oralis induced a protective stress response in the peri-implant mucosa through upregulation of heat shock protein (HSP70) genes. Attenuated inflammatory response was indicated by reduced cytokine levels of interleukin-6 (IL-6), interleukin-8 (CXCL8), and monocyte chemoattractant protein-1 (CCL2). The inflammatory balance was preserved through increased levels of tumor necrosis factor-alpha (TNF-α). A. actinomycetemcomitans induced downregulation of genes important for cell survival and host inflammatory response. The reduced cytokine levels of chemokine ligand 1 (CXCL1), CXCL8, and CCL2 also indicated a diminished inflammatory response. The induced immune balance by S. oralis may support oral health, whereas the reduced inflammatory response to A. actinomycetemcomitans may provide colonisation advantage and facilitate later tissue invasion. The comprehensive characterisation of peri-implant mucosa-biofilm interactions using our 3D model can provide new knowledge to improve strategies for prevention and therapy of peri-implant disease.},
  language  = {en}
}
@article{MuehlemannZdziebloFriedrichetal.2018,
  author    = {M{\"u}hlemann, Markus and Zdzieblo, Daniela and Friedrich, Alexandra and Berger, Constantin and Otto, Christoph and Walles, Heike and Koepsell, Hermann and Metzger, Marco},
  title     = {Altered pancreatic islet morphology and function in SGLT1 knockout mice on a glucose-deficient, fat-enriched diet},
  series = {Molecular Metabolism},
  volume    = {13},
  journal   = {Molecular Metabolism},
  doi       = {10.1016/j.molmet.2018.05.011},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224230},
  pages     = {67-76},
  year      = {2018},
  abstract  = {Objectives Glycemic control by medical treatment represents one therapeutic strategy for diabetic patients. The Na+-d-glucose cotransporter 1 (SGLT1) is currently of high interest in this context. SGLT1 is known to mediate glucose absorption and incretin secretion in the small intestine. Recently, inhibition of SGLT1 function was shown to improve postprandial hyperglycemia. In view of the lately demonstrated SGLT1 expression in pancreatic islets, we investigated if loss of SGLT1 affects islet morphology and function. Methods Effects associated with the loss of SGLT1 on pancreatic islet (cyto) morphology and function were investigated by analyzing islets of a SGLT1 knockout mouse model, that were fed a glucose-deficient, fat-enriched diet (SGLT1-/--GDFE) to circumvent the glucose-galactose malabsorption syndrome. To distinguish diet- and Sglt1-/--dependent effects, wildtype mice on either standard chow (WT-SC) or the glucose-free, fat-enriched diet (WT-GDFE) were used as controls. Feeding a glucose-deficient, fat-enriched diet further required the analysis of intestinal SGLT1 expression and function under diet-conditions. Results Consistent with literature, our data provide evidence that small intestinal SGLT1 mRNA expression and function is regulated by nutrition. In contrast, pancreatic SGLT1 mRNA levels were not affected by the applied diet, suggesting different regulatory mechanisms for SGLT1 in diverse tissues. Morphological changes such as increased islet sizes and cell numbers associated with changes in proliferation and apoptosis and alterations of the β- and α-cell population are specifically observed for pancreatic islets of SGLT1-/--GDFE mice. Glucose stimulation revealed no insulin response in SGLT1-/--GDFE mice while WT-GDFE mice displayed only a minor increase of blood insulin. Irregular glucagon responses were observed for both, SGLT1-/--GDFE and WT-GDFE mice. Further, both animal groups showed a sustained release of GLP-1 compared to WT-SC controls. Conclusion Loss or impairment of SGLT1 results in abnormal pancreatic islet (cyto)morphology and disturbed islet function regarding the insulin or glucagon release capacity from β- or α-cells, respectively. Consequently, our findings propose a new, additional role for SGLT1 maintaining proper islet structure and function.},
  language  = {en}
}
@article{GoettlichKunzZappetal.2018,
  author    = {G{\"o}ttlich, Claudia and Kunz, Meik and Zapp, Cornelia and Nietzer, Sarah L. and Walles, Heike and Dandekar, Thomas and Dandekar, Gudrun},
  title     = {A combined tissue-engineered/in silico signature tool patient stratification in lung cancer},
  series = {Molecular Oncology},
  volume    = {12},
  journal   = {Molecular Oncology},
  doi       = {10.1002/1878-0261.12323},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233137},
  pages     = {1264-1285},
  year      = {2018},
  abstract  = {Patient-tailored therapy based on tumor drivers is promising for lung cancer treatment. For this, we combined in vitro tissue models with in silico analyses. Using individual cell lines with specific mutations, we demonstrate a generic and rapid stratification pipeline for targeted tumor therapy. We improve in vitro models of tissue conditions by a biological matrix-based three-dimensional (3D) tissue culture that allows in vitro drug testing: It correctly shows a strong drug response upon gefitinib (Gef) treatment in a cell line harboring an EGFR-activating mutation (HCC827), but no clear drug response upon treatment with the HSP90 inhibitor 17AAG in two cell lines with KRAS mutations (H441, A549). In contrast, 2D testing implies wrongly KRAS as a biomarker for HSP90 inhibitor treatment, although this fails in clinical studies. Signaling analysis by phospho-arrays showed similar effects of EGFR inhibition by Gef in HCC827 cells, under both 2D and 3D conditions. Western blot analysis confirmed that for 3D conditions, HSP90 inhibitor treatment implies different p53 regulation and decreased MET inhibition in HCC827 and H441 cells. Using in vitro data (western, phospho-kinase array, proliferation, and apoptosis), we generated cell line-specific in silico topologies and condition-specific (2D, 3D) simulations of signaling correctly mirroring in vitro treatment responses. Networks predict drug targets considering key interactions and individual cell line mutations using the Human Protein Reference Database and the COSMIC database. A signature of potential biomarkers and matching drugs improve stratification and treatment in KRAS-mutated tumors. In silico screening and dynamic simulation of drug actions resulted in individual therapeutic suggestions, that is, targeting HIF1A in H441 and LKB1 in A549 cells. In conclusion, our in vitro tumor tissue model combined with an in silico tool improves drug effect prediction and patient stratification. Our tool is used in our comprehensive cancer center and is made now publicly available for targeted therapy decisions.},
  language  = {en}
}
@article{ColungaHayworthKressetal.2019,
  author    = {Colunga, Thomas and Hayworth, Miranda and Kreß, Sebastian and Reynolds, David M. and Chen, Luoman and Nazor, Kristopher L. and Baur, Johannes and Singh, Amar M. and Loring, Jeanne F. and Metzger, Marco and Dalton, Stephen},
  title     = {Human Pluripotent Stem Cell-Derived Multipotent Vascular Progenitors of the Mesothelium Lineage Have Utility in Tissue Engineering and Repair},
  series = {Cell Reports},
  volume    = {26},
  journal   = {Cell Reports},
  doi       = {10.1016/j.celrep.2019.02.016},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223217},
  pages     = {2566-2579},
  year      = {2019},
  abstract  = {In this report we describe a human pluripotent stem cell-derived vascular progenitor (MesoT) cell of the mesothelium lineage. MesoT cells are multipotent and generate smooth muscle cells, endothelial cells, and pericytes and self-assemble into vessel-like networks in vitro. MesoT cells transplanted into mechanically damaged neonatal mouse heart migrate into the injured tissue and contribute to nascent coronary vessels in the repair zone. When seeded onto decellularized vascular scaffolds, MesoT cells differentiate into the major vascular lineages and self-assemble into vasculature capable of supporting peripheral blood flow following transplantation. These findings demonstrate in vivo functionality and the potential utility of MesoT cells in vascular engineering applications.},
  language  = {en}
}
@article{FahmyGarciaFarrellWitteBoumaetal.2019,
  author    = {Fahmy-Garcia, Shorouk and Farrell, Eric and Witte-Bouma, Janneke and Robbesom-van den Berge, Iris and Suarez, Melva and Mumcuoglu, Didem and Walles, Heike and Kluijtmans, Sebastiaan G. J. M. and van der Eerden, Bram C. J. and van Osch, Gerjo J. V. M. and van Leeuwen, Johannes P. T. M. and van Driel, Marjolein},
  title     = {Follistatin Effects in Migration, Vascularization, and Osteogenesis in vitro and Bone Repair in vivo},
  series = {Frontiers in Bioengineering and Biotechnology},
  volume    = {7},
  journal   = {Frontiers in Bioengineering and Biotechnology},
  doi       = {10.3389/fbioe.2019.00038},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227617},
  year      = {2019},
  abstract  = {The use of biomaterials and signaling molecules to induce bone formation is a promising approach in the field of bone tissue engineering. Follistatin (FST) is a glycoprotein able to bind irreversibly to activin A, a protein that has been reported to inhibit bone formation. We investigated the effect of FST in critical processes for bone repair, such as cell recruitment, osteogenesis and vascularization, and ultimately its use for bone tissue engineering. In vitro, FST promoted mesenchymal stem cell (MSC) and endothelial cell (EC) migration as well as essential steps in the formation and expansion of the vasculature such as EC tube-formation and sprouting. FST did not enhance osteogenic differentiation of MSCs, but increased committed osteoblast mineralization. In vivo, FST was loaded in an in situ gelling formulation made by alginate and recombinant collagen-based peptide microspheres and implanted in a rat calvarial defect model. Two FST variants (FST288 and FST315) with major differences in their affinity to cell-surface proteoglycans, which may influence their effect upon in vivo bone repair, were tested. In vitro, most of the loaded FST315 was released over 4 weeks, contrary to FST288, which was mostly retained in the biomaterial. However, none of the FST variants improved in vivo bone healing compared to control. These results demonstrate that FST enhances crucial processes needed for bone repair. Further studies need to investigate the optimal FST carrier for bone regeneration.},
  language  = {en}
}
@phdthesis{MathewSchmitt2024,
  author    = {Mathew-Schmitt, Sanjana},
  title     = {Development of blood-brain barrier spheroid models based on human induced pluripotent stem cells (hiPSCs) and investigation of shear stress on hiPSC-derived brain capillary endothelial-like cells},
  doi       = {10.25972/OPUS-32247},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322475},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {A highly regulated microenvironment is essential in maintaining normal functioning of the central nervous system (CNS). The existence of a biological barrier, termed as the blood-brain barrier (BBB), at the blood to brain interface effectively allows for selective passage of substances and pathogens into the brain (Kadry, Noorani et al. 2020). The BBB chiefly serves in protecting the brain from extrinsic toxin entry and pathogen invasions. The BBB is formed mainly by brain capillary endothelial cells (BCECs) which are responsible for excluding ∼ 100\% of large-molecule neurotherapeutics and more than 98\% of all small-molecule drugs from entry into the brain. Minimal BBB transport of major potential CNS drugs allows for attenuated effective treatments for majority of CNS disorders (Appelt-Menzel, Oerter et al. 2020). Animals are generally used as model systems to study neurotherapeutic delivery into the brain, however due to species based disparity, experimental animal models lead to several false positive or false negative drug efficacy predictions thereby being unable to fully predict effects in humans (Ruck, Bittner et al. 2015). An example being that over the last two decades, much of the studies involving animals lead to high failure rates in drug development with ~ 97\% failure in cancers and ~ 99\% failure for Alzheimer´s disease (Pound 2020). Widespead failures in clinical trials associated with neurological disorders have resulted in questions on whether existing preclinical animal models are genuinely reflective of the human condition (Bhalerao, Sivandzade et al. 2020). Apart from high failure rates in humans, the costs for animal testings is extremely high. According to the Organisation for Economic Co-operation and Development (OECD), responsible for determining animal testing guidelines and methodology for government, industry, and independent laboratories the average cost of a single two-generation reproductive animal toxicity study worldwide is 318,295 € and for Europe alone is ~ 285,842 € (Van Norman 2019). Due to these reasons two separate movements exist within the scientific world, one being to improve animal research and the other to promote new approach methodologies with the European government setting 2025 - 2035 as a deadline for gradually disposing the use of animals in pharmaceutical testing (Pound 2020). The discovery of human induced pluripotent stem cell (hiPSC) technology in 2006 (Takahashi and Yamanaka 2006, Takahashi, Tanabe et al. 2007) revolutionized the field of drug discovery in-vitro. HiPSCs can be differentiated into various tissue types that mimic disease phenotypes, thereby offering the possibility to deliver humanized in-vitro test systems. With respect to the BBB, several strategies to differentiate hiPSCs to BCECs (iBCECs) are reported over the years (Appelt-Menzel, Oerter et al. 2020). However, iBCECs are said to possess an epithelial or undifferentiated phenotype causing incongruity in BBB lineage specifications (Lippmann, 7 Azarin et al. 2020). Therefore, in order to identify a reliable differentiation strategy in deriving iBCECs possessing hallmark BBB characteristics, which can be used for downstream applications, the work in this thesis compared two methods, namely the co-differentiation (CD) and the directed differentiation (DD). Briefly, CD mimics a brain like niche environment for iBCEC specification (Lippmann, Al-Ahmad et al. 2014), while DD focuses on induction of the mesoderm followed by iBCEC specification (Qian, Maguire et al. 2017). The results obtained verified that while iBCECs derived via CD, in comparison to human BCEC cell line hCMEC/D3 showed the presence of epithelial transcripts such as E-Cadherin (CDH1), and gene level downregulation of endothelial specific platelet endothelial cell adhesion molecule-1 (PECAM-1) and VE-cadherin (CDH5) but demonstrated higher barrier integrity. The CD strategy essentially presented iBCECs with a mean trans-endothelial electrical resistance (TEER) of ~ 2000 - 2500 Ω*cm2 and low permeability coefficients (PC) of < 0.50 μm/min for small molecule transport of sodium fluorescein (NaF) and characteristic BCEC tight junction (TJ) protein expression of claudin-5 and occludin. Additionally, iBCECs derived via CD did not form tubes in response to angiogenic stimuli. DD on the other hand resulted in iBCECs with similar down regulations in PECAM-1 and CDH5 gene expression. They were additionally characterized by lower barrier integrity, measured by mean TEER of only ~ 250 - 450 Ω*cm2 and high PC of > 5 μm/min in small molecule transport of NaF. Although iBCECs derived via DD formed tubes in response to angiogenic stimuli, they did not show positive protein expression of characteristic BCEC TJs such as claudin-5 and occludin. These results led to the hypothesis that maturity and lineage specification of iBCECs could be improved by incorporating in-vivo like characteristics in-vitro, such as direct co-culture with neurovascular unit (NVU) cell types via spheroid formation and by induction of shear stress and fluid flow. In comparison to standard iBCEC transwell mono-cultures, BBB spheroids showed enhanced transcript expression of PECAM-1 and reduced expression of epithelial markers such as CDH1 and claudin-6 (CLDN6). BBB spheroids showed classical BCEC-like ultrastructure that was identified by TJ particles on the protoplasmic face (P-face) and exoplasmic face (E-face) of the plasma membrane. TJ strands were organized as particles and particle-free grooves on the E-face, while on the P-face, partly beaded particles and partly continuous strands were identified. BBB spheroids also showed positive protein expression of claudin-5, VE-cadherin, PECAM-1, glucose transporter-1 (GLUT-1), P-glycoprotein (P-gp) and transferrin receptor-1 (Tfr-1). BBB spheroids demonstrated higher relative impedance percentages in comparison to spheroids without an iBCEC barrier. Barrier integrity assessments additionally corresponded with lower permeability to small molecule tracer NaF, with spheroids containing iBCECs showing higher relative fluorescence unit percentages (RFU\%) of ~ 90\% in apical compartments, compared to ~ 80\% in spheroids without iBCECs. In summary, direct cellular contacts in the complex spheroid model resulted in enhanced maturation of iBCECs. 8 A bioreactor system was used to further assess the effect of shear stress. This system enabled inclusion of fluidic flow and shear stress conditions in addition to non-invasive barrier integrity measurements (Choi, Mathew et al. 2022). iBCECs were cultured for a total of seven days post differentiation (d17) within the bioreactor and barrier integrity was non-invasively monitored. Until d17 of long-term culture, TEER values of iBCECs steadily dropped from ~ 1800 Ω*cm2 ~ 400 Ω*cm2 under static conditions and from ~ 2500 Ω*cm2 to ~ 250 Ω*cm2 under dynamic conditions. Transcriptomic analyses, morphometric analyses and protein marker expression showed enhanced maturation of iBECs under long-term culture and dynamic flow. Importantly, on d10 claudin-5 was expressed mostly in the cytoplasm with only ~ 5\% iBCECs showing continuous staining at the cell borders. With increase in culture duration, iBCECs at d17 of static culture showed ~ 18\% of cells having continuous cell border expression, while dynamic conditions showed upto ~ 30\% of cells with continuous cell-cell border expression patterns. Similarly, ~ 33\% of cells showed cell-cell border expression of occludin on d10 with increases to ~ 55\% under d17 static and up to ~ 65\% under d17 dynamic conditions, thereby indicating iBCEC maturation. In conclusion, the data presented within this thesis demonstrates the maturation of iBCECs in BBB spheroids, obtained via direct cellular contacts and by the application of flow and shear stress. Both established novel models need to be further validated for pharmaceutical drug applications together with in-vitro-in-vivo correlations in order to exploit their full potential.},
  subject      = {Blut-Hirn-Schranke},
  language  = {en}
}
@article{SchwabMeeuwsenEhlickeetal.2017,
  author    = {Schwab, Andrea and Meeuwsen, Annick and Ehlicke, Franziska and Hansmann, Jan and Mulder, Lars and Smits, Anthal and Walles, Heike and Kock, Linda},
  title     = {Ex vivo culture platform for assessment of cartilage repair treatment strategies},
  series = {ALTEX - Alternatives to animal experimentation},
  volume    = {34},
  journal   = {ALTEX - Alternatives to animal experimentation},
  number    = {2},
  doi       = {10.14573/altex.1607111},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181665},
  pages     = {267-277},
  year      = {2017},
  abstract  = {There is a great need for valuable ex vivo models that allow for assessment of cartilage repair strategies to reduce the high number of animal experiments. In this paper we present three studies with our novel ex vivo osteochondral culture platform. It consists of two separated media compartments for cartilage and bone, which better represents the in vivo situation and enables supply of factors pecific to the different needs of bone and cartilage. We investigated whether separation of the cartilage and bone compartments and/or culture media results in the maintenance of viability, structural and functional properties of cartilage tissue. Next, we valuated for how long we can preserve cartilage matrix stability of osteochondral explants during long-term culture over 84 days. Finally, we determined the optimal defect size that does not show spontaneous self-healing in this culture system. It was demonstrated that separated compartments for cartilage and bone in combination with tissue-specific medium allow for long-term culture of osteochondral explants while maintaining cartilage viability, atrix tissue content, structure and mechanical properties for at least 56 days. Furthermore, we could create critical size cartilage defects of different sizes in the model. The osteochondral model represents a valuable preclinical ex vivo tool for studying clinically relevant cartilage therapies, such as cartilage biomaterials, for their regenerative potential, for evaluation of drug and cell therapies, or to study mechanisms of cartilage regeneration. It will undoubtedly reduce the number of animals needed for in vivotesting.},
  language  = {en}
}
@article{WeissenbergerWagenbrennerNickeletal.2023,
  author    = {Weißenberger, Manuel and Wagenbrenner, Mike and Nickel, Joachim and Ahlbrecht, Rasmus and Blunk, Torsten and Steinert, Andre F. and Gilbert, Fabian},
  title     = {Comparative in vitro treatment of mesenchymal stromal cells with GDF-5 and R57A induces chondrogenic differentiation while limiting chondrogenic hypertrophy},
  series = {Journal of Experimental Orthopaedics},
  volume    = {10},
  journal   = {Journal of Experimental Orthopaedics},
  doi       = {10.1186/s40634-023-00594-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357770},
  year      = {2023},
  abstract  = {Purpose Hypertrophic cartilage is an important characteristic of osteoarthritis and can often be found in patients suffering from osteoarthritis. Although the exact pathomechanism remains poorly understood, hypertrophic de-differentiation of chondrocytes also poses a major challenge in the cell-based repair of hyaline cartilage using mesenchymal stromal cells (MSCs). While different members of the transforming growth factor beta (TGF-β) family have been shown to promote chondrogenesis in MSCs, the transition into a hypertrophic phenotype remains a problem. To further examine this topic we compared the effects of the transcription growth and differentiation factor 5 (GDF-5) and the mutant R57A on in vitro chondrogenesis in MSCs. Methods Bone marrow-derived MSCs (BMSCs) were placed in pellet culture and in-cubated in chondrogenic differentiation medium containing R57A, GDF-5 and TGF-ß1 for 21 days. Chondrogenesis was examined histologically, immunohistochemically, through biochemical assays and by RT-qPCR regarding the expression of chondrogenic marker genes. Results Treatment of BMSCs with R57A led to a dose dependent induction of chondrogenesis in BMSCs. Biochemical assays also showed an elevated glycosaminoglycan (GAG) content and expression of chondrogenic marker genes in corresponding pellets. While treatment with R57A led to superior chondrogenic differentiation compared to treatment with the GDF-5 wild type and similar levels compared to incubation with TGF-ß1, levels of chondrogenic hypertrophy were lower after induction with R57A and the GDF-5 wild type. Conclusions R57A is a stronger inducer of chondrogenesis in BMSCs than the GDF-5 wild type while leading to lower levels of chondrogenic hypertrophy in comparison with TGF-ß1.},
  language  = {en}
}
@article{ReuterHaufImdahletal.2023,
  author    = {Reuter, Christian and Hauf, Laura and Imdahl, Fabian and Sen, Rituparno and Vafadarnejad, Ehsan and Fey, Philipp and Finger, Tamara and Jones, Nicola G. and Walles, Heike and Barquist, Lars and Saliba, Antoine-Emmanuel and Groeber-Becker, Florian and Engstler, Markus},
  title     = {Vector-borne Trypanosoma brucei parasites develop in artificial human skin and persist as skin tissue forms},
  series = {Nature Communications},
  volume    = {14},
  journal   = {Nature Communications},
  doi       = {10.1038/s41467-023-43437-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358142},
  year      = {2023},
  abstract  = {Transmission of Trypanosoma brucei by tsetse flies involves the deposition of the cell cycle-arrested metacyclic life cycle stage into mammalian skin at the site of the fly's bite. We introduce an advanced human skin equivalent and use tsetse flies to naturally infect the skin with trypanosomes. We detail the chronological order of the parasites' development in the skin by single-cell RNA sequencing and find a rapid activation of metacyclic trypanosomes and differentiation to proliferative parasites. Here we show that after the establishment of a proliferative population, the parasites enter a reversible quiescent state characterized by slow replication and a strongly reduced metabolism. We term these quiescent trypanosomes skin tissue forms, a parasite population that may play an important role in maintaining the infection over long time periods and in asymptomatic infected individuals.},
  language  = {en}
}
@article{BasslerKnoblichGerhardHartmannetal.2023,
  author    = {Bassler, Miriam C. and Knoblich, Mona and Gerhard-Hartmann, Elena and Mukherjee, Ashutosh and Youssef, Almoatazbellah and Hagen, Rudolf and Haug, Lukas and Goncalves, Miguel and Scherzad, Agmal and St{\"o}th, Manuel and Ostertag, Edwin and Steinke, Maria and Brecht, Marc and Hackenberg, Stephan and Meyer, Till Jasper},
  title     = {Differentiation of salivary gland and salivary gland tumor tissue via Raman imaging combined with multivariate data analysis},
  series = {Diagnostics},
  volume    = {14},
  journal   = {Diagnostics},
  number    = {1},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics14010092},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-355558},
  year      = {2023},
  abstract  = {Salivary gland tumors (SGTs) are a relevant, highly diverse subgroup of head and neck tumors whose entity determination can be difficult. Confocal Raman imaging in combination with multivariate data analysis may possibly support their correct classification. For the analysis of the translational potential of Raman imaging in SGT determination, a multi-stage evaluation process is necessary. By measuring a sample set of Warthin tumor, pleomorphic adenoma and non-tumor salivary gland tissue, Raman data were obtained and a thorough Raman band analysis was performed. This evaluation revealed highly overlapping Raman patterns with only minor spectral differences. Consequently, a principal component analysis (PCA) was calculated and further combined with a discriminant analysis (DA) to enable the best possible distinction. The PCA-DA model was characterized by accuracy, sensitivity, selectivity and precision values above 90\% and validated by predicting model-unknown Raman spectra, of which 93\% were classified correctly. Thus, we state our PCA-DA to be suitable for parotid tumor and non-salivary salivary gland tissue discrimination and prediction. For evaluation of the translational potential, further validation steps are necessary.},
  language  = {en}
}
@phdthesis{Kuehnemundt2024,
  author    = {K{\"u}hnemundt, Johanna},
  title     = {Defined microphysiologic 3D tumour models with aspects from the tumour microenvironment for the evaluation of cellular immunotherapies},
  doi       = {10.25972/OPUS-27667},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276674},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Adoptive cellular immunotherapy with chimeric antigen receptor (CAR) T cells is highly effective in haematological malignancies. This success, however, has not been achieved in solid tumours so far. In contrast to hematologic malignancies, solid tumours include a hostile tumour microenvironment (TME), that poses additional challenges for curative effects and consistent therapeutic outcome. These challenges manifest in physical and immunological barriers that dampen efficacy of the CAR T cells. Preclinical testing of novel cellular immunotherapies is performed mainly in 2D cell culture and animal experiments. While 2D cell culture is an easy technique for efficacy analysis, animal studies reveal information about toxicity in vivo. However, 2D cell culture cannot fully reflect the complexity observed in vivo, because cells are cultured without anchorage to a matrix and only short-term periods are feasible. Animal studies provide a more complex tissue environment, but xenografts often lack human stroma and tumour inoculation occurs mostly ectopically. This emphasises the need for standardisable and scalable tumour models with incorporated TME-aspects, which enable preclinical testing with enhanced predictive value for the clinical outcome of immunotherapies. Therefore, microphysiologic 3D tumour models based on the biological SISmuc (Small Intestinal mucosa and Submucosa) matrix with preserved basement membrane were engaged and improved in this work to serve as a modular and versatile tumour model for efficacy testing of CAR T cells. In order to reflect a variety of cancer entities, TME-aspects, long-term stability and to enhance the read-out options they were further adapted to achieve scalable and standardisable defined microphysiologic 3D tumour models. In this work, novel culture modalities (semi-static, sandwich-culture) were characterised and established that led to an increased and organised tissue generation and long-term stability. Application of the SISmuc matrix was extended to sarcoma and melanoma models and serial bioluminescence intensity (BLI)-based in vivo imaging analysis was established in the microphysiologic 3D tumour models, which represents a time-efficient read-out method for quality evaluation of the models and treatment efficacy analysis, that is independent of the cell phenotype. Isolation of cancer-associated-fibroblasts (CAFs) from lung (tumour) tissue was demonstrated and CAF-implementation further led to stromal-enriched microphysiologic 3D tumour models with in vivo-comparable tissue-like architecture. Presence of CAFs was confirmed by CAF-associated markers (FAP, α-SMA, MMP-2/-9) and cytokines correlated with CAF phenotype, angiogenesis, invasion and immunomodulation. Additionally, an endothelial cell barrier was implemented for static and dynamic culture in a novel bioreactor set-up, which is of particular interest for the analysis of immune cell diapedesis. Studies in microphysiologic 3D Ewing's sarcoma models indicated that sarcoma cells could be sensitised for GD2-targeting CAR T cells. After enhancing the scale of assessment of the microphysiologic 3D tumour models and improving them for CAR T cell testing, the tumour models were used to analyse their sensitivity towards differently designed receptor tyrosine kinase-like orphan receptor 1 (ROR1) CAR T cells and to study the effects of the incorporated TME-aspects on the CAR T cell treatment respectively. ROR1 has been described as a suitable target for several malignancies including triple negative breast cancer (TNBC), as well as lung cancer. Therefore, microphysiologic 3D TNBC and lung cancer models were established. Analysis of ROR1 CAR T cells that differed in costimulation, spacer length and targeting domain, revealed, that the microphysiologic 3D tumour models are highly sensitive and can distinguish optimal from sub-optimal CAR design. Here, higher affinity of the targeting domain induced stronger anti-tumour efficacy and anti-tumour function depended on spacer length, respectively. Long-term treatment for 14 days with ROR1 CAR T cells was demonstrated in dynamic microphysiologic 3D lung tumour models, which did not result in complete tumour cell removal, whereas direct injection of CAR T cells into TNBC and lung tumour models represented an alternative route of application in addition to administration via the medium flow, as it induced strong anti-tumour response. Influence of the incorporated TME-aspects on ROR1 CAR T cell therapy represented by CAF-incorporation and/or TGF-β supplementation was analysed. Presence of TGF-β revealed that the specific TGF-β receptor inhibitor SD-208 improves ROR1 CAR T cell function, because it effectively abrogated immunosuppressive effects of TGF-β in TNBC models. Implementation of CAFs should provide a physical and immunological barrier towards ROR1 CAR T cells, which, however, was not confirmed, as ROR1 CAR T cell function was retained in the presence of CAFs in stromal-enriched microphysiologic 3D lung tumour models. The absence of an effect of CAF enrichment on CAR T cell efficacy suggests a missing component for the development of an immunosuppressive TME, even though immunomodulatory cytokines were detected in co-culture models. Finally, improved gene-edited ROR1 CAR T cells lacking exhaustion-associated genes (PD-1, TGF-β-receptor or both) were challenged by the combination of CAF-enrichment and TGF-β in microphysiologic 3D TNBC models. Results indicated that the absence of PD-1 and TGF-β receptor leads to improved CAR T cells, that induce strong tumour cell lysis, and are protected against the hostile TME. Collectively, the microphysiologic 3D tumour models presented in this work reflect aspects of the hostile TME of solid tumours, engage BLI-based analysis and provide long-term tissue homeostasis. Therefore, they present a defined, scalable, reproducible, standardisable and exportable model for translational research with enhanced predictive value for efficacy testing and candidate selection of cellular immunotherapy, as exemplified by ROR1 CAR T cells.},
  subject      = {Immuntherapie},
  language  = {en}
}
@phdthesis{Choi2024,
  author    = {Choi, Jihyoung},
  title     = {Development of an Add-On Electrode for Non-Invasive Monitoring in Bioreactor Cultures and Medical Devices},
  doi       = {10.25972/OPUS-35823},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358232},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Electrochemical impedance spectroscopy (EIS) is a valuable technique analyzing electrochemical behavior of biological systems such as electrical characterization of cells and biomolecules, drug screening, and biomaterials in biomedical field. In EIS, an alternating current (AC) power signal is applied to the biological system, and the impedance of the system is measured over a range of frequencies. In vitro culture models of endothelial or epithelial barrier tissue can be achieved by culturing barrier tissue on scaffolds made with synthetic or biological materials that provide separate compartments (apical and basal sides), allowing for further studies on drug transport. EIS is a great candidate for non-invasive and real-time monitoring of the electrical properties that correlate with barrier integrity during the tissue modeling. Although commercially available transendothelial/transepithelial electrical resistance (TEER) measurement devices are widely used, their use is particularly common in static transwell culture. EIS is considered more suitable than TEER measurement devices in bioreactor cultures that involve dynamic fluid flow to obtain accurate and reliable measurements. Furthermore, while TEER measurement devices can only assess resistance at a single frequency, EIS measurements can capture both resistance and capacitance properties of cells, providing additional information about the cellular barrier's characteristics across various frequencies. Incorporating EIS into a bioreactor system requires the careful optimization of electrode integration within the bioreactor setup and measurement parameters to ensure accurate EIS measurements. Since bioreactors vary in size and design depending on the purpose of the study, most studies have reported using an electrode system specifically designed for a particular bioreactor. The aim of this work was to produce multi-applicable electrodes and established methods for automated non-invasive and real-time monitoring using the EIS technique in bioreactor cultures. Key to the electrode material, titanium nitride (TiN) coating was fabricated on different substrates (materials and shape) using physical vapor deposition (PVD) and housed in a polydimethylsiloxane (PDMS) structure to allow the electrodes to function as independent units. Various electrode designs were evaluated for double-layer capacitance and morphology using EIS and scanning electron microscopy (SEM), respectively. The TiN-coated tube electrode was identified as the optimal choice. Furthermore, EIS measurements were performed to examine the impact of influential parameters related to culture conditions on the TiN-coated electrode system. In order to demonstrate the versatility of the electrodes, these electrodes were then integrated into in different types of perfusion bioreactors for monitoring barrier cells. Blood-brain barrier (BBB) cells were cultured in the newly developed dynamic flow bioreactor, while human umblical vascular endothelial cells (HUVECs) and Caco-2 cells were cultured in the miniature hollow fiber bioreactor (HFBR). As a result, the TiN-coated tube electrode system enabled investigation of BBB barrier integrity in long-term bioreactor culture. While EIS measurement could not detect HUVECs electrical properties in miniature HFBR culture, there was the possibility of measuring the barrier integrity of Caco-2 cells, indicating potential usefulness for evaluating their barrier function. Following the bioreactor cultures, the application of the TiN-coated tube electrode was expanded to hemofiltration, based on the hypothesis that the EIS system may be used to monitor clotting or clogging phenomena in hemofiltration. The findings suggest that the EIS monitoring system can track changes in ion concentration of blood before and after hemofiltration in real-time, which may serve as an indicator of clogging of filter membranes. Overall, our research demonstrates the potential of TiN-coated tube electrodes for sensitive and versatile non-invasive monitoring in bioreactor cultures and medical devices.},
  subject      = {Monitoring},
  language  = {en}
}
@article{SiverinoFahmyGarciaNiklausetal.2023,
  author    = {Siverino, Claudia and Fahmy-Garcia, Shorouk and Niklaus, Viktoria and Kops, Nicole and Dolcini, Laura and Misciagna, Massimiliano Maraglino and Ridwan, Yanto and Farrell, Eric and van Osch, Gerjo J. V. M. and Nickel, Joachim},
  title     = {Addition of heparin binding sites strongly increases the bone forming capabilities of BMP9 in vivo},
  series = {Bioactive Materials},
  volume    = {29},
  journal   = {Bioactive Materials},
  doi       = {10.1016/j.bioactmat.2023.07.010},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350470},
  pages     = {241-250},
  year      = {2023},
  abstract  = {Highlights • Despite not being crucial for bone development BMP9 can induce bone growth in vivo. • BMP9 induced bone formation is strongly enhanced by introduced heparin binding sites. • BMP9s bone forming capabilities are triggered by extracellular matrix binding. • Heparin binding BMP9 (BMP9 HB) can improve the current therapies in treating bone fractures. Abstract Bone Morphogenetic proteins (BMPs) like BMP2 and BMP7 have shown great potential in the treatment of severe bone defects. In recent in vitro studies, BMP9 revealed the highest osteogenic potential compared to other BMPs, possibly due to its unique signaling pathways that differs from other osteogenic BMPs. However, in vivo the bone forming capacity of BMP9-adsorbed scaffolds is not superior to BMP2 or BMP7. In silico analysis of the BMP9 protein sequence revealed that BMP9, in contrast to other osteogenic BMPs such as BMP2, completely lacks so-called heparin binding motifs that enable extracellular matrix (ECM) interactions which in general might be essential for the BMPs' osteogenic function. Therefore, we genetically engineered a new BMP9 variant by adding BMP2-derived heparin binding motifs to the N-terminal segment of BMP9′s mature part. The resulting protein (BMP9 HB) showed higher heparin binding affinity than BMP2, similar osteogenic activity in vitro and comparable binding affinities to BMPR-II and ALK1 compared to BMP9. However, remarkable differences were observed when BMP9 HB was adsorbed to collagen scaffolds and implanted subcutaneously in the dorsum of rats, showing a consistent and significant increase in bone volume and density compared to BMP2 and BMP9. Even at 10-fold lower BMP9 HB doses bone tissue formation was observed. This innovative approach of significantly enhancing the osteogenic properties of BMP9 simply by addition of ECM binding motifs, could constitute a valuable replacement to the commonly used BMPs. The possibility to use lower protein doses demonstrates BMP9 HB's high translational potential.},
  language  = {en}
}
@phdthesis{Peindl2024,
  author    = {Peindl, Matthias},
  title     = {Refinement of 3D lung cancer models for automation and patient stratification with mode-of-action studies},
  doi       = {10.25972/OPUS-31069},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-310693},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Lung cancer is the main cause of cancer-related deaths worldwide. Despite the availability of several targeted therapies and immunotherapies in the clinics, the prognosis for lung cancer remains poor. A major problem for the low benefit of these therapies is intrinsic and acquired resistance, asking for pre-clinical models for closer investigation of predictive biomarkers for refined personalized medicine and testing of possible combination therapies as well as novel therapeutic approaches to break resistances. One third of all lung adenocarcinoma harbor mutations in the KRAS gene, of which 39 \% are transitions from glycine to cysteine in codon 12 (KRASG12C). Being considered "undruggable" in previous decades, KRASG12C-inhibitors now paved the way into the standard-of-care for lung adenocarcinoma treatment in the clinics. Still, the overall response rates as well as overall survival of patients treated with KRASG12C-inhibitors are sobering. Therefore, 3D KRASG12C-biomarker in vitro models were developed based on a decellularized porcine jejunum (SISmuc) using commercial and PDX-derived cell lines and characterized in regards of epithelial-mesenchymal-transition (EMT), stemness, proliferation, invasion and c-MYC expression as well as the sensitivity towards KRASG12C-inhibiton. The phenotype of lung tumors harboring KRAS mutations together with a c-MYC overexpression described in the literature regarding invasion and proliferation for in vivo models was well represented in the SISmuc models. A higher resistance towards targeted therapies was validated in the 3D models compared to 2D cultures, while reduced viability after treatment with combination therapies were exclusively observed in the 3D models. In the test system neither EMT, stemness nor the c-MYC expression were directly predictive for drug sensitivity. Testing of a panel of combination therapies, a sensitizing effect of the aurora kinase A (AURKA) inhibitor alisertib for the KRASG12C-inhibitor ARS-1620 directly correlating with the level of c-MYC expression in the corresponding 3D models was observed. Thereby, the capability of SISmuc tumor models as an in vitro test system for patient stratification was demonstrated, holding the possibility to reduce animal experiments. Besides targeted therapies the treatment of NSCLC with oncolytic viruses (OVs) is a promising approach. However, a lack of in vitro models to test novel OVs limits the transfer from bench to bedside. In this study, 3D NSCLC models based on the SISmuc were evaluated for their capability to perform efficacy and risk assessment of oncolytic viruses (OVs) in a pre-clinical setting. Hereby, the infection of cocultures of tumor cells and fibroblasts on the SISmuc with provided viruses demonstrated that in contrast to a wildtype herpes simplex virus 1 (HSV-1) based OV, the attenuated version of the OV exhibited specificity for NSCLC cells with a more advanced and highly proliferative phenotype, while fibroblasts were no longer permissive for infection. This approach introduced SISmuc tumor models as novel test system for in vitro validation of OVs. Finally, a workflow for validating the efficacy of anti-cancer therapies in 3D tumor spheroids was established for the transfer to an automated platform based on a two-arm-robot system. In a proof-of-concept process, H358 spheroids were characterized and treated with the KRASG12C-inhibitor ARS-1620. A time- and dose-dependent reduction of the spheroid area after treatment was defined together with a live/dead-staining as easy-to-perform and cost-effective assays for automated drug testing that can be readily performed in situ in an automated system.},
  subject      = {Krebs <Medizin>},
  language  = {en}
}
@article{DaeullaryImdahlDietrichetal.2023,
  author    = {D{\"a}ullary, Thomas and Imdahl, Fabian and Dietrich, Oliver and Hepp, Laura and Krammer, Tobias and Fey, Christina and Neuhaus, Winfried and Metzger, Marco and Vogel, J{\"o}rg and Westermann, Alexander J. and Saliba, Antoine-Emmanuel and Zdzieblo, Daniela},
  title     = {A primary cell-based in vitro model of the human small intestine reveals host olfactomedin 4 induction in response to Salmonella Typhimurium infection},
  series = {Gut Microbes},
  volume    = {15},
  journal   = {Gut Microbes},
  number    = {1},
  doi       = {10.1080/19490976.2023.2186109},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350451},
  year      = {2023},
  abstract  = {Infection research largely relies on classical cell culture or mouse models. Despite having delivered invaluable insights into host-pathogen interactions, both have limitations in translating mechanistic principles to human pathologies. Alternatives can be derived from modern Tissue Engineering approaches, allowing the reconstruction of functional tissue models in vitro. Here, we combined a biological extracellular matrix with primary tissue-derived enteroids to establish an in vitro model of the human small intestinal epithelium exhibiting in vivo-like characteristics. Using the foodborne pathogen Salmonella enterica serovar Typhimurium, we demonstrated the applicability of our model to enteric infection research in the human context. Infection assays coupled to spatio-temporal readouts recapitulated the established key steps of epithelial infection by this pathogen in our model. Besides, we detected the upregulation of olfactomedin 4 in infected cells, a hitherto unrecognized aspect of the host response to Salmonella infection. Together, this primary human small intestinal tissue model fills the gap between simplistic cell culture and animal models of infection, and shall prove valuable in uncovering human-specific features of host-pathogen interplay.},
  language  = {en}
}
@article{XuFahmyGarciaWesdorpetal.2023,
  author    = {Xu, Jietao and Fahmy-Garcia, Shorouk and Wesdorp, Marinus A. and Kops, Nicole and Forte, Lucia and De Luca, Claudio and Misciagna, Massimiliano Maraglino and Dolcini, Laura and Filardo, Giuseppe and Labbert{\´e}, Margot and Vanc{\´i}kov{\´a}, Karin and Kok, Joeri and van Rietbergen, Bert and Nickel, Joachim and Farrell, Eric and Brama, Pieter A. J. and van Osch, Gerjo J. V. M.},
  title     = {Effectiveness of BMP-2 and PDGF-BB adsorption onto a collagen/collagen-magnesium-hydroxyapatite scaffold in weight-bearing and non-weight-bearing osteochondral defect bone repair: in vitro, ex vivo and in vivo evaluation},
  series = {Journal of Functional Biomaterials},
  volume    = {14},
  journal   = {Journal of Functional Biomaterials},
  number    = {2},
  issn      = {2079-4983},
  doi       = {10.3390/jfb14020111},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304019},
  year      = {2023},
  abstract  = {Despite promising clinical results in osteochondral defect repair, a recently developed bi-layered collagen/collagen-magnesium-hydroxyapatite scaffold has demonstrated less optimal subchondral bone repair. This study aimed to improve the bone repair potential of this scaffold by adsorbing bone morphogenetic protein 2 (BMP-2) and/or platelet-derived growth factor-BB (PDGF-BB) onto said scaffold. The in vitro release kinetics of BMP-2/PDGF-BB demonstrated that PDGF-BB was burst released from the collagen-only layer, whereas BMP-2 was largely retained in both layers. Cell ingrowth was enhanced by BMP-2/PDFG-BB in a bovine osteochondral defect ex vivo model. In an in vivo semi-orthotopic athymic mouse model, adding BMP-2 or PDGF-BB increased tissue repair after four weeks. After eight weeks, most defects were filled with bone tissue. To further investigate the promising effect of BMP-2, a caprine bilateral stifle osteochondral defect model was used where defects were created in weight-bearing femoral condyle and non-weight-bearing trochlear groove locations. After six months, the adsorption of BMP-2 resulted in significantly less bone repair compared with scaffold-only in the femoral condyle defects and a trend to more bone repair in the trochlear groove. Overall, the adsorption of BMP-2 onto a Col/Col-Mg-HAp scaffold reduced bone formation in weight-bearing osteochondral defects, but not in non-weight-bearing osteochondral defects.},
  language  = {en}
}
@article{StefanakisBasslerWalczuchetal.2023,
  author    = {Stefanakis, Mona and Bassler, Miriam C. and Walczuch, Tobias R. and Gerhard-Hartmann, Elena and Youssef, Almoatazbellah and Scherzad, Agmal and St{\"o}th, Manuel Bernd and Ostertag, Edwin and Hagen, Rudolf and Steinke, Maria R. and Hackenberg, Stephan and Brecht, Marc and Meyer, Till Jasper},
  title     = {The impact of tissue preparation on salivary gland tumors investigated by Fourier-transform infrared microspectroscopy},
  series = {Journal of Clinical Medicine},
  volume    = {12},
  journal   = {Journal of Clinical Medicine},
  number    = {2},
  issn      = {2077-0383},
  doi       = {10.3390/jcm12020569},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304887},
  year      = {2023},
  abstract  = {Due to the wide variety of benign and malignant salivary gland tumors, classification and malignant behavior determination based on histomorphological criteria can be difficult and sometimes impossible. Spectroscopical procedures can acquire molecular biological information without destroying the tissue within the measurement processes. Since several tissue preparation procedures exist, our study investigated the impact of these preparations on the chemical composition of healthy and tumorous salivary gland tissue by Fourier-transform infrared (FTIR) microspectroscopy. Sequential tissue cross-sections were prepared from native, formalin-fixed and formalin-fixed paraffin-embedded (FFPE) tissue and analyzed. The FFPE cross-sections were dewaxed and remeasured. By using principal component analysis (PCA) combined with a discriminant analysis (DA), robust models for the distinction of sample preparations were built individually for each parotid tissue type. As a result, the PCA-DA model evaluation showed a high similarity between native and formalin-fixed tissues based on their chemical composition. Thus, formalin-fixed tissues are highly representative of the native samples and facilitate a transfer from scientific laboratory analysis into the clinical routine due to their robust nature. Furthermore, the dewaxing of the cross-sections entails the loss of molecular information. Our study successfully demonstrated how FTIR microspectroscopy can be used as a powerful tool within existing clinical workflows.},
  language  = {en}
}
@phdthesis{SchliermanngebStratmann2023,
  author    = {Schliermann [geb. Stratmann], Anna Theresa},
  title     = {The Role of FGF Receptor 2 in GDF5 mediated Signal Transduction},
  doi       = {10.25972/OPUS-19288},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-192889},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Bone morphogenetic proteins (BMPs) are involved in various aspects of cell-cell communication in complex life forms. They act as morphogens, help differentiate different cell types from different progenitor cells in development, and are involved in many instances of intercellular communication, from forming a body axis to healing bone fractures, from sugar metabolism to angiogenesis. If the same protein or protein family carries out many functions, there is a demand to regulate and fine-tune their biological activities, and BMPs are highly regulated to generate cell- and context-dependent outcomes. Not all such instances can be explained yet. Growth/differentiation factor (GDF)5 (or BMP14) synergizes with BMP2 on chondrogenic ATDC5 cells, but antagonizes BMP2 on myoblastic C2C12 cells. Known regulators of BMP2/GDF5 signal transduction failed to explain this context-dependent difference, so a microarray was performed to identify new, cell-specific regulatory components. One identified candidate, the fibroblast growth factor receptor (FGFR)2, was analyzed as a potential new co-receptor to BMP ligands such as GDF5: It was shown that FGFR2 directly binds BMP2, GDF5, and other BMP ligands in vitro, and FGFR2 was able to positively influence BMP2/GDF5-mediated signaling outcome in cell-based assays. This effect was independent of FGFR2s kinase activity, and independent of the downstream mediators SMAD1/5/8, p42/p44, Akt, and p38. The elevated colocalization of BMP receptor type IA and FGFR2 in the presence of BMP2 or GDF5 suggests a signaling complex containing both receptors, akin to other known co-receptors of BMP ligands such as repulsive guidance molecules. This unexpected direct interaction between FGF receptor and BMP ligands potentially opens a new category of BMP signal transduction regulation, as FGFR2 is the second receptor tyrosine kinase to be identified as BMP co-receptor, and more may follow. The integration of cell surface interactions between members of the FGF and BMP family especially may widen the knowledge of such cellular communication mechanisms which involve both growth factor families, including morphogen gradients and osteogenesis, and may in consequence help to improve treatment options in osteochodnral diseases.},
  subject      = {Molekularbiologie},
  language  = {en}
}
@article{FeiglStahringerPeindletal.2023,
  author    = {Feigl, Frederik Fabian and Stahringer, Anika and Peindl, Matthias and Dandekar, Gudrun and Koehl, Ulrike and Fricke, Stephan and Schmiedel, Dominik},
  title     = {Efficient redirection of NK cells by genetic modification with chemokine receptors CCR4 and CCR2B},
  series = {International Journal of Molecular Sciences},
  volume    = {24},
  journal   = {International Journal of Molecular Sciences},
  number    = {4},
  issn      = {1422-0067},
  doi       = {10.3390/ijms24043129},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304049},
  year      = {2023},
  abstract  = {Natural killer (NK) cells are a subset of lymphocytes that offer great potential for cancer immunotherapy due to their natural anti-tumor activity and the possibility to safely transplant cells from healthy donors to patients in a clinical setting. However, the efficacy of cell-based immunotherapies using both T and NK cells is often limited by a poor infiltration of immune cells into solid tumors. Importantly, regulatory immune cell subsets are frequently recruited to tumor sites. In this study, we overexpressed two chemokine receptors, CCR4 and CCR2B, that are naturally found on T regulatory cells and tumor-resident monocytes, respectively, on NK cells. Using the NK cell line NK-92 as well as primary NK cells from peripheral blood, we show that genetically engineered NK cells can be efficiently redirected using chemokine receptors from different immune cell lineages and migrate towards chemokines such as CCL22 or CCL2, without impairing the natural effector functions. This approach has the potential to enhance the therapeutic effect of immunotherapies in solid tumors by directing genetically engineered donor NK cells to tumor sites. As a future therapeutic option, the natural anti-tumor activity of NK cells at the tumor sites can be increased by co-expression of chemokine receptors with chimeric antigen receptors (CAR) or T cell receptors (TCR) on NK cells can be performed in the future.},
  language  = {en}
}
@article{KoenigRammeFaustetal.2022,
  author    = {Koenig, Leopold and Ramme, Anja Patricia and Faust, Daniel and Mayer, Manuela and Fl{\"o}tke, Tobias and Gerhartl, Anna and Brachner, Andreas and Neuhaus, Winfried and Appelt-Menzel, Antje and Metzger, Marco and Marx, Uwe and Dehne, Eva-Maria},
  title     = {A human stem cell-derived brain-liver chip for assessing blood-brain-barrier permeation of pharmaceutical drugs},
  series = {Cells},
  volume    = {11},
  journal   = {Cells},
  number    = {20},
  issn      = {2073-4409},
  doi       = {10.3390/cells11203295},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290375},
  year      = {2022},
  abstract  = {Significant advancements in the field of preclinical in vitro blood-brain barrier (BBB) models have been achieved in recent years, by developing monolayer-based culture systems towards complex multi-cellular assays. The coupling of those models with other relevant organoid systems to integrate the investigation of blood-brain barrier permeation in the larger picture of drug distribution and metabolization is still missing. Here, we report for the first time the combination of a human induced pluripotent stem cell (hiPSC)-derived blood-brain barrier model with a cortical brain and a liver spheroid model from the same donor in a closed microfluidic system (MPS). The two model compounds atenolol and propranolol were used to measure permeation at the blood-brain barrier and to assess metabolization. Both substances showed an in vivo-like permeation behavior and were metabolized in vitro. Therefore, the novel multi-organ system enabled not only the measurement of parent compound concentrations but also of metabolite distribution at the blood-brain barrier.},
  language  = {en}
}
@article{WussmannGroeberBeckerRiedletal.2022,
  author    = {Wußmann, Maximiliane and Groeber-Becker, Florian Kai and Riedl, Sabrina and Alihodzic, Dina and Padaric, Daniel and Gerlitz, Lisa and Stallinger, Alexander and Liegl-Atzwanger, Bernadette and Zweytick, Dagmar and Rinner, Beate},
  title     = {In model, in vitro and in vivo killing efficacy of antitumor peptide RDP22 on MUG-Mel2, a patient derived cell line of an aggressive melanoma metastasis},
  series = {Biomedicines},
  volume    = {10},
  journal   = {Biomedicines},
  number    = {11},
  issn      = {2227-9059},
  doi       = {10.3390/biomedicines10112961},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297525},
  year      = {2022},
  abstract  = {The host defense derived peptide was assessed in different model systems with increasing complexity employing the highly aggressive NRAS mutated melanoma metastases cell line MUG-Mel2. Amongst others, fluorescence microscopy and spectroscopy, as well as cell death studies were applied for liposomal, 2D and 3D in vitro models including tumor spheroids without or within skin models and in vivo mouse xenografts. Summarized, MUG-Mel2 cells were shown to significantly expose the negatively charged lipid phosphatidylserine on their plasma membranes, showing they are successfully targeted by RDP22. The peptide was able to induce cell death in MUG-Mel2 2D and 3D cultures, where it was able to kill tumor cells even inside the core of tumor spheroids or inside a melanoma organotypic model. In vitro studies indicated cell death by apoptosis upon peptide treatment with an LC\(_{50}\) of 8.5 µM and seven-fold specificity for the melanoma cell line MUG-Mel2 over normal dermal fibroblasts. In vivo studies in mice xenografts revealed effective tumor regression upon intratumoral peptide injection, indicated by the strong clearance of pigmented tumor cells and tremendous reduction in tumor size and proliferation, which was determined histologically. The peptide RDP22 has clearly shown high potential against the melanoma cell line MUG-Mel2 in vitro and in vivo.},
  language  = {en}
}
@article{EderHollmannMandasarietal.2022,
  author    = {Eder, Sascha and Hollmann, Claudia and Mandasari, Putri and Wittmann, Pia and Schumacher, Fabian and Kleuser, Burkhard and Fink, Julian and Seibel, J{\"u}rgen and Schneider-Schaulies, J{\"u}rgen and Stigloher, Christian and Beyersdorf, Niklas and Dembski, Sofia},
  title     = {Synthesis and characterization of ceramide-containing liposomes as membrane models for different T cell subpopulations},
  series = {Journal of Functional Biomaterials},
  volume    = {13},
  journal   = {Journal of Functional Biomaterials},
  number    = {3},
  issn      = {2079-4983},
  doi       = {10.3390/jfb13030111},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286130},
  year      = {2022},
  abstract  = {A fine balance of regulatory (T\(_{reg}\)) and conventional CD4\(^+\) T cells (T\(_{conv}\)) is required to prevent harmful immune responses, while at the same time ensuring the development of protective immunity against pathogens. As for many cellular processes, sphingolipid metabolism also crucially modulates the T\(_{reg}\)/T\(_{conv}\) balance. However, our understanding of how sphingolipid metabolism is involved in T cell biology is still evolving and a better characterization of the tools at hand is required to advance the field. Therefore, we established a reductionist liposomal membrane model system to imitate the plasma membrane of mouse T\(_{reg}\) and T\(_{conv}\) with regards to their ceramide content. We found that the capacity of membranes to incorporate externally added azide-functionalized ceramide positively correlated with the ceramide content of the liposomes. Moreover, we studied the impact of the different liposomal preparations on primary mouse splenocytes in vitro. The addition of liposomes to resting, but not activated, splenocytes maintained viability with liposomes containing high amounts of C\(_{16}\)-ceramide being most efficient. Our data thus suggest that differences in ceramide post-incorporation into T\(_{reg}\) and T\(_{conv}\) reflect differences in the ceramide content of cellular membranes.},
  language  = {en}
}
@phdthesis{Sivarajan2023,
  author    = {Sivarajan, Rinu},
  title     = {Engineered Human Airway Mucosa for Modelling Respiratory Infections: Characterisation and Applications},
  doi       = {10.25972/OPUS-32241},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322414},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Respiratory infections are a significant health concern worldwide, and the airway epithelium plays a crucial role in regulating airway function and modulating inflammatory processes. However, most studies on respiratory infections have used cell lines or animal models, which may not accurately reflect native physiological conditions, especially regarding human pathogens. We generated human nasal mucosa (hNM) and tracheobronchial mucosa (hTM) models to address this issue using primary human airway epithelial cells and fibroblasts. We characterised these human airway tissue models (hAM) using high speed video microscopy, single cell RNA sequencing, immunofluorescence staining, and ultrastructural analyses that revealed their complexity and cellular heterogeneity. We demonstrated that Bordetella pertussis virulence factor adenylate cyclase toxin (CyaA) elevated the intracellular production of cyclic adenosine monophosphate (cAMP) and secretion of interleukin (IL) 6, IL 8, and human beta defensin 2 (HBD2). In addition, we compared the responses of the tissue models from two different anatomical sites (the upper and lower respiratory mucosa) and are the first to report such differential susceptibility towards CyaA using 3D primary airway cell derivedmodels. The effect of toxin treatment on the epithelial barrier integrity of the tissue models was assessed by measuring the flux of fluorescein isothiocyanate (FITC)-conjugated dextran across the models. Though we observed a cell type specific response with respect to intracellular cAMP production and IL 6, IL 8, and HBD2 secretion in the models treated with CyaA on the apical side, the epithelial membrane barrier integrity was not compromised. In addition to toxin studies, using these characterised models, we established viral infection studies for Influenza A (IAV), Respiratory Syncytial Virus subtype B (RSV), and severe acute respiratory syndrome coronavirus 2. We visualised the morphological consequences of the viral infection using ultrastructural analysis and immunofluorescence. We verified the effective infection in hAM by measuring the viral RNA using RTqPCR and detected elevated cytokine levels in response to infection using biochemical assays. In contrast to cell lines, studies on viral infection using hAM demonstrated that infected areas were localized to specific regions. This led to the formation of infection hotspots, which were more likely to occur when models derived from different donors were infected separately with all three viruses. IAV infected tissue models replicate the clinical findings of H1N1 infection, such as mucus hypersecretion, cytokine release, and infection-associated epithelial cell damage.Finally, we paved the steps towards understanding the impact of IAV infection on disease models. We generated hTM from biopsies obtained from chronic obstructive pulmonary disease (COPD) patients. As a model to study the impact of COPD on respiratory infections, considering the increase in COPD cases in the past decade and the continued predicted increase in the future. We established the IAV infection protocol to capture the early infection signatures in non-COPD and COPD conditions using scRNA-seq. We investigated the infection kinetics of IAV (H1N1-clinical isolate) in hTM and found that viruses were actively released approximately 24 hours post infection. The scRNA-seq data from the hTM derived from non-COPD and COPD patients, revealed lower levels of SCGB1A1 (club cell marker) gene expression in the COPD-control group compared to the non-COPD control group, consistent with previous clinical studies. Furthermore, we observed that IAV infection elevated SCGB1A1 gene expression especially in secretory cells of both the COPD and non COPD groups. This may imply the role of club cells as early responders during IAV infection providing epithelial repair, regeneration, and resistance to spread of infection. This is the first study to address the molecular diversity in COPD and non-COPD disease models infected with IAV investigating the early response (6 h) of specific cell types in the human lower airways towards infection using scRNA-seq. These findings highlight the potential interplay between COPD, IAV infection, and altered vulnerability to other viral infections and respiratory illnesses making the hAM applicable for addressing more specific research questions and validating potential targets, such as SCGB1A1 targeted therapy for chronic lung diseases. Our findings demonstrate the potential of the hNM and hTM for investigating respiratory infections, innate immune responses, and trained immunity in non-immune cells. Our experiments show that hAM may represent a more accurate representation of the native physiological condition and improve our understanding of the disease mechanisms. Furthermore, these models promote non-animal research as they replicate clinical findings. We can further increase their complexity by incorporating dynamic flow systems and immune cells catered to the research question.},
  subject      = {Atemwege},
  language  = {en}
}
@phdthesis{Malkmus2023,
  author    = {Malkmus, Christoph},
  title     = {Establishment of a 3D \(in\) \(vitro\) skin culture system for the obligatory human parasite \(Onchocerca\) \(volvulus\)},
  doi       = {10.25972/OPUS-31717},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-317171},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Onchocerciasis, the world's second-leading infectious cause of blindness in humans -prevalent in Sub-Saharan Africa - is caused by Onchocerca volvulus (O. volvulus), an obligatory human parasitic filarial worm. Commonly known as river blindness, onchocerciasis is being targeted for elimination through ivermectin-based mass drug administration programs. However, ivermectin does not kill adult parasites, which can live and reproduce for more than 15 years within the human host. These impediments heighten the need for a deeper understanding of parasite biology and parasite-human host interactions, coupled with research into the development of new tools - macrofilaricidal drugs, diagnostics, and vaccines. Humans are the only definitive host for O. volvulus. Hence, no small-animal models exist for propagating the full life cycle of O. volvulus, so the adult parasites must be obtained surgically from subcutaneous nodules. A two-dimensional (2D) culture system allows that O. volvulus larvae develop from the vector-derived infective stage larvae (L3) in vitro to the early pre-adult L5 stages. As problematic, the in vitro development of O. volvulus to adult worms has so far proved infeasible. We hypothesized that an increased biological complexity of a three-dimensional (3D) culture system will support the development of O. volvulus larvae in vitro. Thus, we aimed to translate crucial factors of the in vivo environment of the developing worms into a culture system based on human skin. The proposed tissue model should contain 1. skinspecific extracellular matrix, 2. skin-specific cells, and 3. enable a direct contact of larvae and tissue components. For the achievement, a novel adipose tissue model was developed and integrated to a multilayered skin tissue comprised of epidermis, dermis and subcutis. Challenges of the direct culture within a 3D tissue model hindered the application of the three-layered skin tissue. However, the indirect coculture of larvae and skin models supported the growth of fourth stage (L4) larvae in vitro. The direct culture of L4 and adipose tissue strongly improved the larvae survival. Furthermore, the results revealed important cues that might represent the initial encapsulation of the developing worm within nodular tissue. These results demonstrate that tissue engineered 3D tissues represent an appropriate in vitro environment for the maintenance and examination of O. volvulus larvae.},
  subject      = {Tissue Engineering},
  language  = {en}
}
@article{AlHejailanWeigelSchuerleinetal.2022,
  author    = {Al-Hejailan, Reem and Weigel, Tobias and Sch{\"u}rlein, Sebastian and Berger, Constantin and Al-Mohanna, Futwan and Hansmann, Jan},
  title     = {Decellularization of full heart — optimizing the classical sodium-dodecyl-sulfate-based decellularization protocol},
  series = {Bioengineering},
  volume    = {9},
  journal   = {Bioengineering},
  number    = {4},
  issn      = {2306-5354},
  doi       = {10.3390/bioengineering9040147},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270781},
  year      = {2022},
  abstract  = {Compared to cell therapy, where cells are injected into a defect region, the treatment of heart infarction with cells seeded in a vascularized scaffold bears advantages, such as an immediate nutrient supply or a controllable and persistent localization of cells. For this purpose, decellularized native tissues are a preferable choice as they provide an in vivo-like microenvironment. However, the quality of such scaffolds strongly depends on the decellularization process. Therefore, two protocols based on sodium dodecyl sulfate or sodium deoxycholate were tailored and optimized for the decellularization of a porcine heart. The obtained scaffolds were tested for their applicability to generate vascularized cardiac patches. Decellularization with sodium dodecyl sulfate was found to be more suitable and resulted in scaffolds with a low amount of DNA, a highly preserved extracellular matrix composition, and structure shown by GAG quantification and immunohistochemistry. After seeding human endothelial cells into the vasculature, a coagulation assay demonstrated the functionality of the endothelial cells to minimize the clotting of blood. Human-induced pluripotent-stem-cell-derived cardiomyocytes in co-culture with fibroblasts and mesenchymal stem cells transferred the scaffold into a vascularized cardiac patch spontaneously contracting with a frequency of 25.61 ± 5.99 beats/min for over 16 weeks. The customized decellularization protocol based on sodium dodecyl sulfate renders a step towards a preclinical evaluation of the scaffolds.},
  language  = {en}
}
@article{ChristGlaubittBerberichetal.2022,
  author    = {Christ, Bastian and Glaubitt, Walther and Berberich, Katrin and Weigel, Tobias and Probst, J{\"o}rn and Sextl, Gerhard and Dembski, Sofia},
  title     = {Sol-gel-derived fibers based on amorphous α-hydroxy-carboxylate-modified titanium(IV) oxide as a 3-dimensional scaffold},
  series = {Materials},
  volume    = {15},
  journal   = {Materials},
  number    = {8},
  issn      = {1996-1944},
  doi       = {10.3390/ma15082752},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270694},
  year      = {2022},
  abstract  = {The development of novel fibrous biomaterials and further processing of medical devices is still challenging. For instance, titanium(IV) oxide is a well-established biocompatible material, and the synthesis of TiO\(_x\) particles and coatings via the sol-gel process has frequently been published. However, synthesis protocols of sol-gel-derived TiO\(_x\) fibers are hardly known. In this publication, the authors present a synthesis and fabrication of purely sol-gel-derived TiO\(_x\) fiber fleeces starting from the liquid sol-gel precursor titanium ethylate (TEOT). Here, the α-hydroxy-carboxylic acid lactic acid (LA) was used as a chelating ligand to reduce the reactivity towards hydrolysis of TEOT enabling a spinnable sol. The resulting fibers were processed into a non-woven fleece, characterized with FTIR, \(^{13}\)C-MAS-NMR, XRD, and screened with regard to their stability in physiological solution. They revealed an unexpected dependency between the LA content and the dissolution behavior. Finally, in vitro cell culture experiments proved their potential suitability as an open-mesh structured scaffold material, even for challenging applications such as therapeutic medicinal products (ATMPs).},
  language  = {en}
}
@article{SchneiderKruseBernardellideMattosetal.2021,
  author    = {Schneider, Verena and Kruse, Daniel and Bernardelli de Mattos, Ives and Z{\"o}phel, Saskia and Tiltmann, Kendra-Kathrin and Reigl, Amelie and Khan, Sarah and Funk, Martin and Bodenschatz, Karl and Groeber-Becker, Florian},
  title     = {A 3D in vitro model for burn wounds: monitoring of regeneration on the epidermal level},
  series = {Biomedicines},
  volume    = {9},
  journal   = {Biomedicines},
  number    = {9},
  issn      = {2227-9059},
  doi       = {10.3390/biomedicines9091153},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246068},
  year      = {2021},
  abstract  = {Burns affect millions every year and a model to mimic the pathophysiology of such injuries in detail is required to better understand regeneration. The current gold standard for studying burn wounds are animal models, which are under criticism due to ethical considerations and a limited predictiveness. Here, we present a three-dimensional burn model, based on an open-source model, to monitor wound healing on the epidermal level. Skin equivalents were burned, using a preheated metal cylinder. The healing process was monitored regarding histomorphology, metabolic changes, inflammatory response and reepithelialization for 14 days. During this time, the wound size decreased from 25\% to 5\% of the model area and the inflammatory response (IL-1β, IL-6 and IL-8) showed a comparable course to wounding and healing in vivo. Additionally, the topical application of 5\% dexpanthenol enhanced tissue morphology and the number of proliferative keratinocytes in the newly formed epidermis, but did not influence the overall reepithelialization rate. In summary, the model showed a comparable healing process to in vivo, and thus, offers the opportunity to better understand the physiology of thermal burn wound healing on the keratinocyte level.},
  language  = {en}
}
@phdthesis{Berger2023,
  author    = {Berger, Constantin},
  title     = {Influence of the pancreatic extracellular matrix on pancreatic differentiation of human induced pluripotent stem cells and establishment of 3D organ models},
  doi       = {10.25972/OPUS-24126},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241268},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Der Diabetes mellitus bezeichnet eine bislang unheilbare, metabolische Erkrankung, die mit schwerwiegenden Folgeerkrankungen einhergeht. Unter den potentiellen Strategien zur Heilung von Diabetes mellitus stellt die in vitro Generierung adulter β-Zellen des endokrinen Pankreas aus humanen induziert pluripotenten Stammzellen (hiPS) einen vielversprechenden Ansatz dar. Zwar erm{\"o}glichen bisherige Protokolle die Herstellung von Zellen mit einem β-Zell-{\"a}hnlichen Charakter, jedoch zeigen diese eine zun{\"a}chst eingeschr{\"a}nkte Funktion, die sich erst im Verlauf einer vollst{\"a}ndigen, durch Transplantation induzierten, Reifung der Zellen, normalisiert. Vorangegangene Studien zeigen, dass sich die Extrazellularmatrix (EZM) von Geweben positiv auf das {\"U}berleben und die Funktion adulter, isolierter Langerhans-Inseln des Pankreas auswirkt. Vor diesem Hintergrund stellt sich die Frage, ob Einfl{\"u}sse der organspezifischen EZM die finale Reifung in vitro hergestellter β-Zellen herbeif{\"u}hren k{\"o}nnen. Um diese Hypothese zu testen, wurde im Rahmen der vorliegenden Studie die Wirkung der pankreatischen EZM auf die in vitro Differenzierung von hiPS zu endokrinen Zellen des Pankreas untersucht sowie die Eignung der pankreatischen EZM zur Etablierung eines Organmodells des endokrinen Pankreas erprobt. Hierzu wurde zun{\"a}chst eine pankreasspezifische EZM-Tr{\"a}gerstruktur (PanMa) durch Dezellularisierung von Pankreaten des Schweins mittels Natriumdesoxycholat hergestellt. Die generierte PanMa wurde anhand (immun-) histologischer F{\"a}rbungen, Rasterelektronen-mikroskopie, Feststellung des DNA-Gehalts sowie durch Versuche zur Perfusion und Wiederbesiedelung mit Endothelzellen eingehend charakterisiert. Zudem wurde auf Basis der ermittelten Daten ein Bewertungssystem (PancScore) zur standardisierten Herstellung der PanMa entwickelt. Als N{\"a}chstes wurde untersucht, ob die PanMa {\"u}ber gewebespezifische EZM-Merkmale verf{\"u}gt. Zu diesem Zweck wurden biophysikalische und strukturelle Eigenschaften wie Festigkeit, Porosit{\"a}t und Hygroskopie mittels rheologischer Messungen sowie Versuchen zur Teilchendiffusion und zum Wasserbindungsverhalten bestimmt und mit azellul{\"a}ren EZMs des D{\"u}nndarms (SISser) und der Lunge (LungMa) verglichen. Nach der eingehenden Analyse der PanMa wurde deren Effekt auf die Eigenschaften von Stammzellen sowie auf fr{\"u}he Stadien der Stammzellentwicklung untersucht. Hierzu wurde die PanMa als Tr{\"a}gerstruktur w{\"a}hrend der Erhaltung sowie der spontanen Differenzierung von hiPS verwendet und der Einfluss der PanMa anhand von Genexpressionsanalysen und immunhistochemischer F{\"a}rbungen analysiert. In einem n{\"a}chsten Schritt wurde die Wirkung der PanMa auf die Differenzierung von hiPS zu endokrinen Zellen des Pankreas untersucht. Hierf{\"u}r wurde die PanMa zum einen in fl{\"u}ssiger Form als Mediumzusatz sowie als solide Tr{\"a}gerstruktur w{\"a}hrend der Differenzierung von hiPS zu hormonexprimierenden Zellen (Rezania et al. 2012; Rezania et al. 2014) oder maturierenden β-Zellen verwendet (Rezania et al. 2014). Der Effekt der PanMa wurde anhand von Genexpressions-analysen, immunhistochemischer F{\"a}rbungen und Analysen zur Glukose-abh{\"a}ngigen Insulinsekretion untersucht. In einem letzten Teil der Studie wurde die Eignung der PanMa zur verl{\"a}ngerten Kultivierung von hiPS-abgeleiteten endokrinen Zellen des Pankreas im Hinblick auf die Etablierung eines Organmodells des endokrinen Pankreas getestet. Hierzu wurde die PanMa zu einem Hydrogel weiterverarbeitet, welches zur Einkapselung und Kultivierung von hiPS-abgeleiteten hormonexprimierenden Zellen eingesetzt wurde. Um die Auswirkungen der Hydrogel-Kultur nachzuvollziehen, wurden die kultivierten Zellen mittels Genexpression, immun-histochemischer F{\"a}rbungen und Analysen zur Glukose-abh{\"a}ngigen Insulinsekretion untersucht. Mittels Dezellularisierung porziner Pankreaten konnte eine zellfreie, pankreasspezifische EZM-Tr{\"a}gerstruktur mit geringen Restbest{\"a}nden an DNA sowie einer weitgehend erhaltenen Mikro- und Ultrastruktur mit typischen EZM-Komponenten wie Kollagen I, III und IV hergestellt werden. Im Rahmen der Besiedelung arterieller Gef{\"a}ße mit humanen Endothelzellen wurde die Zellkompatibilit{\"a}t der hergestellten PanMa sowie eine weitgehende Unversehrtheit der Gef{\"a}ßstrukturen nachgewiesen. Verglichen zu SISser und LungMa zeichnete sich die PanMa als eine relativ weiche, stark wasserbindende, faserbasierte Struktur aus. Weiterhin konnten Hinweise f{\"u}r einen Effekt der PanMa auf den Stammzellcharakter und die fr{\"u}he Entwicklung von hiPS beobachtet werden. Hierbei f{\"u}hrte die Erhaltung von hiPS auf der PanMa zu einer leicht ver{\"a}nderten Expression von Genen des Kernpluripotenznetzwerks sowie zu einem reduziertem NANOG-Proteinsignal. Einhergehend mit diesen Beobachtungen zeigten hiPS w{\"a}hrend spontaner Differenzierung auf der PanMa eine verst{\"a}rkte endodermale Entwicklung. Im Verlauf der pankreatischen Differenzierung f{\"u}hrte die Kultivierung auf der PanMa zu einer signifikant verringerten Expression von Glukagon und Somatostatin, w{\"a}hrend die Expression von Insulin unver{\"a}ndert blieb, was auf eine Verminderung endokriner α- und δ-Zellen hinweist. Diese Ver{\"a}nderung {\"a}ußerte sich jedoch nicht in einer verbesserten Glukose-abh{\"a}ngigen Insulinsekretion der generierten hormonexprimierenden Zellen. Unter Anwendung der PanMa als Hydrogel konnten hormonexprimierenden Zellen {\"u}ber einen verl{\"a}ngerten Zeitraum kultiviert werden. Nach 21 Tagen in Kultur zeigten die eingekapselten hormonexprimierenden Zellen eine unver{\"a}ndert hohe Viabilit{\"a}t, wiesen allerdings bereits eine erste ver{\"a}nderte Zellanordnung sowie eine leicht verminderte Glukose-abh{\"a}ngige Insulinsekretion auf. Zusammengefasst konnte in dieser Studie ein biologischer Effekt gewebespezifischer EZM-Merkmale auf die Differenzierung von hiPS nachgewiesen werden. Dar{\"u}ber hinaus weisen die Daten auf eine relevante Funktion der EZM im Rahmen der endokrinen Spezifizierung von hiPS w{\"a}hrend der pankreatischen Differenzierung hin. Diese Beobachtungen verdeutlichen die eminente Rolle der EZM in der Herstellung von funktionalen hiPS-abgeleiteten Zellen und pl{\"a}dieren f{\"u}r eine st{\"a}rkere Einbindung organspezifischer EZMs im Bereich des Tissue Engineering und der klinischen Translation in der Regenerativen Medizin.},
  subject      = {Bauchspeicheldr{\"u}se},
  language  = {en}
}
@article{TucaBernardellideMattosFunketal.2022,
  author    = {Tuca, Alexandru-Cristian and Bernardelli de Mattos, Ives and Funk, Martin and Winter, Raimund and Palackic, Alen and Groeber-Becker, Florian and Kruse, Daniel and Kukla, Fabian and Lemarchand, Thomas and Kamolz, Lars-Peter},
  title     = {Orchestrating the dermal/epidermal tissue ratio during wound healing by controlling the moisture content},
  series = {Biomedicines},
  volume    = {10},
  journal   = {Biomedicines},
  number    = {6},
  issn      = {2227-9059},
  doi       = {10.3390/biomedicines10061286},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275115},
  year      = {2022},
  abstract  = {A balanced and moist wound environment and surface increases the effect of various growth factors, cytokines, and chemokines, stimulating cell growth and wound healing. Considering this fact, we tested in vitro and in vivo water evaporation rates from the cellulose dressing epicite\(^{hydro}\) when combined with different secondary dressings as well as the resulting wound healing efficacy in a porcine donor site model. The aim of this study was to evaluate how the different rates of water evaporation affected wound healing efficacy. To this end, epicite\(^{hydro}\) primary dressing, in combination with different secondary dressing materials (cotton gauze, JELONET\(^◊\), AQUACEL\(^®\) Extra\(^™\), and OPSITE\(^◊\) Flexifix), was placed on 3 × 3 cm-sized dermatome wounds with a depth of 1.2 mm on the flanks of domestic pigs. The healing process was analyzed histologically and quantified by morphometry. High water evaporation rates by using the correct secondary dressing, such as cotton gauze, favored a better re-epithelialization in comparison with the low water evaporation resulting from an occlusive secondary dressing, which favored the formation of a new and intact dermal tissue that nearly fully replaced all the dermis that was removed during wounding. This newly available evidence may be of great benefit to clinical wound management.},
  language  = {en}
}
@article{KaltdorfBreitenbachKarletal.2023,
  author    = {Kaltdorf, Martin and Breitenbach, Tim and Karl, Stefan and Fuchs, Maximilian and Kessie, David Komla and Psota, Eric and Prelog, Martina and Sarukhanyan, Edita and Ebert, Regina and Jakob, Franz and Dandekar, Gudrun and Naseem, Muhammad and Liang, Chunguang and Dandekar, Thomas},
  title     = {Software JimenaE allows efficient dynamic simulations of Boolean networks, centrality and system state analysis},
  series = {Scientific Reports},
  volume    = {13},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-022-27098-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313303},
  year      = {2023},
  abstract  = {The signal modelling framework JimenaE simulates dynamically Boolean networks. In contrast to SQUAD, there is systematic and not just heuristic calculation of all system states. These specific features are not present in CellNetAnalyzer and BoolNet. JimenaE is an expert extension of Jimena, with new optimized code, network conversion into different formats, rapid convergence both for system state calculation as well as for all three network centralities. It allows higher accuracy in determining network states and allows to dissect networks and identification of network control type and amount for each protein with high accuracy. Biological examples demonstrate this: (i) High plasticity of mesenchymal stromal cells for differentiation into chondrocytes, osteoblasts and adipocytes and differentiation-specific network control focusses on wnt-, TGF-beta and PPAR-gamma signaling. JimenaE allows to study individual proteins, removal or adding interactions (or autocrine loops) and accurately quantifies effects as well as number of system states. (ii) Dynamical modelling of cell-cell interactions of plant Arapidopsis thaliana against Pseudomonas syringae DC3000: We analyze for the first time the pathogen perspective and its interaction with the host. We next provide a detailed analysis on how plant hormonal regulation stimulates specific proteins and who and which protein has which type and amount of network control including a detailed heatmap of the A.thaliana response distinguishing between two states of the immune response. (iii) In an immune response network of dendritic cells confronted with Aspergillus fumigatus, JimenaE calculates now accurately the specific values for centralities and protein-specific network control including chemokine and pattern recognition receptors.},
  language  = {en}
}
@article{SivarajanOberwinklerRolletal.2022,
  author    = {Sivarajan, Rinu and Oberwinkler, Heike and Roll, Valeria and K{\"o}nig, Eva-Maria and Steinke, Maria and Bodem, Jochen},
  title     = {A defined anthocyanin mixture sourced from bilberry and black currant inhibits Measles virus and various herpesviruses},
  series = {BMC Complementary Medicine and Therapies},
  volume    = {22},
  journal   = {BMC Complementary Medicine and Therapies},
  doi       = {10.1186/s12906-022-03661-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301423},
  year      = {2022},
  abstract  = {Background Anthocyanin-containing plant extracts and carotenoids, such as astaxanthin, have been well-known for their antiviral and anti-inflammatory activity, respectively. We hypothesised that a mixture of Ribes nigrum L. (Grossulariaceae) (common name black currant (BC)) and Vaccinium myrtillus L. (Ericaceae) (common name bilberry (BL)) extracts (BC/BL) with standardised anthocyanin content as well as single plant extracts interfered with the replication of Measles virus and Herpesviruses in vitro. Methods We treated cell cultures with BC/BL or defined single plant extracts, purified anthocyanins and astaxanthin in different concentrations and subsequently infected the cultures with the Measles virus (wild-type or vaccine strain Edmonston), Herpesvirus 1 or 8, or murine Cytomegalovirus. Then, we analysed the number of infected cells and viral infectivity and compared the data to non-treated controls. Results The BC/BL extract inhibited wild-type Measles virus replication, syncytia formation and cell-to-cell spread. This suppression was dependent on the wild-type virus-receptor-interaction since the Measles vaccine strain was unaffected by BC/BL treatment. Furthermore, the evidence was provided that the delphinidin-3-rutinoside chloride, a component of BC/BL, and purified astaxanthin, were effective anti-Measles virus compounds. Human Herpesvirus 1 and murine Cytomegalovirus replication was inhibited by BC/BL, single bilberry or black currant extracts, and the BC/BL component delphinidin-3-glucoside chloride. Additionally, we observed that BC/BL seemed to act synergistically with aciclovir. Moreover, BC/BL, the single bilberry and black currant extracts, and the BC/BL components delphinidin-3-glucoside chloride, cyanidin-3-glucoside, delphinidin-3-rutinoside chloride, and petunidin-3-galactoside inhibited human Herpesvirus 8 replication. Conclusions Our data indicate that Measles viruses and Herpesviruses are differentially susceptible to a specific BC/BL mixture, single plant extracts, purified anthocyanins and astaxanthin. These compounds might be used in the prevention of viral diseases and in addition to direct-acting antivirals, such as aciclovir.},
  language  = {en}
}
@article{GeigerKoenigOberwinkleretal.2022,
  author    = {Geiger, Nina and K{\"o}nig, Eva-Maria and Oberwinkler, Heike and Roll, Valeria and Diesendorf, Viktoria and F{\"a}hr, Sofie and Obernolte, Helena and Sewald, Katherina and Wronski, Sabine and Steinke, Maria and Bodem, Jochen},
  title     = {Acetylsalicylic acid and salicylic acid inhibit SARS-CoV-2 replication in precision-cut lung slices},
  series = {Vaccines},
  volume    = {10},
  journal   = {Vaccines},
  number    = {10},
  issn      = {2076-393X},
  doi       = {10.3390/vaccines10101619},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-289885},
  year      = {2022},
  abstract  = {Aspirin, with its active compound acetylsalicylic acid (ASA), shows antiviral activity against rhino- and influenza viruses at high concentrations. We sought to investigate whether ASA and its metabolite salicylic acid (SA) inhibit SARS-CoV-2 since it might use similar pathways to influenza viruses. The compound-treated cells were infected with SARS-CoV-2. Viral replication was analysed by RTqPCR. The compounds suppressed SARS-CoV-2 replication in cell culture cells and a patient-near replication system using human precision-cut lung slices by two orders of magnitude. While the compounds did not interfere with viral entry, it led to lower viral RNA expression after 24 h, indicating that post-entry pathways were inhibited by the compounds.},
  language  = {en}
}
@article{OckermannLizioHansmann2022,
  author    = {Ockermann, Philipp and Lizio, Rosario and Hansmann, Jan},
  title     = {Healthberry 865\(^®\) and a subset of its single anthocyanins attenuate oxidative stress in human endothelial in vitro models},
  series = {Nutrients},
  volume    = {14},
  journal   = {Nutrients},
  number    = {14},
  issn      = {2072-6643},
  doi       = {10.3390/nu14142917},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281887},
  year      = {2022},
  abstract  = {Oxidative stress and inflammation play a pivotal role in the development of cardiovascular diseases, an ever-growing worldwide problem. As a non-pharmacological approach, diet, especially a flavonoid-rich diet, showed promising results in the reduction of cardiovascular diseases and alleviation of their symptoms. In this study, in vitro systems based on human microvascular endothelial cells (hmvEC) and human umbilical cord endothelial cells (HUVEC) were established to determine the effect of Healthberry 865\(^®\) (HB) and ten of its relating single anthocyanins on oxidative stress. Furthermore, five metabolites were used in order to examine the effect of anthocyanin's most common breakdown molecules. The results showed an effect of HB in both models after 24 h, as well as most of its single anthocyanins. Cyanidin-rutinoside, peonidin-galactoside, and petunidin-glucoside had a model-specific effect. For the metabolites, phloroglucinaldeyhde (PGA) showed an effect in both models, while vanillic acid (VA) only had an effect in HUVEC. When combined, a combination of several anthocyanins did not have a cumulative effect, except for combining glucosides in hmvEC. The combination of PGA and VA even revealed an inhibitive behavior. Overall, the study demonstrates the antioxidative effect of HB and several of its single anthocyanins and metabolites, which are partially model specific, and coincides with animal studies.},
  language  = {en}
}
@article{HerbertFickHeydarianetal.2022,
  author    = {Herbert, Saskia-Laureen and Fick, Andrea and Heydarian, Motaharehsadat and Metzger, Marco and W{\"o}ckel, Achim and Rudel, Thomas and Kozjak-Pavlovic, Vera and Wulff, Christine},
  title     = {Establishment of the SIS scaffold-based 3D model of human peritoneum for studying the dissemination of ovarian cancer},
  series = {Journal of Tissue Engineering},
  volume    = {13},
  journal   = {Journal of Tissue Engineering},
  issn      = {2041-7314},
  doi       = {10.1177/20417314221088514},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301311},
  pages     = {1},
  year      = {2022},
  abstract  = {Ovarian cancer is the second most common gynecological malignancy in women. More than 70\% of the cases are diagnosed at the advanced stage, presenting as primary peritoneal metastasis, which results in a poor 5-year survival rate of around 40\%. Mechanisms of peritoneal metastasis, including adhesion, migration, and invasion, are still not completely understood and therapeutic options are extremely limited. Therefore, there is a strong requirement for a 3D model mimicking the in vivo situation. In this study, we describe the establishment of a 3D tissue model of the human peritoneum based on decellularized porcine small intestinal submucosa (SIS) scaffold. The SIS scaffold was populated with human dermal fibroblasts, with LP-9 cells on the apical side representing the peritoneal mesothelium, while HUVEC cells on the basal side of the scaffold served to mimic the endothelial cell layer. Functional analyses of the transepithelial electrical resistance (TEER) and the FITC-dextran assay indicated the high barrier integrity of our model. The histological, immunohistochemical, and ultrastructural analyses showed the main characteristics of the site of adhesion. Initial experiments using the SKOV-3 cell line as representative for ovarian carcinoma demonstrated the usefulness of our models for studying tumor cell adhesion, as well as the effect of tumor cells on endothelial cell-to-cell contacts. Taken together, our data show that the novel peritoneal 3D tissue model is a promising tool for studying the peritoneal dissemination of ovarian cancer.},
  language  = {en}
}
@article{SiverinoFahmyGarciaMumcuogluetal.2022,
  author    = {Siverino, Claudia and Fahmy-Garcia, Shorouk and Mumcuoglu, Didem and Oberwinkler, Heike and Muehlemann, Markus and Mueller, Thomas and Farrell, Eric and van Osch, Gerjo J. V. M. and Nickel, Joachim},
  title     = {Site-directed immobilization of an engineered bone morphogenetic protein 2 (BMP2) variant to collagen-based microspheres induces bone formation in vivo},
  series = {International Journal of Molecular Sciences},
  volume    = {23},
  journal   = {International Journal of Molecular Sciences},
  number    = {7},
  issn      = {1422-0067},
  doi       = {10.3390/ijms23073928},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284572},
  year      = {2022},
  abstract  = {For the treatment of large bone defects, the commonly used technique of autologous bone grafting presents several drawbacks and limitations. With the discovery of the bone-inducing capabilities of bone morphogenetic protein 2 (BMP2), several delivery techniques were developed and translated to clinical applications. Implantation of scaffolds containing adsorbed BMP2 showed promising results. However, off-label use of this protein-scaffold combination caused severe complications due to an uncontrolled release of the growth factor, which has to be applied in supraphysiological doses in order to induce bone formation. Here, we propose an alternative strategy that focuses on the covalent immobilization of an engineered BMP2 variant to biocompatible scaffolds. The new BMP2 variant harbors an artificial amino acid with a specific functional group, allowing a site-directed covalent scaffold functionalization. The introduced artificial amino acid does not alter BMP2′s bioactivity in vitro. When applied in vivo, the covalently coupled BMP2 variant induces the formation of bone tissue characterized by a structurally different morphology compared to that induced by the same scaffold containing ab-/adsorbed wild-type BMP2. Our results clearly show that this innovative technique comprises translational potential for the development of novel osteoinductive materials, improving safety for patients and reducing costs.},
  language  = {en}
}
@article{RibitschPehamAdeetal.2018,
  author    = {Ribitsch, Iris and Peham, Christian and Ade, Nicole and Duerr, Julia and Handschuh, Stephan and Schramel, Johannes Peter and Vogl, Claus and Walles, Heike and Egerbacher, Monika and Jenner, Florian},
  title     = {Structure-Function relationships of equine menisci},
  series = {PLoS ONE},
  volume    = {13},
  journal   = {PLoS ONE},
  number    = {3},
  doi       = {10.1371/journal.pone.0194052},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225214},
  pages     = {e0194052, 1-17},
  year      = {2018},
  abstract  = {Meniscal pathologies are among the most common injuries of the femorotibial joint in both human and equine patients. Pathological forces and ensuing injuries of the cranial horn of the equine medial meniscus are considered analogous to those observed in the human posterior medial horn. Biomechanical properties of human menisci are site-and depth-specific. However, the influence of equine meniscus topography and composition on its biomechanical properties is yet unknown. A better understanding of equine meniscus composition and biomechanics could advance not only veterinary therapies for meniscus degeneration or injuries, but also further substantiate the horse as suitable translational animal model for (human) meniscus tissue engineering. Therefore, the aim of this study was to investigate the composition and structure of the equine knee meniscus in a site-and age-specific manner and their relationship with potential site-specific biomechanical properties. The meniscus architecture was investigated histologically. Biomechanical testing included evaluation of the shore hardness (SH), stiffness and energy loss of the menisci. The SH was found to be subjected to both age and site-specific changes, with an overall higher SH of the tibial meniscus surface and increase in SH with age. Stiffness and energy loss showed neither site nor age related significant differences. The macroscopic and histologic similarities between equine and human menisci described in this study, support continued research in this field.},
  language  = {en}
}
@article{PeindlGoettlichCrouchetal.2022,
  author    = {Peindl, Matthias and G{\"o}ttlich, Claudia and Crouch, Samantha and Hoff, Niklas and L{\"u}ttgens, Tamara and Schmitt, Franziska and Pereira, Jes{\´u}s Guillermo Nieves and May, Celina and Schliermann, Anna and Kronenthaler, Corinna and Cheufou, Danjouma and Reu-Hofer, Simone and Rosenwald, Andreas and Weigl, Elena and Walles, Thorsten and Sch{\"u}ler, Julia and Dandekar, Thomas and Nietzer, Sarah and Dandekar, Gudrun},
  title     = {EMT, stemness, and drug resistance in biological context: a 3D tumor tissue/in silico platform for analysis of combinatorial treatment in NSCLC with aggressive KRAS-biomarker signatures},
  series = {Cancers},
  volume    = {14},
  journal   = {Cancers},
  number    = {9},
  issn      = {2072-6694},
  doi       = {10.3390/cancers14092176},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270744},
  year      = {2022},
  abstract  = {Epithelial-to-mesenchymal transition (EMT) is discussed to be centrally involved in invasion, stemness, and drug resistance. Experimental models to evaluate this process in its biological complexity are limited. To shed light on EMT impact and test drug response more reliably, we use a lung tumor test system based on a decellularized intestinal matrix showing more in vivo-like proliferation levels and enhanced expression of clinical markers and carcinogenesis-related genes. In our models, we found evidence for a correlation of EMT with drug resistance in primary and secondary resistant cells harboring KRAS\(^{G12C}\) or EGFR mutations, which was simulated in silico based on an optimized signaling network topology. Notably, drug resistance did not correlate with EMT status in KRAS-mutated patient-derived xenograft (PDX) cell lines, and drug efficacy was not affected by EMT induction via TGF-β. To investigate further determinants of drug response, we tested several drugs in combination with a KRAS\(^{G12C}\) inhibitor in KRAS\(^{G12C}\) mutant HCC44 models, which, besides EMT, display mutations in P53, LKB1, KEAP1, and high c-MYC expression. We identified an aurora-kinase A (AURKA) inhibitor as the most promising candidate. In our network, AURKA is a centrally linked hub to EMT, proliferation, apoptosis, LKB1, and c-MYC. This exemplifies our systemic analysis approach for clinical translation of biomarker signatures.},
  language  = {en}
}
@article{WeigelMalkmusWeigeletal.2022,
  author    = {Weigel, Tobias and Malkmus, Christoph and Weigel, Verena and Wußmann, Maximiliane and Berger, Constantin and Brennecke, Julian and Groeber-Becker, Florian and Hansmann, Jan},
  title     = {Fully Synthetic 3D Fibrous Scaffolds for Stromal Tissues—Replacement of Animal-Derived Scaffold Materials Demonstrated by Multilayered Skin},
  series = {Advanced Materials},
  volume    = {34},
  journal   = {Advanced Materials},
  number    = {10},
  doi       = {10.1002/adma.202106780},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276403},
  year      = {2022},
  abstract  = {The extracellular matrix (ECM) of soft tissues in vivo has remarkable biological and structural properties. Thereby, the ECM provides mechanical stability while it still can be rearranged via cellular remodeling during tissue maturation or healing processes. However, modern synthetic alternatives fail to provide these key features among basic properties. Synthetic matrices are usually completely degraded or are inert regarding cellular remodeling. Based on a refined electrospinning process, a method is developed to generate synthetic scaffolds with highly porous fibrous structures and enhanced fiber-to-fiber distances. Since this approach allows for cell migration, matrix remodeling, and ECM synthesis, the scaffold provides an ideal platform for the generation of soft tissue equivalents. Using this matrix, an electrospun-based multilayered skin equivalent composed of a stratified epidermis, a dermal compartment, and a subcutis is able to be generated without the use of animal matrix components. The extension of classical dense electrospun scaffolds with high porosities and motile fibers generates a fully synthetic and defined alternative to collagen-gel-based tissue models and is a promising system for the construction of tissue equivalents as in vitro models or in vivo implants.},
  language  = {en}
}
@article{WeigelBrenneckeHansmann2021,
  author    = {Weigel, Tobias and Brennecke, Julian and Hansmann, Jan},
  title     = {Improvement of the electronic—neuronal interface by natural deposition of ECM},
  series = {Materials},
  volume    = {14},
  journal   = {Materials},
  number    = {6},
  issn      = {1996-1944},
  doi       = {10.3390/ma14061378},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234047},
  year      = {2021},
  abstract  = {The foreign body reaction to neuronal electrode implants limits potential applications as well as the therapeutic period. Developments in the basic electrode design might improve the tissue compatibility and thereby reduce the foreign body reaction. In this work, the approach of embedding 3D carbon nanofiber electrodes in extracellular matrix (ECM) synthesized by human fibroblasts for a compatible connection to neuronal cells was investigated. Porous electrode material was manufactured by solution coelectrospinning of polyacrylonitrile and polyamide as a fibrous porogen. Moreover, NaCl represented an additional particulate porogen. To achieve the required conductivity for an electrical interface, meshes were carbonized. Through the application of two different porogens, the electrodes' flexibility and porosity was improved. Human dermal fibroblasts were cultured on the electrode surface for ECM generation and removed afterwards. Scanning electron microscopy imaging revealed a nano fibrous ECM network covering the carbon fibers. The collagen amount of the ECM coating was quantified by hydroxyproline-assays. The modification with the natural protein coating on the electrode functionality resulted in a minor increase of the electrical capacity, which slightly improved the already outstanding electrical interface properties. Increased cell numbers of SH-SY5Y cell line on ECM-modified electrodes demonstrated an improved cell adhesion. During cell differentiation, the natural ECM enhanced the formation of neurites regarding length and branching. The conducted experiments indicated the prevention of direct cell-electrode contacts by the modification, which might help to shield temporary the electrode from immunological cells to reduce the foreign body reaction and improve the electrodes' tissue integration.},
  language  = {en}
}
@article{BrachnerFragouliDuarteetal.2020,
  author    = {Brachner, Andreas and Fragouli, Despina and Duarte, Iola F. and Farias, Patricia M. A. and Dembski, Sofia and Ghosh, Manosij and Barisic, Ivan and Zdzieblo, Daniela and Vanoirbeek, Jeroen and Schwabl, Philipp and Neuhaus, Winfried},
  title     = {Assessment of human health risks posed by nano-and microplastics is currently not feasible},
  series = {International Journal of Environmental Research and Public Health},
  volume    = {17},
  journal   = {International Journal of Environmental Research and Public Health},
  number    = {23},
  issn      = {1660-4601},
  doi       = {10.3390/ijerph17238832},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219423},
  year      = {2020},
  abstract  = {The exposure of humans to nano-and microplastic particles (NMPs) is an issue recognized as a potential health hazard by scientists, authorities, politics, non-governmental organizations and the general public. The concentration of NMPs in the environment is increasing concomitantly with global plastic production and the usage of plastic materials. NMPs are detectable in numerous aquatic organisms and also in human samples, therefore necessitating a risk assessment of NMPs for human health. So far, a comprehensive risk assessment of NMPs is hampered by limited availability of appropriate reference materials, analytical obstacles and a lack of definitions and standardized study designs. Most studies conducted so far used polystyrene (PS) spheres as a matter of availability, although this polymer type accounts for only about 7\% of total plastic production. Differently sized particles, different concentration and incubation times, and various biological models have been used, yielding hardly comparable data sets. Crucial physico-chemical properties of NMPs such as surface (charge, polarity, chemical reactivity), supplemented additives and adsorbed chemicals have been widely excluded from studies, although in particular the surface of NMPs determines the interaction with cellular membranes. In this manuscript we give an overview about the critical parameters which should be considered when performing risk assessments of NMPs, including novel reference materials, taking into account surface modifications (e.g., reflecting weathering processes), and the possible role of NMPs as a substrate and/or carrier for (pathogenic) microbes. Moreover, we make suggestions for biological model systems to evaluate immediate toxicity, long-term effects and the potential of NMPs to cross biological barriers. We are convinced that standardized reference materials and experimental parameters along with technical innovations in (nano)-particle sampling and analytics are a prerequisite for the successful realization of conclusive human health risk assessments of NMPs.},
  language  = {en}
}
@article{KannapinSchmitzHansmannetal.2021,
  author    = {Kannapin, Felix and Schmitz, Tobias and Hansmann, Jan and Schlegel, Nicolas and Meir, Michael},
  title     = {Measurements of transepithelial electrical resistance (TEER) are affected by junctional length in immature epithelial monolayers},
  series = {Histochemistry and Cell Biology},
  volume    = {156},
  journal   = {Histochemistry and Cell Biology},
  number    = {6},
  issn      = {1432-119X},
  doi       = {10.1007/s00418-021-02026-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267465},
  pages     = {609-616},
  year      = {2021},
  abstract  = {The measurement of transepithelial electrical resistance (TEER) is a common technique to determine the barrier integrity of epithelial cell monolayers. However, it is remarkable that absolute TEER values of similar cell types cultured under comparable conditions show an immense heterogeneity. Based on previous observations, we hypothesized that the heterogeneity of absolute TEER measurements can not only be explained by maturation of junctional proteins but rather by dynamics in the absolute length of cell junctions within monolayers. Therefore, we analyzed TEER in epithelial cell monolayers of Caco2 cells during their differentiation, with special emphasis on both changes in the junctional complex and overall cell morphology within monolayers. We found that in epithelial Caco2 monolayers TEER increased until confluency, then decreased for some time, which was then followed by an additional increase during junctional differentiation. In contrast, permeability of macromolecules measured at different time points as 4 kDA fluorescein isothiocyanate (FITC)-dextran flux across monolayers steadily decreased during this time. Detailed analysis suggested that this observation could be explained by alterations of junctional length along the cell borders within monolayers during differentiation. In conclusion, these observations confirmed that changes in cell numbers and consecutive increase of junctional length have a critical impact on TEER values, especially at stages of early confluency when junctions are immature.},
  language  = {en}
}
@article{SchmidTarauRossietal.2018,
  author    = {Schmid, Richard and Tarau, Ioana-Sandra and Rossi, Angela and Leonhardt, Stefan and Schwarz, Thomas and Schuerlein, Sebastian and Lotz, Christian and Hansmann, Jan},
  title     = {In Vivo-Like Culture Conditions in a Bioreactor Facilitate Improved Tissue Quality in Corneal Storage},
  series = {Biotechnology Journal},
  volume    = {13},
  journal   = {Biotechnology Journal},
  number    = {1,1700344},
  doi       = {10.1002/biot.201700344},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228620},
  pages     = {1-7},
  year      = {2018},
  abstract  = {The cornea is the most-transplanted tissue worldwide. However, the availability and quality of grafts are limited due to the current methods of corneal storage. In this study, a dynamic bioreactor system is employed to enable the control of intraocular pressure and the culture at the air-liquid interface. Thereby, in vivo-like storage conditions are achieved. Different media combinations for endothelium and epithelium are tested in standard and dynamic conditions to enhance the viability of the tissue. In contrast to culture conditions used in eye banks, the combination of the bioreactor and biochrom medium 1 allows to preserve the corneal endothelium and the epithelium. Assessment of transparency, swelling, and the trans-epithelial-electrical-resistance (TEER) strengthens the impact of the in vivo-like tissue culture. For example, compared to corneas stored under static conditions, significantly lower optical densities and significantly higher TEER values were measured (p-value <0.05). Furthermore, healing of epithelial defects is enabled in the bioreactor, characterized by re-epithelialization and initiated stromal regeneration. Based on the obtained results, an easy-to-use 3D-printed bioreactor composed of only two parts was derived to translate the technology from the laboratory to the eye banks. This optimized bioreactor facilitates noninvasive microscopic monitoring. The improved storage conditions ameliorate the quality of corneal grafts and the storage time in the eye banks to increase availability and reduce re-grafting.},
  language  = {en}
}
@phdthesis{Leikeim2022,
  author    = {Leikeim, Anna},
  title     = {Vascularization Strategies for Full-Thickness Skin Equivalents to Model Melanoma Progression},
  doi       = {10.25972/OPUS-27295},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-272956},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Malignant melanoma (MM) is the most dangerous type of skin cancer with rising incidences worldwide. Melanoma skin models can help to elucidate its causes and formation or to develop new treatment strategies. However, most of the current skin models lack a vasculature, limiting their functionality and applicability. MM relies on the vascular system for its own supply and for its dissemination to distant body sites via lymphatic and blood vessels. Thus, to accurately study MM progression, a functional vasculature is indispensable. To date, there are no vascularized skin models to study melanoma metastasis in vitro, which is why such studies still rely on animal experimentation. In the present thesis, two different approaches for the vascularization of skin models are employed with the aim to establish a vascularized 3D in vitro full-thickness skin equivalent (FTSE) that can serve as a test system for the investigation of the progression of MM. Initially, endothelial cells were incorporated in the dermal part of FTSEs. The optimal seeding density, a spheroid conformation of the cells and the cell culture medium were tested. A high cell density resulted in the formation of lumen-forming shapes distributed in the dermal part of the model. These capillary-like structures were proven to be of endothelial origin by staining for the endothelial cell marker CD31. The established vascularized FTSE (vFTSE) was characterized histologically after 4 weeks of culture, revealing an architecture similar to human skin in vivo with a stratified epidermis, separated from the dermal equivalent by a basement membrane indicated by collagen type IV. However, this random capillary-like network is not functional as it cannot be perfused. Therefore, the second vascularization approach focused on the generation of a perfusable tissue construct. A channel was molded within a collagen hydrogel and seeded with endothelial cells to mimic a central, perfusable vessel. The generation and the perfusion culture of the collagen hydrogel was enabled by the use of two custom-made, 3D printed bioreactors. Histological assessment of the hydrogels revealed the lining of the channel with a monolayer of endothelial cells, expressing the cell specific marker CD31. For the investigation of MM progression in vitro, a 3D melanoma skin equivalent was established. Melanoma cells were incorporated in the epidermal part of FTSEs, representing the native microenvironment of the tumor. Melanoma nests grew at the dermo-epidermal junction within the well stratified epidermis and were characterized by the expression of common melanoma markers. First experiments were conducted showing the feasibility of combining the melanoma model with the vFTSE, resulting in skin models with tumors at the dermo-epidermal junction and lumen-like structures in the dermis. Taken together, the models presented in this thesis provide further steps towards the establishment of a vascularized, perfusable melanoma model to study melanoma progression and metastasis.},
  subject      = {Tissue Engineering},
  language  = {en}
}
@article{StuckensenLamoEspinosaMuinosLopezetal.2019,
  author    = {Stuckensen, Kai and Lamo-Espinosa, Jos{\´e} M. and Mui{\~n}os-L{\´o}pez, Emma and Ripalda-Cembor{\´a}in, Purificaci{\´o}n and L{\´o}pez-Mart{\´i}nez, Tania and Iglesias, Elena and Abizanda, Gloria and Andreu, Ion and Flandes-Iparraguirre, Mar{\´i}a and Pons-Villanueva, Juan and Elizalde, Reyes and Nickel, Joachim and Ewald, Andrea and Gbureck, Uwe and Pr{\´o}sper, Felipe and Groll, J{\"u}rgen and Granero-Molt{\´o}, Froil{\´a}n},
  title     = {Anisotropic cryostructured collagen scaffolds for efficient delivery of RhBMP-2 and enhanced bone regeneration},
  series = {Materials},
  volume    = {12},
  journal   = {Materials},
  number    = {19},
  issn      = {1996-1944},
  doi       = {10.3390/ma12193105},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195966},
  year      = {2019},
  abstract  = {In the treatment of bone non-unions, an alternative to bone autografts is the use of bone morphogenetic proteins (BMPs), e.g., BMP-2, BMP-7, with powerful osteoinductive and osteogenic properties. In clinical settings, these osteogenic factors are applied using absorbable collagen sponges for local controlled delivery. Major side effects of this strategy are derived from the supraphysiological doses of BMPs needed, which may induce ectopic bone formation, chronic inflammation, and excessive bone resorption. In order to increase the efficiency of the delivered BMPs, we designed cryostructured collagen scaffolds functionalized with hydroxyapatite, mimicking the structure of cortical bone (aligned porosity, anisotropic) or trabecular bone (random distributed porosity, isotropic). We hypothesize that an anisotropic structure would enhance the osteoconductive properties of the scaffolds by increasing the regenerative performance of the provided rhBMP-2. In vitro, both scaffolds presented similar mechanical properties, rhBMP-2 retention and delivery capacity, as well as scaffold degradation time. In vivo, anisotropic scaffolds demonstrated better bone regeneration capabilities in a rat femoral critical-size defect model by increasing the defect bridging. In conclusion, anisotropic cryostructured collagen scaffolds improve bone regeneration by increasing the efficiency of rhBMP-2 mediated bone healing.},
  language  = {en}
}
@article{MeyerGerhardHartmannLodesetal.2021,
  author    = {Meyer, Till Jasper and Gerhard-Hartmann, Elena and Lodes, Nina and Scherzad, Agmal and Hagen, Rudolf and Steinke, Maria and Hackenberg, Stephan},
  title     = {Pilot study on the value of Raman spectroscopy in the entity assignment of salivary gland tumors},
  series = {PLoS One},
  volume    = {16},
  journal   = {PLoS One},
  number    = {9},
  doi       = {10.1371/journal.pone.0257470},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264736},
  year      = {2021},
  abstract  = {Background The entity assignment of salivary gland tumors (SGT) based on histomorphology can be challenging. Raman spectroscopy has been applied to analyze differences in the molecular composition of tissues. The aim of this study was to evaluate the suitability of RS for entity assignment in SGT. Methods Raman data were collected in deparaffinized sections of pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC). Multivariate data and chemometric analysis were completed using the Unscrambler software. Results The Raman spectra detected in ACC samples were mostly assigned to nucleic acids, lipids, and amides. In a principal component-based linear discriminant analysis (LDA) 18 of 20 tumor samples were classified correctly. Conclusion In this proof of concept study, we show that a reliable SGT diagnosis based on LDA algorithm appears possible, despite variations in the entity-specific mean spectra. However, a standardized workflow for tissue sample preparation, measurement setup, and chemometric algorithms is essential to get reliable results.},
  language  = {en}
}
@phdthesis{Fey2022,
  author    = {Fey, Christina},
  title     = {Establishment of an intestinal tissue model for pre-clinical screenings},
  doi       = {10.25972/OPUS-24410},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244107},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {The small intestine represents a strong barrier separating the lumen from blood circulation thereby playing a major role in the absorption and the transport of pharmacological agents prior to their arrival on the respective target site. In order to gain more knowledge about specialized uptake mechanisms and risk assessment for the patient after oral admission of drugs, intestinal in vitro models demonstrating a close similarity to the in vivo situation are needed. In the past, cell line-based in vitro models composed of Caco-2 cells cultured on synthetic cell carriers represented the "gold standard" in the field of intestinal tissue engineering. Expressive advantages of these models are a reproducible, cost-efficient and standardized model set up, but cell function can be negatively influenced by the low porosity or unwanted molecular adhesion effects of the artificial scaffold material. Natural extracellular matrices (ECM) such as the porcine decellularized small intestinal submucosa (SIS) are used as alternative to overcome some common drawbacks; however, the fabrication of these scaffolds is time- and cost-intensive, less well standardized and the 3Rs (replacement, reduction, refinement) principle is not entirely fulfilled. Nowadays, biopolymer-based scaffolds such as the bacterial nanocellulose (BNC) suggest an interesting option of novel intestinal tissue engineered models, as the BNC shows comparable features to the native ECM regarding fiber arrangement and hydrophilic properties. Furthermore, the BNC is of non-animal origin and the manufacturing process is faster as well as well standardized at low costs. In this context, the first part of this thesis analyzed the BNC as alternative scaffold to derive standardized and functional organ models in vitro. Therefore, Caco-2 cells were cultured on two versions of BNC with respect to their surface topography, the unmodified BNC as rather smooth surface and the surface-structured BNC presenting an aligned fiber arrangement. As controls, Caco-2 in vitro models were set up on PET and SIS matrices. In this study, the BNC-based models demonstrated organ-specific properties comprising typical cellular morphologies, a characteristic tight junction protein expression profile, representative ultrastructural features and the formation of a tight epithelial barrier together with a corresponding transport activity. In summary, these results validated the high quality of the BNC-based Caco-2 models under cost-efficient conditions and their suitability for pre-clinical research purposes. However, the full functional diversity of the human intestine cannot be presented by Caco-2 cells due to their tumorigenic background and their exclusive representation of mature enterocytes. Next to the scaffold used for the setup of in vitro models, the cellular unit mainly drives functional performance, which demonstrates the crucial importance of mimicking the cellular diversity of the small intestine in vitro. In this context, intestinal primary organoids are of high interest, as they show a close similarity to the native epithelium regarding their cellular diversity comprising enterocytes, goblet cells, enteroendocrine cells, paneth cells, transit amplifying cells and stem cells. In general, such primary organoids grow in a 3D Matrigel® based environment and a medium formulation supplemented with a variety of growth factors to maintain stemness, to inhibit differentiation and to stimulate cell migration supporting long term in vitro culture. Intestinal primary spheroid/organoid cultures were set up as Transwell®-like models on both BNC variants, which resulted in a fragmentary cell layer and thereby unfavorable properties of these scaffold materials under the applied circumstances. As the BNC manufacturing process is highly flexible, surface properties could be adapted in future studies to enable a good cell adherence and barrier formation for primary intestinal cells, too. However, the application of these organoid cultures in pre-clinical research represents an enormous challenge, as the in vitro culture is complex and additionally time- and cost-intensive. With regard to the high potential of primary intestinal spheroids/organoids and the necessity of a simplified but predictive model in pre-clinical research purposes, the second part of this thesis addressed the establishment of a primary-derived immortalized intestinal cell line, which enables a standardized and cost-efficient culture (including in 2D), while maintaining the cellular diversity of the organoid in vitro cultures. In this study, immortalization of murine and human intestinal primary organoids was induced by ectopic expression of a 10- (murine) or 12 component (human) pool of genes regulating stemness and the cell cycle, which was performed in cooperation with the InSCREENeX GmbH in a 2D- and 3D-based transduction strategy. In first line, the established cell lines (cell clones) were investigated for their cell culture prerequisites to grow under simplified and cost-efficient conditions. While murine cell clones grew on uncoated plastic in a medium formulation supplemented with EGF, Noggin, Y-27632 and 10\% FCS, the human cell clones demonstrated the necessity of a Col I pre coating together with the need for a medium composition commonly used for primary human spheroid/organoid cultures. Furthermore, the preceding analyses resulted in only one human cell clone and three murine cell clones for ongoing characterization. Studies regarding the proliferative properties and the specific gene as well as protein expression profile of the remaining cell clones have shown, that it is likely that transient amplifying cells (TACs) were immortalized instead of the differentiated cell types localized in primary organoids, as 2D, 3D or Transwell®-based cultures resulted in slightly different gene expression profiles and in a dramatically reduced mRNA transcript level for the analyzed marker genes representative for the differentiated cell types of the native epithelium. Further, 3D cultures demonstrated the formation of spheroid-like structures; however without forming organoid-like structures due to prolonged culture, indicating that these cell populations have lost their ability to differentiate into specific intestinal cell types. The Transwell®-based models set up of each clone exhibit organ-specific properties comprising an epithelial-like morphology, a characteristic protein expression profile with an apical mucus-layer covering the villin-1 positive cell layer, thereby representing goblet cells and enterocytes, together with representative tight junction complexes indicating an integer epithelial barrier. The proof of a functional as well as tight epithelial barrier in TEER measurements and in vivo-like transport activities qualified the established cell clones as alternative cell sources for tissue engineered models representing the small intestine to some extent. Additionally, the easy handling and cell expansion under more cost-efficient conditions compared to primary organoid cultures favors the use of these newly generated cell clones in bioavailability studies. Altogether, this work demonstrated new components, structural and cellular, for the establishment of alternative in vitro models of the small intestinal epithelium, which could be used in pre-clinical screenings for reproducible drug delivery studies.},
  subject      = {D{\"u}nndarm},
  language  = {en}
}
@article{SchwabBussPulligetal.2021,
  author    = {Schwab, Andrea and Buss, Alexa and Pullig, Oliver and Ehlicke, Franziska},
  title     = {Ex vivo osteochondral test system with control over cartilage defect depth - A pilot study to investigate the effect of oxygen tension and chondrocyte based treatments in chondral and full thickness defects in an organ model},
  series = {Osteoarthritis and Cartilage Open},
  volume    = {3},
  journal   = {Osteoarthritis and Cartilage Open},
  number    = {2},
  doi       = {10.1016/j.ocarto.2021.100173},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260511},
  year      = {2021},
  abstract  = {Objective Cartilage defect treatment strategies are dependent on the lesion size and severity. Osteochondral explant models are a platform to test cartilage repair strategies ex vivo. Current models lack in mimicking the variety of clinically relevant defect scenarios. In this controlled laboratory study, an automated device (artificial tissue cutter, ARTcut®) was implemented to reproducibly create cartilage defects with controlled depth. In a pilot study, the effect of cartilage defect depth and oxygen tension on cartilage repair was investigated. Design Osteochondral explants were isolated from porcine condyles. 4 ​mm chondral and full thickness defects were treated with either porcine chondrocytes (CHON) or co-culture of 20\% CHON and 80\% MSCs (MIX) embedded in collagen hydrogel. Explants were cultured with tissue specific media (without TGF-β) under normoxia (20\% O\(_2\)) and physiological hypoxia (2\% O\(_2\)). After 28 days, immune-histological stainings (collagen II and X, aggrecan) were scored (modified Bern score, 3 independent scorer) to quantitatively compare treatment outcome. Results ARTcut® represents a software-controlled device for creation of uniform cartilage defects. Comparing the scoring results of the MIX and the CHON treatment, a positive relation between oxygen tension and defect depth was observed. Low oxygen tension stimulated cartilaginous matrix deposition in MIX group in chondral defects and CHON treatment in full thickness defects. Conclusion ARTcut® has proved a powerful tool to create cartilage defects and thus opens a wide range of novel applications of the osteochondral model, including the relation between oxygen tension and defect depth on cartilage repair.},
  language  = {en}
}
@article{ZimniakKirschnerHilpertetal.2021,
  author    = {Zimniak, Melissa and Kirschner, Luisa and Hilpert, Helen and Geiger, Nina and Danov, Olga and Oberwinkler, Heike and Steinke, Maria and Sewald, Katherina and Seibel, J{\"u}rgen and Bodem, Jochen},
  title     = {The serotonin reuptake inhibitor Fluoxetine inhibits SARS-CoV-2 in human lung tissue},
  series = {Scientific Reports},
  volume    = {11},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-021-85049-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259820},
  pages     = {5890},
  year      = {2021},
  abstract  = {To circumvent time-consuming clinical trials, testing whether existing drugs are effective inhibitors of SARS-CoV-2, has led to the discovery of Remdesivir. We decided to follow this path and screened approved medications "off-label" against SARS-CoV-2. Fluoxetine inhibited SARS-CoV-2 at a concentration of 0.8 mu g/ml significantly in these screenings, and the EC50 was determined with 387 ng/ml. Furthermore, Fluoxetine reduced viral infectivity in precision-cut human lung slices showing its activity in relevant human tissue targeted in severe infections. Fluoxetine treatment resulted in a decrease in viral protein expression. Fluoxetine is a racemate consisting of both stereoisomers, while the S-form is the dominant serotonin reuptake inhibitor. We found that both isomers show similar activity on the virus, indicating that the R-form might specifically be used for SARS-CoV-2 treatment. Fluoxetine inhibited neither Rabies virus, human respiratory syncytial virus replication nor the Human Herpesvirus 8 or Herpes simplex virus type 1 gene expression, indicating that it acts virus-specific. Moreover, since it is known that Fluoxetine inhibits cytokine release, we see the role of Fluoxetine in the treatment of SARS-CoV-2 infected patients of risk groups.},
  language  = {en}
}
@article{HeydarianSchweinlinSchwarzetal.2021,
  author    = {Heydarian, Motaharehsadat and Schweinlin, Matthias and Schwarz, Thomas and Rawal, Ravisha and Walles, Heike and Metzger, Marco and Rudel, Thomas and Kozjak-Pavlovic, Vera},
  title     = {Triple co-culture and perfusion bioreactor for studying the interaction between Neisseria gonorrhoeae and neutrophils: A novel 3D tissue model for bacterial infection and immunity},
  series = {Journal of Tissue Engineering},
  volume    = {12},
  journal   = {Journal of Tissue Engineering},
  doi       = {10.1177/2041731420988802},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259032},
  pages     = {2041731420988802},
  year      = {2021},
  abstract  = {Gonorrhea, a sexually transmitted disease caused by the bacteria Neisseria gonorrhoeae, is characterized by a large number of neutrophils recruited to the site of infection. Therefore, proper modeling of the N. gonorrhoeae interaction with neutrophils is very important for investigating and understanding the mechanisms that gonococci use to evade the immune response. We have used a combination of a unique human 3D tissue model together with a dynamic culture system to study neutrophil transmigration to the site of N. gonorrhoeae infection. The triple co-culture model consisted of epithelial cells (T84 human colorectal carcinoma cells), human primary dermal fibroblasts, and human umbilical vein endothelial cells on a biological scaffold (SIS). After the infection of the tissue model with N. gonorrhoeae, we introduced primary human neutrophils to the endothelial side of the model using a perfusion-based bioreactor system. By this approach, we were able to demonstrate the activation and transmigration of neutrophils across the 3D tissue model and their recruitment to the site of infection. In summary, the triple co-culture model supplemented by neutrophils represents a promising tool for investigating N. gonorrhoeae and other bacterial infections and interactions with the innate immunity cells under conditions closely resembling the native tissue environment.},
  language  = {en}
}
@article{BorovaSchluttNickeletal.2022,
  author    = {Borova, Solomiia and Schlutt, Christine and Nickel, Joachim and Luxenhofer, Robert},
  title     = {A Transient Initiator for Polypeptoids Postpolymerization α-Functionalization via Activation of a Thioester Group},
  series = {Macromolecular Chemistry and Physics},
  volume    = {223},
  journal   = {Macromolecular Chemistry and Physics},
  number    = {3},
  doi       = {10.1002/macp.202100331},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257587},
  year      = {2022},
  abstract  = {Here, a postpolymerization modification method for an α-terminal functionalized poly-(N-methyl-glycine), also known as polysarcosine, is introduced. 4-(Methylthio)phenyl piperidine-4-carboxylate as an initiator for the ring-opening polymerization of N-methyl-glycine-N-carboxyanhydride followed by oxidation of the thioester group to yield an α-terminal reactive 4-(methylsulfonyl)phenyl piperidine-4-carboxylate polymer is utilized. This represents an activated carboxylic acid terminus, allowing straightforward modification with nucleophiles under mild reaction conditions and provides the possibility to introduce a wide variety of nucleophiles as exemplified using small molecules, fluorescent dyes, and model proteins. The new initiator yielded polymers with well-defined molar mass, low dispersity, and high end-group fidelity, as observed by gel permeation chromatography, nuclear magnetic resonance spectroscopy, and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. The introduced method can be of great interest for bioconjugation, but requires optimization, especially for protein conjugation.},
  language  = {en}
}