@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{AlepeeBahinskiDaneshianetal.2014,
  author    = {Alepee, Natalie and Bahinski, Anthony and Daneshian, Mardas and De Weyer, Bart and Fritsche, Ellen and Goldberg, Alan and Hansmann, Jan and Hartung, Thomas and Haycock, John and Hogberg, Helena T. and Hoelting, Lisa and Kelm, Jens M. and Kadereit, Suzanne and McVey, Emily and Landsiedel, Robert and Leist, Marcel and L{\"u}bberstedt, Marc and Noor, Fozia and Pellevoisin, Christian and Petersohn, Dirk and Pfannenbecker, Uwe and Reisinger, Kerstin and Ramirez, Tzutzuy and Rothen-Rutishauser, Barbara and Sch{\"a}fer-Korting, Monika and Zeilinger, Katrin and Zurich, Marie-Gabriele},
  title     = {State-of-the-Art of 3D Cultures (Organs-on-a-Chip) in Safety Testing and Pathophysiology},
  series = {ALTEX - Alternatives to Animal Experimentation},
  volume    = {31},
  journal   = {ALTEX - Alternatives to Animal Experimentation},
  number    = {4},
  doi       = {2014; http://dx.doi.org/10.14573/altex1406111},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117826},
  pages     = {441-477},
  year      = {2014},
  abstract  = {Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs liver, lung, skin, brain are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing.},
  language  = {en}
}
@article{BrendtkeWiehlGroeberetal.2016,
  author    = {Brendtke, Rico and Wiehl, Michael and Groeber, Florian and Schwarz, Thomas and Walles, Heike and Hansmann, Jan},
  title     = {Feasibility Study on a Microwave-Based Sensor for Measuring Hydration Level Using Human Skin Models},
  series = {PLoS ONE},
  volume    = {11},
  journal   = {PLoS ONE},
  number    = {4},
  doi       = {10.1371/journal.pone.0153145},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179934},
  year      = {2016},
  abstract  = {Tissue dehydration results in three major types of exsiccosis—hyper-, hypo-, or isonatraemia. All three types entail alterations of salt concentrations leading to impaired biochemical processes, and can finally cause severe morbidity. The aim of our study was to demonstrate the feasibility of a microwave-based sensor technology for the non-invasive measurement of the hydration status. Electromagnetic waves at high frequencies interact with molecules, especially water. Hence, if a sample contains free water molecules, this can be detected in a reflected microwave signal. To develop the sensor system, human three-dimensional skin equivalents were instituted as a standardized test platform mimicking reproducible exsiccosis scenarios. Therefore, skin equivalents with a specific hydration and density of matrix components were generated and microwave measurements were performed. Hydration-specific spectra allowed deriving the hydration state of the skin models. A further advantage of the skin equivalents was the characterization of the impact of distinct skin components on the measured signals to investigate mechanisms of signal generation. The results demonstrate the feasibility of a non-invasive microwave-based hydration sensor technology. The sensor bears potential to be integrated in a wearable medical device for personal health monitoring.},
  language  = {en}
}
@article{GenslerLeikeimMoellmannetal.2020,
  author    = {Gensler, Marius and Leikeim, Anna and M{\"o}llmann, Marc and Komma, Miriam and Heid, Susanne and M{\"u}ller, Claudia and Boccaccini, Aldo R. and Salehi, Sahar and Groeber-Becker, Florian and Hansmann, Jan},
  title     = {3D printing of bioreactors in tissue engineering: A generalised approach},
  series = {PLoS One},
  volume    = {15},
  journal   = {PLoS One},
  number    = {11},
  doi       = {10.1371/journal.pone.0242615},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231368},
  year      = {2020},
  abstract  = {3D printing is a rapidly evolving field for biological (bioprinting) and non-biological applications. Due to a high degree of freedom for geometrical parameters in 3D printing, prototype printing of bioreactors is a promising approach in the field of Tissue Engineering. The variety of printers, materials, printing parameters and device settings is difficult to overview both for beginners as well as for most professionals. In order to address this problem, we designed a guidance including test bodies to elucidate the real printing performance for a given printer system. Therefore, performance parameters such as accuracy or mechanical stability of the test bodies are systematically analysed. Moreover, post processing steps such as sterilisation or cleaning are considered in the test procedure. The guidance presented here is also applicable to optimise the printer settings for a given printer device. As proof of concept, we compared fused filament fabrication, stereolithography and selective laser sintering as the three most used printing methods. We determined fused filament fabrication printing as the most economical solution, while stereolithography is most accurate and features the highest surface quality. Finally, we tested the applicability of our guidance by identifying a printer solution to manufacture a complex bioreactor for a perfused tissue construct. Due to its design, the manufacture via subtractive mechanical methods would be 21-fold more expensive than additive manufacturing and therefore, would result in three times the number of parts to be assembled subsequently. Using this bioreactor we showed a successful 14-day-culture of a biofabricated collagen-based tissue construct containing human dermal fibroblasts as the stromal part and a perfusable central channel with human microvascular endothelial cells. Our study indicates how the full potential of biofabrication can be exploited, as most printed tissues exhibit individual shapes and require storage under physiological conditions, after the bioprinting process.},
  language  = {en}
}
@article{GroeberEngelhardtLangeetal.2016,
  author    = {Groeber, Florian and Engelhardt, Lisa and Lange, Julia and Kurdyn, Szymon and Schmid, Freia F. and R{\"u}cker, Christoph and Mielke, Stephan and Walles, Heike and Hansmann, Jan},
  title     = {A First Vascularized Skin Equivalent as an Alternative to Animal Experimentation},
  series = {ALTEX - Alternatives to Animal Experimentation},
  volume    = {33},
  journal   = {ALTEX - Alternatives to Animal Experimentation},
  number    = {4},
  doi       = {10.14573/altex.1604041},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164438},
  pages     = {415-422},
  year      = {2016},
  abstract  = {Tissue-engineered skin equivalents mimic key aspects of the human skin, and can thus be employed as wound coverage for large skin defects or as in vitro test systems as an alternative to animal models. However, current skin equivalents lack a functional vasculature limiting clinical and research applications. This study demonstrates the generation of a vascularized skin equivalent with a perfused vascular network by combining a biological vascularized scaffold (BioVaSc) based on a decellularized segment of a porcine jejunum and a tailored bioreactor system. Briefly, the BioVaSc was seeded with human fibroblasts, keratinocytes, and human microvascular endothelial cells. After 14 days at the air-liquid interface, hematoxylin \& eosin and immunohistological staining revealed a specific histological architecture representative of the human dermis and epidermis including a papillary-like architecture at the dermal-epidermal-junction. The formation of the skin barrier was measured non-destructively using impedance spectroscopy. Additionally, endothelial cells lined the walls of the formed vessels that could be perfused with a physiological volume flow. Due to the presence of a complex in-vivo-like vasculature, the here shown skin equivalent has the potential for skin grafting and represents a sophisticated in vitro model for dermatological research.},
  language  = {en}
}
@article{HindererShenRinguetteetal.2015,
  author    = {Hinderer, Svenja and Shen, Nian and Ringuette, L{\´e}a-Jeanne and Hansmann, Jan and Reinhardt, Dieter P and Brucker, Sara Y and Davis, Elaine C and Schenke-Layland, Katja},
  title     = {In vitro elastogenesis: instructing human vascular smooth muscle cells to generate an elastic fiber-containing extracellular matrix scaffold},
  series = {Biomedical Materials},
  volume    = {10},
  journal   = {Biomedical Materials},
  number    = {3},
  doi       = {10.1088/1748-6041/10/3/034102},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254074},
  year      = {2015},
  abstract  = {Elastic fibers are essential for the proper function of organs including cardiovascular tissues such as heart valves and blood vessels. Although (tropo)elastin production in a tissue-engineered construct has previously been described, the assembly to functional elastic fibers in vitro using human cells has been highly challenging. In the present study, we seeded primary isolated human vascular smooth muscle cells (VSMCs) onto 3D electrospun scaffolds and exposed them to defined laminar shear stress using a customized bioreactor system. Increased elastin expression followed by elastin deposition onto the electrospun scaffolds, as well as on newly formed fibers, was observed after six days. Most interestingly, we identified the successful deposition of elastogenesis-associated proteins, including fibrillin-1 and -2, fibulin-4 and -5, fibronectin, elastin microfibril interface located protein 1 (EMILIN-1) and lysyl oxidase (LOX) within our engineered constructs. Ultrastructural analyses revealed a developing extracellular matrix (ECM) similar to native human fetal tissue, which is composed of collagens, microfibrils and elastin. To conclude, the combination of a novel dynamic flow bioreactor and an electrospun hybrid polymer scaffold allowed the production and assembly of an elastic fiber-containing ECM.},
  language  = {en}
}
@article{JannaschGaetznerWeigeletal.2017,
  author    = {Jannasch, Maren and Gaetzner, Sabine and Weigel, Tobias and Walles, Heike and Schmitz, Tobias and Hansmann, Jan},
  title     = {A comparative multi-parametric in vitro model identifies the power of test conditions to predict the fibrotic tendency of a biomaterial},
  series = {Scientific Reports},
  volume    = {7},
  journal   = {Scientific Reports},
  number    = {1689},
  doi       = {10.1038/s41598-017-01584-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170908},
  year      = {2017},
  abstract  = {Despite growing effort to advance materials towards a low fibrotic progression, all implants elicit adverse tissue responses. Pre-clinical biomaterial assessment relies on animals testing, which can be complemented by in vitro tests to address the Russell and Burch's 3R aspect of reducing animal burden. However, a poor correlation between in vitro and in vivo biomaterial assessments confirms a need for suitable in vitro biomaterial tests. The aim of the study was to identify a test setting, which is predictive and might be time- and cost-efficient. We demonstrated how sensitive in vitro biomaterial assessment based on human primary macrophages depends on test conditions. Moreover, possible clinical scenarios such as lipopolysaccharide contamination, contact to autologous blood plasma, and presence of IL-4 in an immune niche influence the outcome of a biomaterial ranking. Nevertheless, by using glass, titanium, polytetrafluorethylene, silicone, and polyethylene representing a specific material-induced fibrotic response and by comparison to literature data, we were able to identify a test condition that provides a high correlation to state-of-the-art in vivo studies. Most important, biomaterial ranking obtained under native plasma test conditions showed a high predictive accuracy compared to in vivo assessments, strengthening a biomimetic three-dimensional in vitro test platform.},
  language  = {en}
}
@article{JannaschWeigelEngelhardtetal.2017,
  author    = {Jannasch, Maren and Weigel, Tobias and Engelhardt, Lisa and Wiezoreck, Judith and Gaetzner, Sabine and Walles, Heike and Schmitz, Tobias and Hansmann, Jan},
  title     = {\({In}\) \({vitro}\) chemotaxis and tissue remodeling assays quantitatively characterize foreign body reaction},
  series = {ALTEX - Alternatives to Animal Experimentation},
  volume    = {34},
  journal   = {ALTEX - Alternatives to Animal Experimentation},
  number    = {2},
  doi       = {10.14573/altex.1610071},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172080},
  pages     = {253-266},
  year      = {2017},
  abstract  = {Surgical implantation of a biomaterial triggers foreign-body-induced fibrous encapsulation. Two major mechanisms of this complex physiological process are (I) chemotaxis of fibroblasts from surrounding tissue to the implant region, followed by (II) tissue remodeling. As an alternative to animal studies, we here propose a process-aligned \({in}\) \({vitro}\) test platform to investigate the material dependency of fibroblast chemotaxis and tissue remodeling mediated by material-resident macrophages. Embedded in a biomimetic three-dimensional collagen hydrogel, chemotaxis of fibroblasts in the direction of macrophage-material-conditioned cell culture supernatant was analyzed by live cell imaging. A combination of statistical analysis with a complementary parameterized random walk model allowed quantitative and qualitative characterization of the cellular walk process. We thereby identified an increasing macrophage-mediated chemotactic potential ranking of biomaterials from glass over polytetrafluorethylene to titanium. To address long-term effects of biomaterial-resident macrophages on fibroblasts in a three-dimensional microenvironment, we further studied tissue remodeling by applying macrophage-material-conditioned medium on fibrous \({in}\) \({vitro}\) tissue models. A high correlation of the \({in}\) \({vitro}\) tissue model to state of the art \({in}\) \({vivo}\) study data was found. Titanium exhibited a significantly lower tissue remodeling capacity compared to polytetrafluorethylene. With this approach, we identified a material dependency of both chemotaxis and tissue remodeling processes, strengthening knowledge on their specific contribution to the foreign body reaction.},
  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{NietzerBaurSieberetal.2016,
  author    = {Nietzer, Sarah and Baur, Florentin and Sieber, Stefan and Hansmann, Jan and Schwarz, Thomas and Stoffer, Carolin and H{\"a}fner, Heide and Gasser, Martin and Waaga-Gasser, Ana Maria and Walles, Heike and Dandekar, Gudrun},
  title     = {Mimicking metastases including tumor stroma: a new technique to generate a three-dimensional colorectal cancer model based on a biological decellularized intestinal scaffold},
  series = {Tissue Engineering Part C-Methods},
  volume    = {22},
  journal   = {Tissue Engineering Part C-Methods},
  number    = {7},
  doi       = {10.1089/ten.tec.2015.0557},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188202},
  pages     = {621-635},
  year      = {2016},
  abstract  = {Tumor models based on cancer cell lines cultured two-dimensionally (2D) on plastic lack histological complexity and functionality compared to the native microenvironment. Xenogenic mouse tumor models display higher complexity but often do not predict human drug responses accurately due to species-specific differences. We present here a three-dimensional (3D) in vitro colon cancer model based on a biological scaffold derived from decellularized porcine jejunum (small intestine submucosa+mucosa, SISmuc). Two different cell lines were used in monoculture or in coculture with primary fibroblasts. After 14 days of culture, we demonstrated a close contact of human Caco2 colon cancer cells with the preserved basement membrane on an ultrastructural level as well as morphological characteristics of a well-differentiated epithelium. To generate a tissue-engineered tumor model, we chose human SW480 colon cancer cells, a reportedly malignant cell line. Malignant characteristics were confirmed in 2D cell culture: SW480 cells showed higher vimentin and lower E-cadherin expression than Caco2 cells. In contrast to Caco2, SW480 cells displayed cancerous characteristics such as delocalized E-cadherin and nuclear location of beta-catenin in a subset of cells. One central drawback of 2D cultures-especially in consideration of drug testing-is their artificially high proliferation. In our 3D tissue-engineered tumor model, both cell lines showed decreased numbers of proliferating cells, thus correlating more precisely with observations of primary colon cancer in all stages (UICC I-IV). Moreover, vimentin decreased in SW480 colon cancer cells, indicating a mesenchymal to epithelial transition process, attributed to metastasis formation. Only SW480 cells cocultured with fibroblasts induced the formation of tumor-like aggregates surrounded by fibroblasts, whereas in Caco2 cocultures, a separate Caco2 cell layer was formed separated from the fibroblast compartment beneath. To foster tissue generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context-especially for substances targeting tumor-stroma interactions.},
  language  = {en}
}