@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{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{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{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{OckermannHeadleyLizioetal.2021, author = {Ockermann, Philipp and Headley, Laura and Lizio, Rosario and Hansmann, Jan}, title = {A Review of the Properties of Anthocyanins and Their Influence on Factors Affecting Cardiometabolic and Cognitive Health}, series = {Nutrients}, volume = {13}, journal = {Nutrients}, number = {8}, issn = {2072-6643}, doi = {10.3390/nu13082831}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245116}, year = {2021}, abstract = {The incidence of cardiovascular and metabolic diseases has increased over the last decades and is an important cause of death worldwide. An upcoming ingredient on the nutraceutical market are anthocyanins, a flavonoid subgroup, abundant mostly in berries and fruits. Epidemiological studies have suggested an association between anthocyanin intake and improved cardiovascular risk, type 2 diabetes and myocardial infarct. Clinical studies using anthocyanins have shown a significant decrease in inflammation markers and oxidative stress, a beneficial effect on vascular function and hyperlipidemia by decreasing low-density lipoprotein and increasing high-density lipoprotein. They have also shown a potential effect on glucose homeostasis and cognitive decline. This review summarizes the effects of anthocyanins in in-vitro, animal and human studies to give an overview of their application in medical prevention or as a dietary supplement.}, language = {en} } @article{WeigelSchmitzPfisteretal.2018, author = {Weigel, Tobias and Schmitz, Tobias and Pfister, Tobias and Gaetzner, Sabine and Jannasch, Maren and Al-Hijailan, Reem and Sch{\"u}rlein, Sebastian and Suliman, Salwa and Mustafa, Kamal and Hansmann, Jan}, title = {A three-dimensional hybrid pacemaker electrode seamlessly integrates into engineered, functional human cardiac tissue in vitro}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, number = {14545}, doi = {10.1038/s41598-018-32790-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177368}, year = {2018}, abstract = {Pacemaker systems are an essential tool for the treatment of cardiovascular diseases. However, the immune system's natural response to a foreign body results in the encapsulation of a pacemaker electrode and an impaired energy efficiency by increasing the excitation threshold. The integration of the electrode into the tissue is affected by implant properties such as size, mechanical flexibility, shape, and dimensionality. Three-dimensional, tissue-like electrode scaffolds render an alternative to currently used planar metal electrodes. Based on a modified electrospinning process and a high temperature treatment, a conductive, porous fiber scaffold was fabricated. The electrical and immunological properties of this 3D electrode were compared to 2D TiN electrodes. An increased surface of the fiber electrode compared to the planar 2D electrode, showed an enhanced electrical performance. Moreover, the migration of cells into the 3D construct was observed and a lower inflammatory response was induced. After early and late in vivo host response evaluation subcutaneously, the 3D fiber scaffold showed no adverse foreign body response. By embedding the 3D fiber scaffold in human cardiomyocytes, a tissue-electrode hybrid was generated that facilitates a high regenerative capacity and a low risk of fibrosis. This hybrid was implanted onto a spontaneously beating, tissue-engineered human cardiac patch to investigate if a seamless electronic-tissue interface is generated. The fusion of this hybrid electrode with a cardiac patch resulted in a mechanical stable and electrical excitable unit. Thereby, the feasibility of a seamless tissue-electrode interface was proven.}, language = {en} } @article{SchwedhelmZdziebloAppeltMenzeletal.2019, author = {Schwedhelm, Ivo and Zdzieblo, Daniela and Appelt-Menzel, Antje and Berger, Constantin and Schmitz, Tobias and Schuldt, Bernhard and Franke, Andre and M{\"u}ller, Franz-Josef and Pless, Ole and Schwarz, Thomas and Wiedemann, Philipp and Walles, Heike and Hansmann, Jan}, title = {Automated real-time monitoring of human pluripotent stem cell aggregation in stirred tank reactors}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-48814-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202649}, pages = {12297}, year = {2019}, abstract = {The culture of human induced pluripotent stem cells (hiPSCs) at large scale becomes feasible with the aid of scalable suspension setups in continuously stirred tank reactors (CSTRs). Innovative monitoring options and emerging automated process control strategies allow for the necessary highly defined culture conditions. Next to standard process characteristics such as oxygen consumption, pH, and metabolite turnover, a reproducible and steady formation of hiPSC aggregates is vital for process scalability. In this regard, we developed a hiPSC-specific suspension culture unit consisting of a fully monitored CSTR system integrated into a custom-designed and fully automated incubator. As a step towards cost-effective hiPSC suspension culture and to pave the way for flexibility at a large scale, we constructed and utilized tailored miniature CSTRs that are largely made from three-dimensional (3D) printed polylactic acid (PLA) filament, which is a low-cost material used in fused deposition modelling. Further, the monitoring tool for hiPSC suspension cultures utilizes in situ microscopic imaging to visualize hiPSC aggregation in real-time to a statistically significant degree while omitting the need for time-intensive sampling. Suitability of our culture unit, especially concerning the developed hiPSC-specific CSTR system, was proven by demonstrating pluripotency of CSTR-cultured hiPSCs at RNA (including PluriTest) and protein level.}, language = {en} } @article{RamirezRodriguezPereiraHerrmannetal.2021, author = {Ram{\´i}rez-Rodr{\´i}guez, Gloria Bel{\´e}n and Pereira, Ana Rita and Herrmann, Marietta and Hansmann, Jan and Delgado-L{\´o}pez, Jos{\´e} Manuel and Sprio, Simone and Tampieri, Anna and Sandri, Monica}, title = {Biomimetic mineralization promotes viability and differentiation of human mesenchymal stem cells in a perfusion bioreactor}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {3}, issn = {1422-0067}, doi = {10.3390/ijms22031447}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285804}, year = {2021}, abstract = {In bone tissue engineering, the design of 3D systems capable of recreating composition, architecture and micromechanical environment of the native extracellular matrix (ECM) is still a challenge. While perfusion bioreactors have been proposed as potential tool to apply biomechanical stimuli, its use has been limited to a low number of biomaterials. In this work, we propose the culture of human mesenchymal stem cells (hMSC) in biomimetic mineralized recombinant collagen scaffolds with a perfusion bioreactor to simultaneously provide biochemical and biophysical cues guiding stem cell fate. The scaffolds were fabricated by mineralization of recombinant collagen in the presence of magnesium (RCP.MgAp). The organic matrix was homogeneously mineralized with apatite nanocrystals, similar in composition to those found in bone. X-Ray microtomography images revealed isotropic porous structure with optimum porosity for cell ingrowth. In fact, an optimal cell repopulation through the entire scaffolds was obtained after 1 day of dynamic seeding in the bioreactor. Remarkably, RCP.MgAp scaffolds exhibited higher cell viability and a clear trend of up-regulation of osteogenic genes than control (non-mineralized) scaffolds. Results demonstrate the potential of the combination of biomimetic mineralization of recombinant collagen in presence of magnesium and dynamic culture of hMSC as a promising strategy to closely mimic bone ECM.}, 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{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} }