TY - JOUR A1 - Bachmann, Barbara A1 - Spitz, Sarah A1 - Schädl, Barbara A1 - Teuschl, Andreas A1 - Redl, Heinz A1 - Nürnberger, Sylvia A1 - Ertl, Peter T1 - Stiffness Matters: Fine-Tuned Hydrogel Elasticity Alters Chondrogenic Redifferentiation JF - Froniers in Bioengineering and Biotechnology N2 - Biomechanical cues such as shear stress, stretching, compression, and matrix elasticity are vital in the establishment of next generation physiological in vitro tissue models. Matrix elasticity, for instance, is known to guide stem cell differentiation, influence healing processes and modulate extracellular matrix (ECM) deposition needed for tissue development and maintenance. To better understand the biomechanical effect of matrix elasticity on the formation of articular cartilage analogs in vitro, this study aims at assessing the redifferentiation capacity of primary human chondrocytes in three different hydrogel matrices of predefined matrix elasticities. The hydrogel elasticities were chosen to represent a broad spectrum of tissue stiffness ranging from very soft tissues with a Young's modulus of 1 kPa up to elasticities of 30 kPa, representative of the perichondral-space. In addition, the interplay of matrix elasticity and transforming growth factor beta-3 (TGF-β3) on the redifferentiation of primary human articular chondrocytes was studied by analyzing both qualitative (viability, morphology, histology) and quantitative (RT-qPCR, sGAG, DNA) parameters, crucial to the chondrotypic phenotype. Results show that fibrin hydrogels of 30 kPa Young's modulus best guide chondrocyte redifferentiation resulting in a native-like morphology as well as induces the synthesis of physiologic ECM constituents such as glycosaminoglycans (sGAG) and collagen type II. This comprehensive study sheds light onto the mechanobiological impact of matrix elasticity on formation and maintenance of articular cartilage and thus represents a major step toward meeting the need for advanced in vitro tissue models to study both re- and degeneration of articular cartilage. KW - Tissue Engineering KW - Chondrogenic Redifferentiation KW - Biomaterials Y1 - 2021 VL - 2020 IS - 8 SP - 373 ER - TY - JOUR A1 - Slezak, Paul A1 - Slezak, Cyrill A1 - Hartinger, Joachim A1 - Teuschl, Andreas A1 - Nürnberger, Sylvia A1 - Redl, Heinz A1 - Mittermayr, Rainer T1 - A Low Cost Implantation Model in the Rat That Allows a Spatial Assessment of Angiogenesis. JF - Frontiers in Bioengineering and Biotechnology N2 - There is continual demand for animal models that allow a quantitative assessment of angiogenic properties of biomaterials, therapies, and pharmaceuticals. In its simplest form, this is done by subcutaneous material implantation and subsequent vessel counting which usually omits spatial data. We have refined an implantation model and paired it with a computational analytic routine which outputs not only vessel count but also vessel density, distribution, and vessel penetration depth, that relies on a centric vessel as a reference point. We have successfully validated our model by characterizing the angiogenic potential of a fibrin matrix in conjunction with recombinant human vascular endothelial growth factor (rhVEGF165). The inferior epigastric vascular pedicles of rats were sheathed with silicone tubes, which were subsequently filled with 0.2 ml of fibrin and different doses of rhVEGF165, centrically embedding the vessels. Over 4 weeks, tissue samples were harvested and subsequently immunohistologically stained and computationally analyzed. The model was able to detect variations over the angiogenic potentials of growth factor spiked fibrin matrices. Adding 20 ng of rhVEGF165 resulted in a significant increase in vasculature while 200 ng of rhVEGF165 did not improve vascular growth. Vascularized tissue volume increased during the first week and vascular density increased during the second week. Total vessel count increased significantly and exhibited a peak after 2 weeks which was followed by a resorption of vasculature by week 4. In summary, a simple implantation model to study in vivo vascularization with only a minimal workload attached was enhanced to include morphologic data of the emerging vascular tree. KW - Tissue Engineering KW - Bioreactor KW - Biomaterial Y1 - ER - TY - GEN A1 - Teuschl, Andreas A1 - Heimel, Patrick A1 - Monforte Vila, Xavier A1 - Nürnberger, Sylvia A1 - Tangl, Stefan A1 - van Griensven, Martijn A1 - Redl, Heinz A1 - Nau, Thomas T1 - Anterior cruciate ligament regeneration using the silk-based RegACL scaffold KW - Tissue Engineering KW - Silk KW - Biomaterial KW - Anterior Cruciate Ligament Y1 - ER - TY - JOUR A1 - Nürnberger, Sylvia A1 - Schneider, Cornelia A1 - van Osch, Gerjo A1 - Keibl, Claudia A1 - Rieder, Bernhard A1 - Monforte, Xavier A1 - Teuschl, Andreas A1 - Mühleder, Severin A1 - Holnthoner, Wolfgang A1 - Schädl, Barbara A1 - Gahleitner, Christoph A1 - Redl, Heinz A1 - Wolbank, Susanne T1 - Repopulation of an auricular cartilage scaffold, AuriScaff, perforated with an enzyme combination. JF - Acta Biomaterialia KW - Tissue Engineering KW - Decellularization KW - Cartilage Y1 - ER - TY - JOUR A1 - Schneider, Karl Heinrich A1 - Aigner, Petra A1 - Holnthoner, Wolfgang A1 - Monforte Vila, Xavier A1 - Nürnberger, Sylvia A1 - Rünzler, Dominik A1 - Redl, Heinz A1 - Teuschl, Andreas T1 - Decellularized human placenta chorion matrix as a favorable source of small-diameter vascular grafts JF - Acta Biomaterialia KW - Grafting KW - Tissue Engineering Y1 - 2018 ER - TY - JOUR A1 - Heimel, Patrick A1 - Swiadek, Nicole V. A1 - Slezak, Paul A1 - Kerbl, Markus A1 - Schneider, Cornelia A1 - Nürnberger, Sylvia A1 - Redl, Heinz A1 - Teuschl, Andreas A1 - Hercher, David T1 - Iodine-Enhanced Micro-CT Imaging of Soft Tissue on the Example of Peripheral Nerve Regeneration JF - Contrast Media & Molecular Imaging KW - µCT KW - Imaging KW - Tissue Engineering KW - Tissue Regeneration Y1 - ER -