TY - JOUR A1 - Hackethal, Johannes A1 - Dungel, Peter A1 - Teuschl, Andreas Herbert T1 - Frequently Used Strategies to Isolate Extracellular Matrix Proteins from Human Placenta and Adipose Tissue JF - Tissue Engineering Part C: Methods N2 - The natural extracellular matrix (ECM) provides the optimal environment for cells. Many enzymatic or non-enzymatic based strategies to extract ECM proteins from tissues were published over the past years. However, every single isolation strategy reported so far is associated with specific bottlenecks. In this study, frequently used strategies to isolate ECM from human placenta or adipose tissue using Tris-, serum-, or pepsin-based buffers were compared. The resulting ECM proteins were biochemically characterized by analysis of cellular remnants using Hoechst DNA staining, glycosaminoglycan (GAG) content by dimethylmethylene blue, visualization of protein bands using sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis combined with amino acid quantification, and assessment of the proangiogenic profile using an angiogenesis array. Tris-NaCl-extracted ECM proteins showed a high heterogenic degree of extracted proteins, bioactive growth factors, and GAGs, but no collagen-I. Active serum-extracted ECM showed significant lower DNA remnants when compared with the Tris-NaCl isolation strategy. Pepsin-extracted ECM was rich in collagen-I and low amounts of remaining bioactive growth factors. This strategy was most effective to reduce DNA amounts when compared with the other isolation strategies. Pepsin-extracted ECM from both tissues easily gelled at 37°C, whereas the other extracted ECM strategies did not gel at 37°C (Tris-NaCl: liquid; serum: sponge). All relevant characteristics (DNA residues, ECM diversity and bioactivity, shape) of the extracted ECM proteins highly depend on its isolation strategy and could still be optimized. Impact statement The natural human extracellular matrix (ECM) is the ideal cell niche. Various strategies were reported to isolate human ECM components from various sources. In this article, we compared frequently used methods and compared their characteristics (DNA remnants, glycosaminoglycan content, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, amino acid quantification, angiogenesis array, and gel formation). We conclude that more research is still necessary to optimize current isolation approaches for in vitro or in vivo applications of human ECM. KW - Tissue Engineering KW - Biomaterials KW - Adipose Tissue KW - extracellular matrix KW - human placenta Y1 - VL - 27 IS - 12 SP - 649 EP - 660 ER - TY - JOUR A1 - Khimich, Margarita A. A1 - Prosolov, Konstantin A. A1 - Mishurova, Tatiana A1 - Evsevleev, Sergej A1 - Monforte, Xavier A1 - Teuschl, Andreas H. A1 - Slezak, Paul A1 - Ibragimov, Egor A. A1 - Saprykin, Alexander A. A1 - Kovalevskaya, Zhanna G. A1 - Dmitriev, Andrey I. A1 - Bruno, Giovanni A1 - Sharkeev, Yurii P. T1 - Advances in Laser Additive Manufacturing of Ti-Nb Alloys: From Nanostructured Powders to Bulk Objects JF - Nanomaterials (Basel) N2 - The additive manufacturing of low elastic modulus alloys that have a certain level of porosity for biomedical needs is a growing area of research. Here, we show the results of manufacturing of porous and dense samples by a laser powder bed fusion (LPBF) of Ti-Nb alloy, using two distinctive fusion strategies. The nanostructured Ti-Nb alloy powders were produced by mechanical alloying and have a nanostructured state with nanosized grains up to 90 nm. The manufactured porous samples have pronounced open porosity and advanced roughness, contrary to dense samples with a relatively smooth surface profile. The structure of both types of samples after LPBF is formed by uniaxial grains having micro- and nanosized features. The inner structure of the porous samples is comprised of an open interconnected system of pores. The volume fraction of isolated porosity is 2 vol. % and the total porosity is 20 vol. %. Cell viability was assessed in vitro for 3 and 7 days using the MG63 cell line. With longer culture periods, cells showed an increased cell density over the entire surface of a porous Ti-Nb sample. Both types of samples are not cytotoxic and could be used for further in vivo studies. KW - Tissue Engineering KW - Biomaterials KW - Laser Additive Manufacturing KW - Bulk Objects Y1 - VL - 11 IS - 5 / 1159 ER - TY - JOUR A1 - Farokhi, Maryam A1 - Aleemardani, Mina A1 - Solouk, Atefeh A1 - Mirzadeh, Hamid A1 - Teuschl, Andreas Herbert A1 - Redl, Heinz T1 - Crosslinking strategies for silk fibroin hydrogels: promising biomedical materials JF - Biomedical Materials N2 - Due to their strong biomimetic potential, silk fibroin (SF) hydrogels are impressive candidates for tissue engineering, due to their tunable mechanical properties, biocompatibility, low immunotoxicity, controllable biodegradability, and a remarkable capacity for biomaterial modification and the realization of a specific molecular structure. The fundamental chemical and physical structure of SF allows its structure to be altered using various crosslinking strategies. The established crosslinking methods enable the formation of three-dimensional (3D) networks under physiological conditions. There are different chemical and physical crosslinking mechanisms available for the generation of SF hydrogels (SFHs). These methods, either chemical or physical, change the structure of SF and improve its mechanical stability, although each method has its advantages and disadvantages. While chemical crosslinking agents guarantee the mechanical strength of SFH through the generation of covalent bonds, they could cause some toxicity, and their usage is not compatible with a cell-friendly technology. On the other hand, physical crosslinking approaches have been implemented in the absence of chemical solvents by the induction of β-sheet conformation in the SF structure. Unfortunately, it is not easy to control the shape and properties of SFHs when using this method. The current review discusses the different crosslinking mechanisms of SFH in detail, in order to support the development of engineered SFHs for biomedical applications. KW - Tissue Engineering KW - hydrogels KW - Biomaterials KW - silk fibroin Y1 - VL - 16 IS - 2 SP - 022004 ER - 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 - Ziadlou, Reihane A1 - Rotman, Stijn A1 - Teuschl, Andreas A1 - Salzer, Elias A1 - Barbero, Andrea A1 - Martin, Ivan A1 - Alini, Mauro A1 - Eglin, David A1 - Grad, Sibylle T1 - Optimization of hyaluronic acid-tyramine/silk-fibroin composite hydrogels for cartilage tissue engineering and delivery of anti-inflammatory and anabolic drugs JF - Materials Science and Engineering: C N2 - Injury of articular cartilage leads to an imbalance in tissue homeostasis, and due to the poor self-healing capacity of cartilage the affected tissue often exhibits osteoarthritic changes. In recent years, injectable and highly tunable composite hydrogels for cartilage tissue engineering and drug delivery have been introduced as a desirable alternative to invasive treatments. In this study, we aimed to formulate injectable hydrogels for drug delivery and cartilage tissue engineering by combining different concentrations of hyaluronic acid-tyramine (HA-Tyr) with regenerated silk-fibroin (SF) solutions. Upon enzymatic crosslinking, the gelation and mechanical properties were characterized over time. To evaluate the effect of the hydrogel compositions and properties on extracellular matrix (ECM) deposition, bovine chondrocytes were embedded in enzymatically crosslinked HA-Tyr/SF composites (in further work abbreviated as HA/SF) or HA-Tyr hydrogels. We demonstrated that all hydrogel formulations were cytocompatible and could promote the expression of cartilage matrix proteins allowing chondrocytes to produce ECM, while the most prominent chondrogenic effects were observed in hydrogels with HA20/SF80 polymeric ratios. Unconfined mechanical testing showed that the compressive modulus for HA20/SF80 chondrocyte-laden constructs was increased almost 10-fold over 28 days of culture in chondrogenic medium which confirmed the superior production of ECM in this hydrogel compared to other hydrogels in this study. Furthermore, in hydrogels loaded with anabolic and anti-inflammatory drugs, HA20/SF80 hydrogel showed the longest and the most sustained release profile over time which is desirable for the long treatment duration typically necessary for osteoarthritic joints. In conclusion, HA20/SF80 hydrogel was successfully established as a suitable injectable biomaterial for cartilage tissue engineering and drug delivery applications. KW - Tissue Engineering KW - Cartilage KW - Mechanical Testing KW - Biomaterials KW - Chondrocytes Y1 - VL - 120 IS - 111701 ER - TY - GEN A1 - Teuschl, Andreas A1 - Schuh, Christina A1 - Weihs, Anna A1 - Guillaume, Olivier A1 - Monforte Vila, Xavier A1 - Redl, Heinz A1 - Kaplan, David A1 - Rünzler, Dominik T1 - Tailoring bioactivity of silk-based biomaterials via delivering and functionalization strategies with fibrinogen/thrombin, plant lectins or laminin KW - Biomaterials KW - Tissue Engineering KW - Silk Y1 - ER - TY - JOUR A1 - Berkovitch, Yulia A1 - Cohen, Talia A1 - Peled, Eli A1 - Schmidhammer, Robert A1 - Hildner, Florian A1 - Teuschl, Andreas A1 - Wolbank, Susanne A1 - Yelin, Dvir A1 - Redl, Heinz A1 - Seliktar, Dror T1 - Hydrogel composition and laser micropatterning to regulate sciatic nerve regeneration. JF - Journal of Tissue Engineering and Regenerative Medicine N2 - Treatment of peripheral nerve injuries has evolved over the past several decades to include the use of sophisticated new materials endowed with trophic and topographical cues that are essential for in vivo nerve fibre regeneration. In this research, we explored the use of an advanced design strategy for peripheral nerve repair, using biological and semi-synthetic hydrogels that enable controlled environmental stimuli to regenerate neurons and glial cells in a rat sciatic nerve resection model. The provisional nerve growth conduits were composed of either natural fibrin or adducts of synthetic polyethylene glycol and fibrinogen or gelatin. A photo-patterning technique was further applied to these 3D hydrogel biomaterials, in the form of laser-ablated microchannels, to provide contact guidance for unidirectional growth following sciatic nerve injury. We tested the regeneration capacity of subcritical nerve gap injuries in rats treated with photo-patterned materials and compared these with injuries treated with unpatterned hydrogels, either stiff or compliant. Among the factors tested were shear modulus, biological composition, and micropatterning of the materials. The microchannel guidance patterns, combined with appropriately matched degradation and stiffness properties of the material, proved most essential for the uniform tissue propagation during the nerve regeneration process. KW - Tissue Engineering KW - Biomaterials KW - Nerve Regeneration Y1 - SP - 1049 EP - 1061 ER - TY - GEN A1 - Teuschl, Andreas A1 - Weihs, Anna A1 - Fuchs, Christiane A1 - Monforte Vila, Xavier T1 - Silk as a versatile biomaterial for musculoskeletal tissue engineering KW - Silk KW - Biomaterials Y1 - 2018 ER - TY - GEN A1 - Hromada, Carina A1 - Tomasch, Janine A1 - Weihs, Anna A1 - Rünzler, Dominik A1 - Teuschl, Andreas T1 - Engineering of 3D Tissue Constructs Using our Novel MagneTissue Bioreactor as Alternatives to Animal Models KW - Bioreactor KW - Biomaterials Y1 - ER - TY - JOUR A1 - Schneider, Karl A1 - Rohringer, Sabrina A1 - Kapeller, Barbara A1 - Grasl, Christian A1 - Kiss, Herbert A1 - Heber, Stefan A1 - Walter, Ingrid A1 - Teuschl, Andreas A1 - Podesser, Bruno K. A1 - Bergmeister, Helga T1 - Riboflavin-mediated photooxidation to improve the characteristics of decellularized human arterial small diameter vascular grafts JF - Acta Biomater. N2 - Vascular grafts with a diameter of less than 6 mm are made from a variety of materials and techniques to provide alternatives to autologous vascular grafts. Decellularized materials have been proposed as a possible approach to create extracellular matrix (ECM) vascular prostheses as they are naturally derived and inherently support various cell functions. However, these desirable graft characteristics may be limited by alterations of the ECM during the decellularization process leading to decreased biomechanical properties and hemocompatibility. In this study, arteries from the human placenta chorion were decellularized using two distinct detergents (Triton X-100 or SDS), which differently affect ECM ultrastructure. To overcome biomechanical strength loss and collagen fiber exposure after decellularization, riboflavin-mediated UV (RUV) crosslinking was used to uniformly crosslink the collagenous ECM of the grafts. Graft characteristics and biocompatibility with and without RUV crosslinking were studied in vitro and in vivo. RUV-crosslinked ECM grafts showed significantly improved mechanical strength and smoothening of the luminal graft surfaces. Cell seeding using human endothelial cells revealed no cytotoxic effects of the RUV treatment. Short-term aortic implants in rats showed cell migration and differentiation of host cells. Functional graft remodeling was evident in all grafts. Thus, RUV crosslinking is a preferable tool to improve graft characteristics of decellularized matrix conduits. KW - Tissue Engineering KW - Biomaterials KW - Vascularization Y1 - 2021 VL - 2020 IS - 116 SP - 246 EP - 258 ER -