@article{WagenbrennerHeinzHorasetal.2020,
  author    = {Wagenbrenner, Mike and Heinz, Tizian and Horas, Konstantin and Jakuscheit, Axel and Arnholdt, Joerg and Mayer-Wagner, Susanne and Rudert, Maximilian and Holzapfel, Boris M. and Weißenberger, Manuel},
  title     = {Impact of Tranexamic Acid on Chondrocytes and Osteogenically Differentiated Human Mesenchymal Stromal Cells (hMSCs) In Vitro},
  series = {Journal of Clinical Medicine},
  volume    = {9},
  journal   = {Journal of Clinical Medicine},
  number    = {12},
  issn      = {2077-0383},
  doi       = {10.3390/jcm9123880},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219410},
  year      = {2020},
  abstract  = {The topical application of tranexamic acid (TXA) helps to prevent post-operative blood loss in total joint replacements. Despite these findings, the effects on articular and periarticular tissues remain unclear. Therefore, this in vitro study examined the effects of varying exposure times and concentrations of TXA on proliferation rates, gene expression and differentiation capacity of chondrocytes and human mesenchymal stromal cells (hMSCs), which underwent osteogenic differentiation. Chondrocytes and hMSCs were isolated and multiplied in monolayer cell cultures. Osteogenic differentiation of hMSCs was induced for 21 days using a differentiation medium containing specific growth factors. Cell proliferation was analyzed using ATP assays. Effects of TXA on cell morphology were examined via light microscopy and histological staining, while expression levels of tissue-specific genes were measured using semiquantitative RT-PCR. After treatment with 50 mg/mL of TXA, a decrease in cell proliferation rates was observed. Furthermore, treatment with concentrations of 20 mg/mL of TXA for at least 48 h led to a visible detachment of chondrocytes. TXA treatment with 50 mg/mL for at least 24 h led to a decrease in the expression of specific marker genes in chondrocytes and osteogenically differentiated hMSCs. No significant effects were observed for concentrations beyond 20 mg/mL of TXA combined with exposure times of less than 24 h. This might therefore represent a safe limit for topical application in vivo. Further research regarding in vivo conditions and effects on hMSC functionality are necessary to fully determine the effects of TXA on articular and periarticular tissues.},
  language  = {en}
}
@article{WagenbrennerMayerWagnerRudertetal.2021,
  author    = {Wagenbrenner, Mike and Mayer-Wagner, Susanne and Rudert, Maximilian and Holzapfel, Boris Michael and Weissenberger, Manuel},
  title     = {Combinations of hydrogels and mesenchymal stromal cells (MSCs) for cartilage tissue engineering — a review of the literature},
  series = {Gels},
  volume    = {7},
  journal   = {Gels},
  number    = {4},
  issn      = {2310-2861},
  doi       = {10.3390/gels7040217},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250177},
  year      = {2021},
  abstract  = {Cartilage offers limited regenerative capacity. Cell-based approaches have emerged as a promising alternative in the treatment of cartilage defects and osteoarthritis. Due to their easy accessibility, abundancy, and chondrogenic potential mesenchymal stromal cells (MSCs) offer an attractive cell source. MSCs are often combined with natural or synthetic hydrogels providing tunable biocompatibility, biodegradability, and enhanced cell functionality. In this review, we focused on the different advantages and disadvantages of various natural, synthetic, and modified hydrogels. We examined the different combinations of MSC-subpopulations and hydrogels used for cartilage engineering in preclinical and clinical studies and reviewed the effects of added growth factors or gene transfer on chondrogenesis in MSC-laden hydrogels. The aim of this review is to add to the understanding of the disadvantages and advantages of various combinations of MSC-subpopulations, growth factors, gene transfers, and hydrogels in cartilage engineering.},
  language  = {en}
}
@article{WagenbrennerPokerHeinzetal.2022,
  author    = {Wagenbrenner, Mike and Poker, Konrad and Heinz, Tizian and Herrmann, Marietta and Horas, Konstantin and Ebert, Regina and Mayer-Wagner, Susanne and Holzapfel, Boris M. and Rudert, Maximilian and Steinert, Andre F. and Weißenberger, Manuel},
  title     = {Mesenchymal stromal cells (MSCs) isolated from various tissues of the human arthritic knee joint possess similar multipotent differentiation potential},
  series = {Applied Sciences},
  volume    = {12},
  journal   = {Applied Sciences},
  number    = {4},
  issn      = {2076-3417},
  doi       = {10.3390/app12042239},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262334},
  year      = {2022},
  abstract  = {(1) Background: The mesenchymal stromal cells (MSCs) of different tissue origins are applied in cell-based chondrogenic regeneration. However, there is a lack of comparability determining the most suitable cell source for the tissue engineering (TE) of cartilage. The purpose of this study was to compare the in vitro chondrogenic potential of MSC-like cells from different tissue sources (bone marrow, meniscus, anterior cruciate ligament, synovial membrane, and the infrapatellar fat pad removed during total knee arthroplasty (TKA)) and define which cell source is best suited for cartilage regeneration. (2) Methods: MSC-like cells were isolated from five donors and expanded using adherent monolayer cultures. Differentiation was induced by culture media containing specific growth factors. Transforming growth factor (TGF)-ß1 was used as the growth factor for chondrogenic differentiation. Osteogenesis and adipogenesis were induced in monolayer cultures for 27 days, while pellet cell cultures were used for chondrogenesis for 21 days. Control cultures were maintained under the same conditions. After, the differentiation period samples were analyzed, using histological and immunohistochemical staining, as well as molecularbiological analysis by RT-PCR, to assess the expression of specific marker genes. (3) Results: Plastic-adherent growth and in vitro trilineage differentiation capacity of all isolated cells were proven. Flow cytometry revealed the clear co-expression of surface markers CD44, CD73, CD90, and CD105 on all isolated cells. Adipogenesis was validated through the formation of lipid droplets, while osteogenesis was proven by the formation of calcium deposits within differentiated cell cultures. The formation of proteoglycans was observed during chondrogenesis in pellet cultures, with immunohistochemical staining revealing an increased relative gene expression of collagen type II. RT-PCR proved an elevated expression of specific marker genes after successful differentiation, with no significant differences regarding different cell source of native tissue. (4) Conclusions: Irrespective of the cell source of native tissue, all MSC-like cells showed multipotent differentiation potential in vitro. The multipotent differentiation capacity did not differ significantly, and chondrogenic differentiation was proven in all pellet cultures. Therefore, cell suitability for cell-based cartilage therapies and tissue engineering is given for various tissue origins that are routinely removed during total knee arthroplasty (TKA). This study might provide essential information for the clinical tool of cell harvesting, leading to more flexibility in cell availability.},
  language  = {en}
}