@article{HanetsederLevstekTeuschlWolleretal., author = {Hanetseder, Dominik and Levstek, Tina and Teuschl-Woller, Andreas and Frank, Julia Katharina and Schaedl, Barbara and Redl, Heinz and Marolt Presen, Darja}, title = {Engineering of extracellular matrix from human iPSC-mesenchymal progenitors to enhance osteogenic capacity of human bone marrow stromal cells independent of their age}, series = {Front Bioeng Biotechnol}, volume = {11}, journal = {Front Bioeng Biotechnol}, doi = {https://doi.org/10.3389/fbioe.2023.1214019}, abstract = {Regeneration of bone defects is often limited due to compromised bone tissue physiology. Previous studies suggest that engineered extracellular matrices enhance the regenerative capacity of mesenchymal stromal cells. In this study, we used human-induced pluripotent stem cells, a scalable source of young mesenchymal progenitors (hiPSC-MPs), to generate extracellular matrix (iECM) and test its effects on the osteogenic capacity of human bone-marrow mesenchymal stromal cells (BMSCs). iECM was deposited as a layer on cell culture dishes and into three-dimensional (3D) silk-based spongy scaffolds. After decellularization, iECM maintained inherent structural proteins including collagens, fibronectin and laminin, and contained minimal residual DNA. Young adult and aged BMSCs cultured on the iECM layer in osteogenic medium exhibited a significant increase in proliferation, osteogenic marker expression, and mineralization as compared to tissue culture plastic. With BMSCs from aged donors, matrix mineralization was only detected when cultured on iECM, but not on tissue culture plastic. When cultured in 3D iECM/silk scaffolds, BMSCs exhibited significantly increased osteogenic gene expression levels and bone matrix deposition. iECM layer showed a similar enhancement of aged BMSC proliferation, osteogenic gene expression, and mineralization compared with extracellular matrix layers derived from young adult or aged BMSCs. However, iECM increased osteogenic differentiation and decreased adipocyte formation compared with single protein substrates including collagen and fibronectin. Together, our data suggest that the microenvironment comprised of iECM can enhance the osteogenic activity of BMSCs, providing a bioactive and scalable biomaterial strategy for enhancing bone regeneration in patients with delayed or failed bone healing.}, subject = {aging}, language = {en} } @article{BernhardMaroltPresenLietal., author = {Bernhard, Jonathan C and Marolt Presen, Darja and Li, Ming and Monforte, Xavier and Ferguson, James and Leinfellner, Gabriele and Heimel, Patrick and Betti, Susanne L and Shu, Sharon and Teuschl-Woller, Andreas H and Tangl, Stefan and Redl, Heinz and Vunjak-Novakovic, Gordana}, title = {Effects of Endochondral and Intramembranous Ossification Pathways on Bone Tissue Formation and Vascularization in Human Tissue-Engineered Grafts}, series = {Cells}, volume = {11}, journal = {Cells}, number = {19:3070}, doi = {10.3390/cells11193070}, abstract = {Bone grafts can be engineered by differentiating human mesenchymal stromal cells (MSCs) via the endochondral and intramembranous ossification pathways. We evaluated the effects of each pathway on the properties of engineered bone grafts and their capacity to drive bone regeneration. Bone-marrow-derived MSCs were differentiated on silk scaffolds into either hypertrophic chondrocytes (hyper) or osteoblasts (osteo) over 5 weeks of in vitro cultivation, and were implanted subcutaneously for 12 weeks. The pathways' constructs were evaluated over time with respect to gene expression, composition, histomorphology, microstructure, vascularization and biomechanics. Hypertrophic chondrocytes expressed higher levels of osteogenic genes and deposited significantly more bone mineral and proteins than the osteoblasts. Before implantation, the mineral in the hyper group was less mature than that in the osteo group. Following 12 weeks of implantation, the hyper group had increased mineral density but a similar overall mineral composition compared with the osteo group. The hyper group also displayed significantly more blood vessel infiltration than the osteo group. Both groups contained M2 macrophages, indicating bone regeneration. These data suggest that, similar to the body's repair processes, endochondral pathway might be more advantageous when regenerating large defects, whereas intramembranous ossification could be utilized to guide the tissue formation pattern with a scaffold architecture.}, subject = {bone tissue engineering}, language = {en} }