Stem cell-synthesized extracellular matrix for bone repair

Abstract

This study investigated the potential use of stem cell-synthesized extracellular matrix (ECM) as a bone graft replacement therapy. ECM was synthesized by both mesenchymal stem cells (MSCs) and amniotic fluid stem cells (AFS cells) and decellularized via freeze-thaw cycling and DNase treatment. A series of in vitro studies were performed to evaluate the effect of the ECM on cell attachment, proliferation, and differentiation. Reseeded MSCs were able to attach to and proliferate on both ECM types in both 2D and 3D culture. In 2D, cells cultured on both ECM types showed increased levels of calcium deposition. In 3D, both ECM types increased the mineralized matrix production of reseeded MSCs, with the ECM produced by the AFS cells inducing a greater amount of mineralized matrix formation than the MSC synthesized ECM. Both ECM types were used to treat a rat femoral segmental defect in vivo. Each ECM type increased the rate of bridging of the defect when compared to collagen coated scaffolds. However, the presence of the ECM did not have a significant effect on the volume of mineralized matrix within the defect site in this study.