Highly effective induction of cell-derived extracellular matrix by macromolecular crowding for osteogenic differentiation of mesenchymal stem cells

The extracellular matrix (ECM) is the non-cellular component that exists in all tissues and provides dynamic microenvironment that initiates crucial biochemical and biophysical cues, including cell adhesion, proliferation, migration, and differentiation. Although the cell-derived ECM mimics the native cellular microenvironment, the long-term maintenance of cells is required to harvest a sufficient amount of ECM for the intended application. In this study, we evaluated the biophysical properties of fucoidan as a macromolecular crowding (MMC) agent to accelerate ECM synthesis and deposition in human dermal fibroblasts and found that the accumulated cell-derived ECM by fucoidan (fCDM) influenced the osteogenic differentiation of mesenchymal stem cells (MSCs). The treatment of fucoidan resulted in significantly higher ECM deposition at 5 days compared with the treatment of dextran sulfate (DxS), a potent MMC agent. The advantages of fCDM were demonstrated in vitro by the promotion of multiple cellular behaviors of MSCs, osteogenic differentiation, and signal transduction pathway. In addition, the PLGA scaffold containing fCDM had significantly higher alkaline phosphatase activity than the PLGA scaffold containing acellular bone tissue ECM. Based on these results, the fCDM can support the development of human cell-derived, xeno-free biomaterials for tissue engineering applications.