Design of fibronectin type III domains fused to an elastin-like polypeptide for the osteogenic differentiation of human mesenchymal stem cells.

Extracellular matrix (ECM) including fibronectin (FN) and elastin plays a pivotal role in providing a microenvironment to support tissue regeneration in stem cell therapy. To develop a novel biomimetic ECM for stem cell differentiation, we engineered FN type III 9 and 10 domains fused to elastin-like polypeptides (FN-ELPs). The recombinant FN-ELP fusion protein was expressed in Escherichia coli and purified by inverse transition cycling. Human mesenchymal stem cells (hMSCs) cultured on plates coated with FN-ELP had significantly greater adhesion activity and proliferation than cells grown on non-coated plates. FN-ELP induced the osteogenic differentiation by elevating alkaline phosphatase (ALP) and mineralization activity of hMSCs. Furthermore, the osteogenic marker gene expressions of ALP, collagen type I (Col I), osteopontin (OPN), and transcriptional coactivator with a PDZ-binding motif (TAZ) were increased in hMSCs cultured on plates coated with FN-ELP. We reported a novel biomimetic ECM with potential for bone regeneration that promotes the osteogenic differentiation of hMSCs.