Culture on a 3,4-dihydroxy-L-phenylalanine-coated surface promotes the osteogenic differentiation of human mesenchymal stem cells

The culture surface can affect the in vitro differentiation of stem cells. In this study, we investigated whether modifying the culture surface with 3,4-dihydroxy-L-phenylalanine (DOPA), an element of mussel adhesion protein, could enhance the in vitro osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMMSCs). hBMMSCs cultured on DOPA-coated plates exhibited better cell adhesion and spreading compared with noncoated conventional tissue culture plates. The DOPA coated did not affect the apoptosis or viability of the cultured hBMMSCs. Also, hBMMSCs cultured on DOPA-coated plates exhibited a higher degree of osteogenic differentiation than did hBMMSCs cultured on noncoated plates, as evaluated with alkaline phosphate (ALP) activity, calcium content, and the mRNA expression of runt-related transcription factor 2, ALP, and osteocalcin. Further, hBMMSCs cultured on DOPA-coated plates demonstrated a higher capability of ectopic bone formation in vivo following implantation in the subcutaneous space of athymic mice compared with hBMMSCs cultured on noncoated plates, as evaluated with microcomputer topography analysis and histomorphometry. These results indicate that modifying the culture surface with DOPA can enhance the in vitro osteogenic differentiation of hBMMSCs.