The influence of the morphology of titania and hydroxyapatite on the proliferation and osteogenic differentiation of human mesenchymal stem cells.

Herein, the proliferation and osteogenic potential of human mesenchymal stem cells (hMSCs) on the disordered and ordered porous morphology of the titania surface and titania surface modified by hydroxyapatite (HA) are compared for the first time. In 5 days, the MTT-assay showed that the ordered porous morphology of electrochemically fabricated titania nanotubes (TNT) and TNT with chemically deposited hydroxyapatite (TNT-HA) was favorable for stem cell proliferation. In 14 days, RT-qPCR demonstrated that the disordered porous morphology of the sonochemically produced titania mesoporous surface (TMS) and TMS modified by the chemical deposition of HA (TMS-HA) led to the differentiation of hMSCs into the osteogenic direction in the absence of osteogenic inductors. These results originate from the mechanism of mechanotransduction, which sheds a light on the interaction of mesenchymal stem cells with the porous interface through focal adhesion, regulating the expression of genes determining stem cell self-renewal and osteogenic differentiation. The strong focal adhesion of hMSCs adjusted by the disordered TMS and TMS-HA is enough to induce osteogenic differentiation with the delay of cellular self-renewal. The weak focal adhesion of hMSCs tuned by the ordered TNT and TNT-HA affects only cellular self-renewal. The present research makes a new contribution to nanomedicine and engineering of porous implant interfaces for the replacement of bone injuries.