Electrochemical Mineralization Regulates Hydroxyapatite Deposition of Silk Fibroin Nanofibers for Promoting Osteogenic Differentiation of Human Mesenchymal Stem Cells

Scaffold and stem cells are the key elements in the procedure of bone repair. Bombyx mori silk fibroin (SF) is the proper material for bone tissue engineering due to its biocompatibility and its easy to obtain nanofiber structure. The suitable cell substrate is also an important factor because different cells have different adaptations to composite. For this case, selecting a scaffold that can promote osteogenic differentiation of various cells is crucial and meaningful. In this work, hydroxyapatite (HA) was deposited precisely onto each silk nanofiber by electrochemical mineralization (EC) to form SF/HA. SF/HA can promote the proliferation and osteogenic differentiation of both human bone marrow mesenchymal-derived stem cells (hMSCs) and human adipose-derived mesenchymal stem cells (hAMSCs). It also promot the expression of alkaline phosphatase (ALP) and osteogenic differentiation related genes. Western blot analyses show mitogen-activated protein kinase (MAPK) signal pathway is regulated by SF/HA. Therefore, the study provides a proper method to obtain a good composite SF/HA and it promotes the osteogenic differentiation of both hMSCs and hAMSCs.