Osteogenic differentiation of mesenchymal stem cell by silica/calcium micro-galvanic effects on Titanium surface
Based on the sensitivity to extracellular H+ concentration of proton-sensing receptors, we immobilized Si/CaCO3 nanoparticles onto titanium surface (TiMNPs) by micro-arc oxidation (MAO) technique to produce micro-galvanic effects by Schottky contact, aiming to regulate hydrogen evolution reaction of micro-galvanic couples and osteogenic response of mesenchymal stem cells (MSCs). The surface zeta potential measurement and dynamic potential polarization test confirmed that micro-galvanic effects were successfully formed on titanium surface after the treatment of Si/CaCO3 nanoparticles. Ti substrate with Si/CaCO3 nanoparticles loading concentration of 100 mg/mL (TiMNPs 100) could produce the highest level of hydrogen evolution reaction. In vitro experiments, TiMNPs 100 were significant superior to down-regulate the expression level of proton-sensing receptors and key proteins in PLC/ Ca2+ signal pathway, which in turn promoted MSCs osteogenesis differentiation. It was confirmed the higher level of ALP activity, mineralization capacity and collagen secretion on TiMNPs 100 as compared to those of other groups. This study provides a new insight to design novel biomaterials for bone generation.