Pro-osteogenic Activity of Soybean Derived Bioactive Peptides on the Surface of Titanium Sheets

In this study, a group of active peptides named P3 isolated from soybean protein is used to modify the surface of titanium sheets. The modified titanium sheets are characterized by X-ray photoelectron spectroscopy and contact angle measurement. The effects of modified titanium sheets coated with P3 on the adhesion, proliferation, differentiation and mineralization of MC3T3-E1 cells are investigated. Amino acid analysis showed that the hydrophobic amino acids and aromatic amino acids are enriched in P3. After being coated with P3, the surface nitrogen content of titanium sheets is significantly increased in adose-dependent manner. The contact angle and surface hydrophobicity of titanium sheets are significantly changed (p < 0.05). In addition, the adhesion and proliferation activity of MC3T3-E1 cells on titanium sheets are significantly enhanced by P3 coating (p < 0.05). Further studies indicated that P3 coating increased the expression of alkaline phosphatase, osteocalcin, consequently promoting the differentiation and mineralization of MC3T3-E1 cells on the surface of titanium sheets. In conclusion, P3 coating enhances the surface hydrophobicity, leading to a significant increase in the cell adhesion, consequently promoting the differentiation and mineralization of MC3T3-E1 cells on the surface titanium sheets, suggesting that P3 may serve as a coating material for titanium-based implants to facilitate fracture healing and other applications.