Biocompatible PVTF Coatings on Ti with Improved Bonding Strength

In this work, a poly(vinylidenefluoride-co-trifluoroethylene) (PVTF) coating on a titanium (Ti) substrate was prepared, and Ti metal surfaces were treated by physical or chemical methods to achieve a high bonding strength with PVTF. Scanning electron microscopy (SEM), atomic force microscope (AFM), and static water contact angles (WCA) were used to characterize the Ti metal surfaces. Further, mechanical stretching testing was employed to measure the bonding strength of PVTF coatings. The possible mechanism for the improved bonding strength could be the higher OH concentrations on Ti metal surfaces, which could lead to the formation of chemical bonds with the F atom of PVTF chains. Finally, a CCK-8 analysis of bone marrow mesenchymal stem cells (BMSCs) cultured on the PVTF coatings confirmed that the physical and chemical treatments had no significant differences in biocompatibility. Such a PVTF coating on a Ti substrate showed the potential of biomedical metal implants.