Rapid apatite induction of polarized hydrophilic HA/PVDF bio-piezoelectric coating on titanium surface

Abstract

Coatings with piezoelectric characteristics were prepared on the titanium alloy's surface to improve its biological properties, so that the titanium alloy possessed a piezoelectric effect similar to that of bones, thereby promoting bone growth and shortening bone repair time. Compared with other piezoelectric ceramic coatings, PVDF bio-piezoelectric coatings have better piezoelectric properties. However, the PVDF coating is hydrophobic, which is not conducive to calcium deposition. In this study, HA/PVDF coating was obtained on the titanium surface, which indicated a piezoelectric effect. The hydrophilicity of the coating has been improved with the increase of HA content. Corona poling gives the HA/PVDF coating piezoelectric characteristics, and also effectively reduces the contact angle. Moreover, the contact angle of the polarized HA/PVDF coating decreased by 66.9%. The synergistic effect of the introduction of HA and the high piezoelectric coefficient promotes the coating's mineralization. Surprisingly, the poled 20HA/PVDF coating surface was entirely covered by apatite after soaking in simulated body fluids (SBF) for 1 day with physiological loading. Additionally, the coating with rapid apatite deposition ability allows titanium alloy implants to obtain excellent biological activity, which has potential application value in the rapid repair of bone defects.