Bioactivity of hydroxyapatite/wollastonite composite films deposited by pulsed laser

Abstract

Hydroxyapatite/wollastonite (HA/WS) composite films on titanium alloy were prepared by pulsed laser deposition, and their bioactivity was studied. The dissolution and precipitation behaviors of the films were evaluated by soaking in simulated body fluid (SBF), and the osseointegration ability was evaluated by in vivo test. In the early soaking stage, the dissolution action will dominate, thus resulting in the gradual disappearance of the smooth spherical feature of the particles. After 7 days of soaking, new precipitates were observed which indicates that reprecipitation reaction dominates, and the surface was almost completely covered by new precipitates after the film was soaked for 28 days. The in vivo test showed that the composite films have excellent osseointegration ability. When the sample was embedded in the shin bone of rabbit for 3 weeks, a good combination of bone tissue and implant was achieved, and after embedding for 6 weeks, osteoblasts were observed between the bone tissue and implant.