Biological and antibacterial properties of plasma sprayed wollastonite coatings grafting gentamicin loaded collagen

In this work, gentamicin loaded collagen was grafted on the surface of plasma sprayed wollastonite coatings to obtain an implant having excellent bioactivity and cytocompatibility as well as antibacterial property. The bioactivity and cytocompatibility of the wollastonite coatings grafting gentamicin loaded collagen were examined by simulated body fluid (SBF) soaking test and in vitro cell culture test. The release rate of gentamicin from collagen was measured using UV spectrophotometer in phosphate-buffered saline (PBS) and the antibacterial activity against Staphylococcus aureus (S. aureus) was evaluated by zone of inhibition test and bacterial counting method. The results showed that a composite layer with collagen and silicon-rich particles was formed on the surface of the coating after the graft of collagen. The grafted collagen layer mixed with silicon-rich particles could induce the precipitation of apatite after soaking in SBF for 14 days and improved the cellular proliferation on wollastonite coatings. The release of gentamicin from the collagen layer sustained 11 days in PBS and effectively inhibited the growth of S. aureus. In conclusion, the wollastonite coating grafting gentamicin loaded collagen had excellent bioactivity and cytocompatibility as well as good antibacterial properties, which would be beneficial for the long term stability and surgical success rate of implants.