Dopamine-TiO₂ Composite Coating On Poly-Ether-Ether-Ketone ?PEEK? For Dental Implants Application

Due to the excellent biosafety and similar elastic modulus with human bone,Poly Ether Ether Ketone(PEEK)has received wide attention in the application of dental implants.However,the tooth tissues and surrounding matrix can be hard to integrate unto the inert PEEK surface.Additionally,PEEK possesses poor antibacterial property.All the drawbacks above limit its further application.Surface modification is an effective way to improve both the surface biocompatibility and antibacterial property without compromising the mechanical properties of the substrate.Thus,an increasing number of modifying strategies has been reported on PEEK in recent years.In this study,polydopamine/titanium dioxide composite coating was formed on the PEEK surface.Dopamine has been reported effectively promoting the adhesion,growth and differentiation of fibroblasts.Moreover,the phenolic hydroxyl group of polydopamine can act as an anchoring site to promote and regulate the deposition of titanium dioxide,which has excellent biocompatibility as well as antibacterial property.The characterization of the coating was implemented by means of SEM,FT-IR,XRD,XPS.and white light interferometer testings.The physicochemical properties of the coating were analyzed by amino quantification,water contact angle Soft tissue sealing,osseointegration and inflammatory activation abilities of the composite coating were evaluated by assays of fibroblasts,osteoblasts and macrophages.Co-culture of Streptococcus mutans and Staphylococcus aureus was carried out to evaluate the antimicrobial properties of the composite coating.The material characterization indicated that titanium dioxide was chemically combined with polydopamine to form a composite coating.The composite coating contains anatase type titanium dioxide and amino groups.The hydrophilicity and surface energy of the coating gradually increased with the increase of the surface titanium dioxide content.In vitro cell culture tests demonstrated that the composite coating promoted the adhesion and proliferation of fibroblasts while this effect decreased with the amino content.Similarly,the composite coating could also obviously promote the proliferation of osteoblasts.With the surface of titanium dioxide content increase,the effect of promoting the proliferation of osteoblasts was more significant.Meanwhile,the composite coating did not cause a strong inflammatory reaction.In vitro antimicrobial experiments showed that the composite coating could inhibit the growth of Staphylococcus aureus and Streptococcus mutans.The good biocompatibility and antibacterial properties of the composite coating are mainly contributed to the promotion of cell adhesion by the amino group and the inhibition of bacterial proliferation by anatase type titanium dioxide and dopamine.