A strontium/vancomycin composite coating on titanium implants for preventing bacterial infection and improving osseointegration

Postoperative bacterial infection and poor osseointegration with surrounding bone tissue are not only the critical causes of implant failure but also the major challenges in clinical application. Hereby, Titania (TiO2) microporous/nanofiber coating was firstly prepared on the surface of titanium (Ti) material by alkali-heat treatment process, and strontium (Sr)-doped coating (TS) was then prepared by hydrothermal synthesis. Finally, polydopamine-assisted co-deposition technology was utilized to deposit vancomycin (Van) onto TS surface (TSV), thus obtaining a medical composite coating with antibacterial property and improved osseointegration ability. According to antibacterial test, TSV has not only a 99.99% killing effect on methicillin-resistant Staphylococcus aureus (MRSA), but also a good anti-biofilm ability. The cell experiments showed that TSV could enhance the adhesion and proliferation of osteoblasts. Compared with pure Ti and TS, TSV induces the formation of bone apatite in simulated body fluid (SBF) test quickly, indicating that the coating has good biological activity. According to histopathological observation and bone morphology analysis, TSV showed highly effective infection prevention and excellent osteointegration in vivo. These test results suggested that it is feasible to prevent implant-associated infection and promote osseointegration by functionalization of the implant, so as to provide a fresh direction for clinical research.