Surface Engineering Of Titanium Substrates With Chitosan-atorvastatin Conjugates For Reduced Inflammation Responses And Improved Cytocompatibility

Titanium and its alloys have been widely used for manufacturing orthopedicprostheses, cardiovascular implants, and dental implants in clinical applications.Nevertheless, it is notable that titanium implants suffer inflammation in some cases afterimplantation. Generally, the inflammatory reaction of an ectogenic implant would beactivated in a few hours after implantation.The clinical performance for the implant siteincludes fever and pain symptoms.In this study, chitosan-atorvastatin (Chi-AT) conjugate was immobilized onto thesurfaces of titanium substrates to reduce inflammation responses and improvecytocompatibility. Polydopamine film was initially formed onto the titanium surfaces asthe intermediate layer for the successful immobilization of Chi-AT, which wasconfirmed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy(XPS), and contact angle measurements, respectively. Endothelial cells grown ontoChi-AT immobilized titanium substrates displayed significantly higher (p<0.01) cellviability and statistically lower (p<0.01) lactate dehydroenase production than those ofnative titanium substrates (control) after culture for4days and7days, respectively.Furthermore, macrophages cells cultured onto Chi-AT immobilized titanium substratesdemonstrated significantly lower (p<0.01) production levels of nitric oxide(NO), acid phosphatase (ACP), reactive oxygen species (ROS), pro-inflammatorycytokines of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) than those ofcontrols. All results indicated that the immobilization of Chi-AT conjugate ontotitanium substrates was beneficial for improving their cytocompatibility and inhibitingpro-inflammatory responses. The study thus presents an alternative to fabricatebio-functionalized titanium-based implants for further clinical application.