Delivery of Interleukin 4 from a Titanium Substrate Coated with Graphene Oxide for Enhanced Osseointegration by Regulating Macrophage Polarization.

Macrophage-related inflammation has been identified as a possible predictor of the success or failure of implants based on their polarization of the pro-inflammatory/anti-inflammatory (M1/M2) phenotype. The purpose of this study was to deliver interleukin 4 (IL-4, a cytokine that triggers M2 polarization of macrophages) from a titanium substrate by a graphene oxide (GO) coating to regulate the macrophage-related inflammatory response and improve the implant performance. The GO/IL-4 coating showed good biocompatibility and promoted macrophages polarization to the M2 phenotype .

Involvement of FAK/P38 Signaling Pathways in Mediating the Enhanced Osteogenesis Induced by Nano-Graphene Oxide Modification on Titanium Implant Surface.

Background: Titanium implants are widely used in dental and orthopedic medicine. Nevertheless, there is limited osteoinductive capability of titanium leading to a poor or delayed osseointegration, which might cause the failure of the implant therapy. Therefore, appropriate modification on the titanium surface for promoting osseointegration of existing implants is still pursued.

Enhanced osteogenic differentiation of BMSCs and M2-phenotype polarization of macrophages on a titanium surface modified with graphene oxide for potential implant applications.

Osseointegration at the bone-implant interface is a complex biological process that is triggered by the immune-inflammatory response and mediated by various cell types such as, bone-forming cells and immune cells, especially macrophages. The polarization of macrophages to inflammatory/regenerative (M1/M2) phenotypes, as well as the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) at the bone-implant interface, significantly affects implant osseointegration and even causes implant failure. Graphene oxide (GO) is a promising candidate for performing implant surface functionalization to modulate the interactions between implants and cells.