Coupling osteogenesis and angiogenesis with controlled osteoclastogenesis: a multifunctional graphene oxide-modified CFR-PEEK implant.

Achieving rapid osseointegration while preventing bacterial infection remains a critical challenge in dental implantology. In this study, we developed a multifunctional interface on carbon fiber-reinforced polyetheretherketone (Cpeek) by combining a sulfurized porous structure with a graphene oxide (GO) coating (Gcpeek). In vitro evaluations were conducted to assess its osteogenic, immunomodulatory, osteoclastic, angiogenic, and antibacterial properties. Results demonstrated that the Gcpeek surface significantly upregulated the expression of key osteogenic genes (e.g., ALP, RUNX2, COL-1) in MC3T3-E1 pre-osteoblasts. Mechanistically, while the physical roughness of the Scpeek porous structure inadvertently triggered pro-inflammatory M1 macrophage polarization and subsequent osteoclast differentiation, the GO coating on Gcpeek effectively reversed this trend. It actively steered macrophages toward an anti-inflammatory M2 phenotype (upregulating Arg-1 and CD206), which subsequently downregulated osteoclast markers (MMP9, TRAP) and inhibited excessive resorption. Additionally, Gcpeek promoted angiogenesis in HUVECs by enhancing VEGF and ANG-1 expression, and exhibited strong antimicrobial activity against Staphylococcus aureus and Porphyromonas gingivalis. In conclusion, these in vitro findings suggest that the GO-modified Gcpeek surface provides a promising dual-action effect. By driving M2 macrophage polarization, it effectively neutralizes the osteoclastogenic risk posed by rough substrates while concurrently supporting osteogenesis, vascularization, and infection control, highlighting its functional potential for peri-implant bone repair.