Bending Properties, compression Properties, biocompatibility and bioactivity of sulfonated carbon Fibers/PEEK composites with graphene oxide coating

Purpose: In order to improve the mechanical properties, carbon fibers (CF) were used as a reinforcer at 25% weight ratio to prepare a CF/PEEK composite through injection molding. Subsequently, to improve the bioactivity of the CF/PEEK composites, samples were modified by sulfonating with 98% concentrated sulfuric acid and then covered with graphene oxide coating (GO). Results: SCF/PEEK (sulfonated CF/PEEK composites) and GOSCF/PEEK (SCF/PEEK composites with GO coating) were obtained. The mechanical properties, surface characterizations, morphologies, biocompatibility and bioactivity of the prepared composites were systematically investigated. CF/PEEK composites exhibited higher bending and compression strength than pure PEEK. After surface modification, GO-SCF/PEEK composites were equipped with a three-dimensional (3D) porous structure and bioactive graphene oxide coating from the results of SEM and XRD testing. Modified composites were nontoxic in vitro and vivo with evaluating by CCK-8 kit and observing histological sections stained by H&E respectively. What's more, we uncovered increased apatite deposition in SBF testing, upregulated expression of osteogenic genes by RT-PCR and better osseointegration by micro-CT analysis after surface modification, including ALP, Runx-2, Col-I and OC. Conclusion: Sulfonated CF/PEEK composites with graphene oxide coating were favorable as implant materials to repair the bone defects which provided positive reference in terms of future biomedical applications.