Graphene oxide-modified PEEK composites: Properties and applications in orthopaedic repair - A review.

Critical-sized bone defect repair remains a major challenge in orthopaedics and tissue engineering. Polyetheretherketone (PEEK) has attracted wide attention due to its excellent mechanical compatibility and radiological transparency; however, its inherent bioinertness and insufficient antibacterial properties restrict its clinical utility. In recent years, the incorporation of graphene oxide (GO) has markedly improved the biological performance of PEEK. GO can increase surface hydrophilicity and roughness, enhance protein/ion adsorption, and promote osteoblast adhesion and differentiation, while simultaneously strengthening antibacterial and immunomodulatory effects without compromising, and in some cases even enhancing, mechanical performance. In vitro studies demonstrate that GO-PEEK stimulates osteogenic gene expression and mineralized nodule formation, while in vivo animal models confirm superior osseointegration and new bone formation compared with controls. Synergistic modifications, such as combination with hydroxyapatite, metallic ions, or antimicrobial peptides, further amplify both osteogenic and antibacterial outcomes. Nevertheless, clinical translation of GO-PEEK remains hampered by challenges including long-term stability, potential particulate-related risks, the dynamic balance between antibacterial and osteogenic functions, and issues of manufacturing scalability, consistency, and sterilization compatibility. Future research should focus on establishing a "structure-property-safety" design paradigm, developing temporally programmed multifunctional strategies, and advancing 3D-printed personalized fabrication, with low-load applications such as alveolar or cranial bone repair as potential pioneer indications. Overall, GO-PEEK composites exhibit significant promise in contexts such as post-tumour bone reconstruction, dental implantation, and spinal or joint implants, and are expected to achieve successful clinical translation under evidence-based validation and standardised manufacturing pathways.