Nano-hydroxyapatite reinforced polyphenylene sulfide biocomposite with superior cytocompatibility and in vivo osteogenesis as a novel orthopedic implant

The design of novel functional biomaterials that possess similar mechanical attributes as human bones, accompanied with admirable osteogenesis to replace conventional metallic implants would be an intriguing accomplishment, especially in the orthopedic, craniomaxillofacial and dental fields where biointerfaces with outstanding osseointegration are in high demand. Guided by this purpose, in the current study, nano-hydroxyapatite reinforced polyphenylene sulfide (PPS/nano-HA) biocomposites via a process of compounding and injection-molding, in an attempt to elevate the bioactivity and osteogenic properties of PPS, were successfully developed for the first time. The resultant binary composites were characterized in terms of topological structure, chemical composition, hydrophilicity, and water uptake capacity. Mechanical property evaluation revealed that the elastic modulus of the PSS/ nano-HA composites was closer to that of natural bones. Besides, in vitro cytotoxicity, cell proliferation, alkaline phosphatase activity, osteocalcin expression and calcium mineral deposition all disclosed that the PSS/nano-HA bioactive composites evoked better cell viability and osteo-differentiation of osteoblasts on account of the contribution of the doped nano-HA. To our delight, in vivo assessment of the calvarial defect model by means of soft X-ray, histological observation, and real-time PCR analysis after 8 weeks confirmed the dramatically accelerated osteogenesis and osteointegration. Overall, our findings demonstrated that the nano-HA enriched PPS biocomposites with impressive cytocompatibility and osteogenic functions hold large potential in load-bearing orthopedic and dental applications. In addition, this work will, as expected, offer a crucial scientific basis and experimental fundamentals to support the adoption of PPS-based biomaterials as new hard tissue repair materials for further clinical therapy.