Bioinspired PEEK/Bioactive Glass/β-TCP Hybrid Composites With Nano-HA Coatings: Interfacial Apatite Nucleation, Wettability Tuning, and In Vitro Bioactivity for Load-Bearing Bone Repair

Abstract

This study addresses the longstanding challenge of balancing mechanical performance and biological activity in load-bearing bone regeneration. A multifunctional composite was developed based on polyetheretherketone (PEEK) reinforced with bioactive glass fibers and β -tricalcium phosphate (β -TCP), followed by surface functionalization using nano-hydroxyapatite (nano-HA) coating. Structural and spectroscopic analyses confirmed preservation of the PEEK molecular backbone and stable incorporation of ceramic phases. At the same time, the nano-HA layer formed a biomimetic hierarchical interface resembling natural bone mineral. Quantitatively, the modified composite exhibited a marked improvement in surface wettability, with a contact angle of 29.83°, indicating excellent hydrophilicity relative to pristine PEEK. In simulated body fluid (SBF), rapid and sustained apatite formation was observed, confirming high in vitro bioactivity. Biological evaluation demonstrated controlled ion release behavior that effectively inhibited bacterial growth while maintaining mammalian cell viability. In addition, the composite exhibited a suitable density of about 1.22 g/cm3, which is close to the reference value of the density of the bone cement composites used in orthopedic applications. Additionally, a controlled coating thickness was about 58.32 micrometres supported structural stability and ensured effective and homogeneous surface coverage Overall, the developed PEEK/bioactive glass/β -TCP/nano-HA composite demonstrates strong potential for next-generation load-bearing implants, offering enhanced osseointegration, improved surface bioactivity, and balanced antibacterial performance while retaining favorable mechanical characteristics.