A new strategy for PEEK-based biocomposites to achieve porous surface for bioactivity and adjustable mechanical properties for orthopedic stress matching

Polyetheretherketone (PEEK) has been widely used in orthopedic implants because of its prime biocompatibility. However, the bioinertness and single mechanical behavior limit its advanced clinical applications. In this study, carbon fiber reinforced surface porous PEEK/hydroxyapatite (HA) (CFR-SP-PEEK/HA) composites were designed and fabricated using the lamina layup-heat press-alkali solution corrosion method and characterized by mechanical tests. Theoretical models and numerical simulations were performed to further analyze the mechanical responses and inner failure mechanisms of CFR-SP-PEEK/HA. Close agreement between the numerical, theoretical and experimental results was observed. Human bones have different elastic modulus under tensile, compressive and bending loads, and the orthotropy of CFR-SP-PEEK/HA improved its ability to match the modulus of the human bone under different loads by adjusting the stacking sequence. The porous PEEK/HA composites on the sample surfaces exhibited potential bioactivity. Overall, CFR-SP-PEEK/HA is a highly competitive candidate for bone restoration and has great potential for medical applications.