Enhancing PEEK Surface Bioactivity Through Phosphate and Calcium Ion Functionalization

Inert polymeric implants must evolve to enhance their biological interactions with host tissue, triggering positive cellular responses and promoting tissue bonding and integration. Poly-ether-ether-ketone (PEEK) is widely used as an implant material; however, its inert nature results in limited biological interactions. Various surface modification techniques have been investigated to enhance its bioactivity and overall biological performance. In this study, the PEEK surface was bioactivated through a chemical treatment involving two steps: surface activation using low-pressure oxygen plasma, followed by biofunctionalization with phosphate and calcium ions. Comprehensive surface characterization by contact angle, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FT-IR) confirmed the effect of plasma and the ionic surface incorporation. The biological response was evaluated through cell viability, adhesion, and proliferation in NIH/3T3 fibroblasts and HOS osteoblasts, and the results indicated the efficacy of the surface modifications. Therefore, the proposed treatments provide an efficient strategy to improve the biological performance of PEEK-based implants.