Advances in Surface Modification Methods for Biomedical Polyetheretherketones

Polyether ether ketone (PEEK) shows great potential in biomedical applications such as orthopedics, spine, and dentistry due to its excellent mechanical properties, chemical resistance, and biocompatibility. However, the bioinertness of its surface severely hampers the osseointegration ability, limiting its wide application in the field of load-bearing bone replacement. Surface modification is one of the effective research avenues to improve the biological properties of PEEK, in which bioactive coating strategies with multiple methods of synergistic modification have become a hot research topic. In this paper, we focus on 1) the coating technology with inorganic molecules, biopolymers and bioactive factors as the core, which can directly enhance the bioactivity by mimicking the bone matrix or providing biochemical signals; and 2) the synergistic strategy integrating the physical structure construction, surface activation pretreatment with chemical/biological functionalization, and antimicrobial functionalization, which is aimed at overcoming the limitations of a single method to achieve the synergistic performance enhancement. The precise modulation of PEEK surface morphology, chemical composition and wettability by surface modification is analyzed in depth, thus revealing the mechanism of promoting osteointegration. Finally, future research directions such as long-lasting stability and reliability, smart responsive coatings, spatio-temporal precise modulation of factor release, immunomodulation and clinical translation are envisioned.