Modification strategies for improving antibacterial properties of polyetheretherketone

Polyetheretherketone (PEEK) is a semi-crystalline thermoplastic polymer that has been gradually used in the repair of bone defects because of its well chemical stability, reliable biocompatibility, excellent X-ray radiolucency, and low modulus. However, PEEK is a biologically inert material, and planktonic bacteria can adhere to its surface and eventually form biofilms, allowing for the rapid development of implant-related infections. This review mainly introduces two important antibacterial modification strategies: antibacterial coating and surface morphology modification. Antibacterial coating include antibiotics, natural extracts, antimicrobial peptides, polymers, metals and metal oxides, selenium, fluoride, silicon nitride, and graphene oxide. These coatings can exert their antibacterial effect by inhibiting bacterial adhesion, killing bacteria by contact, or actively releasing antimicrobial substances. In terms of antibacterial surface topography, different surface microstructures have their respective antibacterial functions. Conical or cylindrical structures can exert stress on the bacterial surface causing the rupture of the cell membrane to kill bacteria. Nano protrusions or particles smaller than the size of bacteria can inhibit the adhesion of bacteria by reducing the contact area of bacteria and PEEK. The pit structure close to the size of bacteria can prevent the contact between adjacent bacteria and delay or prevent the formation of biofilm.