Biomimetic Design of Polyetheretherketone (PEEK) Implantable Medical Devices: Research Progress in Structural Biomimicry and Surface Functionalization

Polyetheretherketone (PEEK) has shown broad application prospects in implantable medical devices, including orthopedic, craniofacial, spinal fusion, dental, and extravascular stent applications, owing to its elastic modulus comparable to human cortical bone, excellent mechanical properties, good biocompatibility, and radiolucency. However, the inherent bioinertness and hydrophobicity of PEEK hinder firm osseointegration with surrounding bone tissue after implantation and limit its multiple biological functions, such as antibacterial, anti-inflammatory, pro-angiogenic, and lubricating activities, thereby restricting its clinical use in complex physiological environments such as infection, post-tumor resection rehabilitation, and artificial joints. In recent years, inspired by natural bone tissue, extracellular matrix, biomineralization processes, and mussel adhesive proteins, biomimetic design strategies have been widely explored to enhance the bioactivity and mechanical adaptability of PEEK implants. This review systematically summarizes recent advances in the biomimetic design of PEEK implantable medical devices, focusing on two main aspects: structural biomimicry (porous/gradient structures, biomimetic lattices and layered architectures, and surface topographies) and surface functionalization (bioactive coatings and mineralization modification, and biomolecule/drug immobilization and controlled release). Their current applications in craniofacial reconstruction, spinal fusion, joint replacement, long-bone prostheses, dental implants, and extravascular stents are also summarized. In addition, current limitations of biomimetic design are analyzed, including coating stability, multifunctional integration, biofunctionalization of three-dimensional structures, and clinical translation. Future research should prioritize multifunctional synergy and spatiotemporal sequential regulation, smart microenvironment-responsive systems, precise fabrication of cross-scale gradient structures, and artificial intelligence-driven personalized design, thereby driving the translation of PEEK implants from passive substitutes to active next-generation high-performance medical devices capable of regulating the tissue microenvironment.