Mussel-inspired “built-up” surface chemistry coating on polyetheretherketone enhances osteogenic, angiogenic, and antibacterial properties for improved osseointegration

Osteogenesis, angiogenesis, and antibacterial activity are essential for the long-term success of dental and orthopedic implants. Polyetheretherketone (PEEK) has been widely utilized in dental and orthopedic implants; however, its clinical applications are impeded by the deficiencies in osteogenic and angiogenic capacities, as well as the absence of antibacterial properties. To address these limitations, a novel mussel-inspired “built-up” surface chemistry strategy is proposed. The “built-up” surface chemistry coating is constructed on PEEK by sequential heaping of a copper-dopamine network basement and a polydopamine (PDA) layer facilitating the secondary grafting of osteogenic growth peptide (OGP). The results demonstrate that the “built-up” surface chemistry coating functionalized PEEK exhibits a controlled and long-term release of Cu^2 + , imparting PEEK with improved angiogenic ability and enhanced antibacterial activity towards Staphylococcus aureus and Escherichia coli. The outer layer grafted OGP potentiates the osteogenic capability of pre-osteoblasts in terms of cell adhesion, spreading, proliferation, alkaline phosphatase activity (ALP), collagen secretion, extracellular matrix mineralization (ECM), as well as osteogenesis-marked genes expressions. With the synergistic effects of Cu²⁺ and OGP, the functionalized PEEK surfaces exhibit superior antibacterial properties and enhanced osteogenic and angiogenic activity, thereby impressively promoting bone regeneration and facilitating bone implant integration in vivo. The mussel-inspired “built-up” surface chemistry strategy provides new perspectives on the design of novel multifunctional surfaces for dental and orthopedic implants.