Polyetheretherketone surface engineered with a degradable hybrid coating for accelerating osteogenesis

Polyetheretherketone (PEEK) is expected to replace medical metal as orthopedic and dental implants owing to its similar elastic modulus to natural bone. Nevertheless, the intrinsically poor osteogenic capability of PEEK resists its clinical application. This study tried to effectively enhance osteogenesis capability of PEEK by engineering its surface with the degradable hybrid coating of alendronate loaded nano-hydroxyapatite (nHA/ALN) and poly(lactide-co-glycolide) (PLGA). The physicochemical properties were investigated by SEM, XRD and water contact angle measurements as well as in vitro release profile of ALN. The biocompatibility was evaluated by the cell morphology observation and CCK-8 assay. In addition, the osteogenic activity was analyzed by alkaline phosphatase activity, extracellular matrix mineralization, and osteogenesis-marked genes expressions. The results revealed that the PLGA@nHA/ALN hybrid coating was successfully constructed on the PEEK surface, and ALN sustained release for up to 98 days. Also, the PLGA@nHA/ALN hybrid coating enhanced the spreading, proliferation, and osteogenic differentiation of human bone mesenchymal stem cells. Boasting good biocompatibility and osteogenic performances, the PEEK implant engineered with the PLGA@nHA/ALN hybrid coating has great potential in orthopedic and dental applications.