Mediation of mechanically adapted TiCu/TiCuN/CFR-PEEK implants in vascular regeneration to promote bone repair in vitro and in vivo

TiCu/TiCuN is a multilayer composite coating comprising TiN and Cu, which provides excellent wear resistance and antibacterial properties. However, its applicability as a functional coating has not been widely realised, and several aspects pertaining to its properties must still be explored.This study uses arc ion-plating technology to apply a TiCu/TiCuN coating on the surface of carbon fibre-reinforced (CFR) polyetheretherketone (PEEK) material.The safety and osteogenic activity of TiCu/TiCuN-coated CFR-PEEK materials were explored through cell experiments and animal experiments, and the molecules behind them were verified.The new material exhibits improved mechanical compatibility (mechanical strength and elastic modulus) and superior light transmittance (elimination of metal artifacts and ray refraction during radiology and radiotherapy). The proposed implant delivers excellent biocompatibility for mesenchymal stem cells and human umbilical vein endothelial cells (HUVECs), and it exhibits excellent osteogenic activity both in vitro and in vivo. Additionally, it was determined that the applied TiCu/TiCuN coating aids in upregulating the expression of angiogenesis-related signals (i.e., cluster-of-differentiation 31, α-smooth muscle actin, vascular endothelial growth factor receptor, and hypoxia-inducible factor-1α) to promote neovascularisation, which is significant for characterising the mechanism of the coating in promoting bone regeneration.The current results reveal that the TiCu/TiCuN-coated CFR-PEEK implants may emerge as an advanced generation of orthopaedic implants.The results of this study indicate that TiCu/TiCuN coating-modified CFR-PEEK materials can promote bone repair through angiogenesis and have broad clinical translation prospects.