Uniform and controllable surface nano-structure on polyetheretherketone implants can regulate mechanical property to enhance soft tissue integration through Piezo1/TGF-β1 signaling axis

Polyetheretherketone (PEEK) has potential to repair the orbital floor bone defects following craniofacial trauma and orbital surgery. However, the inertness of the material impedes the soft tissue integration of implants, leading to complications such as implant migration and infection. Surface patterning modification on PEEK can promote the surface hydrophily to enhance better soft tissue integration, but it is difficult to obtain the uniform and controllable nano-structure. In this study, hot-pressing technology on PEEK implant was used to produce surface nanopores with a uniform diameter of 200, 500, 800 nm. Depending on the controllable craft, the surficial mechanical properties of PEEK can be regulated and assessed by finite element analysis. Furthermore, 500 nm interface has better mechanical properties to promote the proliferation, migration, and fibrosis of fibroblasts and achieved optimal integration effects in animal implantation experiments. To explore the mechanism of biological responses, transcriptomics and molecular biology experiments revealed that Piezo1/TGF-β1 axis played a critical role in the response of soft tissue cells to the mechanical stimulation of PEEK. Our study has established a novel modification technology for constructing uniform and controllable nanostructures on the surface of PEEK, thereby promoting the soft tissues integration with implants and improving the anchoring effect.