A Multifunctional PEEK Composite Scaffold with Immunomodulatory, Angiogenic, and Osteogenic Properties for Enhanced Bone Regeneration.

Polyetheretherketone (PEEK) is a widely used material in bone tissue engineering due to its favorable mechanical properties and radiolucency. However, its bioinert nature and lack of osteogenic activity restrict its ability to support effective bone regeneration. In this study, a novel APS-coated plasma-treated sulfonated bioactive PEEK scaffold (APS/PSBPK) was developed to overcome these limitations. The scaffold integrates strontium-doped bioactive glass (SrBG) to enhance biocompatibility and osteogenic potential, while astragalus polysaccharide (APS) was incorporated via plasma cleaning to modulate immune responses and promote vascularization. In vitro studies demonstrated that the APS/PSBPK scaffold facilitates M2 macrophage polarization, reduces pro-inflammatory cytokines, and enhances the secretion of anti-inflammatory factors. It also promotes endothelial cell migration and angiogenesis while supporting the adhesion, proliferation, and osteogenic differentiation of rBMSCs. In vivo experiments revealed that the scaffold effectively regulates the immune microenvironment, promotes vascularization, and accelerates bone regeneration. Thus, the APS/PSBPK composite scaffold serves as a multifunctional biomaterial with significant potential for applications in bone repair and regeneration by combining immunomodulation, angiogenesis, and osteogenesis.