3D-printed porous PEEK scaffold combined with CSMA/POSS bioactive surface: A strategy for enhancing osseointegration of PEEK implants

As an attractive biomaterial for orthopedic implants, polyetheretherketone (PEEK) has many prominent characteristics such as good biocompatibility and biomechanical properties, as well as natural radiolucency. However, the potential clinical application is limited due to its biologically inert surface and poor osseointegration. To solve this problem, we fabricate a macroporous PEEK scaffold modified with methacrylated chitosan/polyhedral oligomeric silsesquioxane (CSMA/POSS) nanocomposite through 3D printing, sulfonation and UV-induced graft polymerization. The water contact angle, protein adsorption ability and biomineralization study of the sulfonation-treated PEEK (SPEEK)-CSMA/POSS scaffolds were measured in order to evaluate the surface properties. The results indicated that CSMA/POSS as a bioactive microporous surface integrated with nanoparticles promoted the protein adsorption and apatite formation. For the in vitro and in vivo evaluation of the osteogenicity, rat bone marrow mesenchymal stem cells (rBMSCs) and rat calvaria defect repair model were used. Biological results showed that the 3D porous structure and bioactive surface of modified PEEK scaffolds provided a suitable condition for cell adhesion and proliferation, enhanced the osteogenic differentiation of rBMSCs and promoted osteogenesis in vivo compared to the untreated PEEK scaffold. Therefore, 3D-printed macroporous PEEK scaffold modified with CSMA/POSS bioactive microporous surface represents a promising modification strategy for enhancing osseointegration of PEEK implants.