A sulfonated PEEK/PCL composite nanofibrous membrane for periosteum tissue engineering application

The favorable mechanical property and regenerative capacity of bone graft are extremely important for the reconstruction of the large bone defect. Polyetheretherketone (PEEK) has tailored elastic modulus to natural cortical bone, while its application is limited by bio-inert surface. Tissue-engineered periosteum exhibits improved osteogenesis-inducing capacity. However, the present artificial periosteum is difficult to effectively anchor to bone grafts. The use of PEEK-based nanomembrane may be a promising candidate to integrate with PEEK bone graft without anchor problem, which has not been reported until now. In this work, a series of fluorinated PEEK polymers were successfully synthesized and electrospun into nanofibers. The chemical structure, morphology, thermal stability, wettability and mechanical strength of s-PEEK membranes were investigated. Then, a novel flexible nanocomposite membrane for tissue-engineered periosteum based on fibrous sulfonated PEEK (s-PEEK) and polycaprolactone (PCL) was prepared. The functional properties were evaluated accordingly. The s-PEEK/PCL composite membranes showed superior hydrophilic and better ductility than pure s-PEEK film. The capacity of protein adsorption was also evaluated, suggesting the elevated bioactivity of s-PEEK/PCL composite membranes. Finally, the composite membranes were successfully mineralized by a homogenous and thinner calcium phosphate layer, indicating its potential to improve the osteogenic response.