Enhanced Bioactivity Of 3D-Printed Ha/Peek For Bone Regeneration

This study aims to enhance the bioactivity of 3D-printed PEEK by incorporating hydroxyapatite (HA) at varying concentrations and evaluating its effects on osteogenesis and immunomodulation. PEEK and HA/PEEK composites containing 10%, 20%, and 40% HA were fabricated via fused filament fabrication (FFF) 3D printing. Surface characteristics, including microstructure, hydrophilicity, and roughness, were analyzed. In vitro assessments included metabolic activity and osteogenic differentiation of SAOS-2 and hBMSCs. Additionally, the immunomodulatory effects of HA were investigated using RAW264.7 macrophages through CCK-8 assays, immunofluorescence, ELISA, and RT-PCR. For in vivo evaluation, a rat femoral defect model was employed to assess osteogenesis in response to different material compositions. Surface analysis revealed that HA incorporation created a rougher and more porous texture, though surface roughness and hydrophilicity remained comparable among groups. Cell viability assays showed no significant differences, likely due to the encapsulation of HA within the PEEK matrix during printing, delaying its bioactive effects. However, osteogenic differentiation in vitro and bone formation in vivo both increased proportionally with HA content. Furthermore, HA promoted macrophage polarization toward the M2 phenotype, enhancing immune-mediated osteogenesis. HA incorporation enhances the osteogenic potential of 3D-printed PEEK through direct and immune-mediated mechanisms. Among the tested formulations, 40% HA/PEEK demonstrated the most significant osteogenic enhancement, making it a promising candidate for large-scale bone defect repair in oral and maxillofacial applications.