Laser powder bed fusion of poly-ether-ether-ketone/bioactive glass composites: Processability, mechanical properties, and bioactivity

Poly-ether-ether-ketone (PEEK) implants fabricated by laser powder bed fusion (LPBF) are promising candidates for bone tissue engineering because of the excellent biocompatibility of the material and the ability to realize personalized bone repair. However, the weak LPBF processability and biological inertness of PEEK limit the clinical application. In this work, bioactive glass (BG) is blended into PEEK and found to improve the LPBF processability and bioactivity. The results show that PEEK/BG composite powders exhibit better LPBF process -ability due to the wider sintering window (48.9%-79.1% wider) and higher thermal conductivity (5.7%-23.0% higher) compared with the pure PEEK as well as the crystallization inhibition during the cold powder spreading. The melting enthalpy and thermal stability of the composite reduce when the BG content increases, thereby leading to the decrease of the optimal laser power during the LPBF process. The modulus of PEEK/BG composites ranges from 2685.82 MPa to 3729.33 MPa, which can match the modulus of human cancellous bone. The variation of lattice constant c and cell volume with the laser power of the composites all show a similar trend to the mechanical properties. BG can promote hydroxy-carbonate-apatite deposition, suggesting that BG has great potential to promote osteogenesis. By varying the amount of BG incorporated, the PEEK composite implants can be applied to different regions in the body depending on the specific clinical requirements.