Tetracalcium phosphate/polycaprolactone composite scaffold: Mechanical reinforcement, biodegradability regulation and bioactivity induction

Polycaprolactone (PCL) is considered a potential biomaterial due to its good biocompatibility, but its slow degradability and insufficient mechanical properties limit its wide application in bone tissue engineering. Tetracalcium phosphate's (TTCP) good degradability and inherent high stiffness are expected to compensate for the aforementioned defects of PCL and endow it with good biological activity. This goal of this study was to obtain bioactive PCL composite scaffolds with tuneable degradation properties and good mechanical strength via selective laser sintering technology (SLS). Composite porous scaffolds with TTCP contents of 0%, 5%, 10%, 15%, 20%, and 25% were prepared, and the experimental results showed that the addition of TTCP significantly improved the mechanical properties of the scaffold. Notably, the tensile strength of the composite scaffold with 20% TTCP content reached 15.2 MPa, which was 2.9 times that of pure PCL, and the best flexural strength was found in the scaffold with 15% TTCP content (4.7 MPa). More importantly, the introduced TTCP not only achieved the effective pH regulation of the soaking solution and the promotion of biodegradation, but also provided the scaffold with good bioactivity and biocompatibility.