Evaluating the effect of increasing ceramic content on the mechanical properties, material microstructure and degradation of selective laser sintered polycaprolactone/β-tricalcium phosphate materials

• Polymer–ceramic orthopaedic scaffold materials were fabricated using selective laser sintering.
• The effect of increased wt% of β-TCP on mechanical properties and microstructure were evaluated.
• Increasing wt% of β-TCP resulted in reduced strength and a significant increase in stiffness relative to no β-TCP.
• The effect of β-TCP content on the accelerated degradation of materials was evaluated.
• Degradation resulted in reduced elastic modulus and increased strength with increased wt% β-TCP.

Orthopaedic scaffold materials were fabricated from polycaprolactone (PCL) and composite PCL–β-tricalcium phosphate (PCL/β-TCP) powders using selective laser sintering (SLS). Incorporating β-TCP particles is desirable to promote osteogenesis. The effects of increasing β-TCP content on the material's mechanical properties and microstructure were evaluated. The wt% of β-TCP and PCL particle sizes were found to influence material microstructure and mechanical properties, with increasing ceramic content causing a small but significant increase in stiffness but significant reductions in strength. Degradation of materials was achieved using accelerated ageing methods. The influence of β-TCP content on degradation at 7 weeks was evaluated through changes in mechanical properties and microstructure, and the ceramic particles were found to reduce elastic modulus and increase strength. The results of this study highlight the influence of ceramic content on mechanical properties and degradation behaviour of PCL/β-TCP SLS materials, and indicate that these changes must be considered in the design of scaffolds for critical-sized defects.