Additive Manufacturing of Bioactive Poly(trimethylene carbonate)/β-Tricalcium Phosphate Composites for Bone Regeneration

Abstract

Implants of bioresorbable materials combined with osteoconductive calcium phosphate ceramics show promising results to replace and repair damaged bone tissue. Here we present additive manufacturing of patient-specific porous scaffolds of poly(trimethylene carbonate) (PTMC) including high amounts of β-tricalcium phosphate (β-TCP). Tensile testing of composite networks showed that addition of β-tricalcium phosphate reinforces the composites significantly. Three-dimensional structures containing up to 60 wt % β-TCP could be built by stereolithography. By lowering the content to 51 wt %, manufacturing of a large-sized patient-specific prototype was possible at high resolution. Closer examination revealed that the created scaffolds contained more β-TCP on the surface of the builds. Stereolithography therefore provides a manufacturing technique where the bioactive agent is directly available for creating an enhanced microenvironment for cell growth. The biocompatibility and bioresorption of PTMC coupled with the osteoconductivity of β-TCP are an important candidate to consider in additive manufacturing of bone regeneration implants.