Tailoring photocurable polycaprolactone-based composite formulations for the stereolithographic fabrication of...

Recent advances in bone tissue engineering are focused on the fabrication of osteoconductive scaffolds capable of supporting new bone tissue ingrowth. While stereolithography enables the rapid fabrication of porous personalized implants, establishing optimal material formulations with suitable mechanical and biological properties is still challenging. Considering the requirements for mechanical performance, printability, and biodegradation rate, a novel polycaprolactone-methacrylate-based composite with a highly soluble amorphous calcium phosphate dispersed phase was designed. The low stability of amorphous calcium phosphate was addressed by the introduction of highly nucleophilic anions, which provided a notable induction period of crystallization and retention of the stable, highly soluble dispersed phase. After the optimization of the photocurable slurry composition and photopolymerization behavior, a proof-of-concept composite scaffold with a gyroid architecture was successfully printed. The combination of polycaprolactone-methacrylate and amorphous calcium phosphate nanoparticles showed a synergistic effect on mechanical behavior, resulting in the improved tensile strength of the designed composites. This composition opens new paths to surface engineering, aimed at improving cell adhesion and functionalization with proteins. The cytocompatibility assay revealed that the obtained composites are non-toxic and maintain a dense layer of mesenchymal stromal cells. Thus, the developed composite formulation provides a promising platform for the fabrication of scaffolds for bone tissue engineering.