Poly(trimethylene carbonate) and nano-hydroxyapatite porous scaffolds manufactured by stereolithography

Designing calcium phosphate-loaded polymeric porous scaffolds with controlled architecture using stereolithography (SLA) has great potential in the field of bone tissue engineering. However, the use of poly(ester)s with suboptimal degradation property has mainly been reported. In the present work, we introduced a poly(trimethylene carbonate) (PTMC) and nano-hydroxyapatite (HA) resin suitable for SLA manufacturing and created cytocompatible 3D porous structure. First, the resin formulation and HA content were optimized for photo-crosslink-based SLA fabrication process. Subsequently, we evaluated the influence of the resin composition on physico-chemical characteristics of fabricated films and scaffolds. Then, the influence of the biomaterial composition on human bone marrow mesenchymal stem cell viability, adhesion and proliferation was assessed. Films and macroporous scaffolds were successfully produced by photo-crosslinking with up to 40 wt% of HA (relative to PTMC). We demonstrated that addition of HA in PTMC matrices induced a direct effect on the surface properties, in terms of wettability and topography. Additionally, mechanical tests revealed a correlation between the amounts of HA loaded in PTMC and the stiffness of the SLA-fabricated scaffolds. Importantly, the different photo-crosslinked biomaterials exhibited in vitro cytocompatibility, similar to tissue culture polystyrene. Those data suggest the possibility to fabricate highly tunable HA-loaded PTMC 3D porous structures for bone tissue engineering application.