Tough and biocompatible hybrid networks prepared from methacrylated poly(trimethylene carbonate) (PTMC) and methacrylated gelatin

Hybrid networks of PTMC and gelatin were prepared and their mechanical and biological properties were investigated. First, PTMC oligomer and gelatin were methacrylated. Methacrylated macromers, PTMC-dMA and GelMA, were dissolved in DMSO/formic acid (90/10 v/v) at concentrations of 30% or 23% (w/v), at room temperature (RT) or 65 °C. Subsequently, mixtures were prepared at 75:25, 50:50 and 25:75 ratios (v/v) of PTMC-dMA and GelMA. Hybrid networks and networks of only PTMC or gelatin were prepared by solvent casting followed by photo-crosslinking. Mechanical properties were investigated by tensile testing and biological properties by human smooth muscle cell proliferation on the surface of the networks. Although incorporation of gelatin in PTMC networks decreased the toughness of the networks, networks consisting of 75% PTMC and 25% gelatin still had adequate mechanical properties, e.g. for vascular tissue engineering. Hybrid networks prepared at 30% (w/v) macromer concentration at RT had the highest toughness. Cell proliferation on all hybrid networks was similar to that on 100% gelatin networks and significantly higher than on 100% PTMC networks. It is concluded that incorporation of 25% gelatin in a PTMC network is a viable strategy to increase cellular interactions with the network, while retaining sufficient mechanical properties for soft tissue engineering applications.