Engineering of foamed structures for biomedical application

The aim of this study was to combine gas foaming and reverse templating techniques to prepare open-pore polymeric foams suitable as scaffolds for tissue regeneration. Poly(ε-caprolactone) (PCL) has been melt mixed with two different templating agents, sodium chloride microparticles and thermoplastic gelatin (TG), to prepare microparticulate composites and co-continuous blends, respectively. The heterogeneous systems have been subsequently gas foamed by using mixtures of N2 and CO2 as blowing agent. Finally, the foamed materials have been soaked in dH2O to selectively extract the NaCl and TG from the polymeric matrices. The effect of different templating agents on PCL foaming has been surveyed with the aim of designing porous scaffolds with fine controlled open-porous architectures. In particular, the control of the overall porosity, pore size and shape, pore interconnectivity and spatial distribution of PCL scaffolds has been achieved by optimizing the gas foaming process parameters with respect to the specific heterogeneous system selected. The results have demonstrated that the combination of the gas foaming and reverse templating techniques allowed the preparation of PCL scaffolds with open-porous architectures and highly controlled porosity, pore size and shape and also pore size and shape spatial distribution.