Engineering of Foamed Structures for Biomedical Application

Abstract

The aim of this study was to combine gas foaming (GF) and reverse templating techniques to prepare open-pore polymeric foams with pore structures specifically designed for tissue engineering. Poly(ε-caprolactone) (PCL) has been melt mixed with two different templating agents, NaCl microparticles and thermoplastic gelatin (TG), to prepare microparticulate composites and co-continuous blends, respectively. These heterogeneous systems have been subsequently gas foamed by using mixtures of N2 and CO2 as blowing agents. Finally, the foamed materials have been soaked in H2O to selectively extract the NaCl or TG from the polymeric matrices to achieve the final foamed structure. The presence of the different templating agents extensively affected the foaming process of PCL; these effects have been analyzed and the results gathered important information to design porous scaffolds with fine tuned open-pore architectures. In particular, the control of the overall porosity, pore size and shape, pore interconnectivity, and spatial distribution of PCL matrix has been achieved by optimizing the GF process parameters with respect to the specific templating system. Results demonstrated that the combination of the GF and reverse templating techniques allowed the preparation of PCL scaffolds with open-pore architectures and highly controlled porosity and pore size spatial distribution.