Tailoring the porosity and morphology of gelatin-methacrylate polyHIPE scaffolds for tissue engineering applications.

Gelatin is a natural protein with many desirable properties for application as a biomaterial, including scaffolding for tissue engineering. In this work gelatin A with a molecular weight in the range 50-100 kg mol-1 was modified with methacrylic anhydride and processed into a concentrated oil-in-water emulsion. Polymerization of the continuous phase gave rise to a polyHIPE, a porous material possessing a highly interconnected, trabecular morphology. In the paper, we focused on the goal of obtaining matrixes characterized by suitable sizes of both voids and interconnects, to allow an in depth colonization from transplanted cells. In this respect, we investigated the role of the volume percentage of the dispersed phase and the effect of additives. It was established that high pore volumes (>or=90%) are to be preferred, because they allow the production of solid foams characterized by average void and interconnect diameters of approximately 20 and 10 microm, respectively. These values are still inadequate for the intended application of these scaffolds but represent a good starting point for further improvements. These were achieved through the use of additives, namely sodium chloride and dimethyl sulfoxide, which partially destabilized the precursor emulsion and allowed a solid foam to be obtained with void and interconnect diameters in the range of 30-150 microm and 10-50 microm, respectively.