Natural Aerogels Production by Supercritical Gel Drying

Abstract

Aerogel-based scaffolds are frequently used for tissue engineering applications, since their nanofibrous structure is suitable for cells adhesion, proliferation and migration. Nevertheless, to achieve proper physico- chemical characteristics and desired mechanical properties, can be necessary to use more polymers together; among them, natural polymers are preferable because they are biocompatible, non-toxic, biodegradable and mucoahesive. In this study, bi-component natural aerogels Alginate-Gelatin (A/G) and Chitosan-Gelatin (CS/G) have been produced by Supercritical gel drying. The results indicate that both A/G and CS/G mixtures formed uniform gels during the preparation step and Supercritical gel drying preserved their delicate nanostructured morphology, thanks to the near zero surface tension of supercritical mixture (CO2 + organic solvent) formed during the drying process, as observed from FESEM pictures. All the aerogels were characterized by porosity values higher than 80%. Moreover, CS/G aerogels crosslinked with Glutaraldehyde (GTA) showed improved thermal behavior increasing gelatin content inside the starting hydrogel.