Natural Aerogels Production by Supercritical Gel Drying

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 physicochemical 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.