Nanostructured chitosan–gelatin hybrid aerogels produced by supercritical gel drying

In this work, chitosan/gelatin (Ch/G) aerogels with a network organization were produced by supercritical gel drying. Ch structure was characterized by a cellular morphology with smooth pore walls, with a mean pore size of about 20 µm. The morphology of G aerogel was, instead, nanofibrous with a mean fiber size lower than 100 nm. The mixture between Ch and G favored Ch gelification, due to the chemical interaction among the cationic Ch and negatively charged molecules of G. Ch/G hybrid aerogels formed an interpenetrated polymer network, with enhanced mechanical properties with respect to the starting single biopolymers, achieving a Young modulus up to 181 kPa, suitable for bone tissue engineering. Moreover, high surface area (≈250 m 2  g −1 ) and negligible glutaraldehyde (GTA) residues were found after supercritical processing; in particular, the GTA residues in the aerogels were lower than 3 ppm, also in the worst case (i.e., 2.3 ppm of released GTA for the Ch/G 4/1 aerogel), making them useful for potential nanomedicine applications. POLYM. ENG. SCI., 58:1494–1499, 2018. © 2017 Society of Plastics Engineers