Synthesis of hydrogels based on poly(NIPAM) inserted into collagen sponge.

The study presents the preparation of a semi-synthetic hydrogel based on poly(N-isopropyl acrylamide-co-diethylene glycol diacrylate) inserted onto the collagen porous membrane. The synthesis of the hydrogels was performed through radical copolymerization of N-isopropyl acrylamide (NIPAM) with diethylene glycol diacrylate (DEGDA) also as crosslinking agent, using ammonium persulfate as initiator and N,N,N',N'-tetramethylethylene diamine as activator, and it was achieved in the presence of the collagen matrix. The prepared hydrogels were characterized by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy. The swelling behaviour of the semi-interpenetrated polymer network related on the hydrogel composition, it was also evaluated. The pore sizes of the synthesized hydrogels, much larger than the typical mesh size of a conventional hydrogel, allow to consider the hybrid hydrogel based on the inserted poly(NIPAM-co-DEGDA) onto collagen fibrils as a super-porous hydrogel.