Multifunctional chitosan-based hydrogels: characterization and evaluation of biocompatibility and biodegradability in vitro

Creation of novel remedies efficient in supporting wound healing remains an actual task in pharmacology. Hydrogels showed high efficiency in wound healing and tissue regeneration due to viscosity, elasticity and fluidity that provide them with functional characteristics similar to that in extracellular matrix. The aim of the study was to create chitosan-based hydrogels functionalized with different components (chondroitin-6-sulfate, hyaluronic acid, N-stearoylethanolamine) and to estimate their biocompatibility and biodegradabili­ty in vitro. For the first time, a lipid substance N-stearoylethanolamine (NSE) known as suppressor of pro-inflammatory cytokines expression was used as hydrogel component (1.95 mg/g). FTIR analysis confirmed the complexation of chitosan molecule with hyaluronate, chondroitin-6-sulfate, NSE. MTT-test and Trypan blue exclusion test were used to study hydrogels cytotoxicity towards human cells of different tissue origin. Biodegradability of hydrogels was evaluated using direct hydrogel contact with cells and cell-independent degradation. It was shown that chondroitin-6-sulfate (<2 mg/ml), hyaluronic acid (<2 mg/ml) and NSE (26 µg/ml) did not demonstrate significant toxic effects towards pseudonormal human cells of the MCF10A, HaCat, HEK293 lines and mouse cells of the Balb/3T3 line. The studied hydrogels were stable in saline solution, while in a complete culture medium containing 10% fetal bovine blood serum they underwent degradation in >24 h. The identified biodegradability of the chitosan-based hydrogels is important for the release of noncovalently immobilized NSE into biological medium. Further studies on laboratory animals with experimental wounds are expected to explore the potential of created hydrogels as anti-inflammatory and wound-healing agents. Keywords: biodegradability, chitosan hydrogels, chondroitin-6-sulfate, FTIR analysis, human pseudonormal cells, hyaluronic acid, N-stearoylethanolamine, toxicity