Biocompatible hydrogels comprised of collagen, chitosan and polyurethane with potential applications for wound healing and controlled drug release

Chitosan and collagen are two valuable biopolymers for the synthesis and design of biomaterials. In this work, we evaluate the effect of the concentration of chitosan on the physicochemical and biological properties of polyurethane-crosslinked collagen hydrogels. Chitosan was added with a proportion ranging from 0 to 40 wt%. Depending on the aminoglycoside content, semi-interpenetrating polymeric networks (semi-IPNs) or completely IPNs were generated; this is attributed to the occlusion of the chitosan granules in the reticulated fibrillar matrix. The presence of chitosan in these hydrogels provides antibacterial capacity against pathogenic microorganisms such as Escherichia coli, which is corroborated by inhibition halo experiments. Hydrogels with 40 wt% of chitosan only showed improvement in the gelation time and mechanical performance, indicating a dependent relation of these properties with respect to the aminopolysaccharide content. Hydrogels with 10 wt% of chitosan showed the best biomedical performance. They also have the highest reticulation, swelling capability and chemical stability against degradation events such as hydrolysis and proteolysis. Further, they have the best biocompatibility for human monocytes, and they stimulate the secretion of monocyte chemotactic protein-1 and tumor necrosis factor-alpha. Also, these hydrogels showed a controlled release of ketorolac at pH 7 and 37 °C. The results of these in vitro biological tests demonstrate the potential application of novel biopolymer-based hydrogels in chronic wound healing due to their antibacterial capacity and modulation of the biological response of specialized cells in dermal repair treatments, as well as for the design of smart materials for the controlled release of drugs. © 2023 Society of Industrial Chemistry.