Physical, chemical, and biological characterization of biodegradable chitosan dressing for biomedical applications: Could sodium bicarbonate act as a crosslinking agent?

Chitosan, a biomaterial with properties that allows the elaboration of biocompatible and biodegradable systems, was employed to prepare dressings - 2% (w/v) in acetic acid - followed by freezing and lyophilization. Some samples were kept chemically unchanged and used as control, while others were cross-linked with Epichlorohydrin 0.01 mol L−1 for 24 h being washed, frozen and lyophilized. The neutralization procedure was performed with sodium bicarbonate, which ended up leading to a crosslinking by ionic interactions in the polymer network, and characteristics as promising as those of the chemically cross-linked with Epichlorohydrin. SEM showed that the crosslinking leads to a controlled formation of the polymeric network, conferring suitable steam permeation capacity 107 g mm.day−1.m−2.kPa−1, simulated fluid permeation between 2000 and 2500 g m−2.day-1 and porosity with interconnection which allows fluid absorption capacity above 900%. The crosslinking processes favored a better handling mechanical resistance confirmed by biodegradation assays. The dressing blocked micro-organisms permeation, forming an efficient barrier against contamination, is safe and biocompatible, allowing satisfactory cell adhesion and proliferation. These results showed that both dressings present statistically and satisfactory equivalent characteristics to be used as a functional bio dressing suitable for the treatment of different pathologies. [Display omitted] •Chemical cross-linking of chitosan scaffolding may be dispensable.•Chemically non-cross-linked scaffolding provides greater risk-benefit advantage.•Easy-to-handle reagents to create a green biodressing.•Safe biodressing with low cost.•Cell adhesion and degradable biodressing.