Exploration on the multifunctional hydrogel dressings based on collagen and oxidized sodium: A novel approach for dynamic wound treatment and monitoring

Collagen-based hydrogels have attracted growing interest as a promising type of wound dressing. However, designing a multifunctional hydrogel dressing capable of both treating and monitoring dynamic wounds remains a bottleneck. This issue is facilely addressed by developing hydrogel dressings based on collagen and oxidized sodium alginate (OSA) using an innovative biphasic solvent system of acetic acid/1-ethyl-3-methylimidazolim acetate (AA/[EMIM][Ac]). Compatible hydrogel network structure can be achieved by adopting highly polar solvent of AA/[EMIM][Ac] to shield strong electrostatic adsorption between two polyelectrolytes with opposite charges. Through the simple Schiff base click reaction, various compositions ratios of OSA/collagen in the resultant hydrogels were systematically examined. Sufficient covalent crosslinking bonds endowed collagen-based hydrogels with expected physicochemical properties including stable mechanical properties (1007.87 Pa), improved thermal stability (66.59 °C), reduced degradation rate (23.51 %) and compact porous microstructure (44.17 μm). Meanwhile, the biological hydrogels with advantageous responses demonstrated favorable injectability, desirable self-healing capacity, satisfactory biocompatibility and accelerated wound healing performance. More interestingly, the electronic biosensor assembled by the resultant hydrogels was able to precisely monitor human activity. Our findings revealed that the multifunctional OSA-crosslinked collagen hydrogels were ideal candidates for wound dressings in the field of biomedical materials.