Enhancing frost-resistant and electrically conductive properties of bacterial cellulose-based IPN hydrogel wound dressings via photopolymerization: Towards epidermal sensor applications

Conventional wound dressings are limited in their application due to the difficulty of maintaining normal use in cold conditions and a lack of functionality. In this study, photopolymerization was employed to fabricate a wound dressing with the capacity to monitor vital signs in cold environments. Utilizing bacterial cellulose (BC) to form an Interpenetrating Network (IPN) structure, the dressing exhibits enhanced water retention and mechanical properties, with a notable increase in mechanical strength to 540.37 KPa. Moreover, it maintains excellent mechanical resilience and electrical conductivity (9.01 x 10-3 S/cm) even at temperatures as low as -20 degrees C. Incorporation of positively charged quaternary ammonium salts imparts potent antibacterial properties to the hydrogel against Staphylococcus aureus and Escherichia coli by electrostatically adsorbing to and disrupting negatively charged bacterial cell membranes, resulting in the leakage of internal fluids. The efficacy of the hydrogel in promoting wound healing was validated through rat-infected wound models. Hematoxylin and eosin (H&E) staining confirmed a reduction in inflammation at the wound site, improved wound healing, and a marked increase in the wound healing rate. Moreover, the hydrogel has remarkable electrical conductivity (1.25 x 10- 2 S/cm), enabling the detection of subtle signals (e.g., strain 0.25 %) crucial for emergency wound management to prevent infections. Of significant importance, these hydrogels can function as electrodes for monitoring electrocardiogram (ECG) signals and respiratory status, facilitating timely assessment of vital signs in casualties. This innovative hydrogel wound dressing holds promise for simultaneously monitoring human vital signs and treating wounds in cold outdoor settings, thus offering broad applications in the realms of wound management and dressing for cold outdoor sports.