Multifunctional all hydrogel-based smart dressing system fabricated by a self-healing cross-linking strategy for real-time monitoring of wound temperature, strain and on-demand drug delivery

All-hydrogel dressing systems are extremely beneficial for wound monitoring and treatment. The development of all-hydrogel dressing systems is difficult due to the difficulty in integrating different functional gels. Herein, a multifunction all hydrogel-based smart dressing based on three different functional hydrogels was developed for the first time by a self-healing cross-linking strategy for real-time monitoring of wound temperature, strain and on-demand drug delivery. A PNAGA/AuNRs hydrogel was used as a substrate and photothermal conversion component on the underlayer of the dressing system, while PNAGA/PNIPAm and PNAGA/AgNW hydrogels were used as temperature and strain sensing components for the upper layer, respectively. Three different functional hydrogels were easily integrated into a whole by a self-healing cross-linking strategy. Through in vitro antibacterial experiments and in situ rat models studies, it is shown that the smart dressing can monitor wound stress caused by exercise, the increase in wound temperature caused by inflammation and effectively inhibit bacterial growth and promote wound healing. Overall, this self-healing cross-linking strategy provides a novel, facile and rapid idea for the preparation of integrated multifunctional biosystem sensors, and the resulting dressing provides a promising solution for the development of all hydrogel-based systems integrating monitoring, diagnosis, and therapy.