An ionic liquid-functionalized near-infrared fluorescent hydrogel dressing for promoting wound healing and real-time monitoring hypochlorous acid at the diabetic wound site

Diabetic wound is one of the most common complications of diabetes and is difficult to heal. Therefore, diabetic wound commonly turns into chronic ulcers. Some severe patients may face amputation because there is not much clinical treatment option available currently. Hypochlorous acid (HClO) is a ubiquitous reactive oxygen species (ROS) that plays a pivotal role in the inflammatory response at multiple stages and is considered as an important biomarker for monitoring diabetic wound healing. However, real-time monitoring HClO concentration at the injury site in diabetic wound therapy is a challenge and has not been fully explored. In this study, a novel near-infrared (NIR) fluorescent probe, SCy-7, was grafted onto a functionalized polymeric ionic liquid (PIL) and that was cross-linked with a modified hyaluronic acid (HA) to develop a near-infrared fluorescent smart hydrogel dressing (PIL-HA). This new PIL-HA hydrogel possessing excellent adhesion and mechanical properties, good biocompatibility, and highly effective antibacterial property can target the HClO formed at the wound site and followed generate fluorescence signal for real-time quantifying the concentration HClO. Furthermore, the function of PIL-HA smart dressing not only offers real-time monitoring and assessing HClO at diabetic wound sites via NIR fluorescent imaging, but also promoting the diabetic wound repair process. The in vivo therapeutic efficacy and toxicity of PIL-HA smart dressing were also evaluated with a diabetic mouse model.