An antibacterial and anti-oxidative hydrogel dressing for promoting diabetic wound healing and real-time monitoring wound pH conditions with a NIR fluorescent imaging system

Abstract

The design and synthesis of multi-functional chitosan hydrogels based on polymerized ionic liquid and a near-infrared (NIR) fluorescent probe (PIL-CS) is a promising strategy, which not only prevents the transition from acute to chronic wounds, but also provides prompt measures regarding microenvironmental alterations in chronic wounds. PIL-CS hydrogel can real-time visualize wound pH through in vivo NIR fluorescent imaging and also feature the pH-responsive sustained drug release, such as antioxidant, to eliminate reactive oxygen species (ROS) and to boost diabetic wound healing. PIL-CS hydrogel is specific, sensitive, stable and reversible in response to pH changes at the wound site. It, therefore, enables real-time monitoring for a dynamic pH change in the microenvironment of irregular wounds. PIL-CS hydrogel was also designed to possess many merits including high water containment and swelling rate, good biocompatibility, electrical conductivity, antifreeze, tissue adhesion, hemostatic performance, and efficient antibacterial activity against MRSA. In vivo studies showed that PIL-CS hydrogel provided fast diabetic wound healing support, promoted VEGF production, and reduced ROS and TNF-α generation. The results support that the hydrogels coupled with NIR fluorescent probes could be an excellent diabetic wound dressing for enhancing and real-time monitoring skin restoration and regeneration.