Diabetic wounds are a common and serious complication of diabetes, and their difficulty in healing is one of the major burdens on global health systems. Persistent inflammation and bacterial and microbial infection are the main reasons why diabetic wounds are difficult to heal. Therefore, developing dressings that are both anti-inflammatory and anti-infective is the key to accelerating diabetic wound healing.

FIG. 1 Schematic diagram of the development of bioactive OCMC-Tob/PEI hydrogels based on the "Pull-Push" treatment strategy.

The team cross-linked polyamino-polyethylenimide (PEI), Tobramycin (Tob) and other positive molecules with good biocompatibility carboxymethyl cellulose oxide (OCMC) through Schiff base reaction, and constructed OCMC-TOB /PEI cationic hydrogel with injectable, self-healing and good mechanical properties. OCMC-Tob/PEI hydrogel with good biocompatibility can not only eliminate a variety of negative charge dangerous molecules (such as cfDNA, LPS and TNF-α, etc.) to achieve inflammation regulation, but also release Tob in response to low pH conditions, with broad spectrum and long-term antibacterial activity. The healing rate of diabetic wounds infected with P. aeruginosa can be accelerated by a combination of anti-inflammatory and antibacterial pathways. In summary, this work developed cationic hydrogel for the treatment of infectious diabetic wounds, which not only exerts anti-inflammatory activity by removing dangerous molecules, but also has broad spectrum and long-term antibacterial ability, providing a new material for the efficient and safe treatment of diabetic foot. This work further revealed the effects of the composition of cationic elements on the endogenous anti-inflammatory and antibacterial activities of cationic hydrogels, and provided a new idea for the design of efficient and safe multi-functional active hydrogels.