Composite Hydrogel Loading Polysaccharides Derived from Coptis chinensis Franch. for Promoting Diabetic Wound Healing

Efficient treatment of diabetic wounds (DW) remains a major clinical challenge worldwide owing to vascular insufficiency, multiple bacterial infections, and overactivation of pro-inflammatory M1 macrophages caused by hyperglycemia. The development of novel pharmaceutical agents with multiple biological functions is urgently needed. Coptis chinensis Franch. (CC) has been used to treat diabetes for thousands of years in China, but the curative effects and underlying mechanisms of CC in DW remain uncertain. Herein, a homogeneous heteropolysaccharide component, namely CCP, was isolated and purified from CC, which exhibited a molecular weight of 39,697 Da and was primarily composed of Glc, GalA, Ara, Gal, and Xyl. CCP has a light yellowish color and is distributed in a block shape with small surface granulations. In vitro experiments revealed that CCP dose-dependently mitigated high glucose-induced suppression of viability, migration, and tube formation in HUVECs. Meanwhile, CCP promotes the polarization of M1 macrophages toward the M2 phenotype to exert anti-inflammatory effects, while possessing certain antibacterial properties. In addition, a composite hydrogel system was successfully constructed by introducing sodium carboxymethyl cellulose and carbomer 940 for CCP delivery. The obtained hydrogels exhibited reasonable moisturizing, swelling, and drug release capacities, along with favorable rheological behaviors and certain antibacterial activity. More importantly, the in vivo wound healing model evaluation in diabetic rats demonstrated that CCP hydrogel dressings could effectively promote wound healing by reducing inflammation, accelerating collagen deposition, upregulating the expression of VEGF and key angiogenesis-related factors. In addition, composite hydrogels demonstrated excellent cytocompatibility and hemocompatibility, which holds great promise for clinical application in DW treatment.