Rhubarb charcoal-crosslinked chitosan/silk fibroin sponge scaffold with efficient hemostasis, inflammation, and angiogenesis for promoting diabetic wound healing

Diabetic patients often experience long-term risks due to chronic inflammation and delayed re-epithelialization during impaired wound healing. Although the severity of this condition is well known, the treatment options for diabetic wounds are limited. Rhubarb charcoal, a well-known traditional Chinese medicine, has been used to treat skin wounds for thousands of years. We produced a chitosan/silk fibroin sponge scaffold loaded with natural carbonized rhubarb and crosslinked it by freeze-drying to create a highly efficient RCS/SF scaffold. Rhubarb carbon and carboxymethyl chitosan exhibit antibacterial activity and promote wound healing. Owing to its 3D porous structure, this scaffold is antibacterial and pro-angiogenic. It also possesses remarkable properties, such as excellent swelling and biocompatibility. The supportive effect of carbonized rhubarb on mouse fibroblast migration is mediated at the cellular/tissue level by increased skin neovascularization and re-epithelization. Compared to the control group, RCS/SF scaffolds promoted faster healing, increased neovascularization, enhanced collagen deposition, and re-epithelialization within two weeks. The scaffold's pro-healing properties and efficient release of carbonized rhubarb, with rapid hemostatic and good sterilization effects, make it an outstanding candidate for treating diabetic wounds and novel therapeutic interventions for diabetic ulcers.