Charge‐Driven Self‐Assembled Microspheres Hydrogel Scaffolds for Combined Drug Delivery and Photothermal Therapy of Diabetic Wounds

The treatment of diabetic wound remains a big clinical challenge. Hydrogel that can provide physical barrier and humidity displays amazing potentials for managing the diabetic wounds healing. Herein, a new charge‐driven self‐assembled microsphere hydrogel scaffold (SMHS) is reported based on an electric charge interaction, by combining use of black phosphorus (BP)‐contained chitosan methacryloyl (CS) microspheres with positive charge and basic fibroblast growth factor‐contained hyaluronic acid methacryloyl (HA) microspheres with negative charge. The weak charge attraction among microspheres gives the SMHS the injectable characteristic. Due to the existence of BP, near‐infrared (NIR) irradiation has obvious effects on the degradation and drug release behaviors of SMHS. Significantly, SMHS that combines the short‐term physical (photothermal) intervention and long‐term chemical (drug release) intervention may be promising in spatio‐temporal regulation of regenerative microenvironment. SMHS with NIR irradiation (SMHS+NIR) can promote cell proliferation, cell migration, angiogenesis and macrophage polarization. Moreover, in diabetic rat skin wounds, SMHS+NIR significantly accelerates the wound healing process by simultaneously inhibiting the inflammatory response, promoting angiogenesis and tissues remodeling. The outcome of this research not only provides a biomaterial for diabetic wounds healing, but also demonstrates a new strategy for designing novel hydrogel‐based biomaterials which have the free editing and combination functions. Charge‐driven self‐assembled microsphere hydrogel scaffold (SMHS) are fabricated with electric charge interaction, by combining use of black phosphorus ‐contained chitosan methacryloyl microspheres with positive charge and basic fibroblast growth factor‐contained hyaluronic acid methacryloyl microspheres with negative charge. The resultant SMHS can combine drug delivery and photothermal therapy to accelerate diabetic wound healing.