A core-shell multifunctional microneedle patch accelerates infected diabetic wound healing

Diabetic wounds exhibit impaired angiogenesis, drug-resistant bacterial infections, and oxidative damage to the microenvironment, presenting ongoing clinical challenges. In this research, we designed a core-shell structured multifunctional microneedle (MN) array patch (CS-SDFP/HA-Ag@MOF-PAL) to expedite the healing of infected diabetic wounds. The core consists of 10,000 MV hyaluronic acid (HA) and sucrose, integrated with Ag@MOF loaded with Palmatine (Ag@MOF-PAL). The shell, composed of chitosan (CS), encapsulates SDFP (CS-SDFP). Upon application to an infected diabetic wound, the shell swells, releasing the HA core, which dissolves to release Ag@MOF-PAL. The Ag@MOF targets and eradicates bacteria and eliminates biofilms of bacteria in the wound area, such as Staphylococcus aureus , Escherichia coli , and Pseudomonas aeruginosa , while PAL mitigates chronic inflammation in wound macrophages via the NF-κB and MAPK signaling pathways. As the wound microenvironment normalizes, the SDFP released from the swollen CS recruits adipose-derived stem cells (ADSCs) and promotes angiogenesis to facilitate wound repair. Our experiments demonstrate that CS-SDFP/HA-Ag@MOF-PAL accelerates wound healing in a diabetic rat model with Pseudomonas aeruginosa -infected wounds. The property of this core-shell structured multifunctional MN patch presents considerable potential for the development of therapeutic strategies aimed at the healing of infected diabetic wounds.