Electret-Inspired Charge-Injected Hydrogel for Scar-Free Healing of Bacterially Infected Burns Through Bioelectrical Stimulation and Immune Modulation

Abstract

In this study, an electret-inspired, charge-injected hydrogel called QOSP hydrogel (QCS/OD/SDI/PANI/PS/Plasma) that promotes scar-free healing of bacteria-infected burns through bioelectrical stimulation and immune modulation, is presented. The hydrogel, composed of quaternized chitosan (QCS), oxidized dextran (OD), sulfadiazine (SDI), polystyrene (PS), and polyaniline nanowires (PANI), forms a conductive network capable of storing and releasing electric charges, emulating an electret-like mechanism. This structure delivers bioelectrical signals continuously, enhancing wound healing by regulating immune responses and minimizing fibrosis. In a mouse model of second-degree burns infected with Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA), the hydrogel accelerates wound healing by 32% and reduces bacterial load by 60%, significantly inhibited scar formation by 40% compared to controls. QOSP hydrogel modulates the Th1/Th2 immune balance toward a Th1-dominant antifibrotic state through quaternized chitosan, thereby reducing collagen deposition by 35%. Electro-dielectric characterization reveals a dielectric constant of 6.2, a 34% improvement in conductivity (3.33 × 10^-5 S/m) and a 30 °C increase in thermal stability. Proteomic analysis highlights a 50% down-regulation of pro-inflammatory and pro-fibrotic pathways, suggesting a controlled immune response conducive to scar-free healing. This study underscores the potential of bioelectrically active hydrogels as a novel approach for treating infected wounds prone to scarring.

Keywords: bacterially infected burns; bioelectrical stimulation; charge‐injected hydrogel; electrets; fibrosis inhibition; immune modulation; scar‐free healing.