Fabrication of a poly(gallic acid) nanoparticle-reinforced chitosan/xanthan gum hydrogel for treating diabetic oral ulcers

Diabetic oral ulcers present significant therapeutic challenges due to bacterial infections, oxidative stress, and impaired angiogenesis, often leading to delayed healing. To address these limitations, we developed a multifunctional hydrogel patch (abbreviated as DCP1) composed of dialdehyde xanthan gum, carboxymethyl chitosan, and poly(gallic acid) (PGA) nanoparticles. DCP1 synergistically integrates rapid hemostasis, antimicrobial activity, reactive oxygen species (ROS) scavenging, and pro-angiogenic properties. The Schiff base-crosslinked hydrogel exhibits a porous structure, injectability, and self-healing behavior, while PGA nanoparticles enhance ROS neutralization (66.7 % scavenging efficiency) and antioxidant cellular protection. In vitro studies demonstrated DCP1’s potent antibacterial efficacy (>99 % inhibition against S. aureus and E. coli ), biocompatibility (93.2 % cell viability), and hemocompatibility (<5 % hemolysis). In diabetic rat models, DCP1 accelerated ulcer closure by suppressing inflammation (reduced interleukin-6 expression) and promoting angiogenesis (elevated platelet endothelial cell adhesion molecule-1 levels), achieving near-complete healing within seven days. Systemic biosafety assessments confirmed minimal toxicity, supporting its clinical potential. This natural polysaccharide-based hydrogel offers a comprehensive therapeutic strategy for diabetic oral ulcers, addressing multifactorial pathology and outperforming conventional treatments.