Metal-polyphenol nanoparticles-loaded carboxymethyl cellulose-based microneedle for promoting the healing of diabetic wounds

Abstract

Inflammation and infection are significant barriers to the healing of diabetic wounds. Infectious wounds are often associated with the formation of bacterial biofilms, which impede the penetration of conventional drugs. In this study, we developed a novel metal-polyphenol composite nanoparticle (EGCG-Cu²⁺ NPs) by combining epigallocatechin gallate (EGCG) with Cu²⁺ and incorporated these nanoparticles into microneedles (MNs) made from polyvinylpyrrolidone (PVP) and sodium carboxymethyl cellulose (CMCNa). The resulting EGCG-Cu²⁺ MNs exhibited remarkable anti-inflammatory and antibacterial properties, achieving over 95 % inhibition against S. aureus and P. aeruginosa. Moreover, they effectively scavenged reactive oxygen species (ROS), inhibited the M1 polarization of macrophages, and promoted their M2 polarization. In diabetic wound infection models, the EGCG-Cu²⁺ MNs enhanced collagen deposition and angiogenesis, resulting in over 92 % wound closure within 14 days. This study provides a significant theoretical basis for innovative treatment strategies for infectious diabetic wounds, highlighting its promising clinical application potential.