Mild NIR controlled NO-Releasing adenine-based composite hydrogel with excellent Antimicrobial, wound adaptiveness and angiogenic capabilities for rapid bacterial-infected wounds healing

Abstract

Development of wound dressings with antimicrobial activity and promotion of sustained wound healing to reduce the use of antibiotics in infected wounds is important. In this study, we developed a thermosensitive ABA triblock copolymer poly {(N-isopropyl acrylamide)–co-[(6-((3-(6-amino-purin-9-yl)propanoyl)oxy)hexyl acrylates)]-b-PEO-b-Poly (N-isopropyl acrylamide)–co-{[(6-((3-(6-amino-purin-9-yl)propanoyl)oxy)hexyl acrylates)]} as matrix and participating nitric oxide (NO) donor (N,N'-dis-sec-butyl-N,N'-dinitroso-1,4-phenylenediamine, BNN6) loaded SiO2@PDA nanoparticles composed of hydrogel dressings (Gel-APB) for efficient antimicrobial and sustainable treatment of wounds. Thanks to the presence of poly (N-isopropyl acrylamide) (PNIPAM) and unique ABA triblock structure, the NAONA copolymer would self-assemble into temperature-sensitive injectable hydrogel with excellent dermal adaptation to dynamic wounds. Meanwhile, the biobase adenine endowed the hydrogel dressing with self-healing ability. Under 808 nm wavelength irradiation, the hydrogel was able to elevate to a mild temperature (∼48 °C) and release NO on demand, which efficiently kills E. coli and S. aureus, realizing highly efficient and mild photothermal antimicrobial therapy (PTAT). In addition, full-thickness skin wound modeling demonstrated that Gel-APB hydrogel dressing accelerated tissue regeneration, angiogenesis, and collagen deposition in S. aureus infected wounds in vivo, achieving rapid wound healing. Thus, Gel-APB is a multifunctional hydrogel dressing with excellent antimicrobial activity and has considerable potential for application in infected skin wound healing.