AuPt Nanoparticle-Based Injectable Hydrogel as Cascade Nanozyme for Accelerating Bacteria-Infected Wound Healing

Abstract

Bacterial infections have been the main obstacle of wound healing in clinic. Conventional antibiotics have been widely used for bacterial infections therapy. However, the misuse and long-term use of antibiotics could induce drug resistance, resulting in the reduced antibacterial effect. Recently, the nanozyme-based combination therapy mode has emerged as a promising strategy to achieve enhanced antibacterial effect with different antimicrobial mechanisms. Inspired by this, a gold/platinum nanoparticle-based injectable hydrogel with nanozyme and photothermal properties was developed for accelerating bacteria-infected wound healing. In detail, gold/platinum nanoparticles (AuPt NPs) were prepared by reducing metal precursors in the presence of ascorbic acid. Then, AuPt NPs and GOx were incubated with thiol-terminated four-arm polyethylene glycol to form injectable AuPt/GOx gel. The AuPt/GOx gel possessed a cascade catalytic activity: GOx converted glucose into gluconic acid and hydrogen peroxide (H2O2) and subsequently promote peroxidase-like reaction of AuPt NPs to transfer H2O2 into a more toxic hydroxyl free radical for destroying bacteria. More than that, AuPt/GOx gel displayed a good photothermal effect. The wound healing rate in AuPt/GOx gel + glucose + NIR group was the fastest, which is attributed to the synergistic effect of nanozyme activity and photothermal effect. This work provides a safe and robust strategy for bacterial infection therapy.

Superparamagnetic Amine-Functionalized Maghemite Nanoparticles as a Thixotropy Promoter for Hydrogels and Magnetic Field-Driven Diffusion-Controlled Drug Release

“…The initial linear region is called linear viscoelastic region or LVR . A linear viscoelastic material responds instantly and elastically to a stress or strain within its linear viscoelastic zone . This indicates that there was no persistent deformation of the material after the tension or strain was removed.…”

“…50 A linear viscoelastic material responds instantly and elastically to a stress or strain within its linear viscoelastic zone. 51 This indicates that there was no persistent deformation of the material after the tension or strain was removed. Timedependent behavior emerges as stress or strain is increased within the linear viscoelastic zone.…”

Nanozyme-Engineered Hydrogels for Anti-Inflammation and Skin Regeneration

“…Moreover, the injectability of NZ@hydrogels facilitates their use in challenging anatomical sites that may be difficult to reach using traditional methods. For example, Bai et al formulated an injectable hydrogel that integrates Au-Pt NZs to serve as a self-promoted cascade NZ to improve the healing process of bacterial-infected wounds [ 80 ]. Au-Pt NZs directly cross-link with 4arm-PEG-SH, eliminating the necessity for additional cross-linking agents due to the formation of coordination bonds.…”