Sprayable Hydrogel for pH-Responsive Nanozyme-Derived Bacteria-Infected Wound Healing

Area of Science:

• Biomaterials Science
• Nanotechnology
• Wound Healing Research

Background:

• Chronic wounds often suffer from persistent bacterial infections and inflammation, hindering healing.
• Conventional antibiotics face increasing bacterial resistance, necessitating alternative antimicrobial strategies.
• Nanozymes offer a stable, cost-effective, and synthesizable alternative for antimicrobial applications.

Purpose of the Study:

• To develop a novel sprayable hydrogel incorporating a gold nanoparticle-carbon nitride (AuNPs-C3N4) nanozyme for treating bacteria-infected chronic wounds.
• To investigate the antibacterial mechanism and wound healing efficacy of the developed hydrogel.
• To explore the synergistic effects of AuNPs and C3N4 in the nanozyme for enhanced catalytic activity.

Main Methods:

• Fabrication of a sprayable hydrogel using carboxymethyl chitosan (CMCS) and oxidized hyaluronic acid (OHA).
• Incorporation of AuNPs-C3N4 nanozyme, glucose, and Mn2+ into the hydrogel matrix.
• Evaluation of the hydrogel's in situ formation, degradation, and release kinetics.
• Assessment of the nanozyme's glucose oxidase-like activity and Mn2+-mediated Fenton-like reaction for hydroxyl radical generation.
• In vitro antibacterial testing against Staphylococcus aureus (S. aureus) and Methicillin-resistant Staphylococcus aureus (MRSA).
• Computational modeling to understand the synergistic effects within the AuNPs-C3N4 heterojunction.
• In vivo wound healing studies evaluating collagen production and fibroblast proliferation.

Main Results:

• The sprayable hydrogel rapidly formed in situ and degraded gradually, releasing the active nanozyme.
• The AuNPs-C3N4 nanozyme demonstrated potent glucose oxidase-like activity, triggering a catalytic cascade to generate hydroxyl radicals.
• The generated hydroxyl radicals effectively eliminated S. aureus and MRSA.
• Computational analysis revealed that the AuNPs-C3N4 heterojunction maximized synergistic effects, enhancing oxygen adsorption and catalytic efficiency.
• The CMCS component of the hydrogel promoted collagen production and fibroblast proliferation, accelerating wound closure.

Conclusions:

• The developed sprayable hydrogel loaded with AuNPs-C3N4 nanozyme presents a promising strategy for treating bacteria-infected wounds.
• The hydrogel's dual action of bacterial elimination and promotion of tissue regeneration offers a viable solution for chronic wound management.
• The study highlights the potential of nanozyme-based hydrogels as advanced wound care materials.