pH-responsive smart hydrogel dressing for controlled antimicrobial therapy and accelerated wound healing

Area of Science:

• Biomaterials Science
• Nanotechnology
• Wound Healing Research

Background:

• Bacterial wound infections present significant clinical challenges, including delayed healing and antibiotic resistance.
• Conventional antibiotics are often ineffective against biofilm-associated bacteria.
• Silver nanoparticles (AgNPs) show antimicrobial potential but face limitations due to uncontrolled release and cytotoxicity.

Purpose of the Study:

• To develop a pH-responsive hydrogel wound dressing incorporating silver nanoparticles (AgNPs) for enhanced wound management.
• To achieve controlled release of AgNPs based on infection-related pH changes, reducing toxicity.
• To evaluate the antibacterial efficacy, biofilm suppression, and biocompatibility of the developed hydrogel.

Main Methods:

• Fabrication of a hyaluronic acid (HA) and acrylamide (AM) based hydrogel cross-linked with N,N'-methylenebisacrylamide, incorporating well-dispersed AgNPs.
• Assessment of hydrogel pH-responsive swelling and programmable AgNPs release.
• In vitro evaluation of antibacterial activity against Staphylococcus aureus, MRSA, and Escherichia coli, including biofilm suppression assays.
• Biocompatibility testing using Caco-2 and L929 cell lines.

Main Results:

• The hydrogel exhibited pH-dependent swelling, enabling controlled AgNPs release under alkaline conditions (infection) and reduced release at physiological pH.
• Demonstrated potent in vitro antibacterial activity against Gram-positive and Gram-negative bacteria and effective suppression of biofilms.
• Confirmed cytocompatibility with human colorectal adenocarcinoma (Caco-2) and mouse fibroblast (L929) cells.
• Observed hair regrowth, indicating potential benefits for follicle repair and wound regeneration.

Conclusions:

• The developed pH-responsive hydrogel dressing offers a promising, facile, and scalable platform for treating infected wounds.
• Controlled AgNPs release mechanism enhances therapeutic efficacy while mitigating cytotoxicity.
• The hydrogel's properties support wound hydration, cell adhesion, and regeneration, with potential for follicle repair.