Injectable chitosan hydrogels loaded with plant-derived silver nanoparticles speed burn wound healing in mice

Researchers have combined silver nanoparticles made from plant extracts with an injectable, temperature-sensitive chitosan hydrogel and shown that the formulation speeds the repair of second-degree burn wounds in mice. The study, published in Frontiers in Bioengineering and Biotechnology, reports that hydrogels loaded with either castor bean (Ricinus communis) or aloe vera (Aloe barbadensis) leaf-derived nanoparticles achieved nearly complete wound contraction by day 14 and full closure by day 21 in a female BALB/c mouse model.

The hydrogels were built from chitosan mixed with glycerol-2-phosphate, a combination that remains liquid at room temperature but gels rapidly near body temperature, allowing the material to be injected and to conform to the shape of a wound bed. Three formulations were tested: a plain hydrogel (Ch-HI) and two versions carrying the biogenic silver nanoparticles, designated Ch/Rc-AgNP-HI and Ch/Ab-AgNP-HI. The nanoparticle-loaded gels showed near-physiological pH, porous morphology, gradual release of silver-containing species over 30 hours, and slow matrix erosion over 21 days.

In laboratory tests, the nanoparticle-loaded hydrogels showed antibacterial activity against Escherichia coli and Staphylococcus aureus, and they preserved the viability of HFF-1 fibroblast cells above the 70 percent cytotoxicity threshold across concentrations of 1 to 50 micrograms per milliliter. The authors note that embedding silver nanoparticles in a hydrogel addresses a known limitation of applying them directly to wounds, where they can aggregate, release their payload too quickly, and cause local toxicity.

In the mouse burn model, animals received 50 microliters of formulation daily for three consecutive days. The two nanoparticle-loaded hydrogels achieved wound contraction of 99.34 percent (plus or minus 0.4 percent) and 98.75 percent (plus or minus 0.6 percent) by day 14, with complete closure by day 21. Microbial surveillance found no detectable bacterial growth in any group, meaning the model tested repair of non-infected burns rather than treatment of established infection. Histological and biochemical analyses showed improved re-epithelialization, collagen organization, hydroxyproline deposition and dry matter recovery.

The authors present the phytogenic nanoparticle-loaded injectable hydrogels as promising platforms for non-infected burn wound repair, with antibacterial potential demonstrated so far only in vitro. Further work would be needed to establish safety and efficacy in infected wounds and in humans.

Subject of Research: Injectable chitosan hydrogels loaded with plant-derived silver nanoparticles for burn wound repair

Article Title: Biogenic silver nanoparticle-loaded injectable thermosensitive chitosan hydrogels accelerate repair of non-infected burn wounds

Article References: Ahsan, A., Aslam, Q.-U.-A., Gao, G. F., & Tian, W.-X. (2026). Biogenic silver nanoparticle-loaded injectable thermosensitive chitosan hydrogels accelerate repair of non-infected burn wounds. Frontiers in Bioengineering and Biotechnology, 14, Article 1990402. https://doi.org/10.3389/fbioe.2026.1990402

Image Credits: AI Generated

DOI: 10.3389/fbioe.2026.1990402

Keywords: silver nanoparticles, chitosan hydrogel, burn wounds, wound healing, Ricinus communis, Aloe barbadensis, drug delivery, antibacterial, tissue engineering, mouse model, Biogenic, silver