Preparation of polyvinyl alcohol-based CNC@TA composite nano‑silver antibacterial dressings for wound healing

Antibacterial dressings are crucial for the prevention and treatment of wound infections. Silver nanoparticles (AgNPs), known for their high-efficiency and broad-spectrum antibacterial properties, are commonly used in such dressings. However, silver nanoparticles are easily agglomerated under light and environmental media, causing unstable silver ion release in these dressings. This restricts long-term antibacterial effectiveness and fails to meet clinical needs. To solve this problem, negatively charged cellulose nanocrystals (CNC) were used to enhance the dispersion of silver nanoparticles. Meanwhile, tannic acid (TA) was employed to reduce silver ions, while enhancing the complexation between CNC and silver nanoparticles, effectively alleviating the agglomeration of silver nanoparticles. Subsequently, these silver nanoparticles combined with CNC and TA were integrated into a PP (PVA-PEG) hydrogel matrix. Experimental results show that the hydrogel dressing exhibits excellent performance. Silver nanoparticle dispersion is greatly improved, and Ag⁺ release becomes sustained. The antibacterial rate against common pathogens is above 99%, and a high antibacterial rate is still maintained after one week of light exposure. In addition, the physical properties of the PP hydrogel are optimized. Our findings provide a new strategy for antibacterial dressings, aiming to enhance the therapeutic effect of wound dressings, offer a novel preparation method for nano‑silver antibacterial materials, and promote the development of green medical materials.