Chitosan fabricated silver nitroprusside nanocomposites prepared for enhanced antibacterial and cytocompatibility applications through controlled release of metal ions and nitric oxide.

Silver nitroprusside complex nanoparticles (AgN NPs) have garnered significant attention for their antimicrobial properties. However, challenges such as toxicity and limited biocompatibility often hinder their practical applications. Therefore, this study introduces a combined approach to fabricating AgN NPs with chitosan (CS), resulting in CS-AgN nanocomposites (CS-AgN NCs) with cytocompatibility. AgN NPs exhibited a distinct cubic morphology with a mean size of 52.88 ± 15.45 nm, while CS-AgN NCs showed a smaller, spherical, and elongated structure. The incorporation of CS led to significant changes in AgN NPs, including a reduction in the zeta potential from -46.63 ± 1.25 mV to -13.0 ± 2.12 mV and alterations in crystallinity. A key finding was that nitric oxide (NO) release was highly pH-dependent, which could offer targeted therapeutic potential. Both nano systems demonstrated potent antibacterial effects, with minimum inhibitory concentrations (MICs) as low as 6.25 μg/mL against E. coli, alongside strong biofilm inhibition (≥80 % at 12.5-25 μg/mL). The CS-AgN NCs also exhibited superior antioxidant activity compared to AgN NPs without compromising cell viability or causing hemolysis, and low toxicity to Artemia salina, making them promising candidates for biomedical applications. This work highlights the unique interplay between AgN NPs and CS, offering insights into their potential for next-generation antimicrobial therapies.