Synthesis of cytocompatible gum Arabic-encapsulated silver nitroprusside nanocomposites for inhibition of bacterial pathogens and food safety applications

Silver nitroprusside (AgN) exhibits significant antibacterial activity; however, its inherent toxicity poses a major concern. This study synthesized AgN with enhanced antibacterial properties while minimizing toxicity. Gum Arabic (GA), a natural polysaccharide widely utilized in food and biomedical applications owing to its exceptional cytocompatibility, was selected for encapsulating AgN to mitigate toxicity while preserving or enhancing its biological activity. The resulting composite material, GA-AgN nanocomposites (NCs), was systematically characterized using various analytical techniques. Transmission electron microscopy analysis revealed that GA-AgN NCs exhibited a rectangular morphology, with an average size of 230.13 ± 62.8 nm. The zeta potential of GA-AgN NCs was measured at -29.3 ± 0.70 mV. Furthermore, GA-AgN NCs demonstrated stability over diverse storage durations, incubation periods, and pH conditions by maintaining its size and surface charge. X-ray diffraction results indicated a reduction in the crystallinity of AgN when incorporated into the amorphous GA matrix, while Fourier-transform infrared spectroscopy analysis confirmed that the functional properties of both AgN and GA were preserved in the NCs. The release of Ag and Fe ions from the NCs was observed to be time- and pH-dependent. Importantly, the incorporation of GA did not compromise the antibacterial or antibiofilm efficacy of AgN against bacterial pathogens. Additionally, GA significantly mitigated the cytotoxic effects of AgN on NIH3T3 cells and red blood cells. Furthermore, GA-AgN NCs effectively extended the shelf-life of Salmonella enterica-infected green grapes. Thus, this study illustrates that GA-fabricated AgN NCs exhibit potential as an antibacterial agent in food preservation applications.