Biological Functions of Silver Nanowires in Inhibiting Vibrio Pathogens and Modulating Shrimp Hemocyte Immunity

Abstract

Silver nanoparticle (AgNP)-based products have been increasingly applied in aquaculture due to their antimicrobial properties and capacity to modulate host immunity. This study investigated the biological activities of synthesized silver nanowires (AgNWs), with particular emphasis on their anti-Vibrio efficacy and immunomodulatory effects, to evaluate their potential application in shrimp aquaculture. Antibacterial activity was assessed using nonlinear regression analysis to determine minimum inhibitory concentrations (MICs) against three major Vibrio pathogens, while cytotoxicity and immune responses were evaluated using white shrimp hemocytes through cell viability assays and in vitro gene expression analysis, respectively. AgNWs exhibited antibacterial effects on Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio harveyi, with MIC values of 873.7, 58.78, and 672.1 mu g/mL, respectively. Hemocyte viability remained above 90% at AgNW concentrations of up to 1000 mg/L, indicating good biocompatibility. AgNWs significantly upregulated immune-related lipopolysaccharide and beta-1,3-glucan-binding protein (LGBP) and Toll gene expression at specific concentrations, indicating immunostimulation. These results suggest that AgNWs possess antibacterial activity and immunomodulatory potential with low cytotoxicity, supporting their promise as a novel functional agent for shrimp disease management.