Efficacy of amphiphilic core-shell nanostructures encapsulating gentamicin in an in vitro Salmonella and Listeria intracellular infection model

Core-shell nanostructures with nonionic amphiphilic shells and ionic cores encapsulating gentamicin were designed for therapy against intracellular pathogens, including Salmonella and Listeria. Flow cytometry and confocal microscopy showed that their uptake into J774A.1 macrophages proceeded mainly by fluid-phase endocytosis and clathrin-mediated pathways. The nanostructures were nontoxic in vitro at doses of 50 to 250 μg/ml, and they significantly reduced the amounts of intracellular Salmonella (0.53 log) and Listeria (3.16 log), thereby suggesting effective transport into the cells.