Impacts of broth chemistry on silver ion release, surface chemistry composition, and bacterial cytotoxicity of silver nanoparticles

Here, we determine the impact of bacterial growth media on silver nanoparticle (diameter = 24.0 +/- 3.2 nm) surface chemistry, the relationship of this surface chemistry to silver ion release from these nanoparticles, and ultimately the antimicrobial implications of those parameters. Importantly, we investigate the effects of multiple broths, as well as the isolated influence of individual broth components and their bicombinations. Our findings indicate that, in combination, broth components may exhibit additive, synergistic, and/or antagonistic effects on silver ion release. In addition, we find that the silver ion release does not always inversely correlate with ligand density, and interestingly, that the type of correlation (negative or positive) is dependent on the broth media. Finally, the impact of these media-dependent silver ion release profiles on bacterial cytotoxicity is studied using the model organism Escherichia coll. Overall, we establish the specific impacts of silver nanoparticle environment on silver nanoparticle surface chemistry, as well as the influence of those outcomes on bacteria growth in the presence of silver nanoparticles.