Engineered Bio-Silver Nanoparticle Interface Offers Antimicrobial Properties for Improved Cellular Viability

Abstract

Silver nanoparticles (AgNPs) are promising candidates for fighting drug-resistant infections because of their intrinsic antimicrobial effect. The antimicrobial efficacy, shown as a result of high-yield design of AgNPs, may inadvertently cause variation in host cells biological responses. While many factors affect AgNP efficacy, their surface is exposed to the biological environment and thus plays a critical role both in preserving antimicrobial efficacy against pathogens, as well as preventing cytotoxicity for host cells. Our approach for controlling nanoparticle surface properties is built upon engineering a biomimetic interface that provides a competitive advantage. Here, we engineered a fusion protein featuring a silver-binding peptide domain (AgBP) to enable self-assembly with green fluorescence protein (GFP) to track assembly. Following AgNP functionalization with GFP-AgBP, their antimicrobial properties were evaluated in conjunction with their cytotoxic properties. GFP-AgBP binding affinity to AgNPs was evaluated using localized surface plasmon resonance. The GFP-AgBP biomimetic interface on AgNP surfaces provided sustained antibacterial efficacy at relatively low concentrations based upon bacterial (Streptococcus mutans) growth inhibition assays. Viability and cytotoxicity measurements in fibroblast cells (NIH/3T3) exposed to protein-functionalized AgNPs showed significant improvement compared to controls. Biointerface engineering offers promise toward tailoring AgNP efficacy while addressing safety concerns to maintain optimum cellular interactions.