Coiled-Coil Peptide Nanoparticles Impact Bacterial Growth and Viability: Implications for Sustainability and Applications

Abstract

The development of sustainable, environmentally compatible materials should focus on nontoxic materials that degrade naturally in the environment based on their interactions with microorganisms. “Bundlemers” are a promising class of sustainable material building blocks built from amino acids. Bundlemers are computationally designed to form nanoparticles containing four identical peptides. Exposed side chains can be customized for specific purposes, e.g., to promote crosslinking for thin-film formation as a replacement for hydrocarbon polymer films. While bundlemers should be environmentally compatible, the environmental behavior of the building blocks must be assessed. Microbes, particularly bacteria, are responsible for environmental organic material degradation, including peptides. A range of bundlemer nanoparticles with total net charge from –8 to +24 was tested for their effects on growth and viability of two distantly related model bacteria, Escherichia coli and Bacillus subtilis. Negatively charged bundlemers did not affect the growth or viability of either bacterium. Neutral and weakly positively charged (+8) bundlemers prevented bacterial growth in a concentration-dependent manner without affecting viability. Strongly positively charged bundlemer nanoparticles (+24) both inhibited growth and rapidly killed both strains of bacteria.