Interactions of an antimicrobial peptide (Ac-RRWWRF-NH₂) and surfactants: Towards antimicrobial peptide additives for coatings applications

Waterborne coatings are complex formulations containing a number of components to aid stabilization and eventual coalescence of the polymer particles. Almost all systems contain a number of small molecule functional additives to improve different aspects of system performance. How the performance of these additives depends on interaction with other components of the formulation is relatively unexplored from a fundamental basis. A specific objective of this study is to provide a foundation for continued development of antimicrobial peptides as active polymer coatings components. This work addresses the impact of formulation variables, specifically surfactant structure, on the behavior of a model antimicrobial. Antimicrobials are used because a number of microbes are able to flourish within the water phase of the latexes resulting in a loss of properties commonly known as 'spoilage'. The model antimicrobial used in this study is a small oligopeptide (known as Combi1) identified as a powerful antimicrobial and has been extensively studied in the areas of pharmaceutics and medicinal chemistry. Monitoring of antimicrobial strength was done through the use of both conventional microbiology methods and high throughput absorbance and fluorescence measurements.