Cationic Star Polymers Obtained by the Arm-First Approach─Influence of Arm Number and Positioning of Cationic Units on Antimicrobial Activity.

Abstract

Recently, we published a study demonstrating the promising structure-activity relationship of 4-arm star polymers toward bacterial cells and biofilms. The aim of this study was to increase the number of arms to determine if this could further enhance activity via the arm-first approach, which enables access to star structures with a higher number of arms. A library of amphiphilic diblock and miktoarm star polymers was successfully synthesized, and their biological properties were assessed. The increased number of arms failed to increase activity for the diblock stars, possibly due to shielding of the cationic units located at the core from binding to the membrane, which was slightly improved for the miktoarm structures. However, the efficient synthesis of these structures shown herein could be used to synthesize star polymers with a higher cationic ratio or longer arms, thereby circumventing the limitation of reduced interaction of cationic units with the membrane.