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Amino‐acid‐derived polyzwitterions and polybetaines (PBs) are two promising alternatives to non‐ionic polymers, for example, to increase tumor permeability. In this study, amino‐acid‐derived polyzwitterions are synthesized and a strategy to quarternize the amine in the side chain functional group is developed to combine the advantages of both types. The functional monomer is polymerized via reversible addition−fragmentation chain‐transfer polymerization for which a kinetic study is performed. Further, the impact of the permanent positive charge on amino‐acid‐derived polyzwitterions is studied based on two zwitterionic polymers obtained via post‐polymerization modification (PPM) of Poly(N‐acryloxysuccinimide) to allow good comparison between methylated and non‐methylated polymers. Circular dichroism shows that the stereocenter remains intact during PPM. pH titration and ζ‐potential measurements show that the methylated polymer has a negative ζ‐potential over the measured pH range and, therefore, the polymer remains zwitterionic over a broader pH range than its non‐methylated equivalent. Both polymers are well tolerated by mammalian cells up to concentrations of 1 mg mL−1. The study introduces a path to a new polymer class that combines the advantages of both PBs and amino‐acid‐derived polyzwitterions and highlights the impact a permanent charge has on the physiochemical properties. [ABSTRACT FROM AUTHOR]

Antimicrobial polymers are a promising alternative to conventional antibiotics in the fight against antimicrobial resistance. Cationic bottle brush copolymers have shown to be superior to linear topologies in previous studies. Herein, the aspect ratio of such polymers is varied creating differently shaped confined unimolecular structures with varying degrees of side chain mobility. Using reversible addition‐fragmentation chain‐transfer (RAFT) polymerization, bottle brushes are produced in a one‐pot procedure. The morphology is confirmed by atomic force microscopy. The hydrophobicity, as determined via high performance‐liquid chromatography (HPLC) analysis, is drastically influenced by the topology. Using Fourier‐transform infrared (FTIR) spectroscopy, it is found that polymers with a high side chain mobility and increased global hydrophilicity, are less hydrated, and have stronger intramolecular hydrogen bonds. A phase segregated morphology leading to unimolecular micellization is assumed. Biological tests reveal increased antimicrobial activity for such segregated polymers. Their excellent hemocompatibility results in highly selective antimicrobial polymers whose adaptability seems to be a key feature in their excellent performance. This study highlights the tremendous importance of structural control in antimicrobial polymers. [ABSTRACT FROM AUTHOR]

The continuous spread of resistance genes among bacterial populations, in particular in hospital setting, threatens the advances of our medical systems and already costs more than 1 million lives per year. Antimicrobial polymers (APs) are a promising type of materials to counteract these developments, as they are non‐susceptible toward resistance development, and even target resistant bacteria. We herein show the synthesis of an arginine‐containing monomer and its polymerization via photo‐induced reversible addition‐fragmentation chain‐transfer polymerization. The synthesis is straightforward, and the macromolecules possess two charged functions (i.e., guanidinium and ammonium) per repeating unit after deprotection. Assessment of the biological activity reveals that polymers inhibit the growth of methicillin‐resistant Staphylococcus aureus (MRSA) while being relatively inactive against tested Gram‐negative strains. Surprisingly, among the tested polymers, the homopolymer of the arginine‐derived monomer is the best‐performing material, even though it possesses no notable hydrophobic units. Toxicity tests against red blood cells and other mammalian cells show a good biocompatibility of polymers, leading to an overall excellent selectivity. Using membrane models, the mechanism of action was found to be membrane disruption. The good selectivity of the herein presented polymer for MRSA makes them promising materials for the development of therapeutic agents against such infections. [ABSTRACT FROM AUTHOR]