Anisotropy in Antimicrobial Bottle Brush Copolymers and Its Influence on Biological Activity

Abstract

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.

Antibacterial Nanoplatelets via Crystallization-Driven Self-Assembly of Poly(l-lactide)-Based Block Copolymers

“…However, it should be noted that in the present study, grafts are substantially longer. As we have also shown that the degree of freedom of side chains has a severe impact on bioactivity, 46 a direct comparison might not be overly meaningful. Another difference lies in the selectivity between the bacteria strains.…”

“…In our previous work, we have demonstrated how crucial the shape and anisotropy of antimicrobial polymers is on a molecular level. 46,47 The limited and modulated hydrophobicity of these systems based on N-isopropylacrylamide (NIPAM) and amino ethyl acrylamide (AEAM) leads to impressive selectivities. Thus, we aimed to probe if these polymers can be applied as a component in antimicrobial nanostructures via CDSA.…”

Amino-Acid-Derived Anionic Polyacrylamides with Tailored Hydrophobicity–Physicochemical Properties and Cellular Interactions

“…Here, a slightly acidic p K a -value of the polymeric amine is desirable in order to promote endosomal membrane interaction under acidic conditions, but at the same time to minimize interactions with the cytoplasmic membrane to improve the compatibility of the polycations . This high membrane interaction further renders them suitable for applications as antimicrobial polymers. , …”

“… 10 This high membrane interaction further renders them suitable for applications as antimicrobial polymers. 15 , 16 …”