Bioinspired Cationic Antimicrobial Polymers

Antibiotics are an essential tool of modern medicine, which is critically endangered by the spread of antimicrobial resistance (AMR). Without effective antibiotics, a number of medical advancements from the last century are in jeopardy, threatening our global public health and leading to a high death toll. To counteract this development, new therapeutic strategies, that are insusceptible to resistance development have to be established. Among them, antimicrobial polymers (AP)s are a promising class of materials. Their mode-of-action is highly unspecific as they kill bacteria by membrane permeabilization or precipitation of intracellular components. As such, it is unlikely for APs to be affected by AMR. This review highlights recent advances in AP design and understanding of structure-property relationships of these cationic macromolecules. One spotlight is on the polymeric architecture and how it influences AP bioactivity. A second highlight is stimuli-responsive APs and their potential to increase AP selectivity. Moreover, synergistic effects, e.g., between polymer and antibiotics are reviewed. The last focus is on in vivo applications of APs, which could pave a way toward clinical applications.