Cationic Antimicrobial Polymers and Their Assemblies

Abstract

Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs). The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications.

Antimicrobial cationic polymers: from structural design to functional control

“…This can cause the cytoplasm leakage, thus leading to the cell death of microbes. 31 In general, the hydrophobic groups are usually used to penetrate into the membrane and their length and types need to be considered in the monomer design.…”

Enhancing and initiating phage-based therapies

“…Such lysis can be achieved more directly with polymers that have both cationic and hydrophobic groups and, therefore, have cationic detergent character. 41,42 This latter lysis is not analogous to the polymer-induced phage activation of the previous paragraphs. The reasons are that lysis by the cationic detergent-like polymers (1) occurs in biofilms generated by pure bacterial cultures, (2) often occurs "on contact" and (3) occurs via immediate damaging effects on bacterial membranes.…”

“…The reasons are that lysis by the cationic detergent-like polymers (1) occurs in biofilms generated by pure bacterial cultures, (2) often occurs "on contact" and (3) occurs via immediate damaging effects on bacterial membranes. 41,42 However, cationic polymer-activation of endogenous phages is still a possible (apparently unexplored) factor in the wild.…”

Effective axillary malodour reduction by polyquaternium‐16‐containing deodorants

“…This process causes leakage of intracellular components, degradation of proteins and nucleic acids and lysis of cell membranes [26,27]. Out of that reason, these compounds represent promising candidates for the development of antimicrobial substances [27].…”