Antimicrobial polymers prepared by ring-opening metathesis polymerization: manipulating antimicrobial properties by organic counterion and charge density variation.

TitleAntimicrobial polymers prepared by ring-opening metathesis polymerization: manipulating antimicrobial properties by organic counterion and charge density variation.
Publication TypeJournal Article
Year of Publication2009
AuthorsLienkamp K, Madkour AE, Kumar K-N, NĂ¼sslein K, Tew GN
JournalChemistry
Volume15
Issue43
Pagination11715-22
Date Published2009 Nov 2
ISSN1521-3765
KeywordsAnti-Infective Agents, Biomimetic Materials, Cations, Diamines, Hemolysis, Hydrophobic and Hydrophilic Interactions, Microbial Sensitivity Tests, Polymers
Abstract

The synthesis and characterization of a series of poly(oxanorbornene)-based synthetic mimics of antimicrobial peptides (SMAMPs) is presented. In the first part, the effect of different organic counterions on the antimicrobial properties of the SMAMPs was investigated. Unexpectedly, adding hydrophobicity by complete anion exchange did not increase the SMAMPs' antimicrobial activity. It was found by dye-leakage studies that this was due to the loss of membrane activity of these polymers caused by the formation of tight ion pairs between the organic counterions and the polymer backbone. In the second part, the effect of molecular charge density on the biological properties of a SMAMP was investigated. The results suggest that, above a certain charge threshold, neither minimum inhibitory concentration (MIC90) nor hemolytic activity (HC50) is greatly affected by adding more cationic groups to the molecule. A SMAMP with an MIC90 of 4 microg mL(-1) against Staphylococcus aureus and a selectivity (=HC50/MIC90) of 650 was discovered, the most selective SMAMP to date.

DOI10.1002/chem.200900606
Alternate JournalChemistry
PubMed ID19798715