Effect of polyelectrolyte complex formation on the antibacterial activity of copolymer of alkylated 4-vinylpyridine

Abstract

Polymers bearing quaternized 4-vinylpyridine (QVP) groups are known for their antibacterial activities andthese polymers can form polyelectrolyte complexes (PEC) with polyanions through electrostatic interactions. PEC formation can be used to adjust the antibacterial activity of polymers of QVP, deliver active molecules, or design antibacterialsupramolecular structures. However, the antibacterial activity of PECs of QVP polymers has not been investigated. Inthis study, a copolymer of QVP was mixed with polyacrylic acid in various molar ratios of components to form PECs.Hydrodynamic diameters and zeta potentials of formed PECs were determined by dynamic and electrophoretic lightscattering spectroscopy techniques. The zeta potentials of PECs changed between –24 and +16 mV with variation inthe ratio of components. Antibacterial assays against E. coli revealed a relation of PEC formation with antibacterialactivity since MIC values changed between 125–1000 µg/mL according to the ratio of components.