Secondary and Tertiary Polydiallylammonium Salts: Novel Polymers with High Antimicrobial Activity

Abstract

Antimicrobial activity of secondary and tertiary poly(diallylammonium) salts (PDAAs) had not been reported before. Due to difficulties with preparation of polymers from the monomers of the diallylamine (DAA) series in the nonquaternary form, up to recently it was not possible to obtain PDAAs with a sufficiently high molecular mass. Here, we describe the investigations of antimicrobial activity of novel water-soluble cationic polyelectrolytes of the PDAA series, namely secondary poly(diallylammonium trifluoroacetate) (PDAATFA) and tertiary poly(diallylmethylammonium trifluoroacetate) (PDAMATFA), in synthesis of which we have recently succeeded, against gram-positive and gram-negative bacteria, and fungi. We have studied the effect of molecular weight (polymeric chain length) and ionic strength of solution on the biocidal efficiency of those polymers; in addition, the concentration dependences of PDAATFA reduced viscosity in salt-free and KCl aqueous solutions have been investigated. The antimicrobial properties of polybase polydiallylamine (BPDAA), which was obtained in an aqueous solution of PDAATFA in presence of alkali, have been also studied as well as biocidal activity of commercial open-chain polybase branched PEI. Those PDAATFA, BPDAA and PEI polymers served as the systems to study the structure-activity relationships. Transmission electronic microscopy study was carried out to characterize the mode of antimicrobial action of PDAATFA using E. coli . It was shown that the synthesized PDAATFA and PDAMATFA exhibit, unlike the quaternary polymers of this series, a rather high biocidal efficiency that is comparable with the activity of known effective cationic polymer biocides or exceeds it. Novel polyelectrolytes exhibit quite strong biocidal properties at different conditions including aqueous solutions of moderate ionic strength (serum, 0.01 M/0.1 M) and aqueous-alkaline solutions (pH 10.5) until the macrochain retains some positive charge, but complete neutralization of the polyelectrolyte in a 1 M salt solution results in the loss of its biocidal activity. The obtained results evidence that the structure of links, which combine the hydrophobic pyrrolidinium rings with the hydrophilic secondary/tertiary ammonium groups, is responsible for the high biocidal activity of the PDAAs. Polymeric nature of the synthesized compounds is one of the most significant factors of their bactericidal efficiency, unlike their high fungicidal activity, which is evidently related to the secondary/tertiary pyrrolidinium cycle.

Controlling macromolecular structures towards effective antimicrobial polymers

“…Several biophysical methods are utilized to investigate the membrane disrupting mechanism including the measurement of dye-leakage from dye-filled synthetic liposomes [79,83,182,183], quantification of leaked cellular constituents (e.g. phosphorylated compounds) [14,184], fluorescence-based methods [84], and observation of morphologic changes by scanning electron microscopy [159] [66], transmission electron microscopy [144] and atomic force microscopy [185]. However, all of these methods assist to identify the membrane damaging effects of polymers.…”

Antimicrobial Polymers in Solution and on Surfaces: Overview and Functional Principles

“…Palermo and Kurada synthesized similar copolymers by copolymerizing dimethylaminoethylacrylamide and aminoethylacrylamide, respectively, with n-butylacrylamide and showed that these polymers are antimicrobially active and less toxic to blood cells compared to the respective quarternary ammonium derivatives [46,47]. Another recent development in the group of Timoveeva are poly(diallylammonium salts) that contain either secondary or tertiary amino groups [48]. These polymers show excellent activity against S. aureus and Candida albicans.…”

s-Triazine Ring-Modified Waterborne Alkyd: Synthesis, Characterization, Antibacterial, and Electrochemical Corrosion Studies

“…50 Besides, hydrogen bonding might have occurred between the residual hydroxyl group with the phosphate, carbonyl, or hydroxyl oxygen atoms of the molecules of phospholipids, polysaccharides, or teichoic acid embedded in the membrane of the Gram positive cell wall thus causing lateral segregation of negatively charged lipids and permeability of the outer membrane. 51 Potentiodynamic Polarization (PDP) Studies. Figure 8 and Table 4 show the potentiodynamic polarization measurements for different ratios of SA-BMF-coated samples in different corrosive media (3.5 wt % HCl, 3.5 wt % NaOH, and tap water).…”