Closing One of the Last Gaps in Polyionene Compositions: Alkyloxyethylammonium Ionenes as Fast‐Acting Biocides

Abstract

Alkyloxyethylammonium ionenes are reported as biocompatible biocides with a time of biocidal action within a few minutes. The presence of both ethoxyethyl and aliphatic spacers besides long alkyl chain substituents on the quaternary nitrogen atom differentiates these biocides structurally from the known polyionenes. The influence of alkyl spacer length, counter ion and length of the pendant alkyl groups on the antibacterial properties is studied. E. coli is adopted as a test organism. MIC and MBC values are determined via broth dilution methods; time-dependent tests are accomplished by determining the number of viable cells with the spread-plate method after different contact times. Structural characterization is conducted via NMR and mass spectrometry techniques.

Nontoxic, Hydrophilic Cationic Polymers—Identified as Class of Antimicrobial Polymers

“…Using the end‐group/main chain signal ratio to determine the number of repeating units shows that the second reaction step leads to oligomers that have a significantly higher molecular weight than expected from a full conversion according the reaction scheme (see Table ). Obviously, dimerization and/or ring formation is even more pronounced in the second reaction step . The next monomer addition is still resulting in an over proportional chain growth, indicating side reactions here as well.…”

“…Further, they found that the activity of these polymers is increasing with higher molecular weight . Variations of the pendent groups and the alkyl spacers in the main chain performed by the group of Agarwal revealed that the alkyl spacer in the main chain does not significantly influence antimicrobial activity as long as its larger than an ethylene group . In comparison to amphiphilic antimicrobial polymers, much less is known about their toxicity for mammalian cells.…”

Antimicrobial Polymeric Materials with Quaternary Ammonium and Phosphonium Salts

“…The ionenes containing separated longer hydrophobic segments but with lower charge densities exhibited more effectively biocidal ability than those with higher charge densities, suggesting that the hydrophobicity is the dominant factor for cell disruption. Mattheis et al [ 86 ] synthesized various alkyloxyethylammonium ionenes with different alkyl chain substituents on the nitrogens and aliphatic spacers ( Figure 3 c) via step-polymerization of alkyl dibromides with bis(2- N , N -dialkylamino)ethyl ethers. The effects of counter ion, alkyl spacer, and length of the pendant alkyl chains on the antimicrobial performance were investigated via broth dilution method.…”

Effect of Guanidinylation on the Properties of Poly(2‐aminoethylmethacrylate)‐Based Antibacterial Materials

“…In order to evaluate the cytotoxicity, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) tests with L‐929 mouse ( Mus musculus ) connective tissue fibroblast cells (DSMZ, No. ACC 2) were conducted, as reported previously 20. In short, L‐929 cells were seeded in 96‐well plates with 8000 cells per well, incubated at 37 °C, 10% relative humidity and 8.5% CO 2 for 24 h, and after removal of the cell culture medium, exposed to a geometric dilution series of the polymer, starting at a concentration of 4000 µg · mL −1 in tissue culture medium with 0.002 M L ‐glutamine (sterilized by filtration; 0.2 µm), and a blank control with culture medium.…”