The Effects of Amide Bonds and Aromatic Rings on the Surface Properties and Antimicrobial Activity of Cationic Surfactants

Ultrashort cationic lipopeptides (USCLs) and gemini cationic surfactants are classes of potent antimicrobials. Our recent study has shown that the branching and shortening of the fatty acids chains with the simultaneous addition of a hydrophobic N-terminal amino acid in USCLs result in compounds with enhanced selectivity. Here, this approach was introduced into arginine-rich gemini cationic surfactants. L-cystine diamide and L-lysine amide linkers were used as spacers. Antimicrobial activity against planktonic and biofilm cultures of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) strains and Candida sp. as well as hemolytic and cytotoxic activities were examined. Moreover, antimicrobial activity in the presence of human serum and the ability to form micelles were evaluated. Membrane permeabilization study, serum stability assay, and molecular dynamics were performed. Generally, critical aggregation concentration was linearly correlated with hydrophobicity. Gemini surfactants were more active than the parent USCLs, and they turned out to be selective antimicrobial agents with relatively low hemolytic and cytotoxic activities. Geminis with the L-cystine diamide spacer seem to be less cytotoxic than their L-lysine amide counterparts, but they exhibited lower antibiofilm and antimicrobial activities in serum. In some cases, geminis with branched fatty acid chains and N-terminal hydrophobic amino acid resides exhibited enhanced selectivity to pathogens over human cells.

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Characterization, surface properties and biological activity of new prepared cationic surfactants

Journal of Industrial and Engineering Chemistry ◽

10.1016/j.jiec.2013.08.010 ◽

2014 ◽

Vol 20 (4) ◽

pp. 1633-1640 ◽

Cited By ~ 29

Author(s):

Ismail Aiad ◽

Mohamed M. El-Sukkary ◽

E.A. Soliman ◽

Moshira Y. El-Awady ◽

Samy M. Shaban

Keyword(s):

Biological Activity ◽

Surface Properties ◽

Cationic Surfactants

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Development of Novel Thin Polycaprolactone (PCL)/Clay Nanocomposite Films with Antimicrobial Activity Promoted by the Study of Mechanical, Thermal, and Surface Properties

Polymers ◽

10.3390/polym13183193 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3193

Author(s):

Sylva Holešová ◽

Karla Čech Čech Barabaszová ◽

Marianna Hundáková ◽

Michaela Ščuková ◽

Kamila Hrabovská ◽

...

Keyword(s):

Antimicrobial Activity ◽

Surface Properties ◽

Food Packaging ◽

Synergistic Effects ◽

Nanocomposite Films ◽

Mechanical Resistance ◽

X Ray Diffraction ◽

Microbial Strains ◽

And Storage ◽

Structure Properties

Infection with pathogenic microorganisms is of great concern in many areas, especially in healthcare, but also in food packaging and storage, or in water purification systems. Antimicrobial polymer nanocomposites have gained great popularity in these areas. Therefore, this study focused on new approaches to develop thin antimicrobial films based on biodegradable polycaprolactone (PCL) with clay mineral natural vermiculite as a carrier for antimicrobial compounds, where the active organic antimicrobial component is antifungal ciclopirox olamine (CPX). For possible synergistic effects, a sample in combination with the inorganic antimicrobial active ingredient zinc oxide was also prepared. The structures of all the prepared samples were studied by X-ray diffraction, FTIR analysis and, predominantly, by SEM. The very different structure properties of the prepared nanofillers had a fundamental influence on the final structural arrangement of thin PCL nanocomposite films as well as on their mechanical, thermal, and surface properties. As sample PCL/ZnOVER_CPX possessed the best results for antimicrobial activity against examined microbial strains, the synergic effect of CPX and ZnO combination on antimicrobial activity was proved, but on the other hand, its mechanical resistance was the lowest.

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