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Volume 171, Issue 5

-linolenic acid-modified liposomes associate with and modulate antibiotic activity against Open Access

Graphical Abstract

Graphical Abstract

Summary of key findings: (1) Linolenic acid (αLA) was effective in killing , but not or . (2) Liposomes encapsulating αLA and amoxicillin had greatly enhanced bactericidal activity against , compared to liposomes containing just one of these components, or amoxicillin in solution. (3) Liposomes encapsulating αLA rapidly bound to at higher densities compared to liposomes without αLA. Created in BioRender. Robinson, K. (2025) a31l841 https://BioRender.com.

Abstract

Fatty acids have antimicrobial activity against a wide range of bacteria. We therefore aimed to incorporate omega-3 unsaturated -linolenic acid (αLA) into the membrane of antibiotic-loaded liposomes to create a system with dual antibacterial activity against . Liposomes containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, cholesterol, sphingomyelin and the far-red fluorescent DiD label, with varying content of αLA (mol% to total lipid), were fabricated using the thin film evaporation method and hydrated with PBS or amoxicillin solution. The liposomes were characterized for αLA and amoxicillin content, particle size, membrane fluidity and permeability, prior to their addition to cultures of strains and clinical isolates. αLA-modified liposomes enhanced the antibacterial action of amoxicillin against , as determined using a viable count method. The liposomal formulation achieved a 3-log reduction in bacterial density, compared to a 1.5- to 2-log reduction by amoxicillin in solution. The application of imaging cytometry revealed a significantly increased association of αLA-modified liposomes with cells, compared to non-αLA control liposomes. In conclusion, this study demonstrated, for the first time, that the incorporation of αLA increased the attraction of the liposomes to and increased antibiotic potency. This suggests that αLA incorporation into liposomes may not only act as an antimicrobial, but also as a potential targeting strategy.

  • Received:
  • Accepted:
  • Published Online:
Keyword(s): antibiotics , fatty acids , Helicobacter pylori , linolenic acid and liposomes
Funding
This study was supported by the:
  • NIHR Nottingham Biomedical Research Centre (Award NIHR203310)
    • Principal Award Recipient: NotApplicable
  • Wellcome Trust (Award 108876/Z/15/Z)
    • Principal Award Recipient: NotApplicable
© 2025 The Authors
  • This is an open-access article distributed under the terms of the Creative Commons Attribution License. This article was made open access via a Publish and Read agreement between the Microbiology Society and the corresponding author’s institution.
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2025-05-30
2026-01-19

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/content/journal/micro/10.1099/mic.0.001562
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Alpha-linolenic acid-modified liposomes associate with and modulate antibiotic activity against Helicobacter pylori
Microbiology 171, 001562 (2025); https://doi.org/10.1099/mic.0.001562
/content/journal/micro/10.1099/mic.0.001562
/content/journal/micro/10.1099/mic.0.001562
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