Cardiolipin-Based Lipopolyplex Platform for the Delivery of Diverse Nucleic Acids into Gram-Negative Bacteria.

Federico Perche,Chantal Pichon,Jean-Marc Malinge,Tristan Montier,Tony Le Gall

doi:10.3390/ph12020081

Abstract

Antibiotic resistance is a growing public health concern. Because only a few novel classes of antibiotics have been developed in the last 40 years, such as the class of oxazolidinones, new antibacterial strategies are urgently needed (Coates, A.R. et al., 2011). Nucleic acid-based antibiotics are a new type of antimicrobials. However, free nucleic acids cannot spontaneously cross the bacterial cell wall and membrane; consequently, their intracellular delivery into bacteria needs to be assisted. Here, we introduce an original lipopolyplex system named liposome polymer nucleic acid (LPN), capable of versatile nucleic acid delivery into bacteria. We characterized LPN formed with significant therapeutic nucleic acids: 11 nt antisense single-stranded (ss) DNA and double-stranded (ds) DNA of 15 and 95 base pairs (bp), 9 kbp plasmid DNA (pDNA), and 1000 nt ssRNA. All these complexes were efficiently internalized by two different bacterial species, i.e., Escherichia coli and Pseudomonas aeruginosa, as shown by flow cytometry. Consistent with intracellular delivery, LPN prepared with an antisense oligonucleotide and directed against an essential gene, induced specific and important bacterial growth inhibition likely leading to a bactericidal effect. Our findings indicate that LPN is a versatile platform for efficient delivery of diverse nucleic acids into Gram-negative bacteria.

Highlights

Antibiotic resistance is becoming a threat to global human health both in high- and low-income countries, resulting in a growing number of infections and increased mortality, especially due to Gram-negative bacteria [1,2,3]
We characterized liposome polymer nucleic acid (LPN) formed with significant therapeutic nucleic acids: 11 nt antisense single-stranded DNA and double-stranded DNA of 15 and 95 base pairs, 9 kbp plasmid DNA, and 1000 nt ssRNA
Consistent with intracellular delivery, LPN prepared with an antisense oligonucleotide and directed against an essential gene, induced specific and important bacterial growth inhibition likely leading to a bactericidal effect

Summary

Introduction

Antibiotic resistance is becoming a threat to global human health both in high- and low-income countries, resulting in a growing number of infections and increased mortality, especially due to Gram-negative bacteria [1,2,3]. The concept of using small nucleic acids as therapeutics to fight antibiotic resistant bacteria is very promising. Different types of strategies can be developed depending on the nature, form, and length of the nucleic acid to be delivered. Aptamers and CRISPR-Cas nucleases have recently emerged as potential antibacterial strategies [6,7,8]. Functional studies on non-coding bacterial small RNAs have recently highlighted their role in the regulation of genes associated with multiresistance [9] and opened the way to exploit ssRNA molecules as potential antimicrobial molecules [10]. RNA can be delivered or produced in bacteria by pDNA used as expression vector [11]

Methods

Results

Conclusion