Loop-armed DNA tetrahedron nanoparticles for delivering antisense oligos
into bacteria
Abstract
Background and Purpose Antisense oligonucleotides (ASOs) based
technology is considered a potential strategy against
antibiotic-resistant bacteria; however, a major obstacle to the
application of ASOs is how to deliver them into bacteria effectively.
DNA tetrahedra (Td) is an emerging carrier for delivering ASOs into
eukaryotes. However, there is limited information about Td used for
bacteria. In this research, we investigated the uptake features of Td
and the impact of linkage modes between ASOs and Td on gene-inhibition
efficiency in bacteria. Experimental Approach Different bacterial
strains were incubated with Td, and the bacterial uptake efficiency of
Td was measured by flow cytometry and confocal microscopy. Then we
designed two types of linkages modes between Td and ASOs targeting gfp,
encoding green fluorescent protein , or acpP, encoding the acyl carrier
protein, and assessed the efficiency of delivery by flow cytometry and
gene knockdown by RT-PCR, colony counting and confocal microscopy in E.
coli. Key results Td was more likely to adhere to bacterial membranes,
with moderate ability to penetrate into the bacteria. Strikingly,
Lipofectamine 2000 (LP2000) in a 0.125 μL/μg ratio to Td helped Td
penetrate into bacteria, but had no apparent effect on linear DNA in the
same concentration. Furthermore, linkage modes between ASOs and Td
influenced gene-knockdown efficiency. Looped structure of ASOs linked to
one side of the Td exhibited better gene-knockdown efficiency than the
overhung structure. Conclusion and Implications This study established
an effective antisense delivery system based on loop-armed Td, which
open opportunities for developing antisense antibiotics.