Natural polyphenol assisted delivery of single-strand oligonucleotides by cationic polymers

Wanwan Shen,Yiwen Li,Ruojun Wang,Qianqian Fan,Yiyun Cheng

doi:10.1038/s41434-020-0151-y

Abstract

Single-strand oligonucleotides provide promising potential as new therapeutics towards various diseases. However, the efficient delivery of oligonucleotide therapeutics is still challenging due to their susceptibility to nuclease degradation and the lack of effective carriers for condensation. In this study, we reported the use of natural polyphenol to facilitate the condensation of single-strand oligonucleotides by cationic polymers. Green tea catechin complexed with single-strand oligonucleotides to form anionic nanoparticles, which were further coated by low molecular weight cationic polymers to increase their cell internalization. The resulting core-shell structured nanoparticles, so-called green nanoparticles (GNPs), showed improved cargo stability, and achieved high efficiency in the delivery of several types of single-strand oligonucleotides including antisense oligonucleotides, anti-miRNA, and DNAzyme. This study provides a facile strategy for the efficient delivery of single-strand oligonucleotides.

Highlights

Oligonucleotide therapeutics including antisense oligonucleotides (ASOs), splice-switching oligonucleotides, steric blockers, aptamers, small Interfering RNA, microRNA, and other subtypes have shown enormous potential in the treatment of various diseases [1,2,3]
We first investigated the formation of epigallocatechin gallate (EGCG)/single-strand oligonucleotide ASO complexes using DLS and TEM
The fluorescence resonance energy transfer (FRET) signals increased with increasing EGCG/PLL to ASO weight ratios, and this result confirmed the formation of PLL-coated EGCG/ASO nanoparticles (GNPs: the PLL/ EGCG/ASO weight ratio is 5:5:1, 10:10:1 and 20:20:1, respectively for green nanoparticles (GNPs) 1–3) in the solutions

Summary

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Oligonucleotide therapeutics including antisense oligonucleotides (ASOs), splice-switching oligonucleotides, steric blockers, aptamers, small Interfering RNA (siRNA), microRNA (miRNA), and other subtypes have shown enormous potential in the treatment of various diseases [1,2,3]. Chemically modified single-strand oligonucleotides usually possess relatively low membrane permeability, and limited stability during the long-term therapy [12] To address those issues, the single-strand oligonucleotides were either conjugated with functional ligands, polymers, and nanoparticles [13, 14], or complexed with cationic polymers, liposomes, and nanomaterials [15] to increase their cell internalization, stability, and transfection efficiency. Cationic polymers with various chemical structures have widely used for intracellular delivery of biomolecules such as genes and proteins [16,17,18,19,20,21] These materials have been usually puzzled by their unsatisfied correlations between transfection efficiency and cytotoxicity [22,23,24]. Since poor stability is the major challenge for single-strand oligonucleotides in gene therapy and most oligonucleotide drugs possess similar physicochemical properties, we hypothesized that this GNPs strategy may be applicable for the delivery of single-strand oligonucleotides such as ASO, miRNAs, and DNAzymes (Fig. 1)

Materials and methods

Results and discussion

Compliance with ethical standards