Coaxial Synthesis of PEI-Based Nanocarriers of Encapsulated RNA-Therapeutics to Specifically Target Muscle Cells

Biomolecules. 2022 Jul 22;12(8):1012. doi: 10.3390/biom12081012.

Abstract

In this work, we performed a methodological comparative analysis to synthesize polyethyleneimine (PEI) nanoparticles using (i) conventional nanoprecipitation (NP), (ii) electrospraying (ES), and (iii) coaxial electrospraying (CA). The nanoparticles transported antisense oligonucleotides (ASOs), either encapsulated (CA nanocomplexes) or electrostatically bound externally (NP and ES nanocomplexes). After synthesis, the PEI/ASO nanoconjugates were functionalized with a muscle-specific RNA aptamer. Using this combinatorial formulation methodology, we obtained nanocomplexes that were further used as nanocarriers for the delivery of RNA therapeutics (ASO), specifically into muscle cells. In particular, we performed a detailed confocal microscopy-based comparative study to analyze the overall transfection efficiency, the cell-to-cell homogeneity, and the mean fluorescence intensity per cell of micron-sized domains enriched with the nanocomplexes. Furthermore, using high-magnification electron microscopy, we were able to describe, in detail, the ultrastructural basis of the cellular uptake and intracellular trafficking of nanocomplexes by the clathrin-independent endocytic pathway. Our results are a clear demonstration that coaxial electrospraying is a promising methodology for the synthesis of therapeutic nanoparticle-based carriers. Some of the principal features that the nanoparticles synthesized by coaxial electrospraying exhibit are efficient RNA-based drug encapsulation, increased nanoparticle surface availability for aptamer functionalization, a high transfection efficiency, and hyperactivation of the endocytosis and early/late endosome route as the main intracellular uptake mechanism.

Keywords: Nusinersen; RNA-therapeutics; aptamers; coaxial electrospraying; muscle-specific therapy; nanoparticle; polyethylenimine; spinal muscular atrophy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Muscle Cells
  • Nanoconjugates
  • Nanoparticles* / chemistry
  • Polyethyleneimine* / chemistry
  • RNA
  • Transfection

Substances

  • Nanoconjugates
  • RNA
  • Polyethyleneimine

Grants and funding

This work was supported by grant PID2021-126820OB-I00 funded by MCIN/AEI/10.13039/501100011033 to O.T. and J.C.R.-R.; grant 202005-31 funded by Fundació La Marató de TV3 to O.T.; and grants PID2019-105827RB-I00 and PCI2018-092929 (5th EIG-Concert Japan joint call) funded by MCIN/AEI/10.13039/501100011033 to A.U. and N.D.