Modifying internal organization and surface morphology of siRNA lipoplexes by sodium alginate addition for efficient siRNA delivery

J Colloid Interface Sci. 2019 Mar 22;540:342-353. doi: 10.1016/j.jcis.2019.01.043. Epub 2019 Jan 14.


Vectorized small interfering RNAs (siRNAs) are widely used to induce specific mRNA degradation in the intracellular compartment of eukaryotic cells. Recently, we developed efficient cationic lipid-based siRNA vectors (siRNA lipoplexes or siLex) containing sodium alginate (Nalg-siLex) with superior efficiency and stability properties than siLex. In this study, we assessed the physicochemical and some biological properties of Nalg-siLex compared to siLex. While no significant differences in size, ζ potential and siRNA compaction were detected, the addition of sodium alginate modified the particle morphology, producing smoother and heterogeneous particles characterized by transmission electron microscopy. We also noted that Nalg-siLex have surface differences observed by X-ray photoelectron spectroscopy. These differences could arise from an internal reorganization of components induced by the addition of sodium alginate, that is indicated by Small-Angle X-ray Scattering results. Moreover, Nalg-siLex did not trigger significant hepatotoxicity nor inflammatory cytokine secretion compared to siLex. Taken together these results suggest that sodium alginate played a key role by structuring and reinforcing siRNA lipoplexes, leading to more stable and efficient delivery vector.

Keywords: Anionic polymer; Cationic lipid; Delivery system; Nanoparticle; RNA interference; Structure.

MeSH terms

  • Alginates / chemistry*
  • Animals
  • Cations / chemistry
  • Cell Line
  • Female
  • Gene Transfer Techniques*
  • Lipids / chemistry
  • Liposomes / chemistry*
  • Mice, Inbred C57BL
  • Particle Size
  • RNA Interference*
  • RNA, Small Interfering / administration & dosage*
  • RNA, Small Interfering / chemistry
  • RNA, Small Interfering / genetics
  • Static Electricity


  • Alginates
  • Cations
  • Lipids
  • Liposomes
  • RNA, Small Interfering