A galactose-functionalized dendritic siRNA-nanovector to potentiate hepatitis C inhibition in liver cells

Abstract

A RNAi based antiviral strategy holds the promise to impede hepatitis C viral (HCV) infection overcoming the problem of emergence of drug resistant variants, usually encountered in the interferon free direct-acting antiviral therapy. Targeted delivery of siRNA helps minimize adverse 'off-target' effects and maximize the efficacy of therapeutic response. Herein, we report the delivery of siRNA against the conserved 5'-untranslated region (UTR) of HCV RNA using a liver-targeted dendritic nano-vector functionalized with a galactopyranoside ligand (DG). Physico-chemical characterization revealed finer details of complexation of DG with siRNA, whereas molecular dynamic simulations demonstrated sugar moieties projecting "out" in the complex. Preferential delivery of siRNA to the liver was achieved through a highly specific ligand-receptor interaction between dendritic galactose and the asialoglycoprotein receptor. The siRNA-DG complex exhibited perinuclear localization in liver cells and co-localization with viral proteins. The histopathological studies showed the systemic tolerance and biocompatibility of DG. Further, whole body imaging and immunohistochemistry studies confirmed the preferential delivery of the nucleic acid to mice liver. Significant decrease in HCV RNA levels (up to 75%) was achieved in HCV subgenomic replicon and full length HCV-JFH1 infectious cell culture systems. The multidisciplinary approach provides the 'proof of concept' for restricted delivery of therapeutic siRNAs using a target oriented dendritic nano-vector.

Application of Dendrimers for the Treatment of Infectious Diseases

“…Immunological assays indicated that the immunogenicity of the conjugated HBsAg was enhanced when compared to HBsAg alone [ 182 ]. Lakshminarayanan reported liver-targeted dendritic nano-vector functionalized with a galactopyranoside ligand for the delivery of siRNA [ 161 ] ( Table 2 ). Targeted delivery of siRNA to the liver was achieved via a highly specific ligand—receptor interaction between dendritic galactose and the asialoglycoprotein receptor.…”

“…A decrease in HCV RNA levels of 75% was achieved in HCV-JFH1 infectious cell culture systems. The targeted release mechanism of the formulation revealed it is a potential therapeutic for the treatment of infections in the liver such as hepatitis [ 161 ].…”

Hepatitis C virus management: potential impact of nanotechnology

“…siRNA encounters some problems including low cellular uptake, rapid degradation by nucleases as well as inadequate blood stability [56], so many studies have used nanoparticles to solve these problems and to minimize the adverse effect of “off-targeting”. Lakshminarayanan et al used a galactose functionalized dendritic nanovector (DG) as a carrier for siRNA against the 5' untranslated region of the HCV genome [18]. The siRNA-DG formed a stable complex that had target-oriented delivery through the interaction between its free galactose residues and asialoglycoprotein receptor.…”

“…The delivered siRNA localized in the perinuclear region (the site of HCV replication) in which NS3 and NS5b viral proteins are co-localized. There was a significant inhibition in JFH1 RNA titer, so this new siRNA-DG nanovector is a promising option for HCV therapeutics [18]. …”

“…Nanomaterials can also target specific organs, tissues, or even cells [17]. The introduction of anti-HCV targeted delivery using nanovectors, which carry the drug to its site of action, helps minimize the side effects of non-specific targeting and enhances therapeutic efficacy [18]. The aim of this review is to summarize new regimens for HCV treatment and the possible role of nanotechnology as a targeted delivery system that increases bioavailability and sustained drug release while decreasing severe side effects during HCV treatment.…”