Evaluation of liver specific ionizable lipid nanocarrier in the delivery of siRNA.

Hepcidin, a key regulator of iron homeostasis, has been implicated in the pathogenesis of various iron-related diseases. Although small interfering RNA (siRNA) are potent to modulate the expression of hepcidin, their bioavailability remains a major issue. The β-galactopyranoside-conjugated liposomes (GAL-liposome) targeting liver synthesized hepcidin were prepared by thin lipid film hydration method to encapsulate siRNA and the conjugation of β-galactopyranoside to the lipid nanocarrier was achieved by covalent chemistry. The prepared siRNA loaded GAL-lip were spherical with around 50 nm radius in size as observed by HR-TEM. The zeta potential and polydispersity index of the prepared liposomes were - 19.9 ± 0.96 mV and 0.44 ± 0.05, respectively. The encapsulation efficiency as determined by dialysis bag method was around 91.76 ± 1.74%. The cell viability and cellular uptake analysis was examined in HepG2 cells by MTT assay and flow cytometry, respectively. The stability and cumulative release of siRNA was also assessed. The hepcidin mRNA expression on administration of siRNA loaded GAL-lip was determined in HepG2 cells and in lipopolysaccharide-induced mice model followed by examining itsin vivo biodistribution by fluorescence microscopy. The results suggested thatsiRNA loaded GAL-lip reduced the hepcidin levels, thus, highlighting a novel ligand conjugated ionizable lipid-based nanocarrier for inducing RNA interference.