Synthesis and formulations of lipid aminoglycoside conjugates: nanoparticles for efficient gene and sirna delivery

Objective: To design and evaluate efficient lipid-aminoglycoside conjugates for the delivery of genes for gene therapy, and also for the delivery of siRNA molecules to knock down gene expression in mammalian cells Methods: 3β-[5"-(aminoethanethiol)-neomycin B] carbamoyl cholesterol (NeoChol) was synthesized. The abilities of this novel compound to condense DNA and to form nanoparticles were studied using ethidium bromide fluorescence quenching and nanoparticle characterization techniques. Transfection efficiency was studied in FEK4 primary skin cells and in an immortalized cancer cell line (HtTA), and compared with the non-liposomal transfection formulation Lipogen, N,N-dioleoyl-1,12-diamino-4,9-diazadodecane. Also, the abilities of this compound to condense siRNA and to form nanoparticles were studied using a Ribo Green intercalation assay and its abilities to deliver siRNA into cells were studied in FEK4 and HtTA cells using fluorescein-labelled Label IT® RNAi Delivery Control, a sequenced 21-mer from Mirus. Results: We show efficient pEGFP and siRNA formulation and delivery to primary skin (FEK4) and cancer cell lines (HtTA). Conclusion: Synthetic cationic lipid, a conjugate derived from neomycin B antibiotic and cholesterol is highly efficient for in vitro delivery of DNA and fluorescent siRNA.