Efficient Packaging of Plasmid DNA Using a pH Sensitive Cationic Lipid for Delivery to Hepatocytes

Abstract

Plasmid DNA (pDNA) is expected to be a new class of medicine for treating currently incurable diseases. To deliver these nucleic acids, we developed a liposomal delivery system we have called a multifunctional envelope-type nano device (MEND). In this report, we demonstrate that a MEND containing a pH-sensitive cationic lipid, YSK05 (YSK-MEND), efficiently delivered pDNA via systemic injection, and that its expression was highly dependent on the encapsulation state of the pDNA. In the preparation, the pH, ionic strength, and sodium chloride (NaCl) concentration of the lipid/pDNA mixture strongly affected the encapsulation efficiency of pDNA. Additionally, the transgene expression of luciferase in the liver by the injected YSK-MEND was dependent on the encapsulation state of pDNA rather than the nature of the YSK-MEND. Confocal laser scanning microscopy findings revealed that injection of the YSK-MEND led to homogenous gene expression in the liver compared to injection via the hydrodynamic tail vein (HTV). Concerning the safety of the YSK-MEND, a transient increase in the activity of liver enzymes was observed. However, no significant adverse events were observed. Taken together, the YSK-MEND represents a potentially attractive therapy for the treatment of various hepatic diseases.

Synergism between a cell penetrating peptide and a pH-sensitive cationic lipid in efficient gene delivery based on double-coated nanoparticles

“…We recently developed a pH-sensitive cationic lipid (referred to as YSK05) that is neutral at physiological pH but acquires a positive charge in acidic conditions [20]. YSK05 can condense and protect pDNA or siRNA by incorporating them into stable lipid nanoparticles (NPs) owing to its positive charge when used in an acidic medium [21][22][23][24][25]. Subsequent neutralization of the medium produces NPs with a neutral charge, which is advantageous for systemic administration where non-specific interactions and unwanted aggregation in the circulation can be avoided.…”

“…Subsequent neutralization of the medium produces NPs with a neutral charge, which is advantageous for systemic administration where non-specific interactions and unwanted aggregation in the circulation can be avoided. In mice, YSK05 has been shown to mediate efficient pDNA delivery, resulting in efficient gene expression in hepatocytes after in vivo administration [25]. In addition, siRNA encapsulated in YSK05 NPs also resulted in efficient gene silencing in liver tissues in mice [23,24].…”

“…Evaluation of endosomal escape of different NPs Effect of chloroquine on transfection activities of different NPs4. DISCUSSIONYSK05, a pH-sensitive cationic lipid, efficiently delivered pDNA and siRNA to the cytosol of liver cells after systemic administration[20][21][22][23][24][25]. This lipid contains a pH-sensitive group (Nmethylpiperidine) and two unsaturated carbon chains.…”

Understanding and optimising the transfection of lipopolyplexes formulated in saline: the effects of peptide and serum

“…Finally, increasing NaCl concentration has previously been shown to lead to an increase in pDNA encapsulation during lipoplex formulation. 79,80 For the lipopolyplexes prepared in the present study to be effective transfection agents in serum, they must also form stable nanocomplexes that protect the pDNA from enzymatic degradation. Our agarose gel electrophoresis results (Fig.…”

“…Finally, increasing NaCl concentration has previously been shown to lead to an increase in pDNA encapsulation during lipoplex formulation. 79,80…”