An Extrusion-Free and Scalable siRNA/Liposome Preparation for Efficient Encapsulation of siRNA by Simple Mixing

M.K. Lee
Korea Res. Inst. Biosci. Biotech. (KRIBB), KR

Keywords: siRNAencapsulation, liposome preparation, delivery

Summary:

We prepared liposomes encapsulating siRNA by simply discontinuous mixing of lipids in ethanol-ether-water mixture and acidic siRNA solution without any special equipment. By controlling lipid solvent and lipid compostions we prepared with less than average 150 nm particle sizes, 0.1-0.2 polydispersity and more than 85% encapsulation efficiency. Simultaneous increase of lipid and siRNA concentrations did not alter the liposome properties.The siRNA/liposome particles protected siRNA degradation from RNase A digestion, and were proved quite stable under storage in refrigerator. The siRNA/liposomes showed some nonspecific cell penetration, and labeling of a cell penetrating peptide enhanced cell penetration of liposomes. The target-specific enhancement of liposome penetration into non-small cell lung cancer cells was also observed when coupling of anti-EGFR Fab’ on liposomes. The Fab’ labeled siRNA/liposome particles also displayed gene silencing acitivty in cells. The extrusion-free and scalable method without use of any special equipment will be easily applicable for commercial production of siRNA/liposome particles.