Novel siRNA Delivery System Using a Ternary Polymer Complex with Strong Silencing Effect and No Cytotoxicity.

Novel siRNA Delivery System Using a Ternary Polymer Complex with Strong Silencing Effect and No Cytotoxicity. Biol Pharm Bull. 2014;37(8):1274-81 Authors: Kodama Y, Shiokawa Y, Nakamura T, Kurosaki T, Aki K, Nakagawa H, Muro T, Kitahara T, Higuchi N, Sasaki H Abstract We developed a novel small interfering RNA (siRNA) delivery system using a ternary complex with polyethyleneimine (PEI) and γ-polyglutamic acid (γ-PGA), which showed silencing effect and no cytotoxicity. The binary complexes of siRNA with PEI were approximately 73-102 nm in particle size and 45-52 mV in ζ-potential. The silencing effect of siRNA/PEI complexes increased with an increase of PEI, and siRNA/PEI complexes with a charge ratio greater than 16 showed significant luciferase knockdown in a mouse colon carcinoma cell line regularly expressing luciferase (Colon26/Luc cells). However, strong cytotoxicity and blood agglutination were observed in the siRNA/Lipofectamine complex and siRNA/PEI16 complex. Recharging cationic complexes with an anionic compound was reported to be a promising method for overcoming these toxicities. We therefore prepared ternary complexes of siRNA with PEI (charge ratio 16) by the addition of γ-PGA to reduce cytotoxicity and deliver siRNA. As expected, the cytotoxicity of the ternary complexes decreased with an increase of γ-PGA content, which decreased the ζ-potential of the complexes. A strong silencing effect comparable to siRNA...
Source: Biological and Pharmaceutical Bulletin - Category: Drugs & Pharmacology Authors: Tags: Biol Pharm Bull Source Type: research