Supramolecular Assemblies for the Cytoplasmic Delivery of Antisense Oligodeoxynucleotide:  Polyion Complex (PIC) Micelles Based on Poly(ethylene glycol)-SS-Oligodeoxynucleotide Conjugate

• Published in: Biomacromolecules 2005-09, Vol.6 (5), p.2449-2454
• Main Authors: Oishi, Motoi, Hayama, Tetsuya, Akiyama, Yoshitsugu, Takae, Seiji, Harada, Atsushi, Yamasaki, Yuichi, Nagatsugi, Fumi, Sasaki, Shigeki, Nagasaki, Yukio, Kataoka, Kazunori
• Format: Article
• Language: English
• Subjects: Applied sciences; Biocompatible Materials - chemistry; Biological and medical sciences; Carcinoma, Hepatocellular - metabolism; Cations; Cell Line, Tumor; Chemical modifications; Chemical reactions and properties; Chromatography; Cytoplasm - metabolism; Disulfides - chemistry; Exact sciences and technology; General pharmacology; Genes, Reporter; Humans; Hydrogen-Ion Concentration; Ions; Luciferases - metabolism; Medical sciences; Micelles; Models, Biological; Models, Chemical; Oligonucleotides, Antisense - chemistry; Organic polymers; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Physicochemistry of polymers; Polyethylene Glycols - chemistry; Polylysine - chemistry
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm050370l

A novel cytoplasmic delivery system of antisense oligodeoxynucleotide (asODN) was developed by assembling a PEG-asODN conjugate with disulfide linkage (smart linkage) (PEG-SS-asODN) into polyion complex (PIC) micelles through the complexation with branched poly(ethylenimine) (B-PEI). The PIC micelle thus prepared showed a significant antisense effect against luciferase gene expression in HuH-7 cells, far more efficient than nonmicelle systems (asODN and PEG-SS-asODN in free form) and PIC micelle encapsulating the conjugate without the disulfide linkage. Use of poly(l-lysine) (PLL) instead of the B-PEI for PIC micellization led to a substantial decrease in the antisense effect. These results indicate that the PIC micelles formulated from PEG-SS-asODN conjugate and B-PEI is successfully transported from the endosomal compartment into the cytoplasm by the buffering effect of the B-PEI, releasing hundreds of active asODN molecules via cleavage of the disulfide linkage into the cellular interior, responding to a high glutathione concentration in the cytoplasmic compartment. Furthermore, the type of smart linkage (glutathione-sensitive SS linkage vs pH-sensitive linkage) in the conjugates substantially affected the antisense effect of the PIC micelles, depending on the nature of the counter polycation (B-PEI vs PLL).