肝细胞靶向性半乳糖－聚乙二醇－聚乙烯亚胺纳米基因载体的合成及其理化特性

BACKGROUND: Galactosylated poly(ethylene glycol)-graft-polyethylenimine (Gal-PEG-PEI) can be prepared as a nano-gene carrier of hepatocyte-targeting plasmid siRNA (psiRNA) through the glycosyl galactose of PEG-PEI. OBJECTIVE: To synthesize Gal-PEG-PEI and study its physicochemical characteristics, so as to provide references for further study on the transfection. DESIGN, TIME AND SETTING: The controlled experiments concerning about gene engineering were accomplished in Biomedical Engineering Centre of Sun Yat-sen University from October 2007 to June 2008. MATERIALS: The Gal-PEG-PEI was synthesized by two-step method. METHODS: The physicochemical characteristics of the Gal-PEG-PEI/psiRNA nanoparticles were measured by nanoparticle-zeta electric potential instrument, transmission electron microscopy, gel retardation and ethidium bromide binding assay. Cytotoxicity of Gal-PEG-PET was studied in cultured HepG2 cells by Cell Counting Kit-8 assay. The transfection experiments were performed with the Gal-PEG-PEI/psiRNA in HepG2 cells and the transfection efficiency was determined. MAIN OUTCOME MEASURES: The particle sizes and zeta potentials of Gal-PEG-PEI/psiRNA; Encapsulation ability; Cytotoxicity results; Transfection efficiency in HepG2 cells. RESULTS: The particle sizes of Gal-PEG-PEI/psiRNA decreased with increasing charge ratios of Gal-PEG-PEI to psiRNA and had a minimum value of 81.1 nm, while the zeta potentials were increased accordingly. Gal-PEG-PEI had a perfect ability to encapsulate psiRNA. Cytotoxicity of Gal-PEG-PEI was lower than that of PEI and transfection efficiency of Gal-PEG-PEI was higher than that of PEI without modification in HepG2 cells. CONCLUSION: The Gal-PEG-PEI nano-gene carrier can be synthesized successfully, it displays perfect ability to hepatocyte-targeting and little cytotoxicity.