Non-viral vector has been widely used to deliver siRNA and pDNA. MicroRNA (miRNA) was a single-stranded RNA and unstable in vivo. The aim of this work was to investigate PEG grafted chitosan as a potential non-viral vector for miRNA delivery. In our study, chitosan was modified with mPEG and nanoparticles (NPs) were fabricated by ionic gelation method. The degree of substitution (DS) of mPEG moiety was 6.12%. The particle size and zeta potential were 167.6±4.5 nm and +23.5±0.4 mV, respectively. Gel retardation assay indicated that hsa-miR-15a was encapsulated completely by mPEG-g-Chitosan. NPs protected miRNA from nucleases degradation. Cytotoxicity studies indicated that mPEG-g-CS polymer was a safe carrier with low cytotoxicity compared with PEI and Hiperfect Transfection Reagent. The result of in vitro experiment showed that the fluorescence encapsulated in NPs was accumulated in the cells and the cellular uptake efficiency in vitro was 5.98±0.95% after 48 h incubation, and it was increased about 2.31±0.25% and 4.45±0.25% when compared with the free miR-15a group and blank NPs respectively. The in vitro cellular uptake efficiency of NPs encapsulated has-miRNA was increasing from 1.87±0.15% to 45.27±3.67% as the hsa-miR-15a concentration was increasing from 36.25 nM to 580 nM. These data suggest that the PEG grafted chitosan NPs are efficient vector for miRNA delivery.
Wang Mingjuan Zhang He Lu Ying Zou Hao Chen Yan Yu Yuan Sun Duxin Zhang Guoqing Zhong Yanqiang
Department of Pharmaceutical Science, College of Pharmacy, Second Military Medical University,Shangh Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michi Department of Pharmacy, East Hospital of Hepatobiliary Surgery, Second Military Medical University,S Department of Pharmaceutical Science, College of Pharmacy, Second Military Medical University, Shang