Authors: Haisung Lee Dongkyung Sung Murugan Veerapandian Kyusik Yun SooWon Seo
Publish Date: 2011/02/22
Volume: 400, Issue: 2, Pages: 535-545
Abstract
The present paper reports the utilization of hybrid nanocomposite particles consisting of PEI25kPEG5k copolymer grafted silica nanoparticles SiO2NPs for enhanced cellular uptake and siRNA delivery Highresolution transmission electron microscopy and dynamic light scattering measurements ensured the average particle size of the final hybrid component as 45 nm core SiO2 28–30 nm and shell PEI25kPEG5k 12–15 nm Surface morphology from atomic force microscopy analysis showed the significant relationship between the particle size and shape 29Si and 13C crosspolarization–magic angle spinning solid state nuclear magnetic resonance NMR 1HNMR and Fourier transform infrared spectroscopy were used to obtain the relevant structural information such as Q3 silanol Q4 siloxane functional groups of SiO2NPs resonance shifts and bending vibrations of PEI25k –CH2–CH2–NH– and PEG5k –CH2–CH2–O– from copolymer nanoparticle Stable complexation of siRNA and nanocomposite particle wtwt was achieved from 15 to 115 ratio Nanocomposite particle N/P ratio and siRNA concentration determine the stability and knockdown efficiency of the PEI25kPEG5kgraftSiO2NPs–siRNA complexes It was shown that highly positively charged zeta potential +66 mV PEI25kPEG5kgraftSiO2NPs result in strong affinity with negatively charged siRNA Confocal microscopy showed intensified cellular uptake of siRNA into cytoplasm of A549 cancer cell utilized for in vitro study In conclusion the coherence graft density of copolymerSiO2NPs and siRNA concentration were found to strongly influence the stability and hence determine the knockdown efficiency of PEI25kPEG5kgraftSiO2NPs–siRNA complexesThis study was supported by a grant of the Ministry of Health and Welfare A040041 and Samsung Biomedical Research Institute Republic of Korea PB00021 We thank Ms Yunhee Kim for solid NMR spectroscopic analysis in NICEM SNU and Ms Youngshin Yoo for HRTEM analysis in SKKU
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