Polyion complex micelles from plasmid DNA and poly(ethylene glycol)-poly(L-lysine) block copolymer as serum-tolerable polyplex system: physicochemical properties of micelles relevant to gene transfection efficiency
Polyion complex micelles from plasmid DNA and poly(ethylene glycol)-poly(L-lysine) block copolymer as serum-tolerable polyplex system: physicochemical properties of micelles relevant to gene transfection efficiency
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DOI：
10.1016/s0142-9612(03)00347-8
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发表时间：
2003-11-01
期刊：
影响因子：
14
通讯作者：
Kataoka, K
中科院分区：
文献类型：
--
作者：
Itaka, K;Yamauchi, K;Kataoka, K
从物理化学的角度研究了由聚乙二醇-聚赖氨酸（PEG-PLL）嵌段共聚物和质粒DNA（pDNA）组成的聚离子复合物（PIC）胶束载体系统的结构特征，以了解PIC胶束载体系统在含血清介质中的实际基因转染效果。系统中PEG-PLL中的赖氨酸单元与pDNA的磷酸盐单元的残留比率（r）显著影响从动态光散射评估的PIC胶束的尺寸，随着r大于或等于1.0的区域的r值的增加，从约120 nm减小到80 nm。复合物的zeta电位在同一区域内随r的增加而略有增加，但保持一个非常小的绝对值，并在r接近2.0时稳定在几mV。这些结果表明，胶束最有可能采取核-壳结构，其中密集的PEG栅栏围绕PIC核以区室化浓缩的pDNA。此外，在r大于或等于1的区域中增加r值诱导在r = 1.0处形成的化学计量络合物重排为由过量嵌段共聚物组成的非化学计量络合物。由通过静态光散射测量确定的表观胶束分子量估计胶束中pDNA和嵌段共聚物的缔合数，表明在r = 2.0时，单个pDNA分子掺入由PEG（M-w = 12，000 g/mol）-PLL（PLL链段的聚合度：48）（12-48）嵌段共聚物制备的每个胶束中。这些12-48/pDNA胶束显示出与对培养的293细胞的脂质转染相当的基因表达，尽管在转染培养基中需要100 μ m氯喹。值得注意的是，即使在血清的存在下，PIC胶束也实现了明显的细胞缔合以获得高基因表达，这与血清存在下lipoplex系统的基因表达急剧下降形成鲜明对比。病毒相当的大小（类似于100 nm）与血清耐受性的PIC胶束的性质确实表明其作为用于临床基因治疗的非病毒基因载体系统的有前途的可行性。(C)2003 Elsevier Ltd.保留所有权利。
Polyion complex (PIC) micelles composed of the poly(ethylene glycol)-poly(L-lysine) (PEG-PLL) block copolymer and plasmid DNA (pDNA) were investigated in this study from a physicochemical viewpoint to get insight into the structural feature of the PIC micellar vector system to show practical gene transfection efficacy particularly under serum-containing medium. The residual ratio (r) of the lysine units in PEG-PLL to the phosphate units of pDNA in the system significantly affects the size of the PIC micelles evaluated from dynamic light scattering, being decreased from approximately 120 to 80 nm with an increase in the r value for the region with r greater than or equal to 1.0. The zeta potential of the complexes slightly increased with r in the same region, yet maintained a very small absolute value and leveled off to a few mV at r approximate to 2.0. These results suggest that the micelles are most likely to take the core-shell structure with dense PEG palisades surrounding the PIC core to compartmentalize the condensed pDNA. Furthermore, an increasing r value in the region of r greater than or equal to 1 induces a rearrangement of the stoichiometric complex formed at r = 1.0 to the non-stoichiometric complex composed of the excess block copolymer. The association number of pDNA and the block copolymer in the micelle was estimated from the apparent micellar molecular weight determined by static light scattering measurements, indicating that a single pDNA molecule was incorporated in each of the micelles prepared from the PEG (M-w = 12,000 g/mol)-PLL (polymerization degree of PLL segment: 48) (12-48) block copolymer at r = 2.0. These 12-48/pDNA micelles showed a gene expression comparable to the lipofection toward cultured 293 cells, though 100 mum chloroquine was required in the transfection medium. Notably, even in the presence of serum, the PIC micelles achieved appreciable cellular association to attain a high gene expression, which is in sharp contrast with the drastic decrease in the gene expression for lipoplex system in the presence of serum. A virus-comparable size (similar to 100 nm) with a serum-tolerable property of the PIC micelles indeed suggests their promising feasibility as non-viral gene-vector systems used for clinical gene therapy. (C) 2003 Elsevier Ltd. All rights reserved.