Interaction of polycationic polymers with supported lipid bilayers and cells: Nanoscale hole formation and enhanced membrane permeability
Interaction of polycationic polymers with supported lipid bilayers and cells: Nanoscale hole formation and enhanced membrane permeability
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DOI：
10.1021/bc060077y
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发表时间：
2006-05-17
影响因子：
4.7
通讯作者：
Holl, Mark M. Banaszak
中科院分区：
文献类型：
--
作者：
Hong, Seungpyo;Leroueil, Pascale R.;Holl, Mark M. Banaszak
利用原子力显微镜（AFM）、胞浆酶测定、激光共聚焦扫描显微镜（CLSM）和荧光激活细胞分选仪（FACS）研究了聚阳离子聚合物与支撑的1，2-二肉豆蔻酰-sn-甘油-3-磷酸胆碱（DMPC）脂质双层和活细胞膜（KB和Rat 2）的相互作用。聚阳离子聚合物聚-L-赖氨酸（PLL）、聚乙烯亚胺（PEI）和二乙氨基乙基-葡聚糖（DEAE-DEX）以及球形聚（酰胺基胺）（PAMAM）树枝状聚合物由于其对于基因和药物递送的重要性而被采用。AFM研究表明，在1-3 μ g/mL的浓度范围内，所有的聚阳离子聚合物引起在支撑的DMPC双层中预先存在的缺陷的形成和/或扩展。作为对比，含羟基的中性线性聚（乙二醇）（PEG）和聚（乙烯醇）（PVA）不诱导孔形成或扩大在相同的浓度范围内的预先存在的缺陷的大小。所有测试的聚合物在高达12 μ g/mL的浓度下对KB或Rat 2细胞没有毒性（XTT测定）。然而，在6-12 μ g/mL的浓度范围内，释放了大量的胞质酶乳酸脱氢酶（LDH）和荧光素酶（LUC）。PEI在其链上具有最大密度的带电基团，显示出膜渗透性的最显著增加。此外，用聚阳离子聚合物处理允许小染料分子碘化丙啶（PI）和荧光素（FITC）扩散进出细胞。CLSM图像还显示用FITC染料标记的PLL的内化。相比之下，使用中性线性聚合物PEG和PVA的膜渗透性的控制显示出显著更少的LDH和LUC泄漏，并且没有增强的染料扩散。总之，这些数据与聚阳离子聚合物诱导活细胞中瞬时纳米级孔的形成并且这些孔允许大大增强材料跨细胞膜的交换的假设一致。
Interactions of polycationic polymers with supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayers and live cell membranes (KB and Rat2) have been investigated using atomic force microscopy (AFM), cytosolic enzyme assays, confocal laser scanning microscopy (CLSM), and a fluorescence-activated cell sorter (FACS). Polycationic polymers poly-L-lysine (PLL), polyethylenimine (PEI), and diethylaminoethyl-dextran (DEAE-DEX) and sphere-like poly(amidoamine) (PAMAM) dendrimers are employed because of their importance for gene and drug delivery. AFM studies indicate that all the polycationic polymers cause the formation and/or expansion of preexisting defects in supported DMPC bilayers in the concentration range of 1-3 mu g/mL. By way of contrast, hydroxyl-containing neutral linear poly(ethylene glycol) (PEG) and poly(vinyl alcohol) (PVA) do not induce hole formation or expand the size of preexisting defects in the same concentration range. All polymers tested are not toxic to KB or Rat2 cells up to a 12 mu g/mL concentration (XTT assay). In the concentration range of 6-12 mu g/mL, however, significant amounts of the cytosolic enzymes lactate dehydrogenase (LDH) and luciferase (LUC) are released. PEI, which possesses the greatest density of charged groups on its chain, shows the most dramatic increase in membrane permeability. In addition, treatment with polycationic polymers allows the small dye molecules propidium idodide ( PI) and fluorescein ( FITC) to diffuse in and out of the cells. CLSM images also show internalization of PLL labeled with FITC dye. In contrast, controls of membrane permeability using the neutral linear polymers PEG and PVA show dramatically less LDH and LUC leakage and no enhanced dye diffusion. Taken together, these data are consistent with the hypothesis that polycationic polymers induce the formation of transient, nanoscale holes in living cells and that these holes allow a greatly enhanced exchange of materials across the cell membrane.