Endosomal escape and transfection efficiency of PEGylated cationic liposome-DNA complexes prepared with an acid-labile PEG-lipid.
Endosomal escape and transfection efficiency of PEGylated cationic liposome-DNA complexes prepared with an acid-labile PEG-lipid.
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DOI：
10.1016/j.biomaterials.2012.03.038
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发表时间：
2012-06
期刊：
影响因子：
14
通讯作者：
Safinya, Cyrus R.
中科院分区：
文献类型：
--
作者：
Chan, Chia-Ling;Majzoub, Ramsey N.;Shirazi, Rahau S.;Ewert, Kai K.;Chen, Yen-Ju;Liang, Keng S.;Safinya, Cyrus R.
阳离子脂质体- dna （CL-DNA）复合物作为非病毒基因传递系统被用于临床试验等应用领域。然而，为了与病毒载体竞争体内的全身递送，它们的效率和药代动力学需要改进。聚乙二醇脂质（聚乙二醇化）的加入延长了脂质体的循环寿命，但抑制了CL-DNA复合物的细胞摄取和内体逃逸。我们发现这限制了它们的转染效率（TE），这取决于peg -脂质的数量、脂质/DNA电荷比和脂质膜电荷密度。为了提高聚乙二醇化CL-DNA复合物的内体逃逸，我们制备了一种酸不稳定的PEG-脂质（hpeg2k -脂质，PEG MW 2000），其设计目的是在内体后期的pH值处失去其PEG链。hpeg2k -脂质和类似的但酸稳定的peg -脂质被用来制备聚乙二醇化的CL-DNA复合物。TLC和动态光散射表明，HPEG2K-CL-DNA复合物在pH 7.4下稳定24小时以上，但在pH 5下，PEG链在1小时内发生断裂，导致复合物聚集。酸稳定的HPEG2K-CL-DNA复合物比酸稳定的peg -脂质复合物表现出更高的TE。活细胞成像显示，在与细胞孵育的前2小时内，两种类型的复合物被内化到定量相似的颗粒分布。因此，我们将HPEG2K-CL-DNA复合物的TE增加归因于高效的内体逃逸，这是由酸不稳定的hpeg2k -脂质在后期内体的低ph环境中脱落其PEG链所实现的，有效地开启了促进复合物膜和内体融合的静电相互作用。
Cationic liposome–DNA (CL–DNA) complexes are being pursued as nonviral gene delivery systems for use in applications that include clinic trials. However, to compete with viral vectors for systemic delivery in vivo, their efficiencies and pharmacokinetics need to be improved. The addition of poly (ethylene glycol)-lipids (PEGylation) prolongs circulation lifetimes of liposomes, but inhibits cellular uptake and endosomal escape of CL–DNA complexes. We show that this limits their transfection efficiency (TE) in a manner dependent on the amount of PEG-lipid, the lipid/DNA charge ratio, and the lipid membrane charge density. To improve endosomal escape of PEGylated CL–DNA complexes, we prepared an acid-labile PEG-lipid (HPEG2K-lipid, PEG MW 2000) which is designed to lose its PEG chains at the pH of late endosomes. The HPEG2K-lipid and a similar but acid-stable PEG-lipid were used to prepare PEGylated CL–DNA complexes. TLC and dynamic light scattering showed that HPEG2K-CL–DNA complexes are stable at pH 7.4 for more than 24 hours, but the PEG chains are cleaved at pH 5 within one hour, leading to complex aggregation. The acid-labile HPEG2K-CL–DNA complexes showed enhanced TE over complexes stabilized with the acid-stable PEG-lipid. Live-cell imaging showed that both types of complexes were internalized to quantitatively similar particle distributions within the first 2 hours of incubation with cells. Thus, we attribute the increased TE of the HPEG2K-CL–DNA complexes to efficient endosomal escape, enabled by the acid-labile HPEG2K-lipid which sheds its PEG chains in the low-pH environment of late endosomes, effectively switching on the electrostatic interactions that promote fusion of the membranes of complex and endosome.
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影响因子：
16.2
作者：
CORY, AH;OWEN, TC;CORY, JG
通讯作者：
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