The design and synthesis of polymers for eukaryotic membrane disruption
The design and synthesis of polymers for eukaryotic membrane disruption
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DOI：
10.1016/s0168-3659(99)00114-5
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发表时间：
1999-08-27
影响因子：
10.8
通讯作者：
Hoffman, AS
中科院分区：
文献类型：
--
作者：
Murthy, N;Robichaud, JR;Hoffman, AS
药物的细胞内运输对于易受溶酶体酶攻击的药物的功效至关重要。因此，设计和合成能够增强内吞药物从内体区室到细胞质的转运的分子是一个重要的目标。内体的pH比胞质溶胶的pH低一到两个pH单位，这取决于内体发育的阶段。这种pH梯度是设计膜破坏性聚合物的关键因素，其可以增强药物的内体释放。这样的聚合物在pH 6.5及以下时应破坏脂质双层膜，但在pH 7.4时应不溶解。我们设计并合成了pH敏感的合成聚合物，可在严格限定的pH范围内有效破坏红细胞。这些聚合物之一，聚（乙基丙烯酸）（PEAAc）先前已显示以pH依赖性方式破坏合成囊泡[6]。PEAAc以每个红细胞10（7）个分子的活性溶血红细胞，其在摩尔基础上与肽蜂毒肽一样有效。PEAAc对红细胞的溶血机制与胶体渗透机制一致。当pH从6.3降低到5.0时，PEAAc的溶血活性迅速升高，并且在pH 7.4时没有溶血活性。合成了一种相关的聚合物，聚（丙基丙烯酸）（PPAAc），以测试通过添加一个亚甲基使侧链烷基更加疏水是否会增加溶血活性。发现PPAAc在pH 6.1下比PEAAc更有效地破坏红细胞15倍。PPAAc在pH 7.4下也没有活性，并显示出向更高pH转变的pH依赖性溶血。丙烯酸乙酯（EA）和丙烯酸（AAc）的无规1：1共聚物（其含有在PEAAc中存在并规则重复的无规-COOH和-C2 H5基团）也显示出显著的溶血活性，其效率接近于PEAAc。这些结果表明，pH敏感的合成聚合物可以被分子工程化，以有效地破坏真核细胞膜内定义和狭窄的pH范围。因此，这些聚合物可能作为内体破坏剂，对早期或晚期内体具有特异性。(C)1999 Elsevier Science B. V.保留所有权利。
The intracellular trafficking of drugs is critical to the efficacy of drugs that are susceptible to attack by lysosomal enzymes. It is therefore an important goal to design and synthesize molecules which can enhance the transport of endocytosed drugs from the endosomal compartments to the cytoplasm. The pH of an endosome is lower than that of the cytosol by one to two pH units, depending on the stage of endosomal development. This pH gradient is a key factor in the design of membrane-disruptive polymers which could enhance the endosomal release of drugs. Such polymers should disrupt lipid bilayer membranes at pH 6.5 and below, but should be non-lytic at pH 7.4. We have designed and synthesized pH-sensitive synthetic polymers which efficiently disrupt red blood cells within a sharply defined pH range. One of these polymers, poly(ethyl acrylic acid) (PEAAc) has been previously shown to disrupt synthetic vesicles in a pH-dependent fashion [6]. PEAAc hemolyzes red blood cells with an activity of 10(7) molecules per red blood cell, which is as efficient on a molar basis as the peptide melittin. The mechanism of RBC hemolysis by PEAAc is consistent with the colloid osmotic mechanism. PEAAc's hemolytic activity rises rapidly as the pH decreases from 6.3 to 5.0, and there is no hemolytic activity at pH 7.4. A related polymer, poly(propyl acrylic acid) (PPAAc), was synthesized to test whether making the pendant alkyl group more hydrophobic by adding one methylene group would increase the hemolytic activity. PPAAc was found to disrupt red blood cells 15 times more efficiently than PEAAc at pH 6.1. PPAAc was also not active at pH 7.4 and displayed a pH-dependent hemolysis that was shifted toward higher pH's. Random 1:1 copolymers of ethyl acrylate (EA) and acrylic acid (AAc) (which contain random -COOH and -C2H5 groups that are present and regularly repeat in PEAAc) also displayed significant hemolytic activity, with an efficiency close to PEAAc. These results demonstrate that pH-sensitive synthetic polymers can be molecularly engineered to efficiently disrupt eukaryotic membranes within defined and narrow pH ranges. Thus, these polymers might serve as endosomal disruptive agents with specificities for early or late endosomes. (C) 1999 Elsevier Science B.V. All rights reserved.