Factors affecting blood clearance and in vivo distribution of polyelectrolyte complexes for gene delivery
Factors affecting blood clearance and in vivo distribution of polyelectrolyte complexes for gene delivery
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DOI：
10.1038/sj.gt.3300843
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发表时间：
1999-04-01
期刊：
影响因子：
5.1
通讯作者：
Seymour, LW
中科院分区：
文献类型：
--
作者：
Dash, PR;Read, ML;Seymour, LW
自组装多阳离子/DNA复合物是一种很有前途的基因传递合成载体。然而，尽管在体外具有相当大的通用性和转染活性，这些材料在静脉注射后很快从血液中消除（血浆α半衰期通常小于5分钟）。对于有针对性的全身递送，更长的载体血浆循环是必不可少的。在这里，我们研究了有助于从血液中快速消除聚l -赖氨酸(pLL)/DNA复合物的因素，并暗示蛋白质与多电解质复合物的结合可能是其血液清除的原因。从血清中分离的pLL/DNA复合体根据其净电荷与几种蛋白质结合，尽管SDS-PAGE上的主要条带与白蛋白结合。血清白蛋白在体外与pLL/DNA复合物结合，形成pLL/DNA/白蛋白三元复合物，该复合物恢复了一些溴化乙啶荧光，并且在琼脂糖电泳过程中不能移动。白蛋白还会引起复合物浊度的增加，并将其zeta电位降低到与血清中测量的相同水平（-16 mV）。我们认为，多阳离子/DNA复合物的快速血浆消除是由于它们与血清白蛋白和其他蛋白质的结合，可能是由于三元复合物在细毛细血管床中的聚集和吞噬捕获或积累。
Self-assembling polycation/DNA complexes represent a promising synthetic vector for gene delivery. However, despite considerable versatility and transfectional activity in vitro, such materials are quickly eliminated from the bloodstream following intravenous injection (plasma alpha half-life typically less than 5 min). For targeted systemic delivery a more prolonged plasma circulation of the vector is essential. Here we have examined factors contributing to rapid elimination of poly(L-lysine) (pLL)/DNA complexes from the bloodstream, and implicate the binding of proteins to the polyelectrolyte complexes as a likely cause for their blood clearance. pLL/DNA complexes reisolated from serum associate with several proteins depending on their net charge, although the major band on SDS-PAGE comigrates with albumin. Serum albumin binds to pLL/DNA complexes in vitro, forming a ternary pLL/DNA/albumin complex which regains some ethidium bromide fluorescence and fails to move during agarose electrophoresis. Albumin also causes increased turbidity of complexes, and reduces their zeta potential to the same level (-16 mV) as is measured in serum. We propose that rapid plasma elimination of polycation/DNA complexes results from their binding serum albumin and other proteins, perhaps due to aggregation and phagocytic capture or accumulation of the ternary complexes in fine capillary beds.