Pitard Bruno, Bello-Roufaï Mahajoub, Lambert Olivier, Richard Peggy, Desigaux Léa, Fernandes Sarah, Lanctin Caroline, Pollard Hélène, Zeghal Mehdi, Rescan Pierre-Yves, Escande Denis
L'institut du Thorax, Inserm U533, Faculté de Médecine, 44035 Nantes, France.
Nucleic Acids Res. 2004 Nov 16;32(20):e159. doi: 10.1093/nar/gnh153.
Over the past decade, numerous nonviral cationic vectors have been synthesized. They share a high density of positive charges and efficiency for gene transfer in vitro. However, their positively charged surface causes instability in body fluids and cytotoxicity, thereby limiting their efficacy in vivo. Therefore, there is a need for developing alternative molecular structures. We have examined tetrabranched amphiphilic block copolymers consisting of four polyethyleneoxide/polypropyleneoxide blocks centered on an ethylenediamine moiety. Cryo-electron microscopy, ethidium bromide fluorescence and light and X-ray scattering experiments performed on vector-DNA complexes showed that the dense core of the nanosphere consisted of condensed DNA interacting with poloxamine molecules through electrostatic, hydrogen bonding and hydrophobic interactions, with DNA molecules also being exposed at the surface. The supramolecular organization of block copolymer/DNA nanospheres induced the formation of negatively charged particles. These particles were stable in a solution that had a physiological ionic composition and were resistant to decomplexation by heparin. The new nanostructured material, the structure of which clearly contrasted with that of lipoplexes and polyplexes, efficiently transferred reporter and therapeutic genes in skeletal and heart muscle in vivo. Negatively charged supramolecular assemblies hold promise as therapeutic gene carriers for skeletal and heart muscle-related diseases and expression of therapeutic proteins for local or systemic uses.
在过去十年中，人们合成了许多非病毒阳离子载体。它们具有高密度的正电荷，在体外基因转移方面效率较高。然而，其带正电的表面会导致在体液中不稳定并产生细胞毒性，从而限制了它们在体内的功效。因此，需要开发替代的分子结构。我们研究了以乙二胺部分为中心、由四个聚环氧乙烷/聚环氧丙烷嵌段组成的四分支两亲性嵌段共聚物。对载体 - DNA 复合物进行的低温电子显微镜、溴化乙锭荧光以及光散射和 X 射线散射实验表明，纳米球的致密核心由通过静电、氢键和疏水相互作用与泊洛沙姆分子相互作用的凝聚 DNA 组成，DNA 分子也暴露在表面。嵌段共聚物/DNA 纳米球的超分子组织诱导形成带负电荷的颗粒。这些颗粒在具有生理离子组成的溶液中稳定，并且对肝素的解聚具有抗性。这种新型纳米结构材料的结构与脂质体和聚合物复合物的结构明显不同，它能在体内有效地将报告基因和治疗基因转移到骨骼肌和心肌中。带负电荷的超分子组装体有望成为用于治疗骨骼肌和心肌相关疾病以及用于局部或全身使用的治疗性蛋白质表达的治疗性基因载体。
