Ultrasound-responsive polymer-coated microbubbles that bind and protect DNA
Ultrasound-responsive polymer-coated microbubbles that bind and protect DNA
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DOI：
10.1021/la0603828
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发表时间：
2006-08-15
期刊：
影响因子：
3.9
通讯作者：
Sanders, Niek N.
中科院分区：
文献类型：
--
作者：
Lentacker, Ine;De Geest, Bruno G.;Sanders, Niek N.
超声波与微泡的结合最近被基因传递科学家认为是增强基因转移到细胞中的一种有趣的方法。其毒性低且在体内应用简单且没有重大并发症，使得该技术（声孔法）特别有吸引力。通过将游离质粒 DNA (pDNA) 与微泡（如诊断成像中使用的）一起注射到血流中，可以在体内评估 DNA 的声孔作用。然而，这些实验中的体内基因转移效率仍然相当低。注射 pDNA 的酶促降解以及声孔细胞膜附近 pDNA 浓度低都可以解释这种低效率。因此，我们开发了可以结合和保护 pDNA 的聚合物涂层微泡。用聚（盐酸烯丙胺）（PAH）包覆白蛋白壳的微泡，使微泡的表面电荷为正，而不会显着影响微泡的尺寸分布，从而不影响超声响应性和可注射性。阳离子涂层允许每个微泡结合多达 0.1 pg 的 DNA，并保护结合的 DNA 免受核酸酶的侵害。最后，PAH涂层显着增加了微泡的寿命（半衰期约为7小时），使它们更方便体内应用，因为预计有更多的微泡到达目标器官。据我们所知，聚合物涂层诊断微泡对 DNA 的结合和核酸酶保护尚未得到证实。我们得出的结论是，这些 LbL 包被的微泡可能对超声介导的基因传递的进一步发展具有重要意义。
Ultrasound in combination with microbubbles has recently been considered by gene delivery scientists to be an interesting approach to enhance gene transfer into cells. Its low toxicity and simplicity to apply in vivo without major complications make this technology (sonoporation) especially attractive. Sonoporation of DNA has been evaluated in vivo by the injection of free plasmid DNA (pDNA) together with microbubbles (as used in diagnostic imaging) in the bloodstream. However, the in vivo gene-transfer efficiency in these experiments remained rather low. Both the enzymatic degradation of the injected pDNA as well as the low pDNA concentration in the neighborhood of sonoporated cell membranes may explain this low efficiency. Therefore, we developed polymer-coated microbubbles that can bind and protect the pDNA. Coating albumin-shelled microbubbles with poly(allylamine hydrochloride) (PAH) makes the surface charge of the microbubbles positive without drastically affecting the size distribution of the microbubbles, thereby not affecting the ultrasound responsiveness and injectability. The cationic coating allowed both to bind up to 0.1 pg of DNA per microbubble as well as to protect the bound DNA against nucleases. Finally, the PAH coating significantly increased the lifetime of the microbubbles (half-life approximate to 7 h), making them more convenient for in vivo applications because more microbubbles are expected to reach the target organ. Binding and nuclease protection of DNA by polymer-coated diagnostic microbubbles has, to our knowledge, never been demonstrated. We conclude that these LbL-coated microbubbles might be significant in the further development of ultrasound-mediated gene delivery.