DNA-lipid self-assembly: phase behavior and phase structures of a DNA-surfactant complex mixed with lecithin and water
DNA-lipid self-assembly: phase behavior and phase structures of a DNA-surfactant complex mixed with lecithin and water
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DOI：
10.1039/c0sm00650e
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发表时间：
2011-01-01
期刊：
影响因子：
3.4
通讯作者：
Lindman, Bjorn
中科院分区：
文献类型：
--
作者：
Bilalov, Azat;Olsson, Ulf;Lindman, Bjorn
DNA和脂质的共组装具有广泛的意义，从细胞核的结构到基因递送制剂。为了进一步了解DNA与脂质的相互作用，研究了阳离子表面活性剂十二烷基三甲基铵（dodecyltrimethylammonium，DTA）与DNA在水和卵磷脂混合体系中的自组装行为.建立了相图，并通过H-2 NMR，小角X射线散射（SAXS）和其他技术表征了相图的不同区域的微观结构。确定了三种液晶相：立方相、层状相和六方相。所有LC相在20-65 ℃的温度范围内都是稳定的。立方相仅在很窄的组成范围内是稳定的。在增加卵磷脂含量时，相通过扩展的双相区域转变为层状相。干燥的层状相导致六方相的形成。向三元混合物中添加盐导致LC相的晶胞尺寸略有增加。非常高的离子强度可导致DNA从液晶中释放并形成无DNA液晶相。特别是，我们观察到两个层状相共存。一个含有DNA，另一个基本上不含DNA。
The co-assembly of DNA and lipids has broad implications, from the structure of the cell nucleus to gene delivery formulations. To progress in the fundamental understanding of DNA-lipid interactions the self-assembly behavior of a cationic surfactant (dodecyltrimethylammonium, DTA) with DNA as a counterion in mixtures of water and lecithin was investigated. The phase diagram was established and the different regions of the phase diagram characterized with respect to the microstructure by H-2 NMR, small-angle X-ray scattering (SAXS), and other techniques. Three liquid crystalline (LC) phases were identified: cubic, lamellar and hexagonal. All LC phases are stable in the temperature range 20-65 degrees C. The cubic phase is stable only in a narrow composition range. Upon increasing the lecithin content the phase transforms to the lamellar phase via an extended biphasic area. Drying of the lamellar phase leads to the formation of hexagonal phase. Adding salt to the ternary mixtures causes a slight increase in the unit cell dimension of the LC phases. Very high ionic strength may lead to DNA release from liquid crystals and the formation of DNA free liquid crystalline phases. In particular we observe a coexistence of two lamellar phases. One contains DNA and one being essentially free of DNA.