Sternberg B, Sorgi F L, Huang L
Institute of Ultrastructure Research, Medical School, Friedrich-Schiller-University Jena, Germany.
FEBS Lett. 1994 Dec 19;356(2-3):361-6. doi: 10.1016/0014-5793(94)01315-2.
Structures formed during interaction of cationic liposomes and plasmid DNA were studied by freeze-fracture electron microscopy and their morphology was found to be dependent on incubation time and DNA concentration. These structures were formed with liposomes composed of DC-Chol and DOPE after 30 min incubation at DNA:lipid concentrations encompassing maximal transfection activity. They resembled liposome complexes (meatballs) and additionally bilayer-covered DNA tubules (spaghetti), whereby the DNA-tubules were found to be connected to the liposome complexes as well as occurring free in the suspension. At later times and higher DNA-to-liposome ratios the complexes grow larger while their membranes become discontinuous, allowing the self-encapsulation of the DNA. The relative transfection potency of the various morphologically distinct structures is discussed.
通过冷冻断裂电子显微镜研究了阳离子脂质体与质粒DNA相互作用过程中形成的结构，发现其形态取决于孵育时间和DNA浓度。在DNA:脂质浓度涵盖最大转染活性的条件下孵育30分钟后，由DC-Chol和DOPE组成的脂质体形成了这些结构。它们类似于脂质体复合物（肉丸）以及另外的双层覆盖的DNA小管（意大利面），其中发现DNA小管与脂质体复合物相连，也以游离形式存在于悬浮液中。在更长时间和更高的DNA与脂质体比例下，复合物会变得更大，同时其膜变得不连续，从而使DNA能够自我包裹。文中讨论了各种形态不同的结构的相对转染效力。
