Dual asymmetric centrifugation (DAC) - A new technique for liposome preparation
Dual asymmetric centrifugation (DAC) - A new technique for liposome preparation
复制标题
DOI：
10.1016/j.jconrel.2007.09.010
复制
发表时间：
2008-01-04
影响因子：
10.8
通讯作者：
Ziroli, Vittorio
中科院分区：
文献类型：
--
作者：
Massing, Ulrich;Cicko, Sanja;Ziroli, Vittorio
这是首次报道使用“双不对称离心机(DAC)”制备脂质体。DAC与常规离心法的不同之处在于，样品绕其自身垂直轴额外旋转：当常规离心法不断地将样品材料向外推时，这种额外的旋转不断地迫使样品材料朝向离心机的中心。这两个反向旋转运动的独特组合产生了剪切力，从而产生了有效的均化。我们证明了通过DAC法制备脂质体是可能的，方法是将相当浓的氢化磷脂酰胆碱和胆固醇(55：45摩尔%)和0.9%的氯化钠溶液混合均匀，得到粘性的泡状磷脂凝胶(VPG)。生成的VPG随后可以稀释到传统的脂质体分散体中。由于DAC的目的是制造无菌的脂质体制剂，或包裹有毒/放射性化合物，因此该过程在密封的小瓶中进行。结果表明，DAC速度、脂类浓度、均质时间和混合助剂(玻璃珠)的加入对脂质体的大小都是至关重要的。优化条件可得到60+/-5mN的脂质体，模型化合物钙黄绿素的包封率为56+/-3.3%。(C)2007 Elsevier B.V.保留所有权利。
This is the first report on the use of a "dual asymmetric centrifuge (DAC)" for preparing liposomes. DAC differs from conventional centrifugation by an additional rotation of the sample around its own vertical axis: While the conventional centrifugation constantly pushes the sample material outwards, this additional rotation constantly forces the sample material towards the center of the centrifuge. This unique combination of two contra rotating movements results in shear forces and thus, in efficient homogenization. We demonstrated that it is possible to prepare liposomes by DAC, by homogenizing a rather concentrated blend of hydrogenated phosphatidylcholine and cholesterol (55:45 mol%) and 0.9% NaCl-solution, which results in a viscous vesicular phospholipid gel (VPG). The resulting VPG can subsequently be diluted to a conventional liposome dispersion. Since DAC is intended to make sterile preparations of liposomes, or to entrap toxic/radioactive compounds, the process was performed within a sealed vial. It could be shown that the DAC speed, the lipid concentration, the homogenization time and the addition of a mixing aid (glass beads) are all critical for the size of the liposomes. Optimized conditions resulted in liposomes of 60 +/- 5 mn and a trapping efficacy of 56 +/- 3.3% for the model compound calcein. (C) 2007 Elsevier B.V. All rights reserved.