Dipartimento di Scienze del Farmaco, Università G. d'Annunzio, Chieti, Italy.
J Liposome Res. 2010 Sep;20(3):202-10. doi: 10.3109/08982100903244526.
The effect of entrapped beta-cyclodextrin (beta-CD) on the stability of multilamellar vesicles (MLVs) of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), prepared by the dehydration-rehydration method, was studied by monitoring the release of 5(6)-carboxyfluorescein encapsulated into the liposomes. Different hydrophobic guests, such as Fullerene C(60), have been incorporated into the POPC bilayer in order to modify the membrane composition. The kinetic results as well as ESI-MS measurements evidenced that the destabilizing activity of beta-CD is due to the formation of beta-CD inclusion complexes and the consequent removal of selected bilayer constituents from the liposomal membrane. Hence, when beta-CD was added to the liposomes in the form of a strong, water-soluble 2:1 beta-CD/C(60) inclusion complex, such a destabilizing effect was not observed. However, the same beta-CD/C(60) inclusion complex does not form as a result of C(60) extraction from the bilayer. This may be attributed either to the overwhelming concentration of POPC with respect to C(60) and/or to the fact that C(60) is largely aggregated in the bilayer. Turbidimetric and fluorimetric determinations of lamellarity and entrapped volume of the studied MLVs provided further evidence of the alteration of the liposomal bilayer as a consequence of the addition of beta-CD and/or the presence of the studied guests.
包埋β-环糊精（β-CD）对通过脱水再水合方法制备的 1-棕榈酰基-2-油酰基-sn-甘油-3-磷酸胆碱（POPC）的多层囊泡（MLV）稳定性的影响，通过监测包封在脂质体中的 5（6）-羧基荧光素的释放来研究。不同的疏水分子，如富勒烯 C（60），已被掺入到 POPC 双层中以修饰膜组成。动力学结果和 ESI-MS 测量证明，β-CD 的破坏活性是由于β-CD 包合复合物的形成以及随后从脂质体膜中去除选择的双层成分。因此，当β-CD 以强水溶性 2:1β-CD/C（60）包合复合物的形式添加到脂质体中时，没有观察到这种破坏作用。然而，由于 C（60）从双层中提取，不会形成相同的β-CD/C（60）包合复合物。这可能归因于相对于 C（60）而言 POPC 的浓度过高，或者 C（60）在双层中大量聚集。浊度法和荧光法测定研究的 MLV 的层状结构和包封体积提供了进一步的证据，证明由于添加了β-CD 和/或存在研究的客体，脂质体双层发生了变化。
