Physico-chemical studies on the interaction of cyclodextrins with liposomes

已知环糊精可使红细胞溶血，也可增加药物通过生物膜的吸收。为此，我们利用脂质体和单分子膜研究了脂膜与环糊精的相互作用。环糊精识别膜中特定的脂类分子，将形成包合物的脂类分子拉入水相，破坏膜结构。环糊精的破坏能力取决于膜中脂质的组成，这是由于环糊精的分子识别，这源于环糊精的内腔大小和脂类分子的疏水性和大小。环糊精对等摩尔的蛋黄、卵磷脂和胆固醇脂质体的破坏能力与对红细胞的破坏能力一致。环糊精络合物与胆酸盐相互作用，在cmc以下的水溶液中观察到客体分子的交换反应，而在cmc以上的胆酸盐胶束中则分布着自由的客体分子，这些事实对于考虑环糊精络合物在人体内的去向和安全性是非常重要的。

Cyclodextrins have been known to hemolize the erythrocyte and also increase the drug absorption through biomembrane. In this connection we studied the interaction of lipid membrane with cyclodextrins by using liposmes and monomolecular film. Cyclodextrins recognize the specific lipid molecule in membrane and pull out the lipid molecules forming the inclusion complexes into aqueous phase and destruct the membrane structure. The destruction abilities of cyclodextrins depend on the compsition of lipids in membrane, bacause of the molecular recognition of cyclodextrins, which originates from the size of inner cavityis of cyclodextrins and the hydrophobicities and the size of lipid molecules. The destruction abilities of cyclodextrins for the liposome containing equimolar amounts of egg yolk lecithin and cholesterol agreed with those for erythrocyte. The cyclodextrin complexes interacts with cholate and the exchange reaction of guest molecules was observed in aqueous solution below cmc and the free guest molecules were patitioned in cholate micelles above cmc.These facts are quite important for the consideration of the fate and the safety of cyclodextrin complexes administered to human body.