脂质体通透性与脂多型性关系的研究

本文以TPE和TPE/DOPE(1:1.mol:mol)制成包裹荧光分子calcein的脂质体,通过测量荧光强度随扫描温度的变化,探讨了脂质体通透性与脂多型性之间的关系.结果表明,在不发生双层相(L)变成六角形Ⅱ相(H)相转变时,脂质体悬液的荧光强度不增加;当发生该转变时,脂质体悬液的荧光强度开始增加;完成该相转变后,脂质体悬液的荧光强度仍继续增加.据此,我们认为:脂质体的通透性与脂的多型性密切相关,当发生L→HⅡ相转变时,脂质体的通透性增加.由于荧光强度的变化对相变非常敏感,我们建议用测量脂质体荧光强度随温度的变化来监测脂质体稀悬液中脂的多型性.

STUDIES ON THE RELATIONSHIP BETWEEN PERMEABILITY OF LTPOSOMES AND LIPID POLYMORPHISM

By using phosphatidylethanolamine transesterfied from egg ph-osphatidylcoli ne (TPE) and TPE/dioleoyl phosphatidylethanolamine (1:1,mol: mol) liposomes containing calcein, the relationship between permeability of li posomes and lipid polymorphism was studied by measuring fluorecence changes with scanning temperature. The fluorescence does not increase when the transition of bilayer changing into hexagonal II phase does not take place; The fluorescence increases when the polymorphic phase transition takes place; it continues increasing when the polymorphic phase transition is finished. we postulate that the permeability of liposomes is correlated with lipid polymorphism: when bilayer changing into hexagonal II phase transition takes place, the permeability of liposomes is increased. Because the fluorescence changes are very sensitive to phase transition, we suggest the lipid polymorphism can be monitored by measuring fluorscence change of liposome with temperature in dilute liposome suspensions.