荧光素作为酸敏指示剂评价酸敏材料和脂质体酸敏性的方法研究

目的:建立一种简单而快速的评价酸敏材料和脂质体酸敏性的实验分析方法。方法:利用脂质体包裹的荧光素在高浓度环境的自屏蔽作用,以及从脂质体中释放后自屏蔽消失的特性,通过检测试样的荧光发射光信号,来评价酸敏物质诱发细胞膜融合通透性能的强弱和脂质体的酸敏释药性能。结果:选用不同磷脂组分制备的脂质体可以成功的包裹高浓度荧光素,被包裹的荧光素稳定并且能屏蔽自己的发射光;在酸性条件,酸敏物质破坏脂质体膜,荧光素可以从脂质体中释放出来。酸敏材料的酸敏能力、溶液酸度、脂质体磷脂组成都影响荧光素从脂质体中释放的能力和速度;酸度影响荧光素的荧光强度,但在 pH 6.5～10.0不受影响。结论:利用脂质体包裹高浓度荧光素的自我屏蔽性,建立一种简单而快速的实验方法,用来评价酸敏物质诱发细胞膜融合通透性能的强弱以及评价脂质体的酸敏释药性能。

A study of calcein as an index for evaluation of the pH - sensitivity fusion induce materials and liposomes

Objective:To establish a simple and quick method to evaluate pH sensitivity of fusogenic materials, such as polymers and peptides,and pH-sensitive liposome.Methods:Calcein will self-quenching when it is trapped inner of liposome,and the self-quenching will disappear when calcein releases from liposome.Through measuring the calcein fluorescence releasing intensity of trapped calcein,the pH-sensitivity fusion induces cell membrane permeability of pH-sensitivity polymer and liposome can be reflected.Results:Liposmes with different phospholipids constituent all can trap the high concentration of calcein successfully and the trapped calcein can keep stable and shield its emitted light.Under acidic conditions the pH-sensitivity polymer induces membrane dis- ruption and fusion and the trapped ealeein releases from the liposome.The pH-sensitivity fusion of material,acidity of the solution and phospholipids constituent all can affect trapped calein releasing from liposome.The calcein inten- sity is influenced the of the solution but this influence will very little at pH 6.5-10.0.Conclusion:The simple and quick method to evaluate the pH-sensitivity fusion induces cell membrane permeability of pH-sensitivity of poly- mer and liposome is established base on the shelf shield property of the high concentration of calcein trapped in li- posome.All results indicate that this method is simple and reliable.