【摘要】 目的:考察壳聚糖及其衍生物包覆的脂质体对胰岛素细胞旁路转运的促进作用。方法:采用逆相蒸发法制备胰岛素脂质体;利用离体肠黏膜法和Caco-2细胞模型法研究壳聚糖及其衍生物包覆的胰岛素脂质体的肠吸收;分别运用放射免疫法和HPLC法测定离体肠黏膜法和Caco-2细胞模型法接收池中胰岛素含量。结果:胰岛素跨肠黏膜转运能力大小次序为:CH-CEC组>CH组>TMC组>CEC组>Uncoated组>Ins组;胰岛素跨Caco-2细胞单层膜的转运能力大小次序为:CH组>CH-CEC组>CEC组>TMC组>Uncoated组>Ins组。结论:脂质体能增加胰岛素的跨膜转运,而脂质体经壳聚糖及其衍生物包覆后通过打开上皮细胞紧密结,进一步提高胰岛素经细胞旁路的转运能力。更多还原

【Abstract】 AIM:To evaluate the transport of insulin across the isolated small intestinal mucosa of rat and the monolayer of Caco-2 cell in the presence of the liposomes coated with chitosan and its derivatives.METHODS:Insulin-liposomes were prepared by reversed-phase evaporation.The paracellular insulin transport was investigated with the isolated mucosa experiment and Caco-2 cell experiment.The insulin concentrations in receiver cell of the isolated mucosa experiment and Caco-2 cell experiment were determined by radio-immunoassay and HPLC,respectively.RESULTS:In permeability experiments of the isolated small intestinal mucosa model,according to apparent permeability coefficients (P_app),the order of permeation ability of the various formulations was:CH-CEC formula>CH formula>TMC formula>CEC formula>Uncoated formula>Insulin formula.In permeability experiments of the human intestinal epithelial model （Caco-2）,according to P_app,the rank of permeation ability of the various formulations across Caco-2 cell monolayers was:CH formula>CH-CEC formula>CEC formula>TMC formula>Uncoated formula>Insulin formula.And it was identical to the order of reduction of transepithelial electrical resistance （TEER） caused by the various formulations.CONCLUSION:Liposomes could enhance transport of insulin across the intestinal epithelium.When insulin liposomes were coated with chitosan or its derivatives,the permeation enhancement was further improved by an opening of the tight junctions.更多还原