用差示扫描量热法及激光拉曼光谱研究足叶乙甙对二棕榈酰磷脂酰胆碱脂质体膜流动性影响

STUDY OF THE EFFECT OF ETOPOSIDE ON THE FLUIDITY OF DIPALMITOYLPHOSPHATIDYLCHOLINE LIPOSOME BY DIFFERENTIAL SCANNING CALORIMETRY AND RAMAN SPECTROSCOPY

本文用DSC和激光拉曼光谱研究抗癌药物足叶乙甙(4-去甲基表鬼臼毒素-β-D-乙叉吡喃葡萄糖甙,简称VP 16-213)与二棕榈酰磷脂酰胆碱(DPPC)脂质体的作用。VP 16-213分子掺入DPPC脂质体双层中,不但使相转变温度向高温移动,而且吸热峰的半高宽度随VP 16-213浓度增加而变宽。其Raman光谱在频率2850 cm^(-1)处的C-H键对称伸缩振动亦随着药物浓度增加而减弱。这些结果表明VP 16-213分子是定域在脂双层中DPPC分子链的C_1～C_9亚甲基区域,使脂质体的有序性提高而流动性降低。

The interaction of the anticancer drug, etoposide (VP16-213), with DPPC bilayer vesicles was investigated by DSC and Laser Raman techniques. The results present the fact that the incorporation of VP16-213 into aqueous dispersion of DPPC not only shifted the temperatures of phase transition towards higher value but also broadened the half-height width. The Raman spectra of the DPPC liposome in the C—H symmetric strech vibration lost intensity near 2850cm^(-1), therefore, it can be predicted that VP16-213 is localized at C_1～C_9 methylene region of the bilayer, which leads to the increase of the membrane's regularity and the decrease of its fluidity.