Seo Hee Jin, Kim Jin-Chul
College of Biomedical Science and Institute of Bioscience and Biotechnology, Kangwon National University , 192-1, Hyoja 2 dong, Chuncheon, Kangwon-do 200-701, Republic of Korea.
Bioconjug Chem. 2014 Mar 19;25(3):533-42. doi: 10.1021/bc400521r. Epub 2014 Feb 28.
Photoresponsive and cancer cell (KB cell)-targetable liposome was developed by incorporating 7-acetoxycoumarin dimer (ACD) in the liposomal membrane and modifying the surface of liposome with folate. The liposomes were prepared from the dry mixed thin film of egg phosphatidylcholine (EPC), ACD, and folate conjugate (DSPE-PEG2000-folate) by a film hydration method, where the molar ratios of EPC/ACD/DSPE-PEG2000-folate were 10/0/0, 9/1/0, 9/1/0.05, and 9/0/0.05. The liposomal membranes were multilamellar and the diameter was on the order of hundreds of nanometers. The release degrees in 60 min of 5(6)-carboxyfluorescein (CF) from EPC/ACD/DSPE-PEG2000-folate liposome were less than 4% without the irradiation of UV light (λ = 254 nm, 6 W), but more than 20% under the irradiation of UV light (λ = 254 nm, 6W), possibly due to the phototriggered de-dimerization of ACD. Under confocal laser scanning microscopy, KB cells treated with EPC/ACD/DSPE-PEG2000-folate liposomes exhibited CF fluorescence of liposomes at the positions where 4',6-diamidino-2-phenylindole (DAPI) fluorescence of the cell nucleus was shown, indicating the liposomes targeted the cancer cells. In flow cytometric analysis, the cancer cells treated with EPC/ACD/DSPE-PEG2000-folate liposomes exhibited much higher fluorescence than the untreated cells did, indicating that there was a specific interaction between the liposome and the cancer cell. With the irradiation of UV light, EPC/ACD/DSPE-PEG2000-folate liposomes markedly promoted the in vitro anti-cancer efficacy of DOX without causing acute in vitro toxicity.
通过将7-乙酰氧基香豆素二聚体（ACD）掺入脂质体膜并使用叶酸修饰脂质体表面，制备了具有光响应性且可靶向癌细胞（KB细胞）的脂质体。脂质体由卵磷脂酰胆碱（EPC）、ACD和叶酸共轭物（DSPE-PEG2000-叶酸）的干混合薄膜通过薄膜水化法制备，其中EPC/ACD/DSPE-PEG2000-叶酸的摩尔比为10/0/0、9/1/0、9/1/0.05和9/0/0.05。脂质体膜为多层结构，直径在数百纳米量级。在没有紫外线（λ = 254 nm，6 W）照射的情况下，EPC/ACD/DSPE-PEG2000-叶酸脂质体中5(6)-羧基荧光素（CF）在60分钟内的释放度小于4%，但在紫外线（λ = 254 nm，6W）照射下释放度超过20%，这可能是由于ACD的光触发解二聚作用。在共聚焦激光扫描显微镜下，用EPC/ACD/DSPE-PEG2000-叶酸脂质体处理的KB细胞在细胞核4',6-二脒基-2-苯基吲哚（DAPI）荧光显示的位置呈现脂质体的CF荧光，表明脂质体靶向癌细胞。在流式细胞术分析中，用EPC/ACD/DSPE-PEG2000-叶酸脂质体处理的癌细胞比未处理的细胞表现出更高的荧光，表明脂质体与癌细胞之间存在特异性相互作用。在紫外线照射下，EPC/ACD/DSPE-PEG2000-叶酸脂质体显著提高了阿霉素的体外抗癌疗效，且未引起急性体外毒性。
