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[摘要]
目的 考察乳糖化-去甲斑蝥素磷脂复合物pH敏感型脂质体(pH-LPC-lips)的体内外抑瘤作用,及其在小鼠体内的肝脏靶向性。方法 以空白脂质体(blank-lips、blank-pH-lips)为对照,MTT法考察乳糖化-去甲斑蝥素(Lac-NCTD)和2种载药脂质体(Lac-lips、pH-LPC-lips)对人体肝癌细胞HepG2的细胞毒作用。采用HPLC法评价HepG2细胞对Lac-NCTD及其脂质体的摄取过程。建立H22肝癌细胞小鼠荷瘤模型考察脂质体在体内抗肿瘤活性。用Cy-7标记羧甲基壳聚糖(CMCT)制备Cy-7荧光标记的pH-LPC-lips,通过小动物活体成像仪,采集荧光信号,考察该脂质体在小鼠体内的靶向性。结果 与Lac-NCTD、Lac-lips相比,pH-LPC-lips在体外对肿瘤细胞HepG2的亲和性更好,细胞毒作用更显著。体内抑瘤实验表明,pH-LPC-lips可以更好地抑制H22肿瘤的生长。pH-LPC-lips可以靶向聚积在小鼠肝脏和肿瘤部位,有很好的靶向作用,从而减小药物毒副作用,提高抗肿瘤效果。结论 优化的pH-LPC-lips可以在呈弱酸性的肿瘤部位主动释药,并对肝脏和肿瘤部位具有靶向性,从而表现出更好的抗肿瘤作用。
[Key word]
[Abstract]
Objective To investigate the antitumor activity of pH-sensitive liposomes (pH-LPC-lips) loaded with lactosyl-norcantharitin (Lac-NCTD) phospholipids complex in vitro and in vivo, and the liver targeting in mice. Methods Using blank liposomes (blank-lips and blank-pH-lips) as control, the MTT assay was used to study the cytotoxic effects of Lac-NCTD and its liposomes (Lac-lips and pH-LPC-lips) on human hepatoma carcinoma cells HepG2. HPLC assay was used to evaluate the uptake of Lac-NCTD and its liposomes in HepG2. In vivo antitumor activity of Lac-NCTD and its liposomes were evaluated in mice bearing H22 liver tumors. The hepatocyte specificity of near-infrared fluorescence dye (Cy7)-labeled pH-LPC-lips in H22 tumor-bearing mice was monitored through NIR fluorescence real-time tumor imaging instrument. Results The pH-LPC-lips demonstrated stronger cytotoxicity against tumor cells HepG2 and easily permeated the cell membrane, compared with Lac-NCTD and Lac-lips. The results of antitumor activity in vivo showed that pH-LPC-lips displayed best tumor inhibitory effect. The optical imaging results indicated that Cy7-labeled pH-LPC-lips showed excellent hepatocyte specificity in H22 tumor-bearing mice, which could reduced the side effect, and increased the antitumor activity. Conclusion The pH-LPC-lips could take the initiative to release at the tumor site and showed the liver-targeting. As a result, the preparation could be regarded as novel liver-targeting agent which has better antitumor effect.
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[基金项目]
国家科技部“十一五”重大新药创制技术平台项目资助(2009ZX09310-001);国家科技部科技型中小企业技术创新基金(07C26223201333);江苏省“六大人才高峰”资助项目