结肠癌靶向米托蒽醌脂质体的制备及其抗肿瘤活性研究

目的:比较透明质酸(HA)修饰的脂质体(HA-LP)与普通脂质体(LP)的抗转移及抗肿瘤活性。方法:采用薄膜水化法制备空白脂质体,通过透明质酸上的羧基与膜材中DSPE的氨基反应将HA连接在脂质体上,运用硫酸铵梯度法包载模型药物米托蒽醌;通过透射电镜表征脂质体形态;免疫荧光法检测结肠癌细胞(CT26 cells)中透明质酸受体CD44表达情况;高内涵扫描仪检测结肠癌细胞对脂质体的摄取情况;划痕实验考察2组脂质体抑制细胞转移的能力;体内抗肿瘤实验考察2组脂质体的抑瘤效果。结果:所制备的脂质体形态均一,包封率均大于95%。免疫荧光结果显示,结肠癌细胞中CD44受体高度表达。相同的药物浓度下,HA-LP相较于未修饰的脂质体具有明显增加的细胞摄取。划痕实验结果表明,HA可能与受体CD44存在某种相互作用,抑制了结肠癌细胞的转移,表现出HA-LP具有更强的抗转移活性。体内抗肿瘤结果显示,HA-LP对小鼠荷结肠癌实体瘤的抑瘤率为62.1%,显著高于普通脂质体组(46.6%,P<0.05)。结论:HA-LP与细胞膜上的受体CD44作用,显著增加了其细胞摄取,并抑制了结肠癌细胞的转移,体内抑瘤结果同样显示,具有肿瘤靶向功能的HA-LP具有更强的抑制肿瘤生长的能力。

Preparation of colon cancer targeted mitoxantrone liposomes and investigation on its antitumor activity

OBJECTIVE To compare the metastasis inhibiting and anti-tumor activities of hyaluronic acid (HA) modified liposomes (HA-LP) and regular liposomes (LP).METHODS Blank liposomes were prepared by thin film hydration method.Mitoxantrone loaded liposomes were prepared by chloroform injection combined with ammonium sulfate gradient method.Transmission electron microscope was used to characterize liposome morphology.Immunofluorescent method was used to detect expression of hyaluronic acid receptor CD44 in colon cancer cells (CT26 cells).High content scanner was used to detect liposome intake in colon cancer.Scratch test investigated the anti-metastasis of 2 groups of liposomes.In vivo anti-tumor test investigated the anti-tumor effects of 2 groups of liposomes.RESULTS Morphologies of HA-modified and non-modified liposomes were homogeneous,with entrapment efficiencies above 95%.Stronger fluorescence was observed in CT26 cells which indicating higher expression of CD44.As expected,HA-LP treated cells showed enhanced cell internalization compared with LP.In wound healing assay,HA-LP displayed stronger inhibiting effects than LP on cell migration,probably due to interaction with CD44.The inhibitory rate in mice bearing solid colon tumor of HA-LP was 62.1%,remarkably higher than LP (46.6%,P<0.05).CONCLUSION HA-LP targets to colon tumor cells selectively,which enhances cell uptake and inhibits cell metastasis.Moreover,HA-LP exhibits stronger inhibiting effects against tumor growth than LP.