羧甲基壳聚糖载药纳米微球的制备及其对喉肿瘤细胞的杀伤及靶向作用的探测

Killing and targeting effects of carboxymethyl chitosan drug-loaded nanoparticles on Hep-2 laryngo cancer cells

目的:研究羧甲基壳聚糖(CMCS)载药纳米微球的制备及其对肿瘤细胞的杀伤和靶向作用。方法:将壳聚糖分子上的羟基改性成羧基,用于化学偶联阿霉素(ADR),并进一步在载药纳米微球上修饰转铁蛋白(Tf),制备主动靶向载药纳米微球;采用MTT(四甲基氮唑蓝)法评价载药纳米微球对喉肿瘤细胞的杀伤率;应用原子力显微镜(AFM)对载药纳米微球作用后喉肿瘤细胞表面超微结构的变化进行形态学观察。结果:载药纳米微球对喉肿瘤细胞的杀伤率比同剂量的ADR提高了31%,表面进一步修饰Tf后其杀伤率比同剂量ADR提高了41%。ADR与载药纳米微球对喉肿瘤细胞的细胞膜表面超微结构的影响存在较大的差异。结论:载药纳米微球在肿瘤细胞表面受吸附或受体介导的内吞作用,致使微球在细胞表面的释药机制不同于单独药物的扩散模型,从而明显提高对肿瘤细胞的杀伤率,这对探讨药物的作用机制和靶向药物的研发具有重要的指导意义。

Objective：Preparation of targeting carboxymethyl chitosan（CMCS） drug-loaded nanoparticles and study of its killing and targeting effects on cancer cells.Methods： Targeting drug-loaded nanoparticles were prepared by changing the hydroxide on chitosan to carboxyl to form CMCS,and then conjugated with adriamycine（ADR） and transferrrin（Tf）.MTT assay was used to envaluate the killing effect of CMCS drug-loaded nanoparticles on human laryngo Hep-2 cancer,and the morphology of membrane surface ultrastructures of cancer cells were observed by atomic force microscopy（AFM）.Results： The results revealed that CMCS drug-loaded nanoparticles were more potent in killing cancer cells.AFM images showed that there were distinct differences of membrane surface ultrastructures after ADR and CMCS drug-loaded nanoparticle treatment.Conclusion： CMCS drug-loaded nanoparticles are more potent in killing cancer cells than ADR attributing to the adsorption effect or the receptor-mediated endocytosis of CMCS drug-loaded nanoparticles on cancer cells.These results will contribute to better understanding of the anticancer mechanism of targeted drugs.