Design of Dendrimer Modified Carbon Nanotubes for Gene Delivery

Objective: To investigate the efficiency of polyamidoamine dendrimer grafted carbon nanotube (dendrimer-CNT) mediated entrance of anti-survivin oligonucleotide into MCF-7 cells, and its effects on the growth of MCF-7 cells. Methods: Antisense survivin oligonucleotide was anchored onto polyamidoamine dendrimer grafted carbon nanotubes to form dendrimer-CNT-asODN complex and the complex was characterized by Zeta potential, AFM, TEM, and 1% agarose gel electrophoresis analysis. Dendrimer-CNT-asODN complexes were added into the medium and incubated with MCF-7 cells. MTT method was used to detect the effects of asODN and dendrimer-CNT-asODN on the growth of MCF-7 cells. TEM was used to observe the distribution of dendrimer-CNT-asODN complex within MCF-7 cells. Results: Successful synthesis of dendrimer-CNT-asODN complexes was proved by TEM, AFM and agarose gel electrophoresis. TEM showed that the complexes were located in the cytoplasm, endosome, and lysosome within MCF-7 cells. When dendrimer-CNT-asODN (1.0 μmol/L) and asODN (1.0 μmol/L) were used for 120 h incubation, the inhibitory rates of MCF-7 cells were (28.22±3.5)% for dendrimer-CNT-asODN complex group, (9.23±0.56)% for only asODN group, and (3.44±0.25)% for dendrimer-CNT group. Dendrimer-CNT-asODN complex at 3.0 μmol/L inhibited MCF-7 cells by (30.30±10.62)%, and the inhibitory effects were in a time- and concentration- dependent manner. Conclusion: Dendrimer-CNT nanoparticles may serve as a gene delivery vector with high efficiency, which can bring foreign gene into cancer cells, inhibiting cancer cell proliferation and markedly enhancing the cancer therapy effects.     

碳纳米管-树形分子载体递送 Survivin 反义寡核苷酸对肝癌细胞增殖的作用

目的〖HT5"SS〗： 探讨碳纳米管(CNT)树形分子递送Survivin反义寡核苷酸(ASOND)进入肝癌细胞HepG2的效率及其对肝癌细胞增殖的影响。〖HT5W〗方法〖HT5"SS〗： 制备碳纳米管与PAMAM树形分子复合物,与Survivin反义寡核苷酸组装后,用原子力显微镜(AFM)与凝胶电泳观察碳纳米管树形分子反义核苷酸复合物的形态结构;然后将复合物与人肝癌HepG2细胞共培养,同时设立对照,采用透射电镜观察碳纳米管树形分子反义核苷酸复合物在细胞中的定位,采用MTT法检测复合物对癌细胞生长的抑制作用。〖HT5W〗结果： 〖HT5"SS〗AFM与凝胶电泳分析证实碳纳米管树形分子反义核苷酸复合物被成功制备。透射电镜观察证实碳纳米管树形分子反义核苷酸复合物位于细胞质。MTT法检测表明,CNTPAMAMASODN浓度为1.0 μmol/L时,即可抑制(4597±4.28)%的HepG2细胞增殖,而ASODN组和CNTPAMAM组在此浓度条件下对HepG2细胞的抑制率则分别为(933±0.85)%和(6.37±0.69)%; 当CNTPAMAMASODN达到1.50 μmol/L时,细胞抑制率为(70.22±7.25)%,而且抑制作用随培养时间的延长与浓度的增加而增强,实验组与对照组之间细胞抑制率存在显著性差异(P<0.01)。〖HT5W〗结论〖HT5"SS〗： 碳纳米管树形分子复合物是一种高效的基因递送载体,能够携带Survivin反义寡核苷酸进入肝癌细胞,并高效抑制HepG2细胞的增殖,显著增强反义寡核苷酸的作用效果。