Department of Biomedical Sciences, Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 501-746, South Korea.
J Biomed Nanotechnol. 2012 Jun;8(3):361-71. doi: 10.1166/jbn.2012.1407.
Cancer gene therapy involves the replacement of missing or altered genes with healthy ones. In this paper, we have proposed tumor suppressor gene-carrying superparamagnetic iron oxide nanoparticles (SPIONs) for anti-cancer gene therapy. Thermally crosslinked SPIONs (TCL-SPIONs) were conjugated with branched polyethylenimine (PEI 1800 Da) by EDC-NHS chemistry for p53 plasmid DNA delivery. The morphology of the bPEI conjugated TCL-SPIONs (bPEI-TCL-SPION) and pDNA-loaded bPEI-TCL-SPION nanoparticles was measured using transmission electron microscopy (TEM). The particle sizes of the pDNA-loaded bPEI-TCL-SPION nanoparticles were also confirmed by dynamic light scattering, and ranged from 100 to 130 nm, depending on the molar charge ratio. The fluorescently labeled pDNA was complexed with bPEI-TCL-SPION and its intracellular internalization was investigated using confocal microscopy. The p53 plasmid-loaded bPEI-TCL-SPION nanoparticles achieved significantly higher p53 tumor suppressor gene expression and cellular viability compared to positive controls. The expressed wild-type p53 protein suppressed tumor cell proliferation as compared to the mutant control. When transgene expression of the p53 tumor suppressor gene was evaluated at the mRNA level and quantified using real-time PCR, the results were highly dependent on the molar charge ratio (N/P) as well as the cancer cell type. SPIONs internalized within cancer cells were tracked by magnetic resonance (MR) imaging. It was concluded that bPEI-TCL-SPION could be used as efficient gene delivery carriers that can be tracked by MR imaging.
癌症基因治疗包括用健康基因替代缺失或改变的基因。在本文中，我们提出了携带肿瘤抑制基因的超顺磁性氧化铁纳米粒子（SPIONs）用于抗癌基因治疗。通过 EDC-NHS 化学将热交联的 SPIONs（TCL-SPIONs）与支化聚乙烯亚胺（PEI 1800 Da）偶联，用于 p53 质粒 DNA 的递送。使用透射电子显微镜（TEM）测量了 bPEI 偶联的 TCL-SPION（bPEI-TCL-SPION）和负载 pDNA 的 bPEI-TCL-SPION 纳米粒子的形态。负载 pDNA 的 bPEI-TCL-SPION 纳米粒子的粒径也通过动态光散射得到证实，粒径范围为 100-130nm，具体取决于摩尔电荷比。荧光标记的 pDNA 与 bPEI-TCL-SPION 复合，并使用共聚焦显微镜研究其细胞内内化情况。与阳性对照相比，负载 p53 质粒的 bPEI-TCL-SPION 纳米粒子实现了显著更高的 p53 肿瘤抑制基因表达和细胞活力。与突变对照相比，负载的野生型 p53 蛋白抑制肿瘤细胞增殖。当通过实时 PCR 以 mRNA 水平评估 p53 肿瘤抑制基因的转基因表达并进行定量时，结果高度依赖于摩尔电荷比（N/P）以及癌细胞类型。通过磁共振（MR）成像跟踪在癌细胞内内化的 SPIONs。得出的结论是，bPEI-TCL-SPION 可用作有效的基因递送载体，可通过 MR 成像进行跟踪。
