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金纳米颗粒(gold nanoparticles,GNPs)以其独特的理化特点而广泛应用于肿瘤诊疗研究。GNPs生物相容性好,原子序数高,对kV级射线的光电效应截面比软组织高,能提高肿瘤组织的局部能量沉积,是一种有良好应用前景的放射增敏剂。MV级射线通过康普顿散射与GNPs相互作用,但其截面远远低于kV级射线与GNPs作用的截面,因此GNPs对其增敏效应不如kV级射线显著。GNP诱导细胞内活性氧簇(reactive oxygen species,ROS)增加,引起DNA损伤,诱导细胞凋亡。GNPs通过调控细胞周期进程,使细胞阻滞在G_2/M期,增强细胞的放射敏感性。此外,GNPs还能引起细胞内自噬体增多和溶酶体降解能力减弱并最终引起细胞死亡。GNPs也可以抑制缺氧诱导因子1α(hypoxia inducible factor-1α,HIF-1α)和血管内皮生长因子(vascular endothelial growth factor,VEGF)mRNA表达,使裸鼠肝癌血管形态趋于正常。
Gold nanoparticles (GNPs) are widely used in oncology research for their unique physical and chemical characteristics. GNPs have good biocompatibility and high atomic number. The photoelectric effect cross section of kV-ray is higher than that of soft tissue, which can improve the local energy deposition of tumor tissue. GNPs is a promising radiosensitizer. MV-rays interact with GNPs through Compton scattering, but their cross-section is much lower than that of kV-ray interaction with GNPs. Therefore, the sensitizing effect of GNPs is not as significant as kV-ray. GNP induces an increase of intracellular reactive oxygen species (ROS), induces DNA damage and induces apoptosis. GNPs regulate cellular cycle progression and block cells in G2 / M phase, which enhances the radiosensitivity of cells. In addition, GNPs also cause increased intracellular autophagosomes and diminished capacity for lysosomal degradation and ultimately cell death. GNPs can also inhibit the mRNA expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF), so that the blood vessel morphology of liver cancer in nude mice tends to be normal.