中文摘要：

目的研究Au纳米颗粒对HepG2细胞的放射增敏作用。方法首先制备典型的15nm聚乙二醇（PEG）包裹的Au纳米颗粒，然后使用紫外可见分光光度计实时定量检测纳米颗粒的血浆稳定性，同时使用噻唑蓝法研究给药后24h和48h的细胞活性，最后，通过克隆形成实验研究不同浓度的Au纳米颗粒对HepG2细胞的放射增敏作用。结果PEG包裹的Au纳米颗粒具有较好的血浆稳定性，在24h及以后未见表面等离子共振吸收峰有明显的偏移。细胞活性实验表明，24h后，细胞的活性有所降低，但是48h后细胞的活性迅速恢复到90％。进一步研究克隆形成发现，Au纳米颗粒具有明显的放射增敏作用。结论15nmPEG包裹的Au纳米颗粒具有较高的血浆稳定性、较低的细胞毒性和较好的放射增敏作用。

英文摘要：

Objective To investigate the radiosensitivity enhancement of Au nanoparticles to HepG2 cell. Methods 15 nm polyethylene-glycol-coated（PEG） Au nanoparticles were synthesized, and then blood stability were tested by using the UV-vis optical absorption. Meanwhile, 3-（4, 5-dimethyhhia-zol-2-yl）-2, 5-diphenyhetrazolium bromide methods were used to investigate the cell viability after 24 and 48 hours treatments, and cloning formation were used to investigate the radiosensitivity enhancement. Results It was found that PEG-coated Au nanoparticles presented a high blood stability, and surface plasmon response has not shown significant changes after 24 hours. Cell viability was decreased after 24 hours treatment, but it was recovered to 90% after 48 hours. Cloning formation showed Au nanoparticles presented a significant radiosensitivity enhancement. Conclusion 15 nm PEG-coated An nanoparticles presented a good blood stability, low eytotoxieity and high radiosensitivity enhancement.