Abstract: To investigate the effects of AuNPs@MPA-PEG on radiosensitivity of human uterine cervix cancer cell line (Hela), aqueous solutions of AuNPs about 5.4 nm were synthesized by sodium borohydride reduction of tetrachloroauric (III) acid solution in the presence of sodium citrate. Gold nanoparticles (AuNPs) were modified with MPA-PEG or PEG. The intracellular uptake of AuNPs, AuNPs@MPA-PEG and AuNPs@PEG was detected using inductively-coupled plasma ectrometer. Colon forming assay was carried out to study the cells survival rate of Hela cells after exposure to AuNPs,AuNPs@MPA-PEG and AuNPs@PEG combined with radiation. The number of AuNPs, AuNPs@MPA-PEG and AuNPs@PEG in cells and nuclei had dependence on concentration. Gold nanoparticles modified by MPA-PEG or PEG couldn’t promote cells to absorb themselves. But gold nanoparticles modified by MPA-PEG were helpful to the nuclei uptake of gold nanoparticles. At 160 kV X ray energy, AuNPs,AuNPs@MPA-PEG and AuNPs@PEG all could increase the radiation sensitivity of Hela cells. Modification by MPA-PEG or PEG couldn’t increase significantly the radiation sensitivity of Hela cells by comparison with AuNPs.

Key words: gold chloride, gold nanoparticles, Hela cells, radiosensitivity