radiosensitization effect of pegylated gold nanoparticles in orthovoltage x-ray irradiation of the mcf-7 cancerous cell line

objective: due to recent advances in nanotechnology it is now possible to accumulate high atomic-number nanomaterial such as gold nanoparticles (gnps) in cancerous cells and take advantage of their absorbed dose enhancement property as radiosensitizing agents. this study aimed to investigate the absorbed dose enhancement factor due to the presence of pegylated gnps under the irradiation of an mcf-7 cancerous cell line using orthovoltage x-ray beams. methods: we synthesized gnps with an average diameter of 47 nm and joined them to polyethylene glycol. a total of 50 μg/ml of the pegylated gnps were incubated with mcf-7 cells for 1, 2, 6, 12, and 24 hours, after which we compared their cytotoxicities. then, pegylated gnps (50μg/ml) were incubated with mcf-7 cells for 12 and 24 hours and their radiosensitizing effect during 2gy delivery of 120, 180 and 200 kvp x-ray beams were compared by the mtt assay. results: cytotoxicity studies showed no significant effect of gnps on cell viability. significant differences in cell survival were observed between the groups irradiated with and without gnps, which lead to an average absorbed dose enhancement factor of 1.22±0.06. according to the results, there was no radiosensitization difference due to the usage of 120, 180 and 200 kvp x-ray beams. however increased incubation time increased the dose enhancement factor. conclusion: by using pegylated gnps we can decrease the prescribed x-ray dose, yet maintain the same level of cancerous cell killing.