Modulation of cancer cells' radiation response in the presence of folate conjugated Au@FeO nanocomplex as a targeted radiosensitizer.

Objectives: To investigate the effects of Au@FeO core-shell nanoparticle (NP), with and without conjugation to folic acid (FA) as a targeting ligand, on radiosensitization of both cancer and healthy cells.

Methods: Au@FeO NPs were first synthesized, then modified with FA, and finally characterized. Radiation dose enhancement studies were performed on KB cancer cells and L929 healthy cells. NPs at the concentration of 20 µg/ml were first incubated with both cell lines and then different doses of 6 MV X-ray radiation were examined. The end effects were evaluated via MTT assay and flow cytometry using AnnexinV/PI kit.

Results: It was indicated that viability of KB cells has a much lower rate than L929 cells when the cells were treated by {(FA-Au@FeO) + (X-ray)} regimen. Cell viability was even decreased significantly when X-ray dose increased. Moreover, flow cytometry studies revealed that FA-targeted NPs induced higher level of apoptosis for KB cancer cells than L929 healthy cells.

Conclusion: Our findings provide a new perspective on high ability of the synthesized FA-targeted Au@FeO NPs which may be considered as an efficient radiosensitizer in the process of targeted radiation therapy of cancer.