Cellular analysis on the radiation induced bystander effects due to bismuth oxide nanoparticles with 6 MV photon beam radiotherapy

Abstract

BackgroundThe therapeutic strategies in killing the cancerous tissue while keeping the normal healthy tissue uninterrupted can be further improved by introducing nanoparticles as radiosensitizer in radiotherapy. Nevertheless, healthy cells might still be affected by radiation-induced bystander effect (RIBE) response due the presence of nanoparticles. Thus, the potential negative effects in non-irradiated adjacent cells must be investigated. AimThe current study aims to explore the cellular effects of bismuth oxide nanoparticles (Bi2O3 NPs) on human breast cancer (MCF-7) and human foetal osteoblast (hFOB 1.19) cells due to the RIBE after irradiation with 6 MV clinical photon beam. Materials and methodsThe irradiated-cell conditioned medium (ICCM) treated with and without Bi2O3 NPs from the irradiated cells were collected and then transferred into the non-targeted cells. The ability of the bystander cells to proliferate and their ROS generation were analyzed. DNA status of the cells and the possibility of apoptosis were evaluated using FTIR spectroscopy and MUSE Cell Analyzer, respectively. ResultsThe current study revealed that MCF-7 and hFOB 1.19 bystander cells may continue to proliferate and survive following short and long-term incubation with ICCM treatment with Bi2O3 NPs. The survival rate of the treated bystander cells increased approximately 3%–8% compared to the untreated group. Although the bystander cells exhibited an increase in ROS and apoptosis, the addition of Bi2O3 NPs had no significant detrimental influence on the cells. Variation in the DNA vibrational amplitude detected by FTIR in bystander cells was less than 5% compared to the control group. ConclusionThis study discovered that the application of Bi2O3 NPs as a radiosensitizer did not give a negative impact on the bystander cells. This outcome may give an advantage to the application of Bi2O3 NPs as radiosensitizer in radiotherapy to enhance cancer cells death without introducing further detrimental effects to the non-targeted cells.