Enhancing the effect of 4 MeV electron beam using gold nanoparticles in breast cancer cells

Abstract

Gold nanoparticles (GNPs) have been applied as radiosensitizer in radiotherapy. Limited reports have shown that GNPs may be effective as a dose enhancer agent for electron radiation therapy. Some Monte Carlo Simulation studies have shown that selecting suitable size of GNPs and electron energies are critical for effective dose enhancement. The aim of this study was to assess possible radiosensitization effect of GNPs on cancer cell treated with 4MeV electron beams. Approximately 10nm GNPs were synthesized and characterized by electron microscope and dynamic light scattering. MCF-7 and MDA-MB-231 breast cancer cells were used and their viability was measured by MTT assay. Radiosensitization effect of GNPs under 4MeV electron beams was measured by clonogenic assay. The result showed a concentration dependent uptake of GNPs without reducing cell viability at concentrations ≤50mg/L. Incubation of cancer cells with GNPs caused a significant decrease in their viability following exposure to electron beams as well as a decrease in their survival fraction when compared to control. The sensitizer enhancement ratio (SER) by electron beams in MCF-7 cells was 1.43 and 1.40 in presence of 25 and 50mg/L GNPs, respectively. For MDA-MB-231 cells, it was 1.62 in presence of 25mg/L GNPs. Our data demonstrated the significant dose enhancement of the GNPs in combination with 4MeV electron beams that could be applicable for the treatment of superficial tumors and intra operative radiation therapy.

Evaluating the Bystander Effects of Electron Beam Irradiation in Radiotherapy on MCF-7 Human Breast Cancer Cells

“…Furthermore, we examined the bystander effects of irradiated MCF-7 cells on the different cell lines, which are known play pivotal roles in cancer treatment. Consistent with previous studies (20,21), we found that the cell viability and apoptosis rate of irradiated MCF-7 cells were dose-dependently decreased and increased respectively (Fig. 1).…”

Enhancing and Mitigating Radiolytic Damage to Soft Matter in Aqueous Phase Liquid-Cell Transmission Electron Microscopy in the Presence of Gold Nanoparticle Sensitizers or Isopropanol Scavengers

“…In particular, the potential exists for damage to surface ligands or other organic components of the system. Indeed, prior radiation chemistry studies have shown GNPs have a significant “dose enhancement” effect in water. − The sensitization effect of gold, reported to increase the effective dose by nearly 100 times under X-ray radiation, , is chiefly caused by the irradiation-triggered release of secondary electrons and X-rays from GNPs, which directly radiolyze the surrounding solution, causing an effective local dose increase. Thus, in water, any organic molecule is expected to readily undergo indirect beam-induced damage during LCTEM, − , and this chemical damage should be enhanced by GNPs or mitigated by a scavenging alcohol cosolvent.…”

Radiosensitization of breast cancer cells using AS1411 aptamer-conjugated gold nanoparticles

“…In vivo and in vitro works by Chang et al showed GNPs radiosensitizing effect at high energy electron beams (50). To test our hypothesis that GNPs induce radiosensitization effect in the 4 MeV electron radiation beam condition, we made preliminary studies to measure the effect of 10 nm GNPs at different concentrations (51). Our previous data showed that this sensitizing effect depends on GNP's concentrations and the radiation dose.…”