Study on the effect of metal nanoparticles on radiosensitivity of gastric adenocarcinoma cell line with GEANT4 Monte Carlo simulation

Abstract

The aim of this study was to investigate the enhancement effects of radiation therapy using gold, silver, platinum, bismuth, iron oxide, titanium oxide and germanium nanoparticles. In this study, we firstly investigated the enhancement mechanisms of X-ray on physical and chemical levels using Geant4 computational code, then the radiation sensitivity of gastric adenocarcinoma cell line in 6 MV X-ray in the presence of nanoparticles was calculated using LEM radiobiological model. To simulate the AGS cells, a sphere with a radius of 7.72 µm was designed and a sphere with a radius of 3.72 µm was positioned at center as the cell’s nucleus. The effect of 0.05 µM, 0.25 µM and 0.5 µM of the nanoparticles with homogeneous distribution throughout the cell, in the cell’s nucleus, cytoplasm and extracellular matrix were investigated. The results showed that in terms of dose and radiolysis enhancement, the nanoparticles can be divided into three groups: strong enhancers including gold and platinum nanoparticles, medium enhancers containing silver and bismuth nanoparticles and weak enhancers including titanium and germanium oxide and iron oxide nanoparticles. Among the chemical species e_aq- ، H3O+ ، •OH were the most abundant around the nanoparticles. The survival reduction coefficient for light nanoparticles including 0.5 μM titanium oxide and iron oxide and germanium in the cell nucleus was obtained 0.5. For heavy nanoparticles including 0.5 μM gold, silver, bismuth and platinum inside the cell’s nucleus the reduction coefficients were found 0.3 to 0.1. It was found that all of the examined nanoparticles have the potential to be used as radiation sensitizer in the gastric cancer cell line, especially when concentrated in the cell nucleus.