The dependence of radiation enhancement effect on the concentration of gold nanoparticles exposed to low- and high-LET radiations.

Abstract

We examined the dependence of hydroxyl radical production on the concentration of 15 nm citrate-capped AuNPs and dose using coumarin-3-carboxylic acid in phosphate buffered saline (PBS), and investigated the radiosensitisation of different concentration AuNPs on human cervix carcinoma HeLa cells through clonogenic survival assay for X-rays and carbon ions. The enhancement factor of AuNPs for hydroxyl radical production reached a maximum 3.66 for X-rays at the concentration of 0.1 μg/mL while the maximum was 5.52 for carbon ions in presence of 1.0 μg/mL AuNPs in PBS. At 50% survival level, the sensitizer enhancement ratios of X-rays and carbon ions varied from 1.14 to 2.88 and from 1.27 to 1.44, respectively, when cells were co-cultured with 1.5-15.0 μg/mL AuNPs. Our data indicate AuNPs showed radiosensitisation in terms of hydroxyl radical production and cell killing for low- and high-LET radiations. The concentration of AuNPs in PBS and cells played an important role in radiosensitizing effect. Based on the fact-the AuNPs in PBS could improve the production of hydroxyl radical and no accumulation of cells in the G2/M phase was observed, we deduce that the increment of hydroxyl radical production with AuNPs provided a mechanism for radiosensitisation.

• Authors: Yan Liu, Xi Liu, Xiaodong Jin, Pengbo He, Xiaogang Zheng, Zhongying Dai, Fei Ye, Ting Zhao, Weiqiang Chen, Qiang Li
• Journal: Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) (Phys Med) Vol. 31 Issue 3 Pg. 210-8 (May 2015) ISSN: 1724-191X [Electronic] Italy
• PMID: 25651760 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Chemical References

• Citrates
• Coumarins
• Radiation-Sensitizing Agents
• Hydroxyl Radical
• Gold
• coumarin-3-carboxylic acid

Topics

• Cell Cycle (drug effects, radiation effects)
• Cell Survival (drug effects, radiation effects)
• Citrates (chemistry)
• Coumarins (chemistry)
• Dose-Response Relationship, Drug
• Dose-Response Relationship, Radiation
• Endocytosis (drug effects, radiation effects)
• Gold (chemistry, metabolism, pharmacology)
• HeLa Cells
• Heavy Ion Radiotherapy
• Humans
• Hydroxyl Radical (metabolism)
• Intracellular Space (drug effects, metabolism, radiation effects)
• Linear Energy Transfer
• Metal Nanoparticles
• Radiation Tolerance (drug effects)
• Radiation-Sensitizing Agents (chemistry, metabolism, pharmacology)
• X-Rays