Development and characterization of anin vitroalpha radiation exposure system

Abstract

A simple in vitro alpha radiation exposure system (ARES) was designed to study the biological effects of alpha particle radiation. The ARES consists of six (241)Am electroplated stainless steel discs with activities averaging 66 kBq and Mylar-based culture dishes to allow the transmission of alpha particles. The dosimetry of the exposure system was calculated using the GEANT4 Monte Carlo simulation toolkit with the source code adapted from the open-source Microbeam example. The average dose rate and linear energy transfer of the system was simulated to be 0.98 ± 0.01 (statistical)(+0.18)( - 0.00) (systematic) Gy h(-1) and 127.4 ± 0.4 (statistical)(+23)( - 0) (systematic) keV µm(-1), respectively. The system was characterized by a comparison of the survival curves of gamma and alpha irradiated cell lines which showed a relative biological effectiveness of 6.3. This is in good agreement with values obtained using other published alpha particle exposure systems. Results show that the ARES provides a simple, cost-effective exposure platform for research into the biological effects of alpha particle radiation using in vitro modelling of cell cultures.

Identification of gene-based responses in human blood cells exposed to alpha particle radiation

“…Irradiations were performed at doses of 0 (control), 0.5, 1.0 or 1.5 Gy using Americium ( 241 Am) electroplated discs with an activity level of 66.0 kBq ± 3% (dose rate of 0.98 ± 0.01 Gy/h, LET of 127.4 ± 0.4 keV/μm). The absorbed dose of α-particle radiation to which the cells were exposed was calculated using the GEANT4 v.9.1 Monte Carlo tool-kit [25]. Cells destined for X-ray radiation at doses of 0 (control) 2, 5 or 10 Gy were exposed using the X-RAD 320 X-ray irradiation system (Precision X-ray, Inc., North Branford, CT, USA) at a higher dose rate of 0.98 ± 0.05 Gy/min.…”

Differential Effects of Alpha-Particle Radiation and X-Irradiation on Genes Associated with Apoptosis

“…The cells were exposed to α -particle radiation at doses ranging from 0.0 (control) to 1.5 Gy, using 241 Americium-( 241 Am) electroplated discs (Eckert and Ziegler Isotope Products Ltd, Valencia, Calif, USA) having an activity level of 66.0 kBq ± 3% (dose rate of 0.98 ± 0.01 Gy/h, LET of 127.4 ± 0.4 keV/ μ m). The absorbed dose of α -radiation to which cells were exposed was calculated using the GEANT4 v.9.1 Monte Carlo toolkit [19]. For the α -particle exposures, cells were cultured in thin Mylar-based plastic dishes (MD) (Chemplex Industries, Palm City, Fla, USA), which allowed the penetration of the α -particles.…”

Effects of α-Particle Radiation on MicroRNA Responses in Human Cell-Lines

“…The viability remained above 98% in all treatment groups and controls, indicating that the α-particle radiation did not cause a significant degree of cell death (data not shown). Previous studies from our laboratory have assessed the biological impacts of α-particle radiation effects on cellular viability, apoptosis, cell survival and γ-H2AX induction [14, 18]. Immediate effects on cell viability are minimal; however DNA damage induction can be seen 30 minutes post-exposure through γ-H2AX assessment [19].…”

“…The cells were cultured to ~ 90% confluency, then exposed to α-particle radiation at doses ranging from 0.0 (control) to 1.5 Gy, using Am-241 electroplated discs(Eckert and Ziegler Isotope Products Ltd, Valencia, CA, USA) having an activity level of 66.0 kBq ± 3% (dose rate of 0.98 ± 0.01 Gy/h, LET of 127.4±0.4 keV/µm). The absorbed dose of α-radiation to which cells were exposed was calculated using the GEANT4 v.9.1 Monte Carlo toolkit and validated with in vitro experiments [14]. For the α-particle exposures, cells were cultured in thin Mylar based plastic dishes (MD) (Chemplex Industries, Palm City, FL, USA), which allowed the penetration of the α-particles.…”