title: Development and performance evaluation of a three-dimensional clinostat synchronized heavy-ion irradiation system.
abstract: Outer space is an environment characterized by microgravity and space radiation, including high-energy charged particles. Astronauts are constantly exposed to both microgravity and radiation during long-term stays in space. However, many aspects of the biological effects of combined microgravity and space radiation remain unclear. We developed a new three-dimensional (3D) clinostat synchronized heavy-ion irradiation system for use in ground-based studies of the combined exposures. Our new system uses a particle accelerator and a respiratory gating system from heavy-ion radiotherapy to irradiate samples being rotated in the 3D clinostat with carbon-ion beams only when the samples are in the horizontal position. A Peltier module and special sample holder were loaded on a static stage (standing condition) and the 3D clinostat (rotation condition) to maintain a suitable temperature under atmospheric conditions. The performance of the new device was investigated with normal human fibroblasts 1BR-hTERT in a disposable closed cell culture chamber. Live imaging revealed that cellular adhesion and growth were almost the same for the standing control sample and rotation sample over 48h. Dose flatness and symmetry were judged according to the relative density of Gafchromic films along the X-axis and Y-axis of the positions of the irradiated sample to confirm irradiation accuracy. Doses calculated using the carbon-ion calibration curve were almost the same for standing and rotation conditions, with the difference being less than 5% at 1Gy carbon-ion irradiation. Our new device can accurately synchronize carbon-ion irradiation and simulated microgravity while maintaining the temperature under atmospheric conditions at ground level.
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-8511, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-8511, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Souda
authors.affiliation: Gunma University Initiative for Advanced Research, Maebashi, Gunma 371-8511, Japan.
authors.forename: Anggraeini
authors.initials: A
authors.lastname: Puspitasari
authors.affiliation: Gunma University Initiative for Advanced Research, Maebashi, Gunma 371-8511, Japan; Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Kathryn D
authors.initials: KD
authors.lastname: Held
authors.affiliation: Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Hidema
authors.affiliation: Department of Nutritional Physiology, Institute of Medical Nutrition, Tokushima University Graduate School, Tokushima, Tokushima 770-8503, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nikawa
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-8511, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Yoshida
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-8511, Japan.
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Kanai
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-8511, Japan. Electronic address: a-takahashi@gunma-u.ac.jp.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Takahashi
mesh_terms: D002468:Cell Physiological Phenomena / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000528:radiation effects*; D063193:Heavy Ion Radiotherapy / Q000009:adverse effects*; D006801:Humans; D010315:Particle Accelerators / Q000295:instrumentation*; D018474:Weightlessness Simulation / Q000295:instrumentation*
keywords: Combined effects; Heavy-ion; Microgravity; Space radiation; Three-dimensional clinostat