α-Irradiation setup for primary human cell cultures

Abstract

Purpose: We present an α-irradiation setup for the irradiation of primary human cell cultures under controlled conditions using ²⁴¹Am α-particles.

Materials and Methods: To irradiate samples with α-particles in a valid manner, a reliable dosimetry is a great challenge because of the short α-range and the complex energy spectrum. Therefore, the distance between α-source and sample must be minimal. In the present setup, this is achieved by cells growing on a 2 μm thick biaxially-oriented polyethylene terephthalate (boPET) foil which is only 2.7 mm apart from the source. A precise and reproducible exposure time is realized through a mechanical shutter. The fluence, energy spectra and the corresponding linear energy transfer are determined by the source geometry and the material traversed. They were measured and calculated, yielding a dose rate of 8.2 ± 2.4 Gy/min. To improve cell growth on boPET foils, they were treated with air plasma. This treatment increased the polarity and thus the ability of cells attaching to the surface of the foil. Several tests including cell growth, staining for a marker of DNA double-strand breaks and a colony-forming assay were performed and confirm our dosimetry.

Conclusion: With our setup, it is possible to irradiate cell cultures under defined conditions with α-particles. The plasma-treated foil is suitable for primary human cell cultures as shown in cell experiments, confirming also the expected number of particle traversals.

Keywords:

• Keratinocytes
• irradiation
• α-particles
• high LET
• radon

Acknowledgements

The authors thank the GSI mechanical workshop for their fast and accurate manufacturing of all mechanical parts and Franziska Papenfuß for useful discussions.

Disclosure of interest

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by the Federal Ministry of Education and Research (BMBF), Germany under grant number [02NUK017A] and [02NUK050A]; the Forschungsinstitut Bad Gastein under grant number [FOI-15/08-031WIE]; and Euradon.

Notes on contributors

Andreas Maier

Andreas Maier studied Biomedical Engineering at Technical University in Ilmenau, did his PhD at the biophysics department at GSI and is working there as a postdoc in the group “immune system and tissue radiobiology”.

Julia Wiedemann

Julia Wiedemann studied Biology at Technical University in Darmstadt, did her PhD at the biophysics department at GSI and is working there as a postdic in the group “immune system and tissue radiobiology”.

Julia Anna Adrian

Julia Anna Adrian studied Biology at Technical University of Darmstadt and at Norwegian University of Science and Technology. Part of the work presented in this publication was part of her Bachelor Thesis which she performed at GSI in Darmstadt. Currently she is doing her PhD at the University of California in San Diego.

Maximilian Dornhecker

Maximilian Dornhecker studied Biophysics at the Goethe University Frankfurt. Part of the work presented in this publication was part of his Bachelor Thesis which he performed at GSI in Darmstadt.

Andreas Zipf

Andreas Zipf studied Physics at Technical University of Darmstadt. Part of the work presented in this publication was part of his Bachelor Thesis which he performed at GSI in Darmstadt.

Wilma Kraft-Weyrather

Wilma Kraft-Weyrather studied Physics at the University of Cologne and did her PhD at the University of Gießen. At GSI she was leader of the Clinical Radiobiology group.

Gerhard Kraft

Gerhard Kraft studied Physics at the University of Heidelberg and did his PhD at the University of Cologne. At GSI he was head of the Biophysics department and is Helmoltz Professor for radiation biophysics at GSI.

Sandra Richter

Sandra Richter studied Material Science and Engineering at MLU in Halle, did her PhD on the topic of investigations for correlations of plasma parameters and surface properties at FhI in Halle and is currently working on the topic of plasma-surface interactions at the FhI for Microstructure for Materials and Systems in Halle.

Nico Teuscher

Nico Teuscher studied Physical engineering at Merseburg University of Applied Sciences, did his diploma at FhI in Halle and is working at the FhI for Microstructure for Materials and Systems in Halle on topics of surface modification by means of plasma and morphological, chemical and spectroscopic surface analysis.

Claudia Fournier

Claudia Fournier studied Chemical Technology at University of Applied Sciences and Microbiology at Technical University in Darmstadt. She did her PhD at GSI in Darmstadt, is leader of the group “immune system and tissue radiobiology” at GSI and is Professor at the University of Applied Sciences in Darmstadt.