Postdoctoral Researcher (18 months) - SPARTA

2. Mission

The SPARTA project aims to establish a new paradigm for assessing the biological risk associated with micrometric stainless steel particles representative of those generated during maintenance and decommissioning of present and future facilities using tritium (the radioactive hydrogen isotope), such as fusion power plants. The experimental study will be performed using hydrogenated particles to mimic tritiated ones. Building on the European TRANSAT and TITANS projects, SPARTA shifts from conventional population-based toxicology towards quantitative single-cell radiobiology.

Differentiated THP-1 macrophages will be analysed using the AMUTICYT imaging flow cytometry platform. For each individual cell, particle burden, particle geometry, particle-to-nucleus distance, reactive oxygen species (ROS), γH2AX signalling and centromeric or acentromeric micronuclei will be quantified simultaneously. These descriptors will be integrated into Monte Carlo simulations performed with the support of the University of Pavia to predict local energy deposition and DNA damage expected if identical particles were tritiated. The project will establish the first integrated framework combining experimental biology and computational modelling to relate intracellular particle localisation to predicted radiobiological effects.

3. Activities

The successful candidate will develop high-throughput imaging flow cytometry methods to characterize particle internalisation and genotoxicity. Genotoxicity will be assessed using the OECD TG 487 in vitro micronucleus assay together with the γH2AX assay, combined with oxidative stress measurements and particle uptake quantification in differentiated and undifferentiated THP-1 macrophages.

Specific objectives:

• Develop a multiparametric single-cell workflow using the AMUTICYT platform.
• Measure particle number, size, localisation, ROS, γH2AX and micronuclei for each macrophage.
• Build a quantitative single-cell database.
• Interact closely with the University of Pavia for integration of biological descriptors into Monte Carlo micro-dosimetric simulations.
• Contribute to a predictive framework for biological risk assessment relevant to future fusion facilities.

The postdoctoral researcher will also:

• Maintain the state of the art on the genotoxicity of tritiated particles.
• Develop high-throughput imaging versions of the γH2AX and in vitro micronucleus assays.
• Perform experimental studies, analyse data, prepare study reports, scientific communications and peer-reviewed publications.

4. Required skills

• Excellent command of French and very good written and spoken English.
• Strong experience in experimental biology, ideally genetic toxicology and flow cytometry.
• Experience in mammalian cell culture.
• Experience with optical and epifluorescence microscopy.

5. Working environment

The researcher will join the SANTES team at IMBE and will interact closely with all SPARTA consortium partners. The position will be supervised by a Research Engineer leading the team and will involve regular consortium meetings.

Applications (cover letter and CV) should be sent to:
Dr Thierry Orsière : thierry.orsiere@imbe.fr and ISFIN institute : isfin-direction@univ-amu.fr