We custom synthesize different gold nano-objects with controlled sizes and morphologies. This enables us to produce the most suitable nanomaterials for each project, to functionalize them with ligands of interest based on targeted properties (peptide, protein, PEGylated polymer, surfactant, etc.) [Gilles2014], and to control the characteristics obtained for each batch, ensuring reproducibility in subsequent experiments.

Images of different types of gold nanoparticles obtained by electron microscopy

We have a diverse range of instrumental facilities for routine analyses (UV-visible spectroscopy, vibrational spectroscopies, light scattering, zeta potential, HPLC, microcalorimetry) and utilize the Imaging-Gif platform for electron microscopy experiments (transmission, cryo-TEM, EDX).

The characterization of interactions between nanoparticles and radiation is far from being elucidated. [Gilles2018, Brun2016, Brun2024]. Therefore, we have developed a systematic and quantitative approach to the mechanisms involved, which has been lacking in the literature. In particular, we have developed methods to quantify the species produced in solution (electrons, hydroxyl radicals) during the interaction of ionizing radiation with nanoparticles [Sicard-Roselli2014, Gilles 2018, Brun2020]. We have studied the influence of surface coverage and size of nanoparticles, as well as the energy and nature of the incident radiation [Gilles2014, Baldacchino2019]. Different nanomaterials under varied irradiation conditions continue to be studied [Ducrozet2021, Ducrozet2023]. We also pay particular attention to solvent molecules on the surfaces of nanoparticles, whose predominant role has already been experimentally highlighted. A close collaboration with the ThéoSim group at ICP facilitates a back-and-forth between theory and experiment, which aids in a better understanding of these complex phenomena [Tandiana2021, Tandiana2022, Brun2024].

Schematic representation of reactive species production through the interaction of nanoparticles and radiation.

Articles on the radiosensitization of cancer cells are primarily descriptive, offering a binary response (yes/no) to the question: does this nanoparticle induce radiosensitization on the selected cell types? Given the numerous variable parameters from one study to another (NP – nature, size, surface chemistry, etc.; irradiation protocol – type of incubation, radiation type, dose, dose rate, etc.; cells), it is very challenging to extract useful information regarding the origin of radiosensitization. The facilities available at ICP (L2 laboratory, SpiCy platform) allow us to conduct experiments in cellulo. Thus, we can systematically test the radiosensitizing effect of nanoparticles on different models of healthy and cancerous human cells, following our physicochemical studies. We are also interested in the "biological" effect of nanoparticles, meaning independent of the additional energy deposited by the interaction with radiation.