PhD defense of Riccardo Ossanna

In the framework of the project ‘Control of Optical Absorption Properties of Nanovectors for PhotoACoustic Imaging’ (CAP-Photoac) funded by ANR from 2021 to 2025 (ANR 21-CE09-0024-01), we are interested in the development of novel dyes and nanoparticles for photacoustic imaging. These nanoparticles will be designed to be both imaging agents and drug nanovectors. Nanovectors (NVs) are expected to profoundly change the treatment of common diseases such as rheumatoid arthritis or cancer. Improving the efficacy of NVs will require patient selection via accumulation imaging. The CAP-Photoac project therefore aims to prepare NVs labeled with organic contrast agents for photoacoustic imaging (PAI). PAI is an emerging modality capable of mapping (cm depth, ~ 0.1 mm resolution) optical absorption in vivo. We have already developed new molecular absorbers to label polymeric NVs (J.B. Bodin thesis). We are now seeking to develop pH-sensitive fluorophores and to integrate them into NVs to study their cellular penetration (scheme below). Stability, biocompatibility, photophysical and photoacoustic properties of NVs will be characterized. New formulations of fluorophores can be considered. Their intra-tissue and intracellular accumulation kinetics will then be imaged in a mouse model by PAI and fluorescence imaging.