In addition to nano-structure/bacteria interactions, we are also interested in nanoparticles as drug delivery agents in connection with new imaging technologies. Thanks to the ANR Cap-PhotoAc grant, a chromophore (Bodipy – collab. Laboratoire de Photophysique Photochimie Supra- et Macromoléculaires PPSM, ENS Paris-Saclay) has been grafted onto nanovectors (collab. Institut Galien Paris-Saclay). The new dye features an optimized near-infrared absorption band in biological tissues and a low fluorescence quantum yield, leading to good photoacoustic generation (PA) efficiency (Laboratoire d’Imagerie Biologique). Polylactide-Bodipy was formulated into PEGylated nanoparticles. The formulated NPs (100 nm) show excellent PA properties: absorption band at 760 nm and molar absorption coefficient between that of molecular PA absorbers and gold NPs. Significantly improved photostability – compared with cyanine-labeled polylactic acid NPs – and safety in cultured macrophages were also demonstrated. After intravenous injection in healthy animals, the NPs were easily detected using a commercial PA imaging system and spectral unmixing, paving the way for their use as theranostic agents.
Contact :
Rachel Méallet