Rose Bengal coupled to AGuIX NPs for anti-cancer photodynamic therapy

Rose Bengal is a well-known photosensitizer used in the treatment of several diseases [1, 2]. This photosensitizer produces a large amount of singlet oxygen upon specific illumination, which allows its use in pho-todynamic therapy [3]. The work to be presented highlights the passive tumor targeting by coupling Rose Bengal to nanoparticles in clinical phase 2 AGuIX chelated with lanthanides (Terbium or Gadolinium). One of the limitations of photodynamic therapy is the poor penetration of light into the tissues [4]. X-ray excitation of AGuIX(Ln)@RB over-comes this problem. Following the excitation of the lanthanide by X-ray, a FRET energy transfer from lanthanide to Rose Bengal takes place. Rose Bengal is then able to produce singlet oxygen. To enhance the tar-geting, peptide can be covalently couple to the nanoparticles [5]. Two types of peptide targeting NRP1 receptors over-expressed in neovessels were grafted on the nanoparticles.This presentation focuses on the synthesis, photophysical properties of these nanoparticles, physical characterization, the type of energy trans-fer between the species, and the in vitro PDT-X effect.