Development of new bimodal molecular or nanoparticle probes combining MRI and PAI functionalities

Camille Gosée1,3, Cyril Cadiou3, Juliette Moreau3, Maïté Callewaert3, Lionel Larbanoix1,2, Françoise Chuburu3, Sophie Laurent1,2

1 General, Organic and Biomedical Chemistry Unit, NMR and Molecular Imaging Laboratory, University of Mons (UMONS), 7000 Mons, Belgium
2 Center for Microscopy and Molecular Imaging (CMMI), 6041 Gosselies, Belgium
3 Institut de Chimie Moléculaire de Reims, CNRS UMR 7312, University of Reims

Champagne-Ardenne URCA, 51685 Reims Cedex 2, France.
Contact : camille.gosee

The association of magnetic resonance imaging (MRI) with photoacoustic imaging (PAI) offers advantages in the medical field (faster detection of tumours, better understanding, and improvement of therapeutic protocols) owing to the excellent spatial resolution of the former technique and the high sensibility of the latter. This is the context of my thesis. For MRI imaging, T1 contrastophores (gadolinium chelates) will be used. For photoacoustic imaging, non-endogenous luminophores absorbing in the near infrared will be used. The NIR-absorbing luminophore used here is ZW800-1. The latter has been synthesised and fully characterised as shown in the presentation. The encapsulation of ZW800-1 within nanohydrogels, composed of chitosan and hyaluronic acid, was tested. To facilitate the formation of these nano-objects, ZW800-1 was grafted onto the CS backbone. Photophysical measurements were performed on free, grafted, and encapsulated ZW800-1 will be presented. For free ZW800-1, a single band was observed around 770 nm. For grafted and encapsulated ZW800-1, two bands were observed at 770 nm and 600 nm. To avoid this second band at 600 nm, purification tests are in progress. Preliminary optoacoustic experiments on nanoparticles have shown promising results as observed in the ghost images.