Dendronized iron oxide colloids for imaging the sentinel node
Geneviève POURROY (Université de Strasbourg, France)
Abstract:
Nanoparticles combining optical and magnetic signals are promising for the detection of sentinel nodes by hand-held probes in cancer surgery. Now, radioactive colloids (RuS labelled with 99mTc) or/and Vital Blue dye are injected around the primary tumour and detected by nuclear probe or the eye respectively. The aim of our work is to replace the radioactive colloids by magnetic colloids by developing and optimizing dendronized iron oxide nanoparticles.
The nanoparticles were produced in an aqueous basic media and sorted by varying the ionic force, temperature and magnetic field parameters. The dendrons are either of first or second generation and bear a Patent Blue dye and/or a fluorescent dye. The suspensions have been characterized by dynamic light scattering, magnetic susceptibility and the amount of incorporated Patent Blue/fluorescent dye analyzed. We show that the structure and the composition of the aggregates strongly impact the optical and magnetic properties of the suspensions and therefore are critical for optimizing their detection sensitivity. Major attention was given to the effect of the dendron length, the grafting ratios, as well as to the electrostatic interactions between the dendron and the dye. Finally, in-vivo experiments on mice have been performed to determine the biodistribution.
This work was supported by the European Union in the framework of the program «Nano@matrix» INTERREG IV Upper Rhine Valley.
