This work has enabled a comprehensive evaluation of different sequences of siRNAs directed against EWS/Fli-1 in the treatment of tumors of the Ewing sarcoma family of tumors (ESFT). A siRNA was efficiently vectorized by polymeric nanoparticles targeted against a specific membrane marker of ESFT. These nanoparticles were characterized and appear to be well tolerated both in vitro and in vivo. Their evaluation was conducted on human cells and tumors which represents an interesting step forward in the fight against ESFT. The development of a fluorescent model of Ewing's sarcoma will better characterize their effect on metastasis, a key factor in patient survival. Finally, it was shown that in vivo imaging techniques allow to follow the fate of nanoparticles in vivo. That will allow understanding their biodistribution and their mode of action.
