ULTRAFINE NANOPARTICLES COMPRISING A FUNCTIONALIZED POLYORGANOSILOXANE MATRIX AND INCLUDING METAL COMPLEXES; METHOD FOR OBTAINING SAME AND USES THEREOF IN MEDICAL IMAGING AND/OR THERAPY

摘要

The invention relates to novel biocompatible hybrid nanoparticles of very small size that are of use in particular for diagnosis and/or therapy. The objective of the invention is to provide novel nanoparticles which are of use in particular as contrast agents in imaging (e.g. MRI) and/or in other diagnostic techniques and/or as therapeutic agents, which are more effective than the known nanoparticles of the same type and which combine both a small size (for example less than 20 nm) and a high metal (e.g. rare earth) loading rate, in particular so as to have, in imaging (e.g. MRI), a strong enhancement and a correct response (increased relaxivity) at high frequencies. Thus, the nanoparticles according to the invention, of diameter d1 between 1 and 20 nm, each comprise a polyorganosiloxane (POS) matrix including gadolinium cations, optionally associated with doping cations; a DTPABA (diethylenetriaminepentaacetic acid bisanhydride) chelating C1 graft bonded to the POS matrix via -Si-C- covalent bonding, and present in sufficient amount to be able to complex all the gadolinium cations; and optionally an other functionalization graft Gf* bonded to the POS matrix via -Si-C- covalent bonding (it being possible for Gf* to result from a hydrophilic compound (PEG); from a compound comprising an active ingredient PA1; from a targeting compound; from a luminescent compound (fluorescein)). The method for obtaining these nanoparticles and the uses thereof in imaging and in therapy are also part of the invention.