ИСТИНА

Among various nanoparticles for biomedical applications, perfluorocarbon nanoparticles are of special interest, because they are nontoxic, biologically inert and not metabolized in the body. They are currently used in medicine in blood substitute fluids. Also, they are quite prospective for other biomedical applications, in particular, for in vivo magnetic resonance imaging (MRI) taking into account that 19F nuclei are absent in most biological tissues, which eliminates the problem of interfering background signals. The introduction of proton contrast agents (e.g. gadolinium compounds) on the surface of such particles allows one to perform simultaneous 1H and 19F imaging thus improving significantly the quality of visualization. The present work is aimed at the preparation of highly stable perfluorocarbon nanoparticles with polymeric shell containing embedded gadolinium compounds. As gadolinium compounds we used different clinically approved gadolinium chelates (Gadovist, Magnevist, Omniscan) as well as gadolinium oxide nanoparticles synthesized by us. As perfluorocarbons we used Perftoran (mixture of perfluorodecalin and perfluoromethylcyclohexylpiperidine) and perfluorotributylamine. An efficient method of incorporation of gadolinium compounds into polymeric shell surrounding liquid nanoparticles of perfluorocarbons was proposed. It does not degrade the particles stability. The playload reaches ca. 106 Gd atoms per perfluorocarbon nanoparticle giving high local concentration of contrast agent. It was shown that the prepared perfluorocarbon nanoparticles have the same relaxivity as commercial gadolinium contrast agents like Omniscan, at the same time they give a strong 19F-NMR signal. Due to these properties, the elaborated nanoparticles are promising for simultaneous 1H and 19F magnetic resonance imaging.