Nanoemulsions and use thereof as contrast agents

An oil-in-water nanoemulsion composition comprising:

• an aqueous phase,
• a fluorinated phase comprising at least one fluorinated oil,
• a surfactant at the interface between the aqueous and fluorinated phases, the surfactant comprising:
• at least one amphiphilic targeting ligand, the targeting ligand of which is chosen from:
• pharmacophores, peptides, pseudopeptides, peptidomimetics, amino acids, peptides and pseudopeptides, integrin-targeting peptidomimetics, glycoproteins, lectins, biotin, pteroic or aminopteroic derivatives, folic acid, folic and antifolic acid derivatives, antibodies or antibody fragments, avidin, steroids, oligonucleotides, ribonucleic acid sequences, deoxyribonucleic acid sequences, hormones, proteins which are optionally recombinant or mutated, mono- or polysaccharides, agents for targeting cell receptors or enzymes,
• at least one amphiphilic lipid, and
• at least one diblock or tribock fluorophilic compound of formula RF-L-RH(—Z)z
• in which:
• 1) RF is a fluorinated or perfluorinated group (which optionally comprises side chains and/or rings and/or heteroatoms, in particular halogens);
• 2) RH is a hydrocarbon-based group which optionally comprises side chains and/or rings and/or heteroatoms, in particular halogens and/or multiple bonds;
• 3) L is a linker group and may comprise in particular one of the following groups:
• single bond, —CH2—, —CH═CH—, —O—, —S—, —PO4—, CONH;
• 4) Z is H or a group which is more polar or polarizable than the RH groups;
• 5) z represents 0 or 1.