Method to improve the tumor diagnostic efficiency of multivalent ligands by regulating the stoichiometric ratio between inner surface functionalities and ligand moieties for tumor targeting

A method to regulate the tumor diagnostic efficiency of a multivalent ligand by regulating the stoichiometric ratio between inner surface functionalities and ligand moieties for tumor targeting, wherein the multivalent ligand comprises:

• a single core consisting of a circular or spherical symmetric small molecular compound, or a radial-shaped macromolecule, wherein the core comprises terminal functional groups;
• said ligand moieties which are attached to a portion of the terminal functional groups of the core through a spacer;
• said inner surface functionalities comprising the terminal functional groups, modified terminal functional groups or the combination thereof;
• and
• one or more imaging agents which are attached to another portion of the terminal functional groups of the core;
• wherein the inner surface functionalities interact attractively with the surface of the tumor;
• and
• wherein the number of ligand moieties for tumor targeting accounts for 5-90% of the total number of inner surface functionalities and ligand moieties for tumor targeting.