In vivo tumor targeting and spectroscopic detection with surface enhanced raman nanoparticle tags

Abstract

Nanostructures, methods of preparing nanostructures, methods of detecting targets in subjects, and methods of treating diseases in subjects, are disclosed. An embodiment, among others, of the nanostructure includes a metallic gold surface-enhanced Raman scattering nanoparticle, a Raman reporter and a protection structure. The protection structure may include a thiol-polyethylene glycol to which may be attached a target-specific probe.

1 . A surface-enhanced Raman spectroscopic active composite nanostructure comprising:
 a core metallic nanoparticle;   a Raman reporter molecule disposed on the surface of the core; and   an encapsulating protective layer disposed on the surface of the core and the reporter molecule, wherein the encapsulated reporter molecule has a measurable surface-enhanced Raman spectroscopic signature.   
     
     
         2 . The nanostructure of  claim 1 , wherein the Raman reporter molecule is selected from an isothiocyanate dye, a multi-sulfur organic dye, a multi-heterosulfur organic dye, a benzotriazole dye, or combinations thereof. 
     
     
         3 . The nanostructure of  claim 1 , wherein the reporter molecule is selected from a thiacyanine dye, a dithiacyanine dye, a thiacarbocyanine dye, or a dithiacarbocyanine dye. 
     
     
         4 . The nanostructure of  claim 1 , wherein the reporter molecule is selected from malachite green isothiocyanate, tetramethylrhodamine-5-isothiocyante, X-rhodamine-5-isothiocyanate, X-rhodamine-6-isothiocyanate, or 3,3′-diethylthiadicarbocyanine iodide. 
     
     
         5 . The nanostructure of  claim 3 , wherein the core metallic nanoparticle is gold. 
     
     
         6 . The nanostructure of  claim 1 , wherein the core has a diameter less than about 200 nanometers. 
     
     
         7 . The nanostructure of  claim 1 , wherein the encapsulating material is a thiol-polyethylene glycol. 
     
     
         8 . The nanostructure of  claim 1 , further comprising a target-specific probe selectively binding a target on a cell. 
     
     
         9 . The nanostructure of  claim 8  wherein the target-specific probe is selected from the group consisting of an antibody, a polypeptide, a polynucleotide, a drug molecule, an inhibitor compound, and a combination thereof, and wherein the targeting probe has an affinity for a marker on the surface of a target cell. 
     
     
         10 . The nanostructure of  claim 9  wherein the target-specific probe is an immunoglobulin, or a fragment thereof. 
     
     
         11 . The nanostructure of  claim 8 , wherein the probe is disposed on the hydrophobic protection structure. 
     
     
         12 . The nanostructure of  claim 8 , wherein the probe is a tumor-targeting ligand. 
     
     
         13 . A method of preparing a nanostructure, comprising:
 providing a metallic nanoparticle;   introducing the metallic nanoparticle to a Raman reporter, whereupon the Raman reporter is disposed on the surface of the nanoparticle to form a nanoparticle-reporter complex; and   disposing a protection structure layer on the surface of the nanoparticle-reporter complex, wherein the reporter molecule has a measurable surface-enhanced Raman spectroscopic signature.   
     
     
         14 . The method of  claim 13 , further comprising depositing a cell target-specific probe to the protection structure layer, wherein the probe is selected from an antibody, a polypeptide, a polynucleotide, a drug molecule, an inhibitor compound, or a combination thereof. 
     
     
         15 . The method of  claim 13 , wherein the core metallic nanoparticles are a colloid. 
     
     
         16 . The method of  claim 13 , wherein the core metallic nanoparticles is gold 
     
     
         17 . The method of  claim 13 , wherein the Raman reporter molecule is selected from an isothiocyanate dye, a multi-sulfur organic dye, a multi-heterosulfur organic dye, a benzotriazole dye, or combinations thereof. 
     
     
         18 . The method of  claim 13 , wherein the reporter molecule is selected from a thiacyanine dye, a dithiacyanine dye, a thiacarbocyanine dye, or a dithiacarbocyanine dye. 
     
     
         19 . The method of  claim 13 , wherein the reporter molecule is selected from malachite green isothiocyanate, tetramethylrhodamine-5-isothiocyante, X-rhodamine-5-isothiocyanate, X-rhodamine-6-isothiocyanate, or 3,3′-diethylthiadicarbocyanine iodide. 
     
     
         20 . The method of  claim 13 , wherein the encapsulating material is a thiol-polyethylene glycol. 
     
     
         21 . A method of imaging a biological sample, comprising:
 delivering at least one nanostructure to a cultured cell or to an animal or human subject, wherein the nanostructure comprises a core gold nanoparticle, a Raman reporter molecule disposed on the surface of the core, and an encapsulating protective layer disposed over the core and the reporter molecule, and wherein the encapsulated reporter molecule has a measurable surface-enhanced Raman spectroscopic signature;   allowing the nanostructure to contact a targeted biological cell or tissue;   exciting the reporter molecule with a source of radiation; and   measuring the surface enhanced Raman spectroscopy spectrum of the nanostructure corresponding to the reporter molecule, thereby detecting the presence of the nanostructure in the targeted cell or tissue.   
     
     
         22 . The method of  claim 21 , wherein the nanostructure further comprises a target-specific probe, wherein the targeting probe selectively binds the nanoparticle to a targeted cell, thereby allowing detection of the targeted cell. 
     
     
         23 . The method of  claim 22 , wherein the target cell is in a tissue of an animal or human subject. 
     
     
         24 . The method of  claim 21 , wherein the target cell is a cancerous cell of an animal or human subject. 
     
     
         25 . The method of  claim 21 , wherein the target-specific probe is selected from the group consisting of an antibody, a polypeptide, a polynucleotide, a drug molecule, an inhibitor compound, or a combination thereof, and wherein the targeting probe has an affinity for a marker on the surface of a target cell. 
     
     
         26 . The method of  claim 21  wherein the target-specific probe is a tumor-targeting ligand.