Multifunctional Metal Nanoparticles Having a Polydopamine-Based Surface and Methods of Making and Using the Same

Abstract

The present invention provides nanoparticles including a metallic core having a length along each axis of from 1 to 100 nanometers and a coating disposed on at least part of the surface of the metallic core, wherein the coating comprises polydopamine, along with methods for making and using such nanoparticles. The metallic core may be gold, silver or iron oxide and the polydopamine coating may have other substances bound to it, such as silver, targeting ligands or antibodies, or other therapeutic or imaging contrast agents. The disclosed nanoparticles can be targeted to cells for treating cancer or bacterial infections, and for use in diagnostic imaging.

1 . A nanoparticle comprising:
 (a) a metallic core having a length along each axis of from 1 to 100 nanometers; and   (b) a coating disposed on at least part of the surface of the metallic core, wherein the coating comprises polydopamine.   
     
     
         2 . The nanoparticle of  claim 22 , wherein the metallic core is a nanorod having a substantially cylindrical shape. 
     
     
         3 . The nanoparticle of  claim 1 , wherein the coating is disposed on the entire surface of the metallic core. 
     
     
         4 . The nanoparticle of  claim 1 , wherein the metallic core is selected from the group consisting of gold, silver or iron oxide. 
     
     
         5 . The nanoparticle of  claim 4 , wherein the metallic core consists essentially of gold. 
     
     
         6 . The nanoparticle of  claim 1 , wherein the coating further comprises silver, iron oxide, or a mixture thereof. 
     
     
         7 . The nanoparticle of  claim 1 , further comprising one or more antibodies, polyethylene glycol, functionalized polyethylene glycol, or a mixture thereof bound to the coating. 
     
     
         8 . The nanoparticle of  claim 7 , wherein the antibody is an anti-cancer cell surface receptor antibody or an anti-bacterial surface antibody. 
     
     
         9 . The nanoparticle of  claim 1 , further comprising a polymer, a polysaccharide, a sugar-containing peptoid, a pharmaceutical agent, or a mixture thereof bound to the coating. 
     
     
         10 . The nanoparticle of  claim 9 , wherein the pharmaceutical agent is an anti-cancer agent or an anti-microbial agent. 
     
     
         11 . A method of making the nanoparticle of  claim 1 , comprising contacting a metallic core having a length along each axis of from 1 to 100 nanometers with an alkaline solution comprising dopamine, whereby a polydopamine coating is formed on the surface of the metallic core. 
     
     
         12 . The method of  claim 11 , wherein the metallic core is a nanorod having a substantially cylindrical shape that consists essentially of gold. 
     
     
         13 . A method for treating cancer comprising administering to a patient having cancer cells one or more nanoparticles of  claim 8 , wherein the metallic core consists essentially of gold and wherein the antibody is an anti-cancer cell surface receptor antibody, whereby the one or more nanoparticles target the cancer cells and the cancer is effectively treated. 
     
     
         14 . The method of  claim 13 , wherein the anti-cancer cell surface antibody is an anti-epithelial growth factor receptor (EGFR) antibody. 
     
     
         15 . The method of  claim 13 , wherein the one or more nanoparticles further comprise an additional anti-cancer agent bound to the coating. 
     
     
         16 . The method of  claim 15 , wherein the anti-cancer agent is a proteasome inhibitor. 
     
     
         17 . The method of  claim 13 , further comprising the step of exposing the nanoparticles to light. 
     
     
         18 . A method for treating a bacterial infection comprising administering to a patient infected with bacteria one or more nanoparticles of  claim 8 , wherein the metallic core consists essentially of gold and wherein the antibody is an anti-bacterial surface antibody, whereby the one or more nanoparticles target the bacteria and the bacterial infection is effectively treated. 
     
     
         19 . The method of  claim 18 , wherein the anti-bacterial surface antibody is an anti-lipoteichoic acid antibody or an anti-endotoxin antibody. 
     
     
         20 . The method of  claim 18 , wherein the coating of the one or more nanoparticles further comprises silver. 
     
     
         21 . The method of  claim 20 , further comprising the step of exposing the nanoparticles to light. 
     
     
         22 . A method for imaging cancer or bacterial cells comprising:
 (a) contacting cancer or bacterial cells with one or more nanoparticles comprising (i) a gold nanorod metallic core having a length of from 1 to 100 nanometers, (ii) a polydopamine coating disposed on at least part of the surface of the metallic core, and (iii) an antibody selected from the group consisting of an anti-cancer cell surface receptor antibody and an anti-bacterial surface antibody, whereby the one or more nanoparticles target the cancer or bacterial cells; and   (b) detecting the location of the one or more nanoparticles.   
     
     
         23 . The method of  claim 22 , wherein the step of detecting the location of the one or more nanoparticles is performed using bright field microscopy, optical coherence tomography, or 2-photon confocal microscopy. 
     
     
         24 . The method of  claim 22 , wherein the nanoparticle coating further comprises iron oxide, and wherein the step of detecting the location of the one or more nanoparticles is performed using magnetic-based imaging. 
     
     
         25 . A method for treating cancer, the method comprising administering to a patient having cancer cells one or more nanoparticles of  claim 8 , wherein the metallic core consists essentially of gold and wherein the antibody is an anti-cancer cell surface receptor antibody, and exposing the nanoparticles to light, whereby the one or more nanoparticles target the cancer cells and the cancer is effectively treated. 
     
     
         26 . A method for treating a bacterial infection comprising administering to a patient infected with bacteria one or more nanoparticles of  claim 8 , wherein the metallic core consists essentially of gold and herein the antibody is an anti-bacterial surface antibody, and exposing the nanoparticles to light, whereby the one or more nanoparticles target the bacteria and the bacterial infection is effectively treated. 
     
     
         27 . The method of  claim 22 , wherein the nanorod has a diameter from 1 to 50 nanometers. 
     
     
         28 . The method of  claim 22 , wherein the nanoparticle coating is disposed on the entire surface of the metallic core. 
     
     
         29 . The method of  claim 22 , wherein the nanoparticle coating further comprises silver, iron oxide, or a mixture thereof. 
     
     
         30 . The method of  claim 22 , wherein the nanoparticle further comprises polyethylene glycol, functionalized polyethylene glycol, or a mixture thereof, bound to the coating. 
     
     
         31 . The method of  claim 22 , wherein the nanoparticle further comprises a polymer, a polysaccharide, a sugar-containing peptiod, a pharmaceutical agent, or a mixture thereof, bound to the coating. 
     
     
         32 . The method of  claim 31 , wherein the pharmaceutical agent is an anti-cancer agent or an anti-microbial agent.