EGCG stabilized gold nanoparticles and method for making same

Patent metadata

Field	Value
Publication number	US-9358310-B2
Application number	US-201213668916-A
Country	US
Kind code	B2
Filing date	Nov 5, 2012
Priority date	Sep 17, 2007
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

The invention provides stabilized, biocompatible gold nanoparticles that are stabilized with material from epigallocatechin Gallate (EGCg), which is a polyphenols- or flavonoids-rich plant material that can be obtained from green tea. The EGCg is an antioxidant reducing agent derived from green tea. The gold nanoparticles of the invention can be radioactive or non radioactive and are formed via a simple room temperature fabrication method. In preferred embodiment method of making, an aqueous solution containing gold salts is provided. The aqueous solution is mixed with EGCg in a buffer, such as deionized water. The gold salts react to form biocompatible gold nanoparticles that are stabilized with a coating of EGCg. The thermodynamically feasible redox couple of AuCl4-/EGCg leading to the reduction of AuCl4- by EGCg to form gold nanoparticles. In another embodiment, pre-cooled gold salt and EGCg solutions form multi-layered EGCg coated particles.

First claim

The invention claimed is:

1. An environmentally friendly method for making epigallocatechin Gallate (EGCg) stabilized gold nanoparticles, the method comprising:
mixing a solution of epigallocatechin Gallate (EGCg) as a reducing agent with an aqueous solution containing gold salts;
permitting reaction of the gold salts, in the absence of any other reducing agent, to form stabilized, biocompatible gold nanoparticles.

2. The method of claim 1 , wherein the solution containing gold salts comprises AuCl 4 .

3. The method of claim 2 , wherein the solution of EGCg comprises deionized water.

4. The method of claim 3 , wherein the solution of gold salts comprises carrier NaAuCl 4 solution.

5. The method of claim 4 , wherein the carrier NaAuCl 4 solution is adjusted to a neutral pH and isotonic.

6. The method of claim 1 , wherein the solution of gold salts comprises H 198 AuCl 4 .

7. The method of claim 6 , wherein the solution of EGCg comprises deionized water.

8. The method of claim 7 , wherein the solution of gold salts further comprises a carrier NaAuCl 4 solution.

9. The method of claim 8 , wherein the carrier NaAuCl 4 solution is adjusted to a neutral pH and isotonic.

10. The method of claim 1 , further comprising a step of heating the aqueous solution during said step of permitting reaction.

11. The method of claim 10 , wherein said step of heating comprises microwave heating.

12. The method of claim 1 , further comprising a step of adjusting the pH of the aqueous solution after said step of permitting reaction.

13. The method of claim 1 , further comprising a step of adding a stabilizing agent to the aqueous solution after said step of permitting reaction.

14. The method of claim 13 , wherein said stabilizing agent comprises gum Arabic.

15. The method of claim 1 , wherein the gold salts comprises either sodium tetrachloaurate or aurochloric acid.

16. The method of claim 1 , wherein the solution containing gold salts and the solution of EGCg are pre-cooled below room-temperature prior to said mixing.

17. The method of claim 16 , wherein the solution containing gold salts and the solution of EGCg are pre-cooled to ˜4° C. and equilibrated.

Assignees

• Univ Missouri

Inventors

• Katti Kattesh V
• Kannan Raghuraman
• Katti Kativa K
• Nune Satish Kumar
• Cutler Cathy S
• Caldwell Charles
• Shukla Ravi
• Chanda Nripen
• Zambre Ajit
• Upendran Anandhi

Classifications

• A61P35/00

  Antineoplastic agents · CPC title

• A61K41/00

  Medicinal preparations obtained by treating materials with wave energy or particle radiation {; Therapies using these preparations} · CPC title

• A61K51/1244 Primary

  microparticles or nanoparticles, e.g. polymeric nanoparticles · CPC title

• A61K51/1251 Primary

  micro- or nanospheres, micro- or nanobeads, micro- or nanocapsules · CPC title

• A61K9/148

  with compounds of unknown constitution, e.g. material from plants or animals (with oils, fats, waxes, shellac A61K9/145) · CPC title