Coated up-conversion nanoparticles

Patent metadata

Field	Value
Publication number	US-10179177-B2
Application number	US-201615045600-A
Country	US
Kind code	B2
Filing date	Feb 17, 2016
Priority date	May 30, 2012
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

The invention provides novel biocompatible upconversion nanoparticle (UCNP) that comprises a core of cubic nanocrystals (e.g., comprising α-Na Ln a, Ln b Ln c F 4 ) and an epitaxial shell (e.g., formed from CaF 2 ; wherein Ln b is Yb), and related methods of preparation and uses thereof.

First claim

What is claimed is:

1. A method for synthesizing upconversion nanoparticle in a single reaction vessel, comprising:
heating a solvent mixture comprising an organic acid and an organic alkene in the vessel to an elevated temperature from about 300° C. to about 320° C., wherein the organic acid and an organic alkene are selected from the group of solvent pairs consisting of hexadecanoic acid-1-hexadecene, eicosenoic acid-eicosene, and oleic acid-1-octadecene;
injecting a core precursor solution comprising a mixture of sodium trifluoracetate and rare earth trifluoracetates into the vessel, wherein the rare earth trifluoracetates are a combination of yttrium (Y), ytterbium (Yb) and thulium (Tm) trifluoracetates;
injecting a shell precursor solution into the vessel, wherein the shell precursor solution comprises Ca(CF 3 COO) 2 and the solvent mixture; and
collecting the upconversion nanoparticles,

wherein the above steps are carried out in a single reaction vessel.

2. The method of claim 1 , wherein the acid-alkene pair is oleic acid-1-octadecene.

3. The method of claim 2 , wherein the step of heating to the elevated temperature comprises a step of first heating to a temperature of about 120° C., followed by a step of heating to a temperature of about 310° C.

4. A method for synthesizing modified upconversion nanoparticle (UCNPs) in a single reaction vessel, comprising:
combining an upconversion nanoparticle (UCNPs) dispersed in hexane and dimethylformamide (DMF) to form a two-phase mixture, wherein the UCNPs comprise a core of cubic nanocrystals comprising α-Na (Y, Yb, Tm)F 4 and an epitaxial shell of CaF 2 ;
adding a molar excess of Nitrosonium tetrafluoroborate (NOBF 4 ) over the upconversion nanoparticles, wherein the molar excess of NOBF 4 over the UCNPs is about 300%;
the mixture comprising (NOBF 4 ) was stirred at a room temperature for a time required to transfer modified UCNPs from the hexane layer to the DMF layer;
precipitating the modified UCNPs with an anti-solvent;
purifying the modified UCNPs by centrifugation; and
redispersing the modified UCNPs in the polar solvent,

wherein
the above steps are carried out in a single reaction vessel.

5. The method of claim 4 , wherein room temperature is from about 17 to about 23° C.

6. The method of claim 4 , wherein the time required to transfer modified UCNPs from the hexane layer to the DMF layer is from about 3 to about 10 minutes.

7. The method of claim 6 , wherein the time required about 5 minutes.

8. The method of claim 4 , further comprising:
reacting the modified UCNPs with poly-acrylic acid (PAA); and
purifying the PAA modified UCNPs by centrifugation.

9. The method of claim 4 , further comprising a step of washing the PAA modified UCNPs with water.

Assignees

• Univ Massachusetts Medical School
• Univ Massachusetts

Inventors

• Han Gang
• Shen Jie

Classifications

• C01F17/36

  halogen being the only anion, e.g. NaYF4 · CPC title

• C01P2004/02

  obtained by optical microscopy · CPC title

• A61K41/008 Primary

  Two-Photon or Multi-Photon PDT, e.g. with upconverting dyes or photosensitisers · CPC title

• A61K49/0019 Primary

  characterised by the fluorescent group, e.g. oligomeric, polymeric or dendritic molecules · CPC title

• B82Y5/00

  Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery · CPC title