Two-photon fluorescent compounds for specific lipid droplet imaging in live cells and deep tissues at ultralow concentration

Patent metadata

Field	Value
Publication number	US-11220629-B2
Application number	US-201916961569-A
Country	US
Kind code	B2
Filing date	Jan 11, 2019
Priority date	Jan 11, 2018
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

Fluorescent compounds that have aggregation-induced emission (AIE) characteristics. The compounds can be utilized as lipid droplet (LD)-specific bio-probes in cell imaging, with high photostability and brightness. For example, the compounds can be used for specific two-photon LDs staining in live cells and deep-tissues at ultralow concentrations. The compounds exhibit a large Stokes shift (>110 nm), high solid fluorescence quantum yields (up to 0.30), a good two-photon absorption cross-section (45-100 GM at 860 nm), high biocompatibility, and good photostability.

First claim

We claim:

1. A fluorescent compound exhibiting aggregation induced emission properties, the compound having the following backbone structural formula:

wherein R 1 , R 2 , and R 3 are independently selected from the group consisting of C n H 2n+1 , C 6 H 5 , C 10 H 7 , C n H 2n COOH, C n H 2n NCS, C n H 2n N 3 , C n H 2n NH 2 , C n H 2n Cl, C n H 2n Br, C n H 2n I and

wherein R′ is selected from the group consisting of C n H 2n NCS, C n H 2n N 3 , C n H 2n NH 2 , C n H 2n Cl, C n H 2n Br, C n H 2n I, and

wherein R 4 , R 5 , and R 6 are independently selected from the group consisting of H, CH 3 , F, Cl, Br, I, CN, CF 3 , NO 2 , Ph, Py, CH═CHPh, and C≡CPh; and
wherein n is an integer ranging from 1 to 10.

2. The compound according to claim 1 , wherein the compound comprises one or more compounds selected from the group consisting of:

3. A method of cellular imaging, comprising:
contacting a target cell with the compound of claim 1 ; and
identifying a target of interest in the target cell using an imaging method.

4. The method of claim 3 , wherein the target of interest comprises lipid droplets.

5. The method of claim 3 , wherein the imaging method is selected from the group consisting of fluorescence microscopy and confocal laser scanning microscopy.

6. The method of claim 5 , wherein the fluorescence microscopy comprises two-photon fluorescence imaging.

7. The method of claim 3 , wherein the target cell is a live cell.

8. The method of claim 7 , wherein the target cell is in live tissue.

9. The method of claim 3 , wherein a concentration of the compound is 50 nM or less.

10. A fluorescent compound exhibiting aggregation induced emission properties, the compound comprising one or more compounds selected from the group consisting of:

11. A method of cellular imaging, comprising:
contacting a target cell with the compound of claim 10 ; and
identifying a target of interest in the target cell using an imaging method.

12. The method of claim 11 , wherein the target of interest comprises lipid droplets.

13. The method of claim 11 , wherein the imaging method is selected from the group consisting of fluorescence microscopy and confocal laser scanning microscopy.

14. The method of claim 11 , wherein the fluorescence microscopy comprises two-photon fluorescence imaging.

15. The method of claim 11 , wherein the target cell is a live cell.

16. The method of claim 15 , wherein the target cell is in live tissue.

17. The method of claim 11 , wherein a concentration of the compound is 50 nM or less.

18. A method of cellular imaging, comprising:
contacting a target cell with a compound having the following backbone structural formula

wherein R 1 , R 2 , and R 3 are independently selected from the group consisting of C n H 2n+1 , C 6 H 5 , C 10 H 7 , C n H 2n COOH, C n H 2n NCS, C n H 2n N 3 , C n H 2n NH 2 , C n H 2n Cl, C n H 2n Br, C n H 2n I and

wherein R′ is selected from the group consisting of C n H 2n NCS, C n H 2n N 3 , C n H 2n NH 2 , C n H 2n Cl, C n H 2n Br, C n H 2n I, and

wherein R 4 , R 5 , and R 6 are independently selected from the group consisting of H, CH 3 , F, Cl, Br, I, CN, CF 3 , NO 2 , Ph, Py, CH═CHPh, and C≡CPh; and
wherein n is an integer ranging from 1 to 10; and

identifying a target of interest in the target cell using an imaging method.

19. The method according to claim 18 , wherein the compound comprises one or more compounds selected from the group consisting of:

20. The method according to claim 18 , wherein the target of interest comprises lipid droplets.

Assignees

• Univ Hong Kong Science & Tech

Inventors

• Tang Benzhong
• Niu Guangle

Classifications

• C09K11/06 Primary

  containing organic luminescent materials · CPC title

• C07D213/57

  Nitriles · CPC title

• C09K2211/1007

  Non-condensed systems · CPC title

• C09K2211/1011

  Condensed systems · CPC title

• G02B21/0076

  arrangements using fluorescence or luminescence · CPC title