Spiropyran hydrogels and light-driven expansion thereof

Patent metadata

Field	Value
Publication number	US-12466836-B2
Application number	US-202217697286-A
Country	US
Kind code	B2
Filing date	Mar 17, 2022
Priority date	Mar 17, 2021
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

Provided herein are sulfonate-based water-soluble photoswitches that, in contrast to existing systems, trigger a volumetric expansion in hydrogels upon exposure to photons; contraction is in turn observed under dark conditions in a highly reversible manner.

First claim

The invention claimed is:

1 . A compound of formula (I):

or a salt thereof, wherein:
R 1 is —SO 3 H;
R 2 is selected from hydrogen and —SO 3 H;
R 3 is selected from hydrogen and methyl;
m and n are each independently 0, 1, or 2; and
R 4 and R 5 are each independently selected from C 1 -C 3 alkyl, C 1 -C 3 alkoxy, halo, and nitro.

2 . The compound of claim 1 , or a salt thereof, wherein R 1 and R 2 are both —SO 3 H.

3 . The compound of claim 1 , or a salt thereof, wherein R 3 is methyl.

4 . The compound of claim 1 , or a salt thereof, wherein m and n are 0.

5 . The compound of claim 1 , wherein the compound is selected from:

or a salt thereof.

6 . The compound of claim 1 , wherein the compound is a sodium salt or a potassium salt.

7 . The compound of claim 6 , wherein the compound is selected from:

8 . A compound of formula (Ia):

or a salt thereof, wherein:
R 1 is —SO 3 H;
R 2 is selected from hydrogen and —SO 3 H;
m and n are each independently 0, 1, or 2; and
R 4 and R 5 are each independently selected from C 1 -C 3 alkyl, C 1 -C 3 alkoxy, halo, and nitro.

9 . A polymer comprising a monomer unit of formula (II):

or a salt thereof, wherein:
R 1 is —SO 3 H;
R 2 is selected from hydrogen and —SO 3 H;
R 3 is selected from hydrogen and methyl;
m and n are each independently 0, 1, or 2; and
R 4 and R 5 are each independently selected from C 1 -C 3 alkyl, C 1 -C 3 alkoxy, halo, and nitro,
wherein each

represents a point of attachment to the polymer chain.

10 . The polymer of claim 9 , or a salt thereof, wherein R 1 and R 2 are both —SO 3 H.

11 . The polymer of claim 9 , or a salt thereof, wherein R 3 is methyl.

12 . The polymer of claim 9 , or a salt thereof, wherein m and n are 0.

13 . The polymer of claim 9 , wherein the monomer unit has a formula selected from:

or a salt thereof.

14 . The polymer of claim 13 , wherein the monomer unit is in sodium or potassium salt form.

15 . The polymer of claim 14 , wherein the monomer unit has a formula selected from:

16 . The polymer of claim 9 , further comprising one or more additional monomers selected from N-isopropylacrylamide, di(ethylene glycol) methyl ether methacrylate, oligo(ethylene glycol) methyl ether methacrylate, and any combination thereof.

17 . The polymer of claim 9 , further comprising one or more crosslinking monomers.

18 . The polymer of claim 17 , wherein the crosslinking monomer is N,N′-methylenebis(acrylamide).

19 . A method of triggering volumetric expansion of a hydrogel comprising a compound of claim 1 , the method comprising exposing the hydrogel to light.

20 . A method of triggering volumetric contraction of a hydrogel comprising a compound of claim 1 , the method comprising exposing the hydrogel to darkness.

Assignees

• Univ Northwestern

Inventors

• Li Chuang
• Stupp Samuel I

Classifications

• C08F2810/20

  leading to a crosslinking, either explicitly or inherently · CPC title

• C08F2810/50

  wherein the polymer is a copolymer and the modification is taking place only on one or more of the monomers present in minority · CPC title

• C08F2800/10

  as molar percentages · CPC title

• C08F222/1063

  of alcohol terminated polyethers · CPC title

• C07D491/107 Primary

  with only one oxygen atom as ring hetero atom in the oxygen-containing ring · CPC title