# US 11,298,678 B2 · Fabrication of macroporous polymeric hydrogel microparticles

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- Number: US 11,298,678 B2
- Document ID: US11298678B2
- Status: Granted
- Kind: B2
- Application number: 16/090,453
- Filed: 2017-03-22
- Published: 2019-04-18
- Granted: 2022-04-12
- Earliest claimed: 2016-03-30
- Assignees: Trustees of Tufts College
- Applicants: Trustees of Tufts College
- Inventors: Hyunmin Yi; Eunae Kang; Sukwon Jung; John H. Abel
- Web page: https://patentgrep.com/patent/US11298678B2

## CPC

- B01J 20/261: {obtained by reactions only involving carbon to carbon unsaturated bonds (macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F)}
- A61K 47/58: obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. poly[meth]acrylate, polyacrylamide, polystyrene, polyvinylpyrrolidone, polyvinylalcohol or polystyrene sulfonic acid resin
- A61K 47/6927: {the form being a solid microparticle having no hollow or gas-filled cores}
- B01J 20/24: Naturally occurring macromolecular compounds, e.g. humic acids or their derivatives
- B01J 20/28047: {Gels}
- B01J 20/2808: {being less than 2 nm, i.e. micropores or nanopores}
- B01J 20/28083: {being in the range 2-50 nm, i.e. mesopores}
- B01J 20/28085: {being more than 50 nm, i.e. macropores}
- B01J 20/3007: {Moulding, shaping or extruding}
- B01J 20/3064: {Addition of pore forming agents, e.g. pore inducing or porogenic agents}
- B01J 20/3071: {Washing or leaching}
- B01J 20/3085: {Chemical treatments not covered by groups B01J20/3007 - B01J20/3078}
- C08J 3/075: Macromolecular gels
- C08L 5/08: Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
- C08J 2333/26: Homopolymers or copolymers of acrylamide or methacrylamide
- C08J 2405/08: Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

A polymeric hydrogel microparticle that contains polyacrylamide and chitosan, the chitosan uniformly incorporated in a polyacrylamide matrix. The microparticle, having a coefficient variation of 0 to 2% and containing macropores with an average size of 1 to 60 nm, is capable of transporting biomolecules conjugated to it. Also disclosed are a method of fabricating such a microparticle in a micromold via photo-induced radical polymerization and a one-pot method of conjugating biomolecules to polymeric hydrogel microparticles.

## Claims

### Claim 1

A polymeric hydrogel microparticle comprising polyacrylamide and chitosan, the chitosan uniformly incorporated in a polyacrylamide matrix, wherein the microparticle has a coefficient of variation of 0 to 2% and contains macropores having an average size of 1 to 60 nm, wherein the chitosan has an average molar mass of 4,500-200,000 Da and the chitosan contains primary amines each having a pKa value of 6.0-6.9.

### Claim 2 (depends on 1)

The polymeric hydrogel microparticle of claim 1, wherein the microparticle has a total polymer content of 5 to 50 w/v %.

### Claim 3 (depends on 1)

The polymeric hydrogel microparticle of claim 1, wherein the microparticle is capable of conjugating to a biomolecule that has a molecular weight greater than 120,000 Da.

### Claim 4 (depends on 3)

The polymeric hydrogel microparticle of claim 3, wherein the biomolecule has a molecular weight greater than 200,000 Da.

### Claim 5 (depends on 4)

The polymeric hydrogel microparticle of claim 4, wherein the biomolecule has a molecular weight of 240,000 Da.

### Claim 6 (depends on 5)

The polymeric hydrogel microparticle of claim 5, wherein the microparticle has a total polymer content of 5 to 50 w/v % and is capable of conjugating to a biomolecule that has a molecular weight greater than 200,000 Da.

### Claim 7 (depends on 1)

The polymeric hydrogel microparticle of claim 1, wherein the macropores have an average size greater than of 11 nm to 60 nm.

### Claim 8 (depends on 7)

The polymeric hydrogel microparticle of claim 7, wherein the microparticle is capable of conjugating to a biomolecule that has a molecular weight greater than 120,000 Da.

### Claim 9 (depends on 8)

The polymeric hydrogel microparticle of claim 8, wherein the biomolecule has a molecular weight greater than 200,000 Da.

### Claim 10 (depends on 9)

The polymeric hydrogel microparticle of claim 9, wherein the biomolecule has a molecular weight of 240,000 Da.

### Claim 11 (depends on 1)

The polymeric hydrogel microparticle of claim 1, wherein the microparticle has a 2D shape.

### Claim 12 (depends on 11)

The polymeric hydrogel microparticle of claim 11, wherein the 2D shape is hexagon, triangle, square, disk, pentagon, or cross.