# US 11,111,340 B2 · Method for preparing biocompatible poly-γ-glutamic acid hydrogel by using ultraviolet rays

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- Number: US 11,111,340 B2
- Document ID: US11111340B2
- Status: Granted
- Kind: B2
- Application number: 17/255,422
- Filed: 2019-05-09
- Published: 2021-05-13
- Granted: 2021-09-07
- Earliest claimed: 2018-06-26
- Assignees: Kookmin University Industry Academy Cooperation Foundation
- Applicants: Kookmin University Industry Academy Cooperation Foundation
- Inventors: Moon Hee Sung; Misun Kwak; Sang Joon Park
- Web page: https://patentgrep.com/patent/US11111340B2

## CPC

- C08G 69/10: Alpha-amino-carboxylic acids {(polysuccinimides C08G73/1092)}
- C08J 3/075: Macromolecular gels
- A61K 8/042: {Gels}
- A61K 8/88: Polyamides
- A61L 27/18: obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- A61L 27/52: Hydrogels or hydrocolloids
- A61Q 19/00: Preparations for care of the skin
- A61Q 19/08: Anti-ageing preparations
- B33Y 70/00: Materials specially adapted for additive manufacturing
- C08G 69/48: Polymers modified by chemical after-treatment
- C08J 3/24: Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K)
- C08J 3/28: Treatment by wave energy or particle radiation
- C08L 77/04: Polyamides derived from alpha-amino carboxylic acids (C08L77/10 takes precedence)
- A61K 2800/10: General cosmetic use
- C08J 2377/04: Polyamides derived from alpha-amino carboxylic acids (C08J2377/10 takes precedence)
- C08J 2477/04: Polyamides derived from alpha-amino carboxylic acids (C08J2477/10 takes precedence)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- 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)
- 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)
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

The present invention relates to a method of preparing a poly-γ-glutamic acid hydrogel using ultraviolet ray and to a use of the poly-γ-glutamic acid hydrogel prepared by the method, and the method of preparing poly-γ-glutamic acid hydrogel using ultraviolet irradiation according to the present invention solved the problem of microbial contamination in the poly-γ-glutamic acid solution, and produced poly-γ-glutamic acid hydrogel in high yield by only a simple treatment process, and as it was confirmed that the poly-γ-glutamic acid hydrogel has improved storage stability in a solution, the poly-gamma-glutamic acid hydrogel prepared by the method of preparing the same of the present invention can be provided as a tissue engineering scaffold, artificial organs and bio-ink for 3D printing.

## Claims

### Claim 1

A method of preparing a biocompatible poly-γ-glutamic acid hydrogel comprising:
dissolving poly-γ-glutamic acid in a solvent (Step 1);
adding and dissolving N,N,N-trimethyl-3-[(2-methylacryloyl)amino]propane-1-aminium to solution of the poly-γ-glutamic acid of the Step 1 (Step 2); and
irradiating the solution of the Step 2 with ultraviolet rays (Step 3),
wherein the N,N,N-trimethyl-3-[(2-methylacryloyl)amino]propane-1-aminium in the Step 2 is added at a molecular ratio of 1:1 with respect to molecule number of glutamic acid, which is a poly-γ-glutamic acid monomer.

### Claim 2 (depends on 1)

The method of preparing the biocompatible poly-γ-glutamic acid hydrogel of claim 1, wherein the poly-γ-glutamic acid has a weight average molecular weight of 30 to 30,000 kDa.

### Claim 3 (depends on 1)

The method of preparing the biocompatible poly-γ-glutamic acid hydrogel of claim 1, wherein the solvent in the Step 1 is water.

### Claim 4 (depends on 1)

The method of preparing the biocompatible poly-γ-glutamic acid hydrogel of claim 1, wherein in the Step 3 of irradiating ultraviolet rays, ultraviolet rays having an energy amount of 50 to 70 mW/cm2 are irradiated to the solution of the Step 2.

### Claim 5 (depends on 1)

The method of preparing the biocompatible poly-γ-glutamic acid hydrogel of claim 1, further comprising air-drying the solution irradiated with ultraviolet rays in the Step 3 at room temperature.

### Claim 6 (depends on 1)

The method of preparing the biocompatible poly-γ-glutamic acid hydrogel of claim 1, wherein the poly-γ-glutamic acid hydrogel is contained in an artificial organ, tissue engineering scaffold, cosmetic material or a bio-ink composition for 3D printers with improved storage stability and viscoelasticity.