CN-122029222-A - Method for producing hydrogel having porous structure

Abstract

The present invention addresses the problem of providing a novel method for producing a hydrogel material having a porous structure of μm level, which is permeable to a substance such as a cell, by a simpler method. It was found that by controlling the total concentration of the base polymer in the solution within a prescribed range, a biocompatible hydrogel having a μm-sized porous structure can be produced by using a freeze-thawing process as a trigger for porous structuring of the resulting non-porous structure of the initial hydrogel.

Inventors

• ISHIKAWA SHOHEI
• Sakai Takashikamasa
• Takumi Kajima
• NITTA HIROYUKI

Assignees

• 国立大学法人东京大学
• 杰里克有限公司

Dates

Publication Date

20260512

Application Date

20241028

Priority Date

20231102

Claims (11)

1. 1. A method for producing a hydrogel having a porous structure, wherein, Comprising the following steps: a) A step of preparing a first solution in which the compound A is dissolved in a first solvent; b) A step of preparing a second solution obtained by dissolving the compound B in a second solvent; c) Mixing the first solution with the second solution to obtain an initial hydrogel having a non-porous structure, wherein the initial hydrogel is obtained by mixing the first solution with the second solution in such a manner that the total polymer concentration C total in the third solution obtained by mixing the first solution with the second solution is equal to or less than the higher one of the viscosity-increasing characteristic concentration C A inherent to the compound A and the viscosity-increasing characteristic concentration C B inherent to the compound B; d) A step of subjecting the initial hydrogel to a freezing treatment to obtain a frozen hydrogel, and E) A step of treating the frozen hydrogel at a temperature higher than or equal to one of the melting points of the first solvent and the second solvent to obtain a hydrogel having a porous structure; Both the initial hydrogel and the hydrogel having a porous structure are crosslinked with each other by the compound a and the compound B to form a gel, The first solvent and the second solvent are both water-based solvents; The compounds A and B are polyethylene glycol PEG with more than 1 nucleophilic functional group or electrophilic functional group in total on the side chain or terminal, and are 2 branches, 3 branches, 4 branches or 8 branches.
2. 2. The production method according to claim 1, wherein the compound a and/or the compound B has a weight average molecular weight of 4 x 10 4 or less.
3. 3. The production method according to claim 1, wherein the freezing treatment is performed at a temperature of-10 ℃ or lower for 1 hour or more.
4. 4. The production method according to claim 1, wherein when the permeability of the initial hydrogel is X, the permeability of the frozen hydrogel is Y, and the permeability of the hydrogel having a porous structure is Z, the following relational expression is satisfied: X>Z>Y。
5. 5. The production method according to claim 1, wherein when the equilibrium swelling degree of the hydrogel having a porous structure produced at C total of 20g/L is Q low and the equilibrium swelling degree of the hydrogel having a porous structure produced at any C total is Q, the following relational expression is satisfied: Q<1.2*Q low 。
6. 6. The production method according to claim 1, wherein when S initial is set as the tensile breaking stress σ max of the initial hydrogel and S is set as the tensile breaking stress of the hydrogel having a porous structure, the following relational expression is satisfied: S>S initial 。
7. 7. The production method according to claim 1, wherein when the initial hydrogel has an elongation at break λ max of T initial and the hydrogel having a porous structure has an elongation at break of T, the following relational expression is satisfied: T>T initial 。
8. 8. The production method according to claim 1, wherein the young's modulus E max of the initial hydrogel is set to U initial , and the young's modulus of the hydrogel having a porous structure is set to U, satisfying the following relational expression: U>U initial 。
9. 9. the production method according to claim 1, wherein the breaking energy of the hydrogel having a porous structure is a value higher than the breaking energy of the initial hydrogel.
10. 10. The production method according to claim 1, wherein the compound a is a 2-branched, 3-branched, 4-branched or 8-branched PEG having a total of 2 or more nucleophilic functional groups in a side chain or a terminal; The compound B is a PEG having 2, 3, 4 or 8 branches of electrophilic functional groups in total of 2 or more in the side chain or terminal.
11. 11. The method according to claim 1, wherein the nucleophilic functional group is selected from the group consisting of mercapto group and amino group, and the electrophilic functional group is selected from the group consisting of maleimide group, N-hydroxy-succinimidyl NHS, and sulfosuccinimidyl group.

Description

Method for producing hydrogel having porous structure Technical Field The invention relates to a method for manufacturing biocompatible hydrogel with a three-dimensional communicated porous structure. Background In recent years, hydrogels having a polymer network structure have been expected to be applied not only to materials for medical use such as artificial tissues, stent materials for regenerative medicine, sealants, anti-adhesion materials, drug delivery substrates, and contact lenses, but also to materials for various uses such as sensors and surface coating materials because of their excellent water retaining ability, biocompatibility, and the like (for example, non-patent document 1). In particular, gels having three-dimensionally connected μm-sized porous structures are produced, which are expected in the development of materials for tissue engineering applications. However, in order to obtain a porous structure of μm-order, it has been conventionally required to use a top-down method such as micro-processing of a pre-fabricated hydrogel or polymer structure by a technique such as photolithography, or to prepare a polymer material using a polymer material insoluble in a solvent. On the other hand, when hydrophilic polymer materials such as polyethylene glycol (PEG) having biocompatibility are used, although a simple production technique using a two-liquid mixture system is used, only hydrogels having a porous structure with a small size of nm can be produced by this method, and it is difficult to permeate cells and substances having a size of μm. Prior art literature Non-patent literature Non-patent document 1, sakai et al, macromolecules,41,5379-5384,2008 Disclosure of Invention Technical problem Accordingly, an object of the present invention is to provide a novel method for producing a hydrogel material having a μm-sized porous structure permeable to a substance such as a cell by a simpler method. Means for solving the problems In order to solve the above problems, the present inventors have found that a conventional method for producing a hydrogel can be improved, a biocompatible hydrogel having a porous structure of μm level can be produced by controlling the total concentration of a base polymer in a solution within a predetermined range and using a freeze thawing process as a trigger for porous structuring of a non-porous structure of the produced initial hydrogel, and the present invention has been completed. The method of the present invention can produce hydrogels having a porous structure of μm level by a simple method without requiring special equipment or the like. Furthermore, the present inventors have found that the resulting hydrogel has not only a spongy three-dimensional network structure (porous structure) of μm order, but also shows properties in terms of physical properties, such as excellent substance permeability, low swelling, improved strength, etc., as compared with a non-porous hydrogel formed of the same polymer unit. That is, in a representative scenario, the present invention provides: <1> a method for producing a hydrogel having a porous structure, comprising: a) A step of preparing a first solution in which the compound A is dissolved in a first solvent; b) A step of preparing a second solution obtained by dissolving the compound B in a second solvent; c) Mixing the first solution with the second solution to obtain an initial hydrogel having a non-porous structure, wherein the initial hydrogel is obtained by mixing the first solution with the second solution in such a manner that the total polymer concentration (C total) in the third solution obtained by mixing the first solution with the second solution is equal to or less than the higher one of the viscosity-increasing characteristic concentration (C A) inherent to the compound A and the viscosity-increasing characteristic concentration (C B) inherent to the compound B; d) A step of subjecting the initial hydrogel to a freezing treatment to obtain a frozen hydrogel, and E) A step of treating the frozen hydrogel at a temperature higher than or equal to one of the melting points of the first solvent and the second solvent to obtain a hydrogel having a porous structure; Both the initial hydrogel and the hydrogel having a porous structure are crosslinked with each other by the compound a and the compound B to form a gel, The first solvent and the second solvent are both water-based solvents; The compounds A and B are polyethylene glycol (PEG) having 2 branches, 3 branches, 4 branches or 8 branches of nucleophilic functional groups or electrophilic functional groups in total of 1 or more at the side chain or terminal. Furthermore, in a preferred embodiment of the present invention, <2> The production method according to the above <1>, wherein the compound a and/or the compound B has a weight average molecular weight of 4 x 10 4 or less; <3> the production method according to the above <1>, wherein the freezing treatme