KR20230134180A - Hydrogels made of polar aramid nanofibers - Google Patents

Abstract

The present invention provides a hydrogel containing polar aramid nanofibers and a method for manufacturing the same. The hydrogel has excellent moisture content and can have remarkable strength, thereby providing a new material to replace a biological support. It can be used as

Description

Hydrogel made of polar aramid nanofibers

The present invention provides a hydrogel containing polar aramid nanofibers and a method for manufacturing the same, and more specifically, relates to a new hydrogel with excellent strength and no destruction.

Hydrogels and sponges are materials that are being studied as substitutes for biological tissues due to their high moisture content (>70%) and sufficient retention of physiological substances. Therefore, both hydrogels and sponges have been extensively studied as scaffolds for tissue engineering and as promising candidates for drug delivery carriers or biological platforms.

Recently, the demand for wet materials such as hydrogels and sponges has increased significantly by imitating biological tissues in the fields of wearable electronics and soft robotics. However, to mimic biological scaffolds (biological tissues) such as artificial cartilage, conventional methods have been There are limitations in using hydrogels and sponges.

Conventional hydrogels are wetting materials manufactured from cross-linked hydrophilic polymers such as polyvinyl alcohol, starch, cellulose, or hyaluronic acid, and have excellent moisture content, but are not excellent in strength, and especially suffer from the problem of destruction due to strong pressure. However, there are limits to its use as a biological support.

To solve the problem of the strength of the hydrogel, a sponge with excellent strength and no destruction can be used, but it has a significantly lower moisture content than the hydrogel, which limits its use as a biological support.

Recently, in order to solve the above-mentioned shortcomings of conventional sponges, technology has been developed to impart excellent moisture content by increasing the content of polymers with hydrophilic groups, such as polyvinyl alcohol, in sponges. However, this approach inevitably causes moisture. A trade-off between content and strength was encountered, and the strength and moisture content to replace the biosupport were not satisfied at the same time.

Therefore, a new wetting agent is needed to overcome the limitations of conventional hydrogels and sponges, and furthermore, a new approach is needed to simultaneously improve the moisture content and strength of hydrogels and sponges.

Korean Patent Publication No. 10-2018-0057585 A

In order to solve the problems of conventional hydrogels and sponges for mimicking biological scaffolds, the present invention aims to provide a hydrogel containing polar arimide nanofibers and a method for manufacturing the same.

Another object of the present invention is to provide a hydrogel with controlled strength and moisture content by controlling the concentration of the polar aramid nanofiber dispersion solution.

Another object of the present invention is to provide a biosupport including a hydrogel according to one embodiment.

The present invention is a hydrogel containing polar aramid nanofibers,

The hydrogel provides a hydrogel having a moisture content of 50 to 99.9% by weight,

As one embodiment, the polar aramid nanofibers can provide a hydrogel made of a polar aromatic polyamide-based polymer represented by the following formula (1).

[Formula 1]

(In Formula 1 above,

Ar ₁ and Ar ₂ is independently a C6-C20 heteroaromatic group or an aromatic group,

X _{1 and}

n and m are integers that satisfy 1≤m+n≤12.)

In one embodiment, the hydrogel may have a swelling change of 2% or less when immersed in water.

As one embodiment, the polar aramid nanofibers may have an average diameter of 1 to 100 nm.

As one embodiment, the hydrogel may have a moisture content of 60 to 99.5% by weight.

As an embodiment, the hydrogel may be characterized in that it does not fracture even at a strain rate of 85% or less with respect to external pressure.

Additionally, as one embodiment, the hydrogel may have a water diffusion coefficient of 10 ^-9 m ² /s or more.

As one embodiment, the hydrogel may have a compressive modulus of elasticity of 0.3 MPa or more and a tensile modulus of elasticity of 1.0 MPa or more.

The present invention provides a biological scaffold prepared from the above-described hydrogel.

In one embodiment, the biological scaffold may be artificial cartilage.

The present invention includes the steps of preparing a polar aramid nanofiber dispersion solution containing polar aramid nanofiber particles; and

Solvent exchanging the polar aramid fiber dispersion solution;

It provides a method for producing a hydrogel comprising.

As one embodiment, the polar aramid nanofiber dispersion solution may be prepared from a polar aromatic polyamide-based resin, a strong base, and a polar solvent.

As one embodiment, the polar aramid nanofiber particles may have an average diameter of 1 to 100 nm and an average length of 0.1 to 100 ㎛.

As one embodiment, the polar aramid fiber dispersion solution may contain 0.01 to 30% by weight of polar aramid nanofiber particles.

As one embodiment, the solvent exchange step may be solvent exchange by immersing the polar aramid dispersion solution in water.

As an embodiment, the solvent exchange step may be performed two or more times.

As one embodiment, the solvent exchange step may be characterized in that polar aramid nanofiber particles self-assemble into polar aramid nanofibers.

The hydrogel according to one embodiment of the present invention can have significant moisture content and strength at the same time.

The hydrogel according to one embodiment of the present invention has excellent compressive elastic modulus and internal moisture diffusion coefficient, so that failure may not occur even at a strain rate of 85% or less.

The hydrogel production method according to one embodiment of the present invention can produce a hydrogel composed of polar aramid nanofibers with a very small average diameter.

The hydrogel production method according to one embodiment of the present invention can control the strength and moisture content of the produced hydrogel by adjusting the concentration of the polar aramid nanofiber dispersion solution.

1 shows the structural formulas of the aromatic polyamide polymer synthesized in Preparation Example 1 and the aromatic polyamide polymer used in Comparative Example 1; and
This is an actual photograph of the hydrogel prepared in Example 2 and Comparative Example 1.
Figure 2 shows the process of solvent exchange of the polar aramid nanofiber dispersion solution in Example 2.
Figure 3 is a photograph showing the rigid and sponge properties that appear when the hydrogel prepared in Example 2 is compressed with a 2 kg weight.
Figure 4 is a diagram expressing the characteristics of the hydrogel according to an embodiment of the present invention, which has excellent strength at low strain rates and does not break at high strain rates.

Unless otherwise defined, the technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art to which this invention pertains, and the gist of the present invention is summarized in the following description and accompanying drawings. Descriptions of known functions and configurations that may unnecessarily obscure are omitted.

Additionally, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly dictates otherwise.

In addition, units used without special mention in this specification are based on weight, and as an example, the unit of % or ratio means weight % or weight ratio, and weight % refers to the amount of any one component of the entire composition unless otherwise defined. It refers to the weight percent occupied in the composition.

In addition, the numerical range used in this specification includes the lower limit and upper limit and all values within the range, increments logically derived from the shape and width of the defined range, all double-defined values, and the upper limit of the numerical range defined in different forms. and all possible combinations of the lower bounds. Unless otherwise specified in the specification of the present invention, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

The term “nanofiber” in this specification may refer to a fine fiber having an average diameter of 1 to 100 nm, and may be distinguished from conventional nanofibers or fibers manufactured by electrospinning.

As described above, the purpose of the present invention is to solve the problems of each wetting material, such as the low strength of the conventional hydrogel and the problem of being broken under strong pressure and the low moisture content of the conventional sponge, and to provide a wet material with excellent moisture content and The aim is to provide a new hydrogel and a manufacturing method thereof that have strength and at the same time do not break even at high strain rates like a sponge.

As such, the hydrogel can be used in fields that require high moisture content and strength, such as biosupports, due to its excellent moisture content and remarkable strength.

The hydrogel of the present invention will be described below.

The present invention is a hydrogel containing polar arimide nanofibers,

The hydrogel may have a moisture content of 50 to 99.9% by weight.

Specifically, the hydrogel has a porous structure in which polar aramid nanofibers are entangled in a network structure, and the pores of the hydrogel may contain moisture.

The hydrogel contains polar aramid nanofibers to stably maintain moisture and has the rigid properties of aramid nanofibers, so it not only solves the technical trade-off between moisture content and strength of conventional sponges, but surprisingly, It can have a significantly higher moisture content than conventional hydrogels.

Hereinafter, the polar aramid nanofibers included in the hydrogel of the present invention and the effects of the hydrogel accordingly will be described in detail.

As one embodiment, the polar aramid nanofibers may have an average diameter of 1 to 100 nm, specifically 1 to 50 nm.

The hydrogel containing polar aramid nanofibers of the above average diameter is prepared using the aramid nanofiber dispersion solution manufacturing method described in Korean Patent Publication No. 10-2096574 A, and may be much finer than aramid nanofibers manufactured by conventional electrospinning. there is.

Therefore, as the hydrogel contains very fine polar aramid nanofibers, the solid content can be reduced, and the influence of polar groups increases due to an increase in surface area, so it can have a significant moisture content.

The polar aramid nanofiber may be made of a polar aromatic polyamide polymer. More specifically, the polar aromatic polyamide polymer may be one in which one or more polar groups are substituted in the repeating units of the aromatic polyamide-based polymer.

Specifically, the aromatic polyamide polymer includes, for example, poly(m-phenylene isophthalamide) (Nomex), poly(p-phenylene terephthalate) (Kevlar), poly(benzamide) (Conex), and polytere. One or There may be two or more, and more specifically, it may be poly(m-phenylene isophthalamide) (Nomex) or poly(p-phenylene terephthalate) (Kevlar).

As one embodiment, the polar aramid nanofiber may be made of a polar aromatic polyamide-based polymer represented by the following formula (1).

[Formula 1]

(In Formula 1 above,

Ar ₁ and Ar ₂ is independently a C6-C20 heteroaromatic group or an aromatic group,

X _{1 and}

Specifically, in Formula 1, Ar ₁ and Ar ₂ may each independently be a C6-C20 aromatic group, and more specifically, a C6-C12 aryl group.

The polar aromatic polyamide-based polymer, in which Ar ₁ and Ar ₂ are C6-C12 aryl groups, can have superior elongation and strength, and by having a fibrous structure, it can absorb shocks applied from the plane direction to a wide angle. It may be preferred.

Additionally, specifically in Formula 1, X ₁ and X ₂ may each independently be a carboxyl group or a cyano group, and more specifically, may be a cyano group.

In Formula 1, the polar aramid nanofibers in which X _{1 and} It can stably contain moisture.

Also, specifically, in Formula 1, n and m may be integers satisfying 1≤m+n≤6, and more specifically, may be integers satisfying 1≤m+n≤3.

The polar aromatic polyamide-based polymer having a polar group in the above range can not only maintain the remarkable strength, fire resistance, and heat resistance of the aromatic polyamide-based polymer, but also has a polar group, and the hydrogel produced therefrom has a remarkable compressive elastic modulus. , tensile modulus and moisture content, so it can be preferred.

More specifically, the polar aromatic polyamide-based polymer may be a polymerization of a phenylenediamine-based compound and a phenylene diecide-based compound, and may include one or more polar groups in the phenyleneamide-based compound or phenylene diecide-based compound. It may be.

The phenylenediamine-based chemicals include, for example, 2,5-diaminobenzene, 1,2-diaminobenzene, 1,3-diaminobenzene, 2,5-diaminobenzotriazonitrile, and 1,2-diaminobenzene. It may be one or two or more selected from diaminobenzotriazonitrile, 1,3-diaminobenzotriazonitrile, 2,5-diaminobenzoic acid, 1,2-diaminobenzoic acid, and 1,3-diaminobenzoic acid. .

In addition, the phenylene diecide-based compounds include, for example, terephthaloyl chloride, benzene-1,2-dicarbonyl chloride, benzene-1,3-dicarbonyl chloride, and cyanobenzene-1,2-dicarbonyl. Chloride, cyanobenzene-1,3-dicarbonyl chloride, cyanobenzene-2,5-dicarbonyl chloride, 1,3-di(chlorocarbonyl)benzoic acid, 1,2-di(chlorocarbonyl) It may be one or two or more selected from benzoic acid and 2,5-di(chlorocarbonyl)benzoic acid.

Specifically, the phenylenediamine-based compound may be one or two or more selected from 2,5-diaminobenzene and 2,5-diaminobenzotriazonitrile, and the phenylene diecide-based compound is terephthaloyl chloride or It may be 2,5-di(chlorocarbonyl)benzoic acid, etc.

Phenylenediamine-based compounds and phenylene diecid-based compounds having functional groups at positions 2 and 5 can be polymerized to produce para-structured polar aromatic amide-based polymers, which have higher strength than meta-structured polar aromatic amide-based polymers. It may be superior and therefore preferred, but this is not limited.

In one embodiment, the aromatic polyamide-based polymer may have a weight average molecular weight of 2,000 to 1,000,000 g/mol, specifically 5,000 to 500,000 g/mol.

Aramid nanofibers containing a polar aromatic amide-based polymer having the weight average molecular weight may be preferred because they may have excellent strength, but this is not limited as long as they do not impair the physical properties of the hydrogel.

Hereinafter, the hydrogel of the present invention will be described in detail.

As one embodiment, the hydrogel may have a moisture content of 60 to 99.5% by weight, specifically 70 to 99.2% by weight.

As described above, hydrogels with a water content in the above range are a phenomenon that can stably contain water by introducing polar groups into conventional aramid nanofibers, and not only solve the hydrophobicity problem of conventional aramid nanofibers, but also solve the hydrogel problem. , Surprisingly, it can have a moisture content that is superior to that of conventional hydrogels, and thus can have remarkable mass transfer capabilities.

In addition, hydrogels with the above moisture content can have a very low moisture content and can have sponge properties that allow internal moisture to escape without destruction even under strong compression, making them preferred in fields that require excellent strength and durability.

In one embodiment, the hydrogel may have a compressive modulus of elasticity of 0.3 MPa or more and a tensile modulus of elasticity of 1.0 MPa or more. Specifically, the hydrogel may have a compressive modulus of elasticity of 0.3 to 60 MPa and a tensile modulus of elasticity of 1.0 to 100 MPa.

Hydrogels with compressive and tensile moduli in the above range may be the result of hydrophobic inter-fibrillar interaction between the polar aramid nanofibers contained therein, and have excellent elastic modulus, allowing them to change shape under external pressure. It can be maintained and has excellent durability.

As one embodiment, the hydrogel may not be destroyed even at a strain rate of 85% or less with respect to external pressure.

The hydrogel has the excellent tensile strength and moisture diffusion coefficient of polar aramid nanofibers, so not only can it have a remarkable elastic modulus at low pressure as described above, but it also does not fracture even at high pressures such as a strain rate of 85% or less. Therefore, for example, it can be used in fields with strong external pressure, such as biological scaffolds.

As one embodiment, the hydrogel may have a water diffusion coefficient of 10 ^-9 m ² /s or more.

In more detail, the water diffusion coefficient of the hydrogel is a value measured at 25 ℃ and the hydrogel solid content is 10% by weight, and the hydrogel with the water diffusion coefficient quickly loses internal moisture at a strain rate of 85% as described above. You can go out and no destruction will occur.

As one embodiment, when the hydrogel is immersed in water, the swelling ratio may be 2% or less, and specifically, 1% or less.

The swelling change in the above range is a phenomenon that occurs when the elastic pressure of the hydrogel is higher than the osmotic pressure, so it can be morphologically very stable and the strength of the hydrogel may not decrease due to additional moisture absorption. It may be preferred.

Hereinafter, the method for producing the hydrogel of the present invention will be described in detail.

The present invention includes the steps of preparing a polar aramid nanofiber dispersion solution containing polar aramid nanofiber particles; and

Solvent exchanging the polar aramid fiber dispersion solution;

It provides a method for producing a hydrogel comprising.

In more detail, the hydrogel manufacturing method uses a method of preparing a polar aramid nanofiber dispersion solution and using a non-solvent phase transfer method, thereby producing a hydrogel containing polar aramid nanofibers with an average diameter of 1 to 100 nm as described above. can be manufactured.

Hereinafter, the steps for preparing the polar aramid nanofiber dispersion solution will be described.

As one embodiment, the polar aramid nanofiber dispersion solution may be prepared from a polar aromatic polyamide-based resin, a strong base, and a polar solvent.

The polar aromatic polyamide-based resin may be in the form of a spun fiber made of the above-described polar aromatic polyamide-based polymer or in a solid form that is not spun in the form of a fiber, and may be formed in a particle size recognizable by a person skilled in the art during the manufacturing process of the polar aramid nanofiber dispersion solution. If you have one, you can use it without restrictions.

The polar aromatic polyamide polymer may be an aromatic polyamide-based polymer substituted with a polar group. Specifically, it may be one in which a repeating unit of the aromatic polyamide polymer is substituted with one or more polar groups. More specifically, it is represented by the following formula (1): It may be displayed.

[Formula 1]

(In Formula 1 above,

Ar ₁ and Ar ₂ is independently a C6-C20 heteroaromatic or aromatic group,

X _{1 and}

As another embodiment, the polar aromatic polyamide-based resin may further include an additive, and the additive may include 0.1 to 5 parts by weight based on 100 parts by weight of the polar aromatic polyamide-based polymer, but this is limited. That is not the case.

Specifically, the additive may be, for example, one or two or more selected from plasticizers, pigments, fillers, lubricants, and stabilizers, but any additive recognized by a person skilled in the art may be used without limitation.

In one embodiment, the polar solvent is dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA), N ,N,N',N'-tetramethyl urea (TMU) and N,N-dimethylformamide (DMF).

Specifically, the polar solvent may be one or two or more selected from dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF), and more specifically, dimethyl sulfoxide. It may be side (DMSO), N,N-dimethylacetamide (DMAc), or a mixture thereof.

The DMSO or DMAc has excellent solubility in polar aromatic polyamide-based polymers, so it can shorten the peeling time of polar aromatic polyamide-based resins and produce finer-sized polar aramid nanofiber particles. It may be preferred because it mixes well with water and can shorten the solvent exchange time.

In one embodiment, the polar aramid nanofiber dispersion solution may contain 0.01 to 5 parts by weight of a strong base, and specifically 0.01 to 3 parts by weight, based on 100 parts by weight of the polar solvent.

The polar aramid nanofiber dispersion solution containing the above strong base concentration may not impair the physical properties of the polar aromatic polyamide-based polymer and may be preferred because it does not cause environmental pollution due to excessive strong base.

Specifically, the strong base may be a halogen alkali metal salt, and for example, may be one or two or more selected from sodium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide.

Even if a trace amount of the halogen alkali metal salt is added, the polar aromatic polyamide-based resin can be very finely peeled off, the peeling time can be shortened, and its solubility in water is very excellent, so it does not remain in the produced hydrogel. It may not be possible, so it may be preferred.

The polar aramid nanofiber dispersion solution may be prepared by adding a polar aromatic polyamide-based resin to a polar solvent containing a strong base, followed by stirring at 50° C. or lower for 70 hours or less to finely exfoliate the aromatic polyamide-based resin. there is.

Specifically, the stirring temperature may be performed at a temperature of 20 to 30° C., and the stirring may be performed under an inert gas atmosphere such as nitrogen or argon, but is not limited thereto.

Additionally, the stirring may be performed at 1 to 1000 rpm, specifically 5 to 800 rpm, and more specifically 10 to 500 rpm, but is not limited thereto.

Specifically, the stirring time may be 1 to 70 hours, and more specifically 10 to 60 hours, but is carried out until no polar aramid nanofiber particles are visible when checked inside, so it is within a range recognizable to those skilled in the art. can be adjusted.

Hereinafter, the step of solvent exchange in the hydrogel production method of the present invention will be described.

As one embodiment, the solvent exchange step may be performed by self-assembling polar aramid nanofiber particles into polar aramid nanofibers.

Specifically, the polar aramid nanofiber dispersion solution is composed of polar aramid nanofiber particles, a polar solvent, and a strong base. In the solvent exchange step, removal of the polar solvent and strong base and phase transition of the polar aramid nanofiber particles may occur.

The solvent exchange step may be performed by condensing the polar aramid nanofiber particles contained in the polar nanofiber dispersion solution to form network-structured polar aramid nanofibers to produce a hydrogel.

As one embodiment, the polar aramid nanofiber dispersion solution may contain 0.01 to 30% by weight of polar aramid nanofiber particles, specifically 0.05 to 20% by weight.

The polar aramid nanofiber dispersion solution at the above concentration can be preferred because the stirring time can be shortened and the solid content of the hydrogel produced from it can be adjusted to achieve significant moisture content and strength at the same time.

As one embodiment, the polar aramid nanofiber particles may have an average diameter of 1 to 100 nm and an average length of 0.1 to 100 ㎛, specifically, an average diameter of 1 to 50 nm and an average length of 0.1 to 50 ㎛. It can be.

Polar aramid nanofiber particles with an average length and average diameter in the above range are much finer particles than aramid nanofibers produced by conventional electrospinning, and the hydrogel produced including them is a polar aramid with an average diameter of 1 to 100 nm. By including nanofibers, it can have a significant moisture content compared to conventional sponges and may be preferred.

As one embodiment, the solvent exchange step may be solvent exchange by immersing the polar aramid dispersion solution in water.

In more detail, the solvent exchange step may involve putting the polar aramid nanofiber dispersion solution in a solid frame or dialysis pack and then exchanging the solvent with water.

The solid frame or dialysis pack may be permeable only to the polar solvent and strong base contained in the polar aramid nanofiber dispersion solution in the solvent exchange step, and the pore size may be 1 to 10 kDa MWCO (Molecular weight cut off). This is not intended to limit this.

In addition, the solid frame or transparent pack may be better to use a polymer with excellent chemical resistance, such as polyvinyl chloride, polyvinylidene fluoride, or polyphenylene ether, as it does not dissolve in polar solvents. It is not limiting.

Specifically, in the solvent exchange step, water may be at a temperature of 10 to 50°C, and specifically, may be at a temperature of 20 to 30°C.

Water at the above temperature may be preferred because it may have excellent solvent exchange with polar solvents, and polar arimide nanofiber particles may condense and undergo phase transition quickly, shortening the hydrogel production time.

Also, specifically, the solvent exchange step; the immersion time in water may be 1 to 50 hours, more specifically 1 to 24 hours, but may be shortened or extended depending on the dialysis pack or solid mold used. Just because it exists does not exclude it.

As an embodiment, the solvent exchange step may be performed two or more times, and specifically, may be performed 2 to 5 times.

More specifically, the solvent exchange step may not be to solvent exchange the polar aramid nanofiber dispersion solution two or more times, but to additionally solvent exchange the hydrogel prepared by phase transition in one solvent exchange.

By exchanging the solvent twice or more, trace amounts of remaining polar solvent and strong base can be removed, and by re-phase-transferring the polar aramid nanofiber particles that failed to undergo phase transformation, a hydrogel with superior purity and strength can be manufactured. may be preferred.

The above-described hydrogel can have significant moisture absorption and strength, and can not be destroyed even at high strain rates. In addition, its physical properties can be adjusted in its manufacturing method, making it possible to manufacture hard or soft material, making it suitable for use in various fields. It may be applicable, and in particular, it may be possible to replace bio-scaffolds.

More specifically, the physical properties and measurement methods of the hydrogel may be as follows.

The hydrogel may have a moisture content of 50 to 99.99% by weight, and in another embodiment, the hydrogel has sponge characteristics, so that the moisture content is 1 to 99.99% by weight, the moisture content is 10% by weight or more, and 20% by weight. % or more, 30% by weight or more, 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 99.99wt% or less and between each of the above values. It may have a content of

Preferably, it may be 60wt% or more, 70wt% or more, 80wt% or more, 90wt% or more, 99wt% or less, and a content between each of the above values.

In addition, the hydrogel was manufactured into a specimen of 25mm When calculating the average value, the tensile modulus may be 0.5 MPa or more, 1 MPa or more, 5 MPa or more, 10 MPa or more, 20 MPa or more, 40 MPa or more, 50 MPa or more, 70 MPa or less, and a value different from the above values.

In addition, the compressive elastic modulus of the hydrogel was measured by making the produced hydrogel into a specimen of 20mm When measured multiple times and the average value is calculated, it may be 0.5 MPa or more, 1 MPa or more, 5 MPa or more, 10 MPa or more, 20 MPa or more, 40 MPa or more, 50 MPa or more, 70 MPa or less, and a value different from the above values.

In addition, the change in swelling ratio of the hydrogel was recorded by measuring the mass of the prepared hydrogel using an electronic balance (Mettler toledo, Mettler precision balance ME30021) and then placed in deionized water at 25°C for 12 hours. When left to stand for a while, the weight is measured and recorded with an electronic scale, and calculated using Equation 3 below, the value can be within 2%, within 1%, within 0.5%, and within 0.1%.

In more detail, the bioscaffold may be, for example, an extracellular matrix (ECM), an artificial organ, an artificial cartilage, an artificial skeleton, or a bioabsorbable shield, and plays the role of supporting cells or tissues and transporting substances in vivo. By doing so, the artificially manufactured biological support has excellent moisture content and strength. In addition, the biological scaffold must have excellent harmlessness to the human body to prevent inflammation.

Hereinafter, a bioscaffold prepared from the hydrogel of the present invention will be described.

The present invention can provide a biological scaffold manufactured from the above-described hydrogel.

The hydrogel produced in one embodiment of the present invention has excellent moisture content and strength, so the bioscaffold produced therefrom can have excellent material shear and has remarkable strength to support cells and tissues more stably. there is.

As one embodiment, the biological scaffold may be artificial cartilage.

The hydrogel produced in one embodiment does not break even at a strain rate of 85%, so it can be suitable for artificial cartilage that requires strong durability, can have a significantly higher moisture content than sponges used conventionally, and can be used in metal prosthetics. Inflammation problems may not occur.

Hereinafter, the present invention will be described by way of examples. That is, the present invention can be better understood by the following examples, and the following examples are for illustrative purposes of the present invention. However, the embodiments of the present invention are not intended to limit the scope of protection limited by the appended patent claims.

[measurement method]

1. Inherent viscosity measurement

Measured according to ISO 3105 regulations, the viscosity of a sulfuric acid (concentration: 98% by weight) solution was measured and recorded at 25°C using an Ubbelohde viscometer (IIc, diameter of 1.36 mm), and the polymer was added to the sulfuric acid solution at 0.5 g/dl. After dissolving to the correct concentration, the viscosity was measured in the same manner as above and the polymer solution viscosity was recorded.

After that, the logarithmic viscosity was obtained by calculating using Equation 1 below.

[Equation 1]

Logarithmic viscosity (dL/g) = In (polymer solution viscosity/sulfuric acid solution viscosity)/0.5 g/dl

2. Hydrogel moisture content measurement

The initial mass of the prepared hydrogel was measured and recorded, and the hydrogel was dried at 120°C for 48 hours using a vacuum oven (Samheung Scientific Company, SH-VDO-08NG), and then dried using an electronic balance. The mass was measured and recorded.

Afterwards, the recorded initial hydrogel mass and dried hydrogel mass were calculated using Equation 2 below to obtain the hydrogel water content.

[Equation 2]

Hydrogel water content (%) = (W _h -W _d /W _h ) × 100

(W _h is the initial hydrogel mass, and W d is the dried hydrogel mass.)

3. Tensile modulus measurement

The prepared hydrogel was manufactured into a specimen of 25 mm At this time, the crosshead speed was measured at 1 mm/min, measured a total of 5 times, and the average value was recorded.

4. Compressive modulus measurement

The prepared hydrogel was manufactured into a specimen of 20 mm At this time, 1 KN was used for the load shell, and the average value was obtained by measuring a total of 5 times.

5. Measurement of change in swelling ratio

The mass of the prepared hydrogel was measured and recorded using an electronic balance (Mettler toledo, Mettler precision balance ME30021), and then left in deionized water at 25°C for 12 hours, and the weight was measured and recorded using an electronic balance. .

Afterwards, the change in swelling ratio was obtained by calculating using Equation 3 below.

[Equation 3]

Swelling rate change (%) = ((W _s -W _h )/W _h )

(Ws is the mass of the hydrogel left standing in water, and Wh is the initial mass of the produced hydrogel.)

6. Measurement of diffusion coefficient of water inside hydrogel

At 20°C, 0% relative humidity, and 1 atm pressure, distilled water in a 10 mm × 10 mm × 10 mm container was left for 8 hours, and then the mass (A) of the evaporated distilled water was measured. After leaving the hydrogel for 8 hours, the diffusion coefficient of the hydrogel was measured by measuring the mass (B) of the evaporated water and substituting N as the B/A value in Equation 4 below.

Afterwards, the water diffusion coefficient inside the hydrogel was obtained by calculating using Equation 4 below.

[Equation 4]

D = D ₀ × N

(D is the diffusion coefficient of water inside the hydrogel, D ₀ is the diffusion coefficient of distilled water (1.95 × 10 ^-9 m ² /s), and N is the ratio of the diffusion coefficient of distilled water to the diffusion coefficient of water inside the hydrogel.)

7. Nanofiber average diameter measurement

The hydrogel specimen was cut to a thickness of 20 nm or less through a cryo-ultramicrotoming process and then photographed using a transmission electron microscope (FEI company (USA), FEI Tecnai G2 Spirit TWIN).

The photos taken with the TEM were used to measure the nanofiber diameters at 100 locations using software (Image J), and the average values were shown.

[Production Example 1]

Add 10.06 g (75.6 mmol) of 2,5-diaminobenzonitrile, 5.58 g (75.6 mol) of lithium carbonate, and 100 ml of N,N-dimethylacetamide to a 250 ml round bottom flask. and stirred at 350 rpm for 1 hour at 2°C and in a nitrogen environment.

Afterwards, 15.35 g (75.6 mol) of terephthaloyl chloride powder was added to the flask in two portions at 1-minute intervals, and stirred at 10 rpm for 24 hours.

After stirring, it was precipitated in a mixed solvent of 700 ml of distilled water and 700 ml of methanol, and the precipitate was separated using a filter (LK LAB Korea Inc, Membrane filter, PTFE Membrane filter (Φ47mm)). The separated precipitate was mixed with distilled water and acetone for a total of 5 times. After washing, it was dried for 24 hours using a vacuum dryer (Samheung Science & Technology, SH-VDO-08NG).

Afterwards, the yield and logarithmic viscosity were measured using the above measurement method, and it was confirmed that a polymer with a yield of 97% and a logarithmic viscosity of 4.9 dL/g was synthesized.

[Example 1]

0.1 g of the polymer prepared in Preparation Example 1, 0.15 g of KOH, and 9.9 g of dimethyl sulfoxide were added to a round bottom flask and stirred at 100 rpm for 7 days at 25°C and in a nitrogen environment to obtain a concentration of 1% by weight. A nanofiber dispersion solution was prepared.

The nanofiber dispersion solution was placed in a dialysis pack (Spectra/Por® 6 Dialysis Membrane, Pre-wetted RC tubing MWCO: 3.5 kD, Width: 45 mm, Diameter: 29 mm, Length: 10 mm) and then placed in water at 25°C. Solvent exchange was performed by soaking for 72 hours.

The dialysis pack that had undergone one solvent exchange was further solvent exchanged twice in the same manner as the solvent exchange, and the dialysis pack was removed to obtain a hydrogel.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

Example 2]

A hydrogel was prepared in the same manner, except that a nanofiber dispersion solution with a concentration of 2% by weight was prepared using 0.2 g of the polymer prepared in Preparation Example 1, 0.3 g of KOH, and 9.8 g of dimethyl sulfoxide. did.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

[Example 3]

In Example 1, a nanofiber dispersion solution with a concentration of 3% by weight was prepared using 0.3 g of aromatic polyamide, 0.45 g of KOH, and 9.7 g of dimethyl sulfoxide (DMSO) of Preparation Example 1. A gel was prepared.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

[Example 4]

In Example 1, a nanofiber dispersion solution with a concentration of 5% by weight was prepared using 0.5 g of aromatic polyamide, 0.75 g of KOH, and 9.5 g of dimethyl sulfoxide (DMSO) of Preparation Example 1. A gel was prepared.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

[Example 5]

In Example 1, 1 g of aromatic polyamide, 1.5 g of KOH, and 8.5 g of dimethyl sulfoxide (DMSO) prepared in Preparation Example 1 were used, except that a nanofiber dispersion solution with a concentration of 10% by weight was prepared. A hydrogel was prepared as follows.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

[Comparative Example 1]

In Example 1, a nanofiber dispersion solution with a concentration of 1 mass% was prepared using 0.1 g of Kevlar fiber (Kevlar-49, average diameter 12 μm), 0.15 g of KOH, and 9.9 g of dimethyl sulfoxide. Hydrogel was prepared in the same manner except that.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

[Comparative Example 2]

Add 0.97 g of acrylamide, 0.01 g of N,N,N',N'-tetramethylethylenediamine (TEMED), 0.02 g of ammonium persulfate (APS), and 9.0 g of distilled water into a round bottom flask and incubate at 100 rpm for 1 minute in a nitrogen environment at 25°C. An aqueous solution with a concentration of 10% by mass was prepared by stirring.

The aqueous solution was poured into a mold and left for 72 hours to prepare a hydrogel.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

[Comparative Example 3]

1.0 g of PVA (polyvinyl alcohol) and 9.0 g of distilled water were added to a round bottom flask and stirred at 100 rpm for 12 hours in a nitrogen environment at 25°C to prepare an aqueous polymer solution with a concentration of 10% by mass.

The aqueous solution was poured into a mold and frozen at -15°C for 10 hours, and the frozen aqueous solution was left at room temperature for 24 hours to thaw. The above freezing and thawing process was repeated a total of two times to prepare a hydrogel.

Afterwards, the prepared hydrogel was measured using the above measurement method, and is shown in Table 1 below.

fiber diameter
(nm) moisture content
(%) Compressive modulus
(MPa) tensile modulus
(MPa) Swelling rate change
(%) diffusion coefficient
( ^m2 /s) Example 1 9.5±3.4 99 0.61 2.34 0.1 D ₀ × 0.95 Example 2 9.8±4.1 98 One 3.98 0.2 D ₀ × 0.90 Example 3 10.5±4.8 97 8.3 7.75 0.3 D ₀ × 0.81 Example 4 11.8±5.4 95 25.8 15.1 0.6 D ₀ × 0.75 Example 5 12.9±6.6 90 50.5 79.9 0.8 D ₀ × 0.69 Comparative Example 1 9.6±3.4 Not measurable Not measurable Not measurable Not measurable Not measurable Comparative Example 2 Not measurable 90 0.1 0.02 5.8 D ₀ ×0.09 Comparative Example 3 Not measurable 90 0.2 0.05 5.1 D ₀ ×0.28

Looking at Examples 1 to 5 in Table 1, it can be seen that the average diameter of the polar aramid nanofibers included in the hydrogels prepared in Examples 1 to 5 varies as the concentration of the polar aramid nanofiber dispersion solution varies.

More specifically, Example 5 of Table 1 is a hydrogel prepared from a polar aramid nanofiber dispersion solution containing 10% by weight of polar aramid nanofiber particles. As the diameter increases, the tensile modulus and compressive modulus increase. , it was confirmed that the moisture content was reduced.

Therefore, it is suggested that the strength and moisture content of the hydrogel can be adjusted by adjusting the average diameter of the polar aramid nanofibers included by adjusting the concentration of the aramid nanofiber dispersion solution as in Examples 1 to 5 above.

Looking at Comparative Example 1 in Table 1 above, it was confirmed that hydrogels made from conventional Kevlar fibers did not contain polar groups and thus could not be produced.

Looking at Comparative Example 2 in Table 1, Comparative Example 2 is a hydrogel manufactured using acrylamide and TEMED using ammonium persulfate, a strong oxidizing agent, and has an excellent moisture content of 90%, but has low compressive modulus and tensile strength. The elastic modulus is significantly lower than that of Examples 1 to 5, and the change in swelling rate is 5.8%, which suggests that when immersed in water, the hydrogel cannot withstand osmotic pressure and water penetrates into the hydrogel, further deteriorating its physical properties.

In particular, Comparative Example 2 has a diffusion coefficient of D ₀ × 0.09 m ² /s, which is significantly lower than that of Examples 1 to 5, suggesting that destruction occurs when strong pressure is applied.

In Table 1, Comparative Example 3 is a hydrogel manufactured including polyvinyl alcohol, and like Comparative Example 2, it has significantly lower compressive and tensile modulus than Examples 1 to 5, and fracture occurs under strong pressure. Confirmed.

Therefore, as confirmed in Table 1, Examples 1 to 5 have a moisture content of 90% by weight, and have a compressive elastic modulus of about 10 times more and a tensile modulus of about 100 times more than Comparative Examples 2 to 3, showing remarkable strength. It was confirmed to have.

In addition, Examples 1 to 5 have a swelling rate change of 1% or less and do not absorb additional moisture, so there is no decrease in physical properties. In particular, they have a moisture diffusion coefficient of D ₀ × 0.69 to D ₀ × 0.95 m ² /s, and are It was confirmed to have sponge properties that allow moisture to escape quickly without destruction.

The present invention described above is merely illustrative, and those skilled in the art will appreciate that various modifications and other equivalent embodiments are possible therefrom. Therefore, it will be understood that the present invention is not limited to the forms mentioned in the detailed description above. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and the scope of the patent claims described below as well as all modifications that are equivalent or equivalent to the scope of this patent claim shall fall within the scope of the spirit of the present invention. .

Claims (17)

A hydrogel comprising polar aramid nanofibers,
The hydrogel is a hydrogel having a moisture content of 50 to 99.9% by weight. According to clause 1,
The polar aramid nanofiber is a hydrogel made of a polar aromatic polyamide-based polymer represented by the following formula (1):
[Formula 1]

In Formula 1,
Ar ₁ and Ar ₂ is independently a C6-C20 heteroaromatic group or an aromatic group,
X _{1 and}
n and m are integers that satisfy 1≤m+n≤12. According to clause 1,
The hydrogel is a hydrogel that has a swelling change of 2% or less when immersed in water. According to clause 1,
The polar aramid nanofiber is a hydrogel with an average diameter of 1 to 100 nm. According to clause 1,
The hydrogel is a hydrogel with a moisture content of 60 to 99.5% by weight. According to clause 1,
The hydrogel is a hydrogel characterized by no destruction even at a strain rate of 85% or less with respect to external pressure. According to clause 6,
The hydrogel is a hydrogel with a water diffusion coefficient of 10 ^-9 m ² /s or more. According to clause 1,
The hydrogel is a hydrogel having a compressive modulus of elasticity of 0.3 MPa or more and a tensile modulus of elasticity of 1.0 MPa or more. A bioscaffold manufactured from a hydrogel selected from claims 1 to 8. According to clause 9,
The biological scaffold is an artificial cartilage. Preparing a polar aramid nanofiber dispersion solution containing polar aramid nanofiber particles; and
Solvent exchanging the polar aramid fiber dispersion solution;
Hydrogel manufacturing method comprising. According to clause 11,
A hydrogel production method wherein the polar aramid nanofiber dispersion solution is prepared from a polar aromatic polyamide-based resin, a strong base, and a polar solvent. According to clause 11,
The polar aramid nanofiber particles have an average diameter of 1 to 100 nm and an average length of 0.1 to 100 ㎛. According to clause 11,
A hydrogel production method wherein the polar aramid fiber dispersion solution contains 0.01 to 30% by weight of polar aramid nanofiber particles. According to clause 11,
The solvent exchange step is a method of producing a hydrogel in which the solvent is exchanged by immersing the polar aramid dispersion solution in water. According to clause 16,
A hydrogel manufacturing method wherein the solvent exchange step is performed two or more times. According to clause 11,
The solvent exchange step is a hydrogel manufacturing method characterized in that the polar aramid nanofiber particles self-assemble into polar aramid nanofibers.