KR102166153B1 - Synthesis method of Polyacrylamide Hydrogel for Tissue Repairation - Google Patents

Abstract

The present invention relates to a method for preparing a polyacrylamide hydrogel from which unreacted acrylamide monomers have been removed, and more specifically, a purification step of removing unreacted acrylamide monomers by filtering a diluted polyacrylamide-containing solution. It relates to a method of manufacturing a polyacrylamide hydrogel. According to the manufacturing method of the present invention, the unreacted acrylamide monomer is removed to a concentration less than harmless to the human body in a short time through the purification step, and the viscoelasticity is adjusted to facilitate injection into the subcutaneous tissue by polymerizing the crosslinking agent and the acrylamide monomer. Polyacrylamide hydrogel can be prepared.

Description

Synthesis method of Polyacrylamide Hydrogel for Tissue Repairation

The present invention relates to a method for preparing a polyacrylamide hydrogel from which unreacted acrylamide monomers have been removed, and more specifically, a purification step of removing unreacted acrylamide monomers by filtering a diluted polyacrylamide-containing solution. It relates to a method of manufacturing a polyacrylamide hydrogel.

Autologous tissue transplantation is a method mainly used in medical applications for correcting deformation or defects in the human body, repairing tissues, and cosmetic applications such as breast enlargement, penis enlargement, and contour correction. However, since there may be problems such as limitations of the donor site, unexpected necrosis, deformation, and complications of the transplanted site, studies on various substances that can replace autologous tissue have been conducted. Among them, hydrogel, which forms three-dimensional crosslinks, is a kind of material that is in the spotlight due to its high moisture content. Republic of Korea Patent Publication No. 10-0737954 discloses a hyaluronic acid hydrogel classified as a permanent filler among hydrogels, but hyaluronic acid has a disadvantage of poor viscoelasticity. On the other hand, a polyacrylamide hydrogel to be classified as a semi-permanent filler has a high water-swellable, excellent biocompatible plastic surgery applications were first introduced in Ukraine in the late 1980s (Niechajev I. Lip enhancement:. Surgicalalternatives and histologic aspects Plast Reconstr Surg. , 2000;105:1173-1183.).

However, due to the carcinogenicity and nervous system irritation of acrylamide, which is a monomer of polyacrylamide hydrogel, there remains a task in which acrylamide present in polyacrylamide hydrogel must be removed to a concentration below harmless to the human body. Currently, a washing process is being performed to remove acrylamide, but there is a problem in that the washing process must be repeatedly performed several times, and it takes several hours to several days. Furthermore, it must have viscoelasticity in an appropriate range that can be used for the human body.

Korean Patent Publication No. 10-0737954

The present invention was conceived to solve the above problems, and an object of the present invention is to remove unreacted acrylamide monomer to a concentration less than harmless to the human body in a short time, and at the same time, adjust viscoelasticity to facilitate injection into the subcutaneous tissue. It is to provide a method for producing polyacrylamide hydrogel.

To achieve the above object, the present invention is a step of (1) polymerizing a crosslinking agent and an acrylamide monomer in an aqueous system to prepare a stock solution containing polyacrylamide, wherein the bisacrylamide The crosslinking agent and the acrylamide monomer are polymerized in a weight ratio of 1: 125, (2) saline solution is added to the stock solution so that the concentration of the polyacrylamide is 3.5 to 3.75 v/v% based on the total volume of the aqueous system. (3) purifying the diluted polyacrylamide-containing solution by ultrafiltration under nitrogen pressurization of 50 psi and a flow rate of 12.5 m ³ /hr to remove unreacted acrylamide monomer, and (4) the After passing through the purification step, it provides a method for producing a polyacrylamide hydrogel comprising the step of recovering the polyacrylamide in a gel state.

According to the manufacturing method of the present invention, the unreacted acrylamide monomer is removed to a concentration less than harmless to the human body in a short time through the purification step, and the viscoelasticity is adjusted to facilitate injection into the subcutaneous tissue by polymerizing the crosslinking agent and the acrylamide monomer. Polyacrylamide hydrogel can be prepared.

1 is a view showing HPLC-UV results for hydrogels of Examples and Comparative Examples.
Figure 2 is a view showing the viscoelastic results for the hydrogels of Examples and Comparative Examples.
3 is a view showing the viscoelastic results for the hydrogels of Examples and Comparative Examples.
4 is a view showing the solubility and flowability of the hydrogels of Examples and Comparative Examples.

Hereinafter, the present invention will be described in detail with reference to examples and drawings.

The method for preparing a polyacrylamide hydrogel to achieve the above object is (1) preparing a stock solution containing polyacrylamide by polymerizing a crosslinking agent and an acrylamide monomer in an aqueous system. , (2) diluting the polyacrylamide concentration so that the concentration of the polyacrylamide becomes 3.3 to 4.0 v/v% based on the total volume of the aqueous system by adding saline solution, (3) the diluted polyacrylamide-containing solution A purification step of removing unreacted acrylamide monomer by filtration and (4) recovering a gelled polyacrylamide after passing through the purification step.

The polymerization of the crosslinking agent and the acrylamide monomer may be carried out according to a conventional organic synthesis method, and is not limited to a special method. The crosslinking agent in step (1) may be an internal crosslinking agent or a surface crosslinking agent. Internal crosslinking agents include methylenebisacrylamide, trimethylolpropane tri(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol (meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol (meth)acrylate )Acrylate, butanediol di(meth)acrylate, butylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate )Acrylate, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipentaerythritol pentaacrylate, glycerin tri(meth)acrylate, pentaerythritol tetraacrylate, triarylamine, It may be one or more selected from the group consisting of ethylene glycol diglycidyl ether, propylene glycol, glycerin, and ethylene carbonate, and the surface crosslinking agent includes polyhydric alcohol compounds, epoxy compounds, polyamine compounds, haloepoxy compounds, and haloepoxy compounds. It may be at least one selected from the group consisting of condensation products, oxazoline compounds, oxazolidinone compounds, cyclic urea compounds, polyvalent metal salts, and alkylene carbonate compounds. Preferably, it may be an internal crosslinking agent, and more preferably, it may be an internal crosslinking agent, bisacrylamide.

When the acrylamide monomer is polymerized using bisacrylamide as a crosslinking agent, it is preferable that the bisacrylamide crosslinking agent and the acrylamide monomer are polymerized in a weight ratio of 1: 120 to 150. If the polymerization ratio of the bisacrylamide crosslinking agent is out of the above range, the elastic modulus is small and the viscosity is low, making the polyacrylamide hydrogel unsuitable for use for tissue expansion, repair, or wrinkle removal, or because of its high elastic modulus and high viscosity, injection through a fine needle is not possible. It can be difficult. The bisacrylamide crosslinking agent and the acrylamide monomer are more preferably polymerized in a weight ratio of 1: 125 to 135, and most preferably polymerized in a weight ratio of 1: 125 to 1: 130.

The polymerization in step (1) is preferably performed at a temperature of 1 to 22°C. If the polymerization temperature is less than 1°C, it is not preferable because the polymerization reaction does not proceed sufficiently, and if it exceeds 22°C, side reactions occur and the activity is severely deteriorated, and it is not preferable because it adversely affects polymer properties. The polymerization is more preferably carried out at a temperature of 2 to 10 ℃, most preferably carried out at a temperature of 4 ℃.

In order to apply the polyacrylamide hydrogel to the human body, it may further include a step of sterilizing the solution after the polymerization in step (1). Sterilization may be performed by a method such as autoclave or in situ sterilization by steam heating, or may be performed by filtering with a syringe filter.

In the step of diluting the stock solution by adding saline, it is preferable to dilute the polyacrylamide concentration to be 3.3 to 4.0 v/v% based on the total volume of the aqueous system. When the concentration of polyacrylamide is less than 3.3 v/v%, the elastic modulus is small and the viscosity is low, making it inappropriate to use polyacrylamide hydrogel for tissue enlargement, repair, or wrinkle removal, and the concentration of polyacrylamide is 4.0 v/v%. If it exceeds, the elastic modulus is high and the viscosity is high, so injection through a fine needle may be difficult. It is more preferable that the concentration of polyacrylamide is diluted to 3.5 to 3.75 v/v%, most preferably 3.75 v/v%.

In order to remove the unreacted acrylamide monomer from the polymerized polyacrylamide-containing solution, filtration is performed. As a method of removing the unreacted acrylamide monomer, a washing process that repeats powdering and solution is currently being carried out in order to remove acrylamide, but this washing process has a problem that it takes from several hours to several days. have.

In order to solve such a problem, the present invention was conceived, and studies using a nitrogen pressure filtration method for removing unreacted acrylamide monomers from a polymerized polyacrylamide-containing solution were investigated to have not been conducted so far. Purification can be completed much faster within an hour if the nitrogen pressure filtration is performed, and even if the purification time is reduced, the effect of reducing the content of unreacted acrylamide monomer does not fall compared to the effect in the water washing process.

It is preferable that the nitrogen pressure filtration of the present invention is ultrafiltration under nitrogen pressure conditions.

In the nitrogen pressure filtration of the present invention, the pressure condition is preferably 35 to 70 psi. When the nitrogen is pressurized to less than 35 psi, the unreacted acrylamide monomer is not effectively removed, making it unsuitable for application to the human body.If the nitrogen is supplied in excess of 70 psi, it is not preferable because it may cause denaturation of the ultrafiltration membrane. Nitrogen pressurization conditions of the ultrafiltration are more preferably made under 40 to 60 psi, most preferably made under 50 psi.

The present invention also provides a polyacrylamide hydrogel obtained by the above production method.

More specifically, according to the present invention, it is possible to provide a polyacrylamide hydrogel in which the unreacted acrylamide monomer is removed to contain 0.946 ppm or less with respect to 1 g of the hydrogel. Whether unreacted acrylamide monomer was removed is shown in Test Example 1 and FIG. 1 below.

Acrylamide is classified as a human carcinogen by the International Cancer Institute and is rapidly absorbed by parenteral routes including the skin and skin mucosa. At a content of 50 ppm to 100 ppm per 1 g of hydrogel, nerve defects may be caused, and at a content of 300 ppm or more, the central nervous system and cardiovascular system may be affected.

The present invention has succeeded in simply and efficiently removing acrylamide to a concentration less than harmless to the human body through the purification step using nitrogen pressure.

The polyacrylamide hydrogel of the present invention was also prepared to have viscoelasticity. This is to facilitate injection into the subcutaneous tissue, and this viscoelasticity can be controlled by varying the concentration of polyacrylamide and the weight ratio of the crosslinking agent to be polymerized and the acrylamide monomer. The effect of the concentration of polyacrylamide and the weight ratio of the crosslinking agent to be polymerized and the acrylamide monomer on the viscoelasticity is shown in Test Example 2 and FIG. 2.

The present invention also provides a composition for tissue enlargement, repair, or wrinkle removal comprising polyacrylamide hydrogel. The composition may be applied using a surgical procedure or an injection procedure, but the composition may be provided with viscoelasticity to provide a composition particularly suitable for an injection procedure.

More specifically, the storage modulus of the hydrogel or composition according to the present invention is preferably 4.5 to 83 Pa at an applied stress of 0.1 to 10 Hz, and the loss modulus is preferably 4.7 to 33 Pa at an applied stress of 0.1 to 10 Hz, The complex viscosity is preferably 0.5 to 12 Pa·s at an applied stress of 0.1 to 10 Hz. When the storage modulus, loss modulus, and complex viscosity are out of the preferred numerical ranges, the elastic modulus is small and the viscosity is low, making the polyacrylamide hydrogel unsuitable for tissue expansion, repair, or wrinkle removal, or the elastic modulus is large and the viscosity is high. Injection through a fine needle can be difficult.

{Example}

Hereinafter, the present invention will be described in detail by examples. However, the following examples are merely illustrative of the present invention, and the contents of the present invention are not limited to the following examples.

[Reference example]

Bisacrylamide crosslinking agent (≥99.5%) and acrylamide monomer (≥99%) were purchased from Sigma-Aldrich (USA), and APS (ammonium persulfate) and TEMED (tetramethylethylenediamine) were manufactured by Bio-Rad. (USA). Polymerization, shaking, and sterilization were all performed at a temperature of about 4°C.

<Test Example 1> Evaluation of unreacted acrylamide monomer content

1. Sample preparation

Preparation of [Example 1]

(1) Pre-refining step

In an aqueous system, a bisacrylamide crosslinking agent and an acrylamide monomer were added to a measuring cylinder at a weight ratio of 1:125, and distilled water was added to prepare 10 mL of a stock solution containing polyacrylamide. The raw solution was placed in a conical tube, shaken with a reciprocating shaker in a light-shielding state, and then filtered through a 0.45 μm syringe filter. Polymerization was carried out by adding 100 μL of APS as a polymerization initiator and 5 μL of TEMED as a polymerization accelerator to the filtered stock solution in a fume hood.

Saline was added to the stock solution including APS and TEMED, and the polyacrylamide concentration was diluted to 3.75 v/v% based on the total volume of the aqueous system.

(2) purification step

In order to remove the unreacted acrylamide monomer from the polymerized polyacrylamide-containing solution, ultrafiltration was performed. A cellulose membrane (Millipore, MA, USA) having a fractional molecular weight (Molecular weight cut-off, MWCO) of 10 kDa was used as the ultrafiltration membrane used for the ultrafiltration, and a batch stirring cell (Amicon 8400, Millipore, USA) was used. An ultrafiltration membrane fixed on an O-ring was laid on the stirring cell, the polymerized polyacrylamide-containing solution was added, and then saline was added.

A magnetic stir bar was placed in the stirring cell, the lid was closed, and the valve was mounted on a black aluminum stand with the valve in a horizontal direction. After aligning the valve in the vertical direction and performing ultrafiltration for 3 hours under the condition of 50 psi pressure of nitrogen and a flow rate of 12.5 m ³ /hr, the polyacrylamide in the gel state was recovered to prepare 10 g of the polyacrylamide hydrogel of Example 1. I did.

Preparation of [Comparative Example 1]

Instead of nitrogen pressure ultrafiltration, 10 g of polyacrylamide hydrogel was prepared in the same manner as in Example 1, except that the unreacted monomer was removed by a water washing process.

2. Method for evaluating the content of unreacted acrylamide monomer

(1) Standard solution preparation

1.0 ml of acrylamide was dissolved in 1.0 ml of HPLC pure water to prepare a standard stock solution of 1 mg/ml of acrylamide. The standard stock solution was diluted with 50, 100, 200, 300, 400, 500, and 1000 μg/L of HPLC pure water, and then filtered through a 0.45 μm syringe filter to prepare a 20 μL standard solution.

(2) Preparation of test solution

1.00 g of the polyacrylamide hydrogel of Example 1 and Comparative Example 1 pulverized to a mesh size of 1 mm or less was placed in a 50 mL conical tube together with 0 mL of distilled water. The conical tube was shaken at 25° C. for 24 hours in a reciprocating shaker, and then centrifuged in a centrifuge at 8000 rpm for 5 minutes. The centrifuged supernatant was filtered through a 0.45 μm syringe filter to prepare 20 μL of a test solution.

(3) Evaluation conditions

The content of unreacted acrylamide monomer was evaluated through HPLC-UV (Agilent 1100 series). In this evaluation, Kromasil ODS-C18 (Eka chem., Sweden, 250 × 4.6 nm, 5 μm) was used as the column, and the column injection temperature was set to 50°C. The UV detection wavelength was fixed at 210 nm. As a solvent, a 10:90 v/v mixed solvent of acetonitrile:water and a 100% acetonitrile solvent were used as a gradient solvent composition method, and the gradient conditions of the solvent are shown in Table 1 below. The flow rate of the mobile phase was fixed at 0.40 mL/min.

Time (minutes) Acetonitrile: water
10: 90 v/v mixed solvent Acetonitrile
100% solvent 15 100 0 17 20 80 22 20 80 24 100 0 40 100 0

3. Evaluation result of unreacted acrylamide monomer content

The results of qualitative HPLC-UV analysis of the hydrogels of Example 1 and Comparative Example 1 are shown in FIG. 1 below. The asterisk peak in FIG. 1 is a peak corresponding to the acrylamide monomer, and the acrylamide monomer of Comparative Example 1 detected in FIG. 1 (a) was not detected in FIG. 1 (b) showing Example 1. It can be seen that this is a result of removing the unreacted acrylamide monomer in the purification step.

In addition, a calibration curve of the acrylamide monomer was obtained for quantitative analysis. The regression equation y=93.734x+1.402 (r ² =0.9885) showed good linearity between the peak area and the acrylamide monomer content.

In the hydrogel of Comparative Example 1, 206.21 ppm of acrylamide monomer was detected with respect to 1 g of the hydrogel, but in the hydrogel of Example 1, 0.946 ppm of acrylamide monomer was detected with respect to 1 g of the hydrogel and significantly removed. I can. In order to remove the monomer detected in Comparative Example 1 to the level of Example 1, about 5 times of washing with water had to be performed for a total of 24 hours.

The hydrogel polymerization and purification results of Example 1 and Comparative Example 1 are summarized in Table 2 below.

division Concentration of polyacrylamide (v/v%) Weight ratio of bisacrylamide crosslinking agent and acrylamide monomer Purification method Refining time
(time) Monomer content after purification
(ppm/g) Example 1 3.75 1: 125 Nitrogen pressurized ultrafiltration 3 0.946 Comparative Example 1 3.75 1: 125 Washing process 24 206.21

<Test Example 2> Viscoelasticity evaluation of hydrogel according to polyacrylamide concentration and polymerization ratio

1. Sample preparation

[Example 1]

The sample of Example 1 above was used as it is.

[Example 2]

10 g of polyacrylamide hydrogel was prepared in the same manner as in Example 1, except that the concentration of polyacrylamide was diluted to 3.5 v/v% based on the total volume of the aqueous system (polymerization ratio = 1:125. ).

[Example 3]

10 g of polyacrylamide hydrogel was prepared in the same manner as in Example 1, except that the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer was 1:150.

[Example 4]

Polyacrylamide in the same manner as in Example 1, except that the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer was 1:150 and the concentration of polyacrylamide was diluted to 3.5 v/v% based on the total volume of the aqueous system. 10 g of acrylamide hydrogel was prepared.

[Comparative Example 2]

10 g of polyacrylamide hydrogel was prepared in the same manner as in Example 1, except that the concentration of polyacrylamide was diluted to 3.25 v/v% based on the total volume of the aqueous system (polymerization ratio=1:125 ).

[Comparative Example 3]

Polyacrylamide in the same manner as in Example 1, except that the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer was 1:150 and the concentration of polyacrylamide was diluted to 3.25 v/v% based on the total volume of the aqueous system. 10 g of acrylamide hydrogel was prepared.

The concentration of polyacrylamide, the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer, and purification methods in Examples 1 to 4 and Comparative Examples 2 and 3 are summarized in Table 3 below.

division Concentration of polyacrylamide (v/v%) Bisacrylamide crosslinking agent and
Weight ratio of acrylamide monomer Purification method Example 1 3.75 1: 125 Nitrogen pressurized ultrafiltration Example 2 3.5 1: 125 Nitrogen pressurized ultrafiltration Example 3 3.75 1: 150 Nitrogen pressurized ultrafiltration Example 4 3.5 1: 150 Nitrogen pressurized ultrafiltration Comparative Example 2 3.25 1: 125 Nitrogen pressurized ultrafiltration Comparative Example 3 3.25 1: 150 Nitrogen pressurized ultrafiltration

2. Viscoelasticity evaluation conditions of hydrogel

The viscoelasticity of the hydrogels of Examples 1 to 4, Comparative Examples 2 and 3 was evaluated rheologically through a dynamic elastic flow meter (Thermo Scientific Haake, Rheometer RS1). The dynamic elastic flowmeter was installed in a parallel structure having a diameter of 2.5 cm and an interval of 0.5 mn at 25° C., and a stress of 0.1 to 10 Hz was applied in the linear viscoelastic region to measure the shear stress.

3. Viscoelasticity evaluation result of hydrogel

(1) Overview

The results of viscoelastic evaluation of the hydrogels of Examples 1 to 4, Comparative Examples 2 and 3 are shown in Tables 4 to 6 and FIG. 2 below. The y-axis of FIGS. 2A to 2C represent storage modulus, loss modulus and complex viscosity, respectively. As shown in FIG. 2, the storage modulus is higher than the loss modulus in the entire stress area of 0.1 to 10 Hz, which is the hydrogel of Examples 1 to 4, Comparative Examples 2 and 3 showing the behavior of the elastic gel. Means that.

(2) According to the polymerization ratio Viscoelasticity evaluation result

2A to 2C, when comparing Example 1 and Example 3 in which the polyacrylamide concentration was 3.75 v/v%, the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer at the same concentration was 1:150 Compared to the case of, the viscoelasticity was better in the case of 1:125.

Likewise, when comparing Examples 2 and 4 with the same polyacrylamide concentration of 3.5 v/v% and the comparison of Comparative Example 2 and Comparative Example 3 with the same polyacrylamide concentration of 3.25 v/v% Also, it can be seen that the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer is excellent in the viscoelasticity in the case of 1:125 compared to the case in which the weight ratio of 1:150.

(3) according to the concentration Viscoelasticity evaluation result

2A to 2C, when the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer is 1:125 compared to each other in Examples 1, 2 and Comparative Example 2, the polyacrylamide concentration is 3.25 v/v% The viscoelasticity was better in the case of 3.5 v/v% than in the case of, and the case of 3.75 v/v% was much better than the case of 3.5 v/v%.

In contrast to each other in Examples 3, 4, and 3 in which the weight ratio of the bisacrylamide crosslinking agent and the acrylamide monomer is 1: 150, it is 3.5 v/v% compared to the case where the polyacrylamide concentration is 3.25 v/v%. The viscoelasticity was better in the case of, and the case of 3.75 v/v% was much better than the case of 3.5 v/v%.

(4) Optimal Example

In addition, it can be seen that the hydrogel storage modulus, loss modulus, and complex viscosity values of Examples 1 to 4 are higher than that of the hydrogels of Comparative Examples 2 to 3. This indicates that the storage modulus, loss modulus, and complex viscosity values increase as the concentration of polyacrylamide increases within the polymerization ratio range of the bisacrylamide crosslinking agent according to the present invention. In particular, the polyacrylamide hydrogel of Example 1 in which the crosslinking agent and the acrylamide monomer are polymerized in a weight ratio of 1: 125 and the concentration of polyacrylamide is 3.75 v/v% for tissue expansion, repair, or wrinkle removal It is suitable for use in medicine and exhibits physical properties that are easy to inject through a fine needle.

The storage modulus (G'), loss modulus (G"), and complex viscosity (η) of the hydrogels according to Examples 1 to 4, Comparative Examples 2 and 3 are summarized in Tables 4 to 6 below.

G’
(Pa) Applied stress (Hz) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 One 2 3 4 5 6 7 8 9 10 Example 1 5.25 8.34 10.01 11.01 11.67 13.88 14.52 14.57 16.32 16.56 17.77 19.30 21.76 26.79 27.04 28.06 30.47 51.72 73.83 Example 2 7.37 8.34 7.60 8.79 9.27 13.04 13.28 12.79 12.68 12.00 12.68 12.79 20.24 24.53 20.00 24.19 28.33 32.58 51.70 Example 3 4.73 4.86 5.33 6.00 6.20 6.45 6.66 6.82 6.90 7.23 7.98 8.53 11.27 11.60 12.89 15.84 22.28 37.78 37.78 Example 4 5.14 4.64 5.36 5.59 5.85 6.11 6.26 6.44 6.35 6.70 7.22 8.84 9.13 7.79 18.21 28.85 50.23 64.85 82.91 Comparative Example 2 4.03 4.20 4.58 5.23 5.12 4.87 5.24 5.36 5.99 6.75 6.78 7.59 7.42 7.93 11.11 16.67 33.88 49.56 65.47 Comparative Example 3 3.74 3.81 4.23 4.77 4.79 4.74 4.65 4.69 4.79 5.17 6.16 7.79 5.24 7.62 14.56 29.43 53.71 75.93 97.57

G”
(Pa) Applied stress (Hz) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 One 2 3 4 5 6 7 8 9 10 Example 1 3.86 4.00 4.75 4.50 5.75 5.67 7.88 7.32 7.95 9.85 10.74 12.66 13.74 14.85 14.25 18.68 21.09 30.08 32.28 Example 2 4.15 3.59 3.69 3.58 5.72 3.96 4.73 5.77 7.84 8.27 9.39 9.88 11.36 14.16 12.23 13.50 13.91 14.26 30.19 Example 3 2.19 2.48 2.59 2.73 3.05 3.29 3.41 3.49 3.74 3.90 4.80 6.50 7.72 7.52 8.74 8.50 11.15 12.24 28.87 Example 4 2.41 2.03 2.29 2.60 2.71 2.80 3.04 3.09 3.58 3.68 4.25 5.68 7.61 8.41 8.63 7.88 8.35 11.28 25.96 Comparative Example 2 2.24 2.12 2.24 2.75 2.77 2.79 2.99 3.15 3.47 3.33 3.93 5.89 7.01 7.64 7.75 7.75 7.88 11.10 24.50 Comparative Example 3 1.92 2.12 2.18 2.29 2.78 2.88 3.03 3.09 3.15 3.12 3.83 5.94 6.47 7.07 8.10 8.86 9.02 11.10 31.11

η (Pa·s) Applied stress (Hz) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 One 2 3 4 5 6 7 8 9 10 Example 1 11.20 7.33 5.88 4.98 4.27 3.85 3.23 2.88 2.61 2.71 1.49 1.13 1.08 0.94 0.87 0.59 0.74 0.86 1.36 Example 2 11.88 7.20 5.26 4.37 3.91 3.27 3.00 2.65 2.12 2.09 1.16 0.95 0.94 0.75 0.62 0.59 0.77 0.99 1.38 Example 3 2.19 2.48 2.59 2.73 3.05 3.29 3.41 3.49 3.74 3.90 4.80 6.50 7.72 7.52 8.74 8.50 11.15 12.24 28.87 Example 4 2.41 2.03 2.29 2.60 2.71 2.80 3.04 3.09 3.58 3.68 4.25 5.68 7.61 8.41 8.63 7.88 8.35 11.28 25.96 Comparative Example 2 2.24 2.12 2.24 2.75 2.77 2.79 2.99 3.15 3.47 3.33 3.93 5.89 7.01 7.64 7.75 7.75 7.88 11.10 24.50 Comparative Example 3 1.92 2.12 2.18 2.29 2.78 2.88 3.03 3.09 3.15 3.12 3.83 5.94 6.47 7.07 8.10 8.86 9.02 11.10 31.11

<Test Example 3> Viscoelasticity evaluation compared to commercial product 1

1. Sample preparation

[Example 1]

The sample of Example 1 above was used as it is.

[Comparative Example 4]

10 g of AQUAlift® hydrogel (corresponding to a commercial product) were prepared.

2. Viscoelasticity evaluation conditions

The viscoelasticity of the hydrogels of Example 1 and Comparative Example 4 was evaluated rheologically through a dynamic elastic flow meter (Thermo Scientific Haake, Rheometer RS1). The dynamic elastic flowmeter was installed in a parallel structure having a diameter of 2.5 cm and an interval of 0.5 mn at 25° C., and a stress of 0.1 to 10 Hz was applied in the linear viscoelastic region to measure the shear stress.

3. Viscoelasticity evaluation result

(1) Overview

The results of viscoelasticity evaluation of the hydrogels of Example 1 and Comparative Example 4 are shown in Tables 7 to 9 and FIG. 3. The y-axis of FIGS. 3A to 3C represent storage modulus, loss modulus, and complex viscosity, respectively. As shown in FIG. 3, the storage modulus is higher than the loss modulus in the entire stress range of 0.1 to 10 Hz, which means that the hydrogels of Example 1 and Comparative Example 4 exhibit the behavior of the elastic gel.

(2) Viscoelasticity evaluation result

According to FIG. 3A, when the applied stress is 0.1 Hz, it can be seen that the storage modulus of Example 1 hydrogel is about 3.6 times higher than that of Comparative Example 4 hydrogel. As the applied stress increased, the storage modulus of the hydrogel in Comparative Example 4 increased significantly, but the storage modulus of the hydrogel in Example 1 was still large, and when the applied stress was 10 Hz, the storage modulus of the hydrogel in Example 1 was significantly increased. It was about 1.5 times higher than that of the gel.

3B, it can be seen that when the applied stress is 0.1 Hz, the loss modulus of the Example 1 hydrogel is about 2.5 times higher than that of the Comparative Example 4 hydrogel. As the applied stress increased, the loss modulus of the hydrogel in Comparative Example 4 was greatly increased, except for the case where the applied stress was 10 Hz.Example 1 Example 1 only when the applied stress was 10 Hz The loss modulus of the hydrogel was found to be 9.839 Pa, and the loss modulus of the hydrogel in Comparative Example 4 was 14.61 Pa, indicating that the loss modulus of Comparative Example 4 was about 1.5 times higher.

Referring to FIG. 3C, it can be seen that the complex viscosity of the Example 1 hydrogel is about 3.6 times higher than that of the Comparative Example 4 hydrogel when the applied stress is 0.1 Hz. As the applied stress increased, the complex viscosity of the hydrogel in Comparative Example 4 decreased significantly, but the complex viscosity of Example 1 hydrogel was still large, and when the applied stress was 10 Hz, the complex viscosity of Example 1 hydrogel was significantly reduced. It was about 1.4 times higher than that of the gel.

The storage modulus (G'), loss modulus (G"), and complex viscosity (η) of the hydrogels according to Example 1 and Comparative Example 4 are summarized in Tables 7 to 9 below.

<Test Example 4> Evaluation of solubility and flowability compared to commercial product 2

1. Sample preparation

[Example 1]

The sample of Example 1 above was used as it is.

[Comparative Example 5]

10 g of AQUAMID® hydrogel (corresponding to a commercially available product) were prepared.

2. Solubility and Flowability Evaluation Conditions

After adding 0.2 mL of the hydrogel of Example 1 and of Comparative Example 5 and 0.6 mL of PBS (polybutylene succinate) to the microtube, incubating at 37°C for 2 hours using a rotary incubator, and visually inspecting the solubility and flowability It was confirmed as.

3. Solubility and flow evaluation results

The results of evaluating the solubility and flowability of the hydrogel of Example 1 and Comparative Example 5 are shown in FIG. 4 below. The upper figure of FIG. 4 shows the hydrogel of Comparative Example 5, and the lower figure of FIG. 4 shows the hydrogel of Example 1.

According to FIG. 4, while the hydrogel of Comparative Example 5 absorbs PBS and maintains the original gel shape, it was observed that the hydrogel of Example 1 is dissolved in PBS. As a result of visual inspection by tilting the microtube, the hydrogel of Comparative Example 5 did not show flowability, but the hydrogel of Example 1 showed flowability.

The above properties mean that the hydrogel of Example 1 has a heterolinear polymer structure or a partially crosslinked polymer cluster structure.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will include such modifications or variations as long as they fall within the gist of the present invention.

Claims (10)

In the manufacturing method of polyacrylamide hydrogel,
(1) A step of polymerizing bisacrylamide and acrylamide monomers as crosslinking agents in an aqueous system to prepare a stock solution containing polyacrylamide, wherein the bisacrylamide crosslinking agent and the acrylamide monomer are Polymerization at a temperature of 4° C. in a weight ratio of 1: 125;
(2) diluting the concentration of the polyacrylamide to 3.75 v/v% based on the total volume of the aqueous system by adding saline to the stock solution;
(3) purification step of removing the unreacted acrylamide monomer by ultrafiltration of the diluted polyacrylamide-containing solution under nitrogen pressure at 50 psi and flow rate of 12.5 m ³ /hr; And
(4) After passing through the purification step, it characterized in that it comprises the step of recovering the polyacrylamide in a gel state, a method of producing a polyacrylamide hydrogel. delete As a polyacrylamide hydrogel obtained by the manufacturing method of claim 1,
Polyacrylamide hydrogel, characterized in that the content of unreacted acrylamide monomer is 0.946 ppm or less based on 1 g of the hydrogel. As a polyacrylamide hydrogel obtained by the manufacturing method of claim 1,
Polyacrylamide hydrogel, characterized in that the storage modulus of the polyacrylamide hydrogel is 4.5 to 83 Pa at an applied stress of 0.1 to 10 Hz. As a polyacrylamide hydrogel obtained by the manufacturing method of claim 1,
Polyacrylamide hydrogel, characterized in that the loss modulus of the polyacrylamide hydrogel is 4.7 to 33 Pa at an applied stress of 0.1 to 10 Hz. As a polyacrylamide hydrogel obtained by the manufacturing method of claim 1,
Polyacrylamide hydrogel, characterized in that the complex viscosity of the polyacrylamide hydrogel is 0.5 to 12 Pa·s at an applied stress of 0.1 to 10 Hz. A composition for tissue enlargement, repair or wrinkle removal, comprising a polyacrylamide hydrogel obtained by the method of claim 1. The method of claim 7,
The storage modulus of the polyacrylamide hydrogel is a composition for tissue expansion, repair or wrinkle removal, characterized in that 4.5 to 83 Pa at an applied stress of 0.1 to 10 Hz. The method of claim 7,
The loss modulus of the polyacrylamide hydrogel is 4.7 to 33 Pa at an applied stress of 0.1 to 10 Hz, wherein the composition for tissue enlargement, repair or wrinkle removal. The method of claim 7,
The complex viscosity of the polyacrylamide hydrogel is 0.5 to 12 Pa·s at an applied stress of 0.1 to 10 Hz. Composition for tissue enlargement, repair, or wrinkle removal.

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