TW201429502A - Silk hydrogel composition and silk hydrogel mask - Google Patents

Abstract

Disclosed is a silk hydrogel composition comprising 0.01-30 wt% of silk fibroin powder and 0.01-10 wt% of urea based on the total weight of the composition. According to the present disclosure, it is possible to increase the solubility of a silk fibroin material and to carry out gelling in a short time, thereby allowing a continuous process. In addition, the silk hydrogel composition may be packaged directly after cutting to avoid a need for additional processes, thereby enhancing production safety and efficiency. Further, the silk hydrogel composition of the present disclosure shows high strength and adhesion, is controllable in moisture emission rate, reduces skin irritation by virtue of the use of a silk material having high affinity to the human body, is effective in terms of moisture content, moisturizing activity, exfoliation, brightening and flush reduction, and thus may be useful for cosmetic masks.

Description

Silk hydrogel composition and silk hydrogel mask

The present disclosure relates to a silk hydrogel composition and a silk hydrogel mask. More particularly, the present disclosure relates to a silk hydrogel composition having a shortened gel time by dissolving silk fibroin powder in an aqueous urea solution, and using one of the silk hydrogel compositions. Hydrogel mask.

Recently, skin care using hydrogels has been widely used in various fields in the fields of cosmetics, skin care products, or the like. The hydrogel mask has been evaluated as having the most advanced form of technology, taking into account the effects, activities and formulations of the hydrogel mask. The hydrogel mask is a skin care delivery system designed to store a cosmetic material in a polymer by crosslinking a cosmetic material with a water soluble polymer in the hydrogel or by using a carrier property of the polymer. The effect and activity of the active ingredient of the active cosmetic material are continuously and efficiently transferred. Compared to the type of sheet mask including the non-woven fabric impregnated with the essence, the hydrogel mask shows little sag and provides a good feeling of use, but the disadvantage is insufficient physical strength. The hydrogel itself is too smooth to provide high adhesion, or the water may be rapidly separated from the hydrogel, so that the active ingredient is not sufficiently delivered to skin. To overcome this physical disadvantage of hydrogels, attempts have been made to apply silk proteins.

At the same time, depending on the degree of orientation of the inner and outer fibers, the content of the amino acid component, and the molecular weight and crystallinity, the silk can be generally classified into two types: silk fibrin and sericin. Silk fibrin and sericin exhibited a 75:25 silk fibrin: sericin ratio. Since sericin has a high solubility, in general, sericin is removed during the refining process, so that fibrin is separately retained in the form of a so-called silk fabric which is widely used for medical purposes and clothing. Silk protein has excellent film forming ability and does not exhibit rejection when applied to human body. Silk fibroin films or hydrogels have excellent dissolved oxygen permeability in a wet state similar to human skin, indicating the suitability of the film for wound dressings and artificial skin systems.

According to the related art, most skin care masks using silk are made by impregnating silk with essence, and sericin is not used instead of silk fibrin. This is because water-soluble sericin is easy to use by virtue of its low molecular weight as compared with water-insoluble silk fibroin, and water-soluble sericin is known to have natural moisturizing activity. There have been no examples of the use of sericin in hydrogel masks to date, since the lower molecular weight sericin is only suitable for use as an active ingredient in hydrogel masks and is almost unsuitable for use as a gelling agent. Silk fibroin-based polymers, and undergoing structural changes upon chemical stimulation, make silk fibrin sufficient for use as a gelling agent. When silk fibrin is used as a gelling agent, silk fibrin exhibits higher adhesion than conventional hydrogels and promotes delivery of active ingredients. Despite the known hydrogel masks using silk proteins, these masks exhibit unsatisfactory use and are attributed to the inefficient productivity of silk fibroin solutions.

In general, silk proteins are in the form of a solution via an alkali refining process. Produced, the alkali refining process involves treating the silk protein in a suitable temperature of alkaline water (e.g., soap refining or soap soda) for a predetermined period of time. The resulting sericin-removed silk fibroin solution is advantageous because it does not require redissolving the silk protein when the solution is applied to the formulation. However, a less stable silk protein solution requires substantial freezing and undergoes precipitation upon physical impact or after a certain period of time. In addition, when a hydrogel is prepared from a silk protein solution, only the silk protein is immersed in alcohol or a metal salt is added to the silk protein solution to form a finished gel product, and gelation is not instantaneous. In contrast, silk fibroin powder is highly resistant to physical shock, can be stored at room temperature, and is cost effective. However, the solubility of the silk fibroin powder is lower than that of the silk fibroin solution.

The film composed of silk protein can be dissolved in water without any additional manipulation due to its remarkable random coil protein structure. Thus, protein structural properties can be converted from a random coil to a beta sheet by heating, mechanical stretching, immersion into a polar organic solvent, and curing in water vapor. Such structural changes can result in water insolubility, but provide a system that is softer than films made from pure silk proteins.

Although a number of masks using silk have been developed, there is no mask that utilizes the advantageous properties of the silk. Therefore, there is a need to provide an ideal silk hydrogel mask that utilizes the advantageous properties of silk and compensates for the shortcomings of hydrogels.

The technical problem to be solved by the present disclosure is to provide a method for producing a silk hydrogel mask and a silk hydrogel composition, wherein the silk protein powder is dissolved in an aqueous urea solution to increase the solubility of the silk protein material. In a short time Perform gelation in between and allow continuous process.

In a general aspect, a silk hydrogel composition is provided which comprises from 0.01 to 30% by weight, based on the total weight of the composition, of silk fibroin powder and from 0.01 to 10% by weight of urea.

According to an embodiment, the silk protein powder may have a molecular weight of from 1,000 to 400,000.

According to another embodiment, the composition may further comprise a thickener.

According to yet another embodiment, the thickening agent can be a polyoxyxide thickener, an oil thickener, or an acrylic thickener.

According to still another embodiment, the content of the polyoxyxylene thickener or the oil thickener may be 0.01-30% by weight based on the total weight of the composition, and the content of the acrylic thickener may be based on the total weight of the composition. 0.01 to 5% by weight.

According to a further embodiment, the composition may have a strength of from 0.1 kgf/cm ^{2 to} 1.5 kgf/cm ² .

In another general aspect, there is provided a method for making a silk hydrogel mask, the method comprising the steps of: dissolving silk fibroin powder in an aqueous urea solution; gelling the resulting composition; and generating The gelled product is formed into the desired shape.

According to an embodiment, the gelling operation can be carried out for a period of from 0.1 second to 10 minutes.

According to another embodiment, the gelling and forming steps can be carried out in a continuous process.

In yet another general aspect, a silk hydrogel mask obtained by the method is provided.

According to the method for producing the silk hydrogel composition of the present disclosure, it is possible to increase the solubility of the silk protein material and perform gelation in a short time, thereby allowing a continuous process. In addition, the silk hydrogel composition can be encapsulated directly after cutting to avoid the need for additional processing to enhance production safety and efficiency. Moreover, the silk hydrogel composition of the present disclosure exhibits high strength and adhesion, can control the rate of water release, and reduces skin irritation by using a silk material having high affinity to the human body, in water content, moisturizing It is effective in excreting, exfoliating, brightening and reducing redness of the face, and thus can be used for make-up masks.

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30‧‧‧Protective film

40‧‧‧ cutting

A‧‧‧Content discharge

B‧‧‧Coating

Figure 1 is a schematic diagram showing one method for making a silk hydrogel according to the prior art.

2 is a schematic diagram showing one method for making a silk hydrogel in accordance with an embodiment of the present disclosure.

Figure 3 is a graph illustrating the moisture removal rate of a silk hydrogel in accordance with an embodiment of the present disclosure.

Figure 4 is a graph illustrating the moisture content of a silk hydrogel in accordance with one embodiment of the present disclosure.

Figure 5 is a graph illustrating the moisture content of a silk hydrogel in accordance with an embodiment of the present disclosure.

Figure 6 is a diagram illustrating one of the present disclosures Variations in the optical properties of the silk hydrogels of the examples.

Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings in which FIG. However, the present disclosure may be embodied in many different forms and should not be construed as being limited to the exemplary embodiments described herein.

Figure 1 illustrates one method for making a hydrogel mask according to the prior art. The hydrogel mask according to the prior art requires a longer gel time, so based on a discontinuous process, the process includes discharging (as indicated by A) the contents 10 and placing the contents on the tray 20 to the contents A metal salt or alcohol is added thereto, gelation is carried out for several hours (for example, 24 hours), and then cutting 40 is carried out (see Fig. 1).

In accordance with the present disclosure, as shown in FIG. 2, a method for making a silk hydrogel mask via a continuous process is provided, the process comprising performing a coating while discharging the contents 10 (as indicated by A) (as indicated by B) and rapid gelation for continuous cutting 40.

The present disclosure provides a silky hydrogel composition comprising 0.01-30% by weight silk protein powder and 0.01-10% by weight urea based on the total weight of the composition.

The silk protein powder may have a molecular weight of 1,000 to 400,000, but is not limited thereto.

Further, the silk hydrogel composition may further include a thickener. The thickener may comprise a polyoxyn thickener, an oil thickener, or an acrylic thickener.

According to a non-limiting embodiment, the polyoxygenated thickener is included or The oil thickener may be included in an amount of from 0.01 to 30% by weight based on the total weight of the composition, and the acrylic thickener may be included in an amount of from 0.01 to 5% by weight based on the total weight of the composition.

Moreover, the strength of the composition may be from 0.1 kgf/cm ^{2 to} 1.5 kgf/cm ² , specifically from 0.8 kgf/cm ^{2 to} 1.5 kgf/cm ² , and more specifically from 1.2 kgf/cm ^{2 to} 1.35. Kgf/cm ² .

The silk hydrogel mask according to the present disclosure can be obtained by a method comprising the steps of: dissolving the silk fibroin powder in an aqueous urea solution; gelling the resulting composition; and shaping the formed gelled product into a desired form shape.

Hereinafter, the method for producing a silk hydrogel mask will be explained in more detail.

First, silk fibroin powder was dissolved in an aqueous urea solution to obtain a silk hydrogel composition.

There is no particular limitation on the method for preparing the silk protein powder, and any known method can be used. In a preferred manner, the silk fibroin powder can be prepared by treating the gelatinous material with an aqueous alkaline solution followed by milling. Although the stability of the silk fibroin solution is low, it needs to be frozen and precipitates after a certain period of time, but the stability of the silk fibroin powder is excellent. In this context, since the silk fibroin powder itself acts as a gelling agent, it can be gelled in a few seconds without any additional thickener or gelling operation or with a small amount of thickener or gelling agent. .

The silk protein powder may have a molecular weight of 1,000 to 400,000, but is not limited thereto.

The amount of silk protein powder used may be based on the total weight of the composition 0.01 to 30% by weight, preferably 0.1 to 10% by weight, and more preferably 1 to 5% by weight. When the amount of silk protein powder used is less than 0.01% by weight, the silk fibroin powder does not provide the unique characteristics of the gelling agent. When the amount of the silk protein powder used is more than 30% by weight, the remaining salt ions in the silk fibroin powder hinder gelation, so that the hydrogel cannot be sufficiently obtained. However, an appropriate amount of salt ions contributes to gelation, and therefore, the silk protein powder is preferably used in an amount of from 1 to 5% by weight.

Herein, an aqueous urea solution can be obtained by dissolving urea in water at room temperature or higher. The solubility of the silk fibroin powder can be improved by dispersing or dissolving the silk fibroin powder in an aqueous urea solution.

The aqueous urea solution may include urea in an amount of from 0.01 to 10% by weight, based on the total weight of the composition, preferably from 1 to 10% by weight, and more preferably from 1 to 5% by weight. When the amount of urea present is less than 0.01% by weight, the solubility of the silk fibroin powder cannot be effectively improved. As the amount of urea increases, the effects of whitening and exfoliating cells are enhanced. However, when urea is present in an amount greater than 10% by weight, urea causes skin irritation and degradation in the performance of the hydrogel.

Further, the concentration of the aqueous urea solution may be from 0.01 to 10% by weight, but is not limited thereto.

The silk hydrogel composition may further comprise a thickener. There are no particular restrictions on the thickener, and specific examples of the thickener include self-butylene glycol, glycerin, 1,2-hexanediol, dimethicone, cyclomethoxane, and hydroxyethyl acrylate. At least one of sodium acrylate, polymethyl methacrylate and acrylate, carrageenan, xanthan gum, locust bean gum, and cold gel.

Herein, the thickener may be a polyoxyxide thickener, an oil thickener, or an acrylic thickener.

The polyoxyxide thickener or oil thickener may be included in an amount of from 0.01 to 30% by weight, based on the total weight of the composition, preferably from 0.1 to 5% by weight. When the content of the polyoxyl or oil thickener included is less than 0.01% by weight, a significant drop in viscosity is caused, resulting in coating loss. When the content of the polyoxyl or oil-increasing agent included is more than 30% by weight, a significant increase in viscosity is caused, so that it is difficult to perform mixing.

Further, the acrylic thickener may be included in an amount of from 0.01 to 5% by weight, based on the total weight of the composition, preferably from 0.1 to 2% by weight. When the content of the acrylic thickener included is less than 0.01% by weight, a significant drop in viscosity is caused, resulting in coating loss. When the content of the acrylic thickener included is more than 5% by weight, a significant increase in viscosity is caused, so that it is difficult to perform mixing.

The resulting silk hydrogel composition is then subjected to gelation. Gelation can be carried out by natural cooling. The gel time may range from 0.1 second to 10 minutes, preferably from 0.1 second to 3 minutes, but is not limited thereto. In particular, when the gel solution of the resulting silk hydrogel composition is poured into a coating machine at a temperature of 10-80 ° C, the gel is cooled by natural cooling at the same time as coating to Formed in a few minutes. As mentioned previously, the gel time can range from 0.1 second to 3 minutes. The gelled hydrogel that has been gelled can be molded in a mold having a desired shape, or cut with a blade conforming to a part of the human body to provide a make-up mask.

Finally, the resulting gelled product is molded into the desired shape to obtain a mask. Any desired shape can be obtained depending on the particular application. For example, the gel obtained as described above can be cut and molded.

In other words, as shown in Figure 2, the system for use according to the present disclosure The method of making a silky hydrogel mask allows for a continuous process with a shorter gel time. In contrast, when a hydrogel mask is produced according to the related art, a longer gelation time is required, and a metal salt or alcohol should be added for some time (for example, 24 hours) before gelation is performed. Thus, the hydrogel mask production according to the related art is basically based on a discontinuous process (Fig. 1).

Further, the present disclosure provides strength 0.1kgf / cm ² to 1.5kgf / cm ² of silk hydrogel mask. In other words, the strength of the silk hydrogel mask according to the present disclosure is as high as 0.1 kgf/cm ² to 1.5 kgf/cm ² , specifically 0.8 kgf/cm ² to 1.5 kgf/cm ² , and more specifically 1.2 kgf/cm. ² to 1.35 kgf/cm ² .

The silk hydrogel composition according to the present disclosure allows rapid delivery of the cosmetic or pharmaceutical agent from the hydrogel composition to the skin by virtue of the presence of silk proteins. In particular, the rate of migration of the control component of the silk hydrogel composition is constant so that an acceptable cosmetic or dosage can be expelled and delivered to the skin.

In addition, the silk hydrogel composition exhibits a compacting effect in which the silk protein undergoes a structural change due to temperature changes or physical changes, and the hydrogel shrinks itself. Due to this, the silk hydrogel composition has excellent adhesion to accelerate the delivery of the active ingredient to the skin, and ensures activity when used as a peeling cosmetic mask for convenience. This property is unique to the silk hydrogel and is hardly found in the hydrogel mask according to the related art. Moreover, this compacting effect assists in skin elastic care and anti-wrinkle care in addition to shrinking pores. Moreover, the silk natural material has a high affinity for the skin, whereby the silk hydrogel mask according to the present disclosure reduces skin irritation as compared with the conventional mask.

The silk hydrogel composition according to the present disclosure has a silk fibroin β structure and thus exhibits high strength and a high swelling ratio. This high strength further enhances the elasticity of the silk hydrogel to help improve the feel of use and to cut/package during manufacture of the silk hydrogel composition.

Furthermore, structural changes in silk proteins in the composition according to the present disclosure allow for control of water content. The inventors of the present disclosure have found that the hydrogel containing the silk protein has a higher water content than the conventional hydrogel, which indicates that a greater moisture content can be supplied to the skin. This finding stems from the structural properties of silk proteins.

The silk hydrogel composition according to the present disclosure uses urea to aid in the salt dissolution of the less soluble silk fibroin powder, and urea to finely remove dead skin cells from the skin. Thus, the silky hydrogel according to the present disclosure provides a more effective supply of sufficient moisture content, brightening the complexion, and reducing the effect of facial redness.

The silk hydrogel composition according to the present disclosure improves the weak stability of the silk fibroin solution by using silk fibroin powder, allowing gelation in a short period of seconds to minutes without any additional process And thereby enabling continuous processes to increase processing efficiency.

Examples and comparative examples will now be described in detail. The following examples are for illustrative purposes only and are not intended to limit the scope of the disclosure.

[Preparation Example 1] Preparation of silk protein powder

The natural silk and silkworm cocoons were boiled in a 0.5% (w/v/w) sodium carbonate aqueous solution at 85 ° C for 1 hour, and rinsed several times with distilled water, followed by drying at 90 ° C for 24 hours. The degummed silk is then hydrolyzed in the presence of a base. To this end, the reaction vessel is filled with water at a ratio of 10-40 based on silk fibroin. The base used herein is a solution of calcium hydroxide (Ca(OH) ₂ ) or barium hydroxide (Ba(OH) ₂ ), and the concentration of the solution is adjusted to 0.4-2.0 w/v% (based on the pH of the solution 11.5) -12.4). The reaction mixture was heated at 90-100 ° C for 8-48 hours and then cooled to obtain precipitates. A sufficient amount of water is added to the separated precipitate. The filtration and separation process is then repeated until the base is no longer dissolved. The resulting solid is dried and ground to obtain a water-insoluble silk protein powder having a relatively high molecular weight.

[Preparation Example 2] Preparation of silk fibroin solution

The natural silk and silkworm cocoons were boiled in a 0.5% (w/v) aqueous solution of sodium carbonate at 85 ° C for 1 hour, rinsed several times with distilled water, and then dried at 90 ° C for 24 hours. Then, the product was introduced into a molecular weight of 3,500 by melting the silk in a 85 ° C solution of molar ratio of CaCl ₂ :dH ₂ O:EtOH of 1:8:2 for 3 minutes. The film was dialyzed so that the product was subjected to desalting for 3 days. The final concentration of the silk protein solution was 4%.

[Example 1-3]

The composition and content of the composition of the hydrogel mask used in the examples and the comparative examples are shown in Table 1 below. Each content is expressed in units of % by weight based on the total weight of the composition.

[Test Example 1] Determination of moisture discharge rate

The hydrogel mask obtained from Example 1 and Comparative Example 1 was cut into a size of 0.07 cm x 1.2 cm x 4 cm to provide a sample. The sample was placed on the skin, and the weight of each sample was measured after 10, 20, 30, 60, and 90 minutes to determine the moisture content discharged in each sample. The measurement results are shown in Fig. 3.

[Test Example 2] Determination of shrinkage rate

The hydrogel mask obtained from Example 1, Example 3, and Comparative Example 1 was cut to a size of 0.07 cm x 1.2 cm x 4 cm to provide a sample. The sample was placed on the skin and the total area of each sample was measured after 15 minutes to determine the hydrogel shrinkage of each sample. In this way, the compacting effect of each sample was indirectly determined. The hydrogel shrinkage rate is calculated according to the formula of [(initial area) - (area after shrinkage)] / (initial area) x 100%. The measurement results are shown in Table 2 below.

[Test Example 3] Reduce the effect of stimulation

The hydrogel mask obtained from Example 1 and Comparative Example 1 was cut into a size of 0.07 cm x 1.2 cm x 4 cm to provide a sample. Two samples of each sample were placed on the arms of 100 subjects, and then the degree of skin irritation was evaluated after 30 minutes. The evaluation results are shown in Table 3 below.

[Test Example 4] Determination of tensile strength

The peeling hydrogel mask obtained from Example 1, Example 3, and Comparative Example 1 was cut into a size of 1.0 cm x 8.0 cm x 0.07 cm to provide a sample. Each sample was subjected to a tensile force at a rate of 10 mm/min at both ends thereof in a tensile tester (MInimat type tester, Rheometric Scientific, USA) to measure the shear stress at the time of fracture of the adhesive surface. Each test was performed 5 times and the average was calculated. The measurement results are shown in Table 4 below.

[Test Example 5] Determination of water content

The peeling hydrogel mask obtained from Example 1 and Comparative Example 1 was cut into a size of 0.07 cm x 1.2 cm x 4 cm to provide a sample. Each sample was completely dried in an oven at 80 ° C, each sample was again immersed in water, allowed to swell, and the swelling ratio of each sample was calculated according to the following formula. The measurement results are shown in Fig. 4.

Swell ratio = (initial weight - dry weight) / initial weight x 100

[Test Example 6] Determination of the use of feeling

The hydrogel mask obtained from Example 1, Example 2, and Comparative Example 1 was shaped into a shape similar to a face. Then, 100 women aged 20-30 were divided into groups, and questionnaires on the feeling of use of each hydrogel mask were implemented. The results of the survey are shown in Table 5 below. Most groups showed a high level of satisfaction with the answers to all survey items containing silk hydrogels (Examples 1 and 2). In Comparative Example 1 and Example 2, as the urea content increased, the active ingredient penetrated better after removing the dead skin cells, thereby making the moisturizing feeling and the moisturizing effect, particularly the satisfaction of brightening the skin color, higher.

[Test Example 7] Determination of moisture content

The hydrogel mask obtained from Example 1 and Comparative Example 1 was cut into a size of 0.07 cm x 1.2 cm x 4 cm to provide a sample. Each sample was placed in the testee's chick and the moisture content was measured using a moisture tester after 15 minutes. The measurement results are shown in Fig. 5.

[Test Example 8] Brighten the skin color effect and reduce the facial redness effect

The peeling hydrogel mask obtained from Example 1 and Comparative Example 1 was cut into a size of 0.07 cm x 1.2 cm x 4 cm to provide a sample. Place two pieces of each sample under the eyes on both sides by using a polarizing imaging device The optical properties of the subject's bones were measured to assess the effect of brightening the skin tone and facial redness. The evaluation results are shown in Figure 6.

[Test Example 9] Solubility measurement in the case of containing urea

A hydrogel was prepared according to Example 1 and Comparative Example 2. A smooth hydrogel product was obtained in Example 1 when observed with the naked eye, while white silk protein crystals were observed in Comparative Example 2 containing no urea.

[Test Example 10] Gelation rate in silk protein powder and silk protein solution

A comparison of gelation rates was performed between Example 1 and Comparative Example 3. Each sample of the same amount was prepared and gelled at room temperature without additional treatment. The results of the comparison are shown in Table 6 below.

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A‧‧‧Content discharge

Claims (10)

A silk hydrogel composition comprising 0.01-30% by weight of silk fibroin powder and 0.01-10% by weight of urea based on the total weight of the composition. The silk hydrogel composition according to claim 1, wherein one of the silk fibroin powders has a molecular weight of from 1,000 to 400,000. The silk hydrogel composition of claim 1, which further comprises a thickener. The silk hydrogel composition according to claim 3, wherein the thickener is a polyoxyxide thickener, an oil thickener, or an acrylic thickener. The silk hydrogel composition according to claim 4, wherein the polythene oxygen thickener or the oil thickener is contained in an amount of 0.01 to 30% by weight based on the total weight of the composition, and One of the acrylic thickeners is present in an amount of from 0.01 to 5% by weight, based on the total weight of the composition. The silk hydrogel composition according to any one of claims 1 to 5, wherein one of the compositions has a strength of from 0.1 kgf/cm ^{2 to} 1.5 kgf/cm ² . A method for producing a silky hydrogel mask, the method comprising the steps of: dissolving the silk protein powder in an aqueous urea solution; Gelling the resulting composition; and shaping the resulting gelled product into a desired shape. A method of producing a silky hydrogel composition according to claim 7, wherein the gelation step is carried out for a period of from 0.1 second to 10 minutes. A method of producing a silky hydrogel composition according to claim 7, wherein the gelling step and the forming step are carried out in a continuous process. A silky hydrogel mask obtained by the method as defined in any one of claims 7 to 9.