Water response shrinkage collagen membrane and preparation method thereof

Abstract

The invention provides a preparation method of a water-responsive shrinkage collagen membrane. The preparation method comprises the following steps: providing a cyanidin-coated gallium-indium liquid metal and a collagen solution; mixing the cyanidin-coated gallium-indium liquid metal with a collagen solution, and carrying out vacuum drying to obtain slices; and salting out the slices by using a sodium citrate solution, and stretching to obtain the water-responsive shrinkage collagen membrane. The collagen membrane prepared by the method disclosed by the invention has excellent water response shrinkage performance, can be quickly shrunk under the stimulation of water, and also has excellent mechanical properties, electrical conductivity and oxidation resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of biomedical materials, and particularly relates to a water-responsive shrinkable collagen membrane and a preparation method thereof. BACKGROUND

[0002] Collagen is one of the important components of natural animal skin (or hide), has many unique advantages, such as excellent biological activity, biocompatibility and biodegradability, and is a cylindrical protein formed by superhelix entanglement of three polypeptide chains, contains rich functional groups (such as carboxyl, oxymere, amino, etc.), provides multiple physical interaction possibilities for the construction of adhesive interfaces and the combination of functional components, as a natural raw material for medical materials, has an important position in biomedical materials, such as based on the correlation with human connective tissue, collagen is often made into a membrane to replace human blood vessels, ligaments and other tissues, collagen has no irritation and no toxicity, however, due to the limitation of structure, it usually lacks some functions, for example, it lacks excellent antioxidant performance and conductive sensing performance, which greatly limits its actual application prospect.

[0003] Intelligentization and responsiveness modification of membrane materials is one of the main directions to expand the practical application of collagen membranes, such as dressing composite membranes for wound repair, which can produce pressure by shrinkage triggered by body temperature, accelerate hemostasis and promote wound repair, or temperature-responsive and pH-responsive gel dressings, which can deliver drugs in tissue fluid, in the field of collagen membranes, there are few responsiveness studies, in the process of realizing the present application, the inventors found that at least the following problems exist in the prior art: the main reason for limiting the responsiveness modification of collagen membranes is that the overall structure of the collagen membranes is easily destroyed, and the modification process inevitably causes irreversible influence on the structure and mechanical properties of the collagen membranes. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a water-responsive shrinkable collagen membrane and a preparation method thereof, which solves the problems of the prior art.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is:

[0006] On the one hand, a preparation method of a water-responsive shrinkable collagen membrane is provided, comprising:

[0007] Providing cyanidin-wrapped gallium-indium liquid metal and collagen solution;

[0008] Mixing the cyanidin-wrapped gallium-indium liquid metal and the collagen solution, vacuum drying to obtain a thin sheet;

[0009] The thin sheet is salted out with a sodium citrate solution, unidirectionally stretched, and a water-responsive shrinking collagen membrane is obtained.

[0010] In another aspect, a water-responsive shrinking collagen membrane prepared by the preparation method of the water-responsive shrinking collagen membrane is provided, and the water-responsive shrinking collagen membrane has a shrinking response time of ≤5s.

[0011] Compared with the prior art, the present application has the following advantages:

[0012] 1. The present application is creatively based on the characteristics of collagen that can respond to salt ions, and a collagen membrane with both wet shrinking and mechanical properties is provided by adding salt ions for salting out and orientation stretching. The method of the present application can endow the collagen membrane with intelligent response and expand its application in the field of biological medicine.

[0013] 2. The present application provides a preparation method of a water-responsive shrinking collagen membrane, and the prepared thin film has excellent water-responsive shrinking, significantly improved mechanical properties, antioxidant and conductive properties.

[0014] 3. Preferably, the water-responsive shrinking collagen membrane of the present application is prepared by salting out and orientation stretching using collagen and gallium-indium liquid metal wrapped with cyanidin as raw materials, and compared with traditional exogenous modified raw materials, the modified materials are more easily incorporated into collagen.

[0015] The technical solutions of the present application will be further described in detail below in combination with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The photographs show the morphologies of the thin film 1 of Example 1 and the thin film 5 of Comparative Example 1.

[0017] Figure 2 The photographs show the morphologies of the cyanidin-wrapped liquid metal dispersion and the gallium-indium liquid metal in water.

[0018] Figure 3 The schematic diagram shows the state of the thin film during the preparation of the water-responsive shrinking collagen membrane of Example 1.

[0019] Figure 4 The scanning electron microscope result of the thin film 1 of Example 1 is shown in the figure.

[0020] Figure 5 The scanning electron microscope result of the thin film 3 of Example 1 is shown in the figure.

[0021] Figure 6 The small-angle scattering result of the thin film 3 of Example 1 is shown in the figure.

[0022] Figure 7 Figure for X-ray diffraction test results of the films 1-4 of Example 1;

[0023] Figure 8 Figure for mechanical property test results of the films 1-4 of Example 1;

[0024] Figure 9 Figure for maximum stress test results of the film 7 of Comparative Example 1 to the film 3 of Example 1;

[0025] Figure 10 Figure for shrinkage ratio test results of the film 3 of Example 1 under water stimulation;

[0026] Figure 11 Figure for oxidation resistance test results of the film 7 of Comparative Example 1 and the film 3 of Example 1;

[0027] Figure 12 Figure for conductive ability test results of the film 3 of Example 1;

[0028] Figure 13 Figure for the morphology of the film 8 of Comparative Example 2.

[0029] Figure 14 Figure for the morphology of the film 9 of Comparative Example 3. DETAILED DESCRIPTION

[0030] The technical solutions will be described clearly and completely below by combining the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0031] In the following description, the term “and / or” is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, B alone and A and B together. Wherein A and B can be singular or plural.

[0032] In the following description, the terms “include”, “contain”, “have” and “contain” and the like are all open terms, that is, they mean to include but not limited to.

[0033] Those skilled in the art should understand that in the following description of the embodiments of the present application, the sequence of the serial numbers does not mean the sequence of the execution, and part or all of the steps can be executed in parallel or in sequence, and the execution sequence of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0034] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0035] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0036] The technical principle adopted in this invention is based on the Hofmeister effect of salt ions on collagen. Salting out and uniaxial stretching are combined to increase the hydrogen bonds between collagen molecules, enhance the binding force between network molecules, improve the structural strength, and endow the film with water-responsive shrinkage properties.

[0037] On the one hand, a method for preparing a water-responsive shrinkage collagen membrane is provided, comprising:

[0038] Provides gallium-indium liquid metal encapsulated with cyanidin and collagen solution;

[0039] Gallium-indium liquid metal coated with cyanidin was mixed with a collagen solution and then vacuum dried to obtain a thin sheet.

[0040] Thin sheets were salted out with sodium citrate solution and then stretched uniaxially to obtain a water-responsive, shrinking collagen membrane.

[0041] Using gallium-indium liquid metal encapsulated with collagen and cyanidin as the main raw materials, a water-responsive shrinkage collagen membrane is constructed by salting out and oriented stretching of collagen molecules. In particular, when unidirectional oriented stretching is performed, such as stretching along the axial direction of the thin sheet after salting out, the resulting collagen membrane exhibits the most obvious water-responsive shrinkage performance and significantly enhanced mechanical properties.

[0042] In some embodiments, the cyanidin-encapsulated gallium indium liquid metal is formed by crushing and mixing cyanidin and gallium indium liquid metal; the mass of cyanidin is 30% of the mass of gallium indium liquid metal.

[0043] The method for preparing the water-responsive shrinkage collagen membrane of the present invention includes gallium indium liquid metal coated with cyanidin as the raw material. Compared with conventional exogenous modified raw materials, gallium indium liquid metal can fully combine the biocompatibility and processability of collagen. After uniformly coating with cyanidin, gallium indium liquid metal is highly dispersed in cyanidin, and the water solubility of gallium indium liquid metal is increased, making it easier to incorporate into collagen solution.

[0044] In some embodiments, the collagen solution is a collagen solution obtained by dissolving collagen in acetic acid solution under light-protected conditions. In some specific embodiments, the mass-to-volume ratio of collagen to acetic acid solution is 1200 mg:60 mL, and the concentration of acetic acid solution is 3 wt%.

[0045] In some embodiments, the mass ratio of cyanidin-encapsulated gallium-indium liquid metal to collagen is 1:(2-4). In some preferred embodiments, the mass ratio of cyanidin-encapsulated gallium-indium liquid metal to collagen is 1:3.

[0046] In some specific embodiments, the mass ratio of cyanidin-encapsulated gallium-indium liquid metal to collagen is 1:(2-4). This allows for the high dispersion of collagen after cyanidin is uniformly encapsulated in gallium-indium liquid metal, fully leveraging its strong hydrogen-donating ability, conjugated stability, and glycosylation-capable structural characteristics, thereby endowing the collagen membrane with antioxidant properties and strong mechanical properties.

[0047] In particular, when the mass ratio of cyanidin-encapsulated gallium-indium liquid metal to collagen is 1:3, the collagen film exhibits the highest surface properties and mechanical strength. When the content of cyanidin-encapsulated gallium-indium liquid metal is too high, the resulting film structure is uneven and does not exhibit significant water shrinkage properties.

[0048] In some embodiments, the vacuum drying temperature is 60–80°C; preferably, the drying temperature is 75°C.

[0049] In some embodiments, the concentration of sodium citrate solution is 30 wt%, and the salting-out time is 12–24 h; preferably, the salting-out time is 24 h.

[0050] In particular, when the concentration of sodium citrate solution is 30wt% and the salting-out time is 24h, the resulting collagen membrane has better mechanical properties, possibly because the internal hydrogen bonds of the salted-out collagen membrane increase under these conditions.

[0051] On the other hand, a water-responsive shrinkable collagen membrane prepared by the above-described method is provided, wherein the shrinkage response time of the water-responsive shrinkable collagen membrane is ≤5s.

[0052] Prior to this application, a series of experiments were conducted. Some of the experimental results are listed below to provide a more detailed description of the invention. The following is a detailed description in conjunction with the embodiments.

[0053] In the following examples, all reagents were commercially available. Changing the order of reagents in the following examples does not exceed the scope of protection of this invention.

[0054] Example 1

[0055] This embodiment provides a method for preparing a water-responsive shrinkage collagen membrane, including:

[0056] Step 1: Place 30g of cyanidin and 100g of gallium indium liquid metal in a cell disruptor, add water and disrupt to obtain a dispersion of gallium indium liquid metal coated with cyanidin; the concentration of gallium indium liquid metal coated with cyanidin in the dispersion is 100mg / mL; both cyanidin and gallium indium liquid metal were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0057] Step 2: Dissolve 1200mg of collagen in 60mL of 3wt% acetic acid solution, and stir in the dark until dissolved to obtain a collagen solution; the stirring time in the dark is 1 day.

[0058] Step 3: Mix 3 mL of the collagen solution described in Step 2 and 200 μL of gallium indium liquid metal dispersion coated with cyanidin evenly, and dry in a vacuum oven at 75°C to obtain a thin film, named Thin Film 1.

[0059] Step 4: Immerse the sheet described in Step 3 in a 30wt% sodium citrate solution to allow salting out for 24 hours to obtain the salted-out sheet, named Film 2;

[0060] Step 5: Stretch the salted-out sheet obtained in Step 4 unidirectionally along its length to twice its original length to obtain a water-responsive shrinkage collagen film, named Film 3; the unidirectional stretching is achieved by clamping one end of the sheet and pulling and stretching the other end.

[0061] The water-responsive collagen film was immersed in water and showed obvious shrinkage within 5 seconds. The shrunken film was named film 4.

[0062] Comparative Example 1

[0063] This comparative example provides a method for preparing a water-responsive collagen film, which is the same as in Example 1, except that cyanidin-encapsulated gallium-indium liquid metal is not added. The preparation method includes:

[0064] Step 1: Dissolve 1200mg of collagen in 60mL of 3wt% acetic acid solution, stir in the dark for 1 day to obtain a collagen solution;

[0065] Step 2: Dry the collagen solution in a vacuum oven at 75°C to obtain a thin film, named film 5. Immerse it in a 30wt% sodium citrate solution to salt out for 24 hours to obtain a salt-out thin film, named film 6.

[0066] Step 3: Stretch the salt-precipitated sheet obtained in Step 2 unidirectionally along its length to twice its original length to obtain the stretched film, named Film 7.

[0067] Comparative Example 2

[0068] This comparative study investigated the effect of the concentration of gallium-indium liquid metal encapsulated with cyanidin on the water-responsive shrinkage properties of collagen films. The preparation method was the same as in Example 1, except that the volume of the collagen solution in step three was 4 mL, and the film obtained after drying was labeled as film 8.

[0069] Comparative Example 3

[0070] This comparative study investigated the effect of the concentration of gallium-indium liquid metal encapsulated with cyanidin on the water-responsive shrinkage properties of collagen films. The preparation method was the same as in Example 1, except that the volume of the collagen solution in step three was 2 mL, and the film obtained after drying was labeled as film 9.

[0071] Performance evaluation:

[0072] Figure 1 Image a is a sample image of film 1 from Example 1. Figure 1 Image b is a sample image of film 5 from Comparative Example 1. As can be seen from the comparison, the film of Example 1 has a uniform color and high flatness, while the film of Comparative Example 1 has poor mechanical strength and obvious cracks.

[0073] Figure 2 Photograph a is a morphological image of the gallium-indium liquid metal dispersion coated with cyanidin from Example 1. Figure 2 Image b shows the morphology of gallium-indium liquid metal in water. It can be seen that no obvious liquid metal is observed in the gallium-indium liquid metal dispersion coated with cyanidin. The liquid metal is uniformly dispersed in water, while the liquid metal without cyanidin coating is obviously insoluble in water.

[0074] Figure 3 This is a schematic diagram of steps four to six in Example 1, showing the morphological changes of the film after salting out, including uniaxial stretching and water-contact shrinkage. Figure 3 As shown, the film of the present invention can be stretched and oriented in one direction and has the characteristic of wetting and shrinking.

[0075] Figure 4 This is a scanning electron microscope (SEM) image of thin film 1 from step three of Example 1. The sample preparation process includes: sputtering gold onto thin film 1 to obtain the sample. According to...Figure 4 As can be seen, the surface of film 1 is flat and does not have an orientation structure.

[0076] Figure 5 This is a scanning electron microscope (SEM) image of thin film 3 from step five of Example 1. The sample preparation process includes: sputtering gold onto thin film 3 to obtain the sample. According to... Figure 5 It is evident that the collagen film aligns in the same direction and exhibits an oriented structure when water responds to contraction.

[0077] Figure 6 The small-angle scattering pattern of film 3 in step five of Example 1 shows that the scattering pattern is clearly elliptical, indicating that the water-responsive shrinkage collagen film of the present invention has a high degree of orientation.

[0078] Figure 7 These are X-ray diffraction patterns of thin films 1-4 from Example 1. Figure 7 It can be seen that the X-ray diffraction pattern of film 3 shows an increase in peaks compared to other films, proving that film 3 has a higher degree of orientation. Water stimulation destroys the orientation, and the peaks of film 4 disappear after shrinking upon contact with water, indicating a lower degree of orientation.

[0079] Figure 8 These are stress-strain diagrams of films 1-4 in Example 1. Figure 8 It is evident that the mechanical strength of film 3 is increased by 3 to 4 times compared to film 1, indicating that the method of the present invention can effectively improve the mechanical properties of collagen films.

[0080] Figure 9 The maximum stress diagrams for film 3 in Example 1 and film 7 in Comparative Example 1 are shown. It can be seen that the mechanical strength of film 3 is significantly higher than that of film 5, indicating that the liquid metal encapsulated with cyanidin can effectively improve the mechanical properties of the film.

[0081] Figure 10 This is a diagram showing the shrinkage ratio of film 3 in Example 1 under water-stimulated conditions. (Source: [Diagram showing shrinkage ratio of film 3 in Example 1]) Figure 9 It can be seen that the collagen membrane of the present invention can shrink under water stimulation, with a shrinkage rate of about 66.7%, exhibiting obvious wet shrinkage characteristics.

[0082] Figure 11 The graph shows the antioxidant capacity test results of the water-responsive shrinkage collagen membrane (film 3) in Example 1 and film 7 in Comparative Example 1. The test method was to evaluate the antioxidant performance of the film in water using ABTS. The specific steps are as follows: The above film and 100uLABTS solution were placed in 2900uL of aqueous solution and shaken thoroughly. Then, the absorbance (714nm) was measured at different times (every 5min, for a total of 30min) using a microplate reader. Figure 11As can be seen, the anti-oxidation ability of the thin film 3 prepared by adding cyanidin-encapsulated gallium indium liquid metal is significantly improved compared with that of the thin film 7 prepared by not adding cyanidin-encapsulated gallium indium liquid metal. This indicates that the preparation method of introducing cyanidin-encapsulated gallium indium liquid metal of the present invention can endow water-responsive shrinkage collagen film with excellent anti-oxidation properties.

[0083] Figure 12 The graph shows the conductivity test results of the water-responsive shrinkage collagen membrane (film 3) in Example 1. The test method includes connecting film 3 to a constant voltage conductive path. The results show that the film of the present invention can drive the operation of external devices, while the small light bulbs of Comparative Examples 1 and 2 did not light up when connected to the same constant voltage conductive path.

[0084] The film morphologies of Comparative Examples 2 and 3 are as follows: Figure 13 and Figure 14 As shown, when the mass ratio of cyanidin-encapsulated gallium-indium liquid metal to collagen is 1:4, that is, when the concentration of cyanidin-encapsulated gallium-indium liquid metal in the system is low, the film surface is smooth. Figure 13 When the mass ratio of cyanidin-encapsulated gallium-indium liquid metal to collagen is 1:2, that is, when the concentration of cyanidin-encapsulated gallium-indium liquid metal in the system is high, the film surface is uneven. Figure 14 It does not have water-responsive shrinkage properties.

Claims

1. A method for preparing a water-responsive contractile collagen membrane, characterized in that, include: Provides gallium-indium liquid metal encapsulated with cyanidin and collagen solution; Gallium-indium liquid metal coated with cyanidin was mixed with a collagen solution and then vacuum dried to obtain a thin sheet. Thin sheets were salted out with sodium citrate solution and then stretched uniaxially to obtain a water-responsive, shrinking collagen membrane.

2. The method for preparing a water-responsive contractile collagen membrane according to claim 1, characterized in that, The gallium indium liquid metal encapsulated by cyanidin is formed by crushing and mixing cyanidin and gallium indium liquid metal.

3. The method for preparing a water-responsive contractile collagen membrane according to claim 2, characterized in that, The mass of the cyanidin is 30% of the mass of the gallium indium liquid metal.

4. The method for preparing a water-responsive contractile collagen membrane according to claim 1, characterized in that, The collagen solution is obtained by dissolving collagen in acetic acid solution under light-protected conditions.

5. The method for preparing a water-responsive contractile collagen membrane according to claim 4, characterized in that, The mass-to-volume ratio of collagen to acetic acid solution is 1200 mg: 60 mL, and the concentration of acetic acid solution is 3 wt%.

6. The method for preparing a water-responsive contractile collagen membrane according to claim 1, characterized in that, The mass ratio of cyanidin-encapsulated gallium-indium liquid metal to collagen is 1:(2-4).

7. The method for preparing a water-responsive contractile collagen membrane according to claim 6, characterized in that, The mass ratio of cornflower seed extract-encapsulated gallium-indium liquid metal to collagen is 1:

3.

8. The method for preparing a water-responsive contractile collagen membrane according to claim 4, characterized in that, The vacuum drying temperature is 60–80℃; the concentration of sodium citrate solution is 30 wt%; and the salting-out time is 12–24 h.

9. The method for preparing a water-responsive contractile collagen membrane according to claim 8, characterized in that, The vacuum drying temperature was 75℃; the salting-out time was 24 hours.

10. A water-responsive shrinkable collagen membrane prepared by the method for preparing a water-responsive shrinkable collagen membrane according to any one of claims 1 to 9, characterized in that, The contraction response time of the water-responsive shrinkage collagen membrane is ≤5s.

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