CN106265129A - A kind of fibroin albumen alginate composite membrane and its preparation method and application - Google Patents

Abstract

The invention discloses a preparation method of a silk fibroin-alginate composite film, which belongs to the field of composite materials and the field of biotechnology. The present invention uses sodium alginate, a marine biomass extracted from brown algae, as a matrix, mixes high-molecular-weight silk fibroin protein extracted from waste silkworm cocoons, adopts supramolecular self-assembly and ion cross-linking technology, and prepares a two-component composite film by casting method . The prepared silk fibroin-alginate composite film has more intermolecular hydrogen bonds, which can improve the comprehensive mechanical properties of the film. At the same time, because of its special interpenetrating mesh structure, the composite film has good moisture retention and water absorption , The hygroscopic performance is significantly improved, and it is possible to load other slow-release substances. The raw materials of the invention are natural and green, and the composite film prepared combines the good biocompatibility, non-toxicity, and biodegradability of silk fibroin and alginate, and can be applied to the beauty and skin care mask industry. The preparation process is simple, the solution can be recycled, the solution is green and environmentally friendly, and has good application prospects.

Description

A kind of silk fibroin-alginate composite film and its preparation method and application

technical field

The present invention relates to a silk fibroin film and a preparation method thereof, in particular to a high-strength loadable silk fibroin-alginate composite film and a preparation method thereof, and the present invention also relates to the silk fibroin-alginate The application of the composite film as a facial mask belongs to the field of composite materials and the field of biotechnology.

Background technique

With the rapid development of science and technology, the concept of low-carbon environmental protection has been deeply rooted in the hearts of the people, and human beings have attached great importance to the protection of the environment. Facing the increasingly scarce oil resources today, the chemical synthesis industry with high energy consumption and high pollution is facing enormous pressure. Looking for New green biomass materials have become the mainstream of development.

Silk fibroin (SF) is the main component of natural silk, which accounts for 70-80% of the silk volume. There are a wide range of applications in the biological field. Among them, silk fibroin film has a long research history, and its biggest disadvantage is its high brittleness and poor mechanical properties. Pure silk fibroin film is easily soluble in water, which limits its application in the biomedical field to a large extent. In order to improve and improve the comprehensive mechanical properties of silk fibroin film, many researchers have used blending, grafting, Composite silk fibroin membranes were prepared by cross-linking and other methods. Although some methods have improved the mechanical properties of silk fibroin films to some extent, they also brought problems such as uneven degradation of silk fibroin films and decreased biocompatibility, which narrowed the scope of its application. At the same time, the preparation process conditions Harsh, easy to cause environmental pollution and harmful substance residues and other problems. Sodium alginate (SA) is a polysaccharide polymer extracted from brown algae and some bacteria, which has good film-forming properties. Because the structure of sodium alginate contains a large number of hydrophilic groups such as carboxyl and hydroxyl groups, when it is dissolved in water, the dissociated small molecules of counter ions are easy to lose, resulting in the problem of unstable membrane dissolution. A single sodium alginate has a large High hydrophilicity, insufficient strength and flexibility after film formation.

Contents of the invention

The purpose of the present invention is to provide a silk fibroin-alginate composite film and its preparation method. In this paper, the non-toxic silk fibroin and sodium alginate solution, both of which are biomass materials, are blended to form a film, and then A high-strength, non-toxic, biocompatible and biodegradable silk fibroin-alginate composite membrane was prepared by coagulation bath treatment with an aqueous calcium chloride solution. Provides the possibility to release substances.

The preparation of the silk fibroin-alginate composite film of the present invention is based on sodium alginate, a marine biomass extracted from brown algae, mixed with high-molecular-weight silk fibroin extracted from waste silkworm cocoons, and adopts supramolecular self-assembly and ion cross-linking process to produce a two-component composite membrane with an interpenetrating mesh structure. Concrete preparation process is as follows:

(1) Extracting silk fibroin from silkworm cocoons;

(2) configure sodium alginate aqueous solution;

(3) Take the silk fibroin solution prepared in step (1) and mix evenly with the sodium alginate aqueous solution prepared in step (2) to obtain a silk fibroin-sodium alginate mixed solution, which is defoamed and allowed to stand for later use; The solid mass ratio of silk fibroin and sodium alginate is 1:10～5:10;

(4) Take the silk fibroin-sodium alginate mixed solution obtained in step (3), and spread the mixed solution on a glass plate naturally by casting method, the solution thickness is 2 to 3mm, and a composite film is obtained;

(5) with the calcium chloride aqueous solution that is 1～3% with massfraction, the composite film that step (4) is made is carried out coagulation solidification treatment, and the consumption of calcium chloride solution is as the criterion that the solution has just completely submerged the composite film, and then at a constant temperature The silk fibroin-sodium alginate composite film was obtained by natural drying in a constant humidity chamber.

Further, in the above technical scheme, the extraction process in step (1) is as follows: first degumming the shredded cocoons with sodium carbonate aqueous solution to obtain degummed silk fibroin, and placing the degummed silk fibroin in CaCl ₂ , CH ₃ CH ₂ OH, Dissolve in a mixed solution of H ₂ O, and the solution is then subjected to dialysis and centrifugation to obtain a pure silk fibroin solution.

Further, in the above technical solution, the mass fraction of the sodium carbonate aqueous solution is 0.5-1%.

Further, in the above technical solution, the molar ratio of CaCl ₂ , CH ₃ CH ₂ OH, and H ₂ O in the mixed solution of CaCl ₂ , CH ₃ CH ₂ OH, and H ₂ O is 1:2:8.

Further, in the above technical solution, the centrifugation is to centrifuge the silk fibroin solution at a rotational speed of 3500r/min for 5-10min.

Further, in the above technical solution, the dialysis is carried out by putting the centrifuged and filtered silk fibroin solution into a dialysis bag and sealing it, the temperature is 5-12°C, and the dialysis time is 72 hours.

Further, in the above technical scheme, the mass fraction of the sodium alginate solution described in step (2) is 1-4%; the preparation method is: in a hot water bath at 50-60°C, mix sodium alginate and deionized water As the raw material, an aqueous solution of sodium alginate is prepared by gentle stirring.

Further, in the above technical solution, the drying in step (5) is constant temperature and constant humidity drying, the temperature is 30-60° C., and the relative humidity is 40-90%.

The invention provides a silk fibroin-alginate composite film prepared by the above method.

Another object of the present invention is to provide the silk fibroin-alginate composite film as a facial mask in the field of daily life.

The present invention further provides an application of the silk fibroin-alginate composite film prepared by the above method as a cosmetic facial mask.

The invention principle of the silk fibroin-alginate composite film is: the silk fibroin and sodium alginate are blended to form a film, thereby changing the conformation of the silk fibroin, and part of the β-fold structure is transformed into a random coil structure , and the hydrogen bond between sodium alginate and silk fibroin molecules is beneficial to improve the comprehensive mechanical properties of the composite membrane. Because the composite membrane has a special interpenetrating mesh structure, its hygroscopicity, water absorption and moisture retention are significantly improved compared with pure alginate membranes, and more pores provide the possibility to load other slow-release substances.

Description of drawings

Fig. 1 is the scanning electron micrograph of silk fibroin-alginate composite film;

Fig. 2 is the infrared spectrogram of silk fibroin-alginate composite film;

Figure 3 is the moisture absorption curve of the silk fibroin-alginate composite film.

detailed description

The present invention will be described in further detail below through examples, and these examples are only used to illustrate the present invention, and do not limit the scope of the present invention.

Example 1

First, degumming, centrifugation, filtration, dialysis, and concentration of the shredded silk cocoons were performed to obtain a silk fibroin solution with a mass fraction of 5%. In a hot water bath at 60°C, 2g of sodium alginate and 100ml of deionized water were used as raw materials. Use gentle stirring to configure sodium alginate aqueous solution; mix the aqueous solution containing 0.2g silk fibroin with the prepared sodium alginate aqueous solution evenly to obtain a silk fibroin-sodium alginate mixture, which is defoamed and left to stand for later use . The mixed solution is naturally spread on the glass plate by casting method, the solution thickness is 2mm, and the composite film is solidified with a calcium chloride aqueous solution with a mass fraction of 3%. The membrane is used as the standard, and then the calcium chloride on the surface of the membrane is washed with deionized water, and then dried naturally in a constant temperature and humidity chamber with a temperature of 50°C and a relative humidity of 70%, to obtain a silk fibroin-alginate composite membrane.

Example 2

First, degumming, centrifugation, filtration, dialysis, and concentration of the shredded silk cocoons were performed to obtain a silk fibroin solution with a mass fraction of 5%. In a hot water bath at 60°C, 2g of sodium alginate and 100ml of deionized water were used as raw materials. Use gentle stirring to configure sodium alginate aqueous solution; mix the aqueous solution containing 0.4g silk fibroin with the prepared sodium alginate aqueous solution evenly to prepare silk fibroin-sodium alginate mixed solution, defoam and stand for backup use. The mixed solution is naturally spread on the glass plate by casting method, the solution thickness is 2mm, and the composite film is solidified with a calcium chloride aqueous solution with a mass fraction of 3%. The membrane shall prevail, and then be cleaned with deionized water until calcium chloride-free, and then dried naturally in a constant temperature and humidity chamber with a temperature of 50° C. and a relative humidity of 70%, to obtain a silk fibroin-alginate composite membrane.

Example 3

Same as Example 2, the difference is that the aqueous solution containing 0.6g silk fibroin is uniformly mixed with the prepared aqueous sodium alginate solution.

Example 4

Same as Example 2, the difference is that the aqueous solution containing 0.8g silk fibroin is uniformly mixed with the prepared aqueous sodium alginate solution.

Example 5

Same as Example 2, the difference is that the aqueous solution containing 1g of silk fibroin is uniformly mixed with the prepared aqueous solution of sodium alginate.

Comparative example 1

Meanwhile embodiment 2, the difference is that silk fibroin is not added.

In the above-mentioned embodiments, the centrifugation is to centrifuge the silk fibroin solution for 5-10 minutes at a speed of 3500 r/min in a centrifuge.

In the above examples, the shredded silkworm cocoons were first degummed with sodium carbonate aqueous solution to obtain degummed silk fibroin, and the degummed silk fibroin was dissolved in CaCl ₂ -CH ₃ CH ₂ OH-H ₂ O aqueous solution, and the solution was dialyzed and Centrifuge to obtain pure silk fibroin solution. The CaCl ₂ -CH ₃ CH ₂ OH-H ₂ O aqueous solution is a ternary solution with a substance molar ratio of 1:2:8.

In the above examples, the dialysis is carried out by putting the centrifuged and filtered silk fibroin-lithium bromide solution into a cellulose dialysis bag and sealing it, the temperature is 5-12°C, and the dialysis time is 72 hours.

Structural Characterization of Silk Fibroin-Alginate Composite Film

1. Macroscopic appearance

The silk fibroin-alginate composite membrane prepared by the invention is a colorless and transparent membrane material.

2. SEM analysis

Among Fig. 1 (a), (c) are the scanning electron micrographs of pure sodium alginate film, (b), (d) are the scanning electron micrographs of embodiment 2, as can be seen from the microscopic scanning electron microscope, the silk prepared by the present invention The cross-section of the protein-alginate composite membrane has an interpenetrating mesh structure and good dispersion inside, indicating that this membrane material has the possibility of loading other slow-release substances. The presence of two substances, silk fibroin and alginate, will facilitate the loading of substances with different molecular weights, thus having good slow-release performance.

3. Infrared spectral analysis

Figure 2 is the infrared spectrogram of Example 2, and the results in Figure 2 show that the addition of silk fibroin makes the -OH absorption peak of alginate at 3450 cm ^-1 move to a low wavenumber of 3429 cm ^-1 , which is due to silk fibroin It is caused by the hydrogen bond interaction between the -NH and -OH of the protein and the -OH of sodium alginate. The introduction of silk fibroin weakened and shifted the asymmetric stretching vibration absorption peak of C=O at 1615 cm ^-1 and the antisymmetric stretching vibration absorption peak of C=O on the 1090 cm ^-1 ring of sodium alginate, indicating that silk There is a strong hydrogen bond between the protein and sodium alginate, which is an important reason for the improvement of the comprehensive mechanical properties of the composite membrane.

4. Hygroscopic performance analysis

Figure 3 is the moisture absorption curve of the silk fibroin-alginate composite film prepared in Comparative Example 1 and Examples 1-5, it can be seen that the moisture absorption rate of the composite film has a process of first increasing and then decreasing as the silk fibroin content increases , generally speaking, the moisture absorption rate of the composite film increases. When the content of silk fibroin in the two-system components is small, the moisture absorption rate of the film increases significantly with the increase of the content of silk fibroin, which is the result of the joint action of the water-absorbing groups of the system and the interpenetrating mesh structure. With the increase of content, the increase of various groups in the system leads to the decrease of the number of meshes, and the amount of water vapor is limited, the moisture absorption rate of the composite membrane tends to decrease, and finally reaches equilibrium. In summary, when the solid mass ratio of silk fibroin and sodium alginate is 2:10, the moisture absorption rate of silk fibroin-sodium alginate composite film is the largest.

The research results show that the silk fibroin/alginate composite film has a tight, uniform, colorless and transparent structure, and the film-forming performance is significantly improved. The strong hydrogen bond between silk fibroin and sodium alginate makes the composite film have good properties. Mechanical properties, because of its special interpenetrating mesh structure, hygroscopicity, water absorption and moisture retention are significantly improved compared with pure alginate membranes, and more pores provide the possibility to load other slow-release substances. It is suitable for the manufacture of facial masks and the development of daily skin care products.

Claims (10)

1. A preparation method of silk fibroin-alginate composite film, characterized in that: it is the following specific steps: (1) Extracting silk fibroin from silkworm cocoons; (2) configure sodium alginate aqueous solution; (3) Take the silk fibroin solution prepared in step (1) and mix evenly with the sodium alginate aqueous solution prepared in step (2) to obtain a silk fibroin-sodium alginate mixed solution, which is defoamed and allowed to stand for later use; The solid mass ratio of silk fibroin and sodium alginate is 1:10～5:10; (4) Take the silk fibroin-sodium alginate mixed solution obtained in step (3), and spread the mixed solution on a glass plate naturally by casting method, the solution thickness is 2 to 3mm, and a composite film is obtained; (5) with the calcium chloride aqueous solution that is 1～3% with massfraction, the composite film that step (4) is made is carried out coagulation solidification treatment, and the consumption of calcium chloride solution is as the criterion that the solution has just completely submerged the composite film, and then at a constant temperature The silk fibroin-sodium alginate composite film was obtained by natural drying in a constant humidity chamber. 2. the preparation method of silk fibroin-sodium alginate composite film according to claim 1 is characterized in that: in the step (1), the extraction process is, first degumming the silkworm cocoons that are shredded through sodium carbonate aqueous solution, obtains degummed silk The degummed silk fibroin is dissolved in a mixed solution of CaCl ₂ , CH ₃ CH ₂ OH and H ₂ O, and the solution is dialyzed and centrifuged to obtain a pure silk fibroin solution. 3. The preparation method of silk fibroin-sodium alginate composite film according to claim 2, characterized in that: the mass fraction of the sodium carbonate aqueous solution is 0.5-1%. 4. The preparation method of silk fibroin-sodium alginate composite film according to claim 2, characterized in that: CaCl ₂ , CH ₃ CH ₂ in the mixed solution of CaCl ₂ , CH ₃ CH ₂ OH and H ₂ O The substance molar ratio of OH and H ₂ O is 1:2:8. 5. The preparation method of silk fibroin-sodium alginate composite membrane according to claim 2, characterized in that: the centrifugation is to centrifuge the silk fibroin solution at a rotation speed of 3500r/min for 5-10min. 6. The preparation method of silk fibroin-sodium alginate composite membrane according to claim 2, characterized in that: said dialysis is carried out by putting the centrifuged and filtered silk fibroin solution into a dialysis bag for sealing, The temperature is 5-12°C, and the dialysis time is 72 hours. 7. The preparation method of silk fibroin-sodium alginate composite film according to claim 1, characterized in that: the mass fraction of sodium alginate solution described in step (2) is 1 to 4%; the preparation method is: In a hot water bath at 50-60°C, use sodium alginate and deionized water as raw materials, and use gentle stirring to prepare an aqueous solution of sodium alginate. 8. The preparation method of silk fibroin-alginate composite membrane according to claim 1, characterized in that: the drying in step (5) is constant temperature and humidity drying, the temperature is 30-60°C, and the relative humidity is 40°C. ~90%. 9. The silk fibroin-alginate composite film prepared by the method according to any one of claims 1-8. 10. The silk fibroin-alginate composite film as claimed in claim 9 is used as a facial mask.