An irradiated modified fish gelatin composite film, its preparation method and application

Abstract

The present invention discloses an irradiated modified fish gelatin composite film, its preparation method and application. In the present invention, fish gelatin, glycerol and graphene oxide are mixed, and then gallic acid is added and mixed evenly, followed by irradiation treatment to obtain the irradiated modified fish gelatin composite film. The present invention uses fish gelatin extracted from fishery waste as raw material to prepare fish gelatin film, with simple and easy operation steps, low cost, safety and environmental protection, and improves the comprehensive utilization value of fishery waste. The present invention improves the application performance of the fish gelatin composite film, has good biocompatibility, ensures the product quality, and has a wide application prospect in the field of biomedical membrane materials.

Description

Technical Field

[0001] The present invention belongs to the field of materials, and particularly relates to an irradiated modified fish gelatin composite film, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, the aquatic product processing industry has developed rapidly, and a large amount of aquatic product processing waste such as fish skin, fish bone, and fish scale has been generated during processing. Except for a small part used for processing feed and fertilizer, most of them are directly discarded. If these waste materials during the processing cannot be fully utilized, it will cause environmental pollution. And the gelatin content in aquatic product processing waste such as fish skin, fish scale, and fish bone is relatively high. Therefore, the research and development of fish gelatin products have gradually attracted great attention. If fishery waste can be fully utilized, it can not only greatly improve the economic value of aquatic waste, further promote the high-value utilization of aquatic products, but also achieve the purposes of environmental protection, pollution reduction, and comprehensive utilization of resources.

[0003] Fish gelatin is mainly a hydrophilic protein obtained by partially hydrolyzing collagen in parts such as fish scales, skin, bones, and internal organs of fish. It is a rich and safe protein source and a potential ideal substitute for mammalian gelatin. Fish gelatin has good film-forming properties, environmental degradability, and biocompatibility. The fish gelatin film made from fish gelatin has become a research hotspot in the food and pharmaceutical fields and is applied in food packaging, wound dressings, drug delivery, etc. However, the fish gelatin film has defects such as poor stretchability and water barrier performance. To improve the application performance of the fish gelatin film, many researchers have tried methods such as physical and chemical cross-linking and introducing polymer modification. Currently, chemical cross-linking methods are mostly used, but after chemical cross-linking modification, the biological activity and stability of gelatin decrease, and more seriously, there is the problem of chemical residue. In addition, because gelatin contains a large number of active amino acid residues and is affected by monomers and high temperature, oxidation and decomposition reactions are extremely likely to occur during the chemical cross-linking process. Summary of the Invention

[0004] The primary object of the present invention is to overcome the deficiencies of the prior art and provide a preparation method of an irradiated modified fish gelatin composite film.

[0005] Another object of the present invention is to provide an irradiated modified fish gelatin composite film obtained by the above preparation method.

[0006] Still another object of the present invention is to provide an application of the above irradiated modified fish gelatin composite film.

[0007] The object of the present invention is achieved by the following technical solutions: A preparation method of an irradiated modified fish gelatin composite film, comprising the following steps:

[0008] (1) Swell fish gelatin in water and stir until dissolved to obtain a gelatin solution; then add glycerol and continue stirring to mix evenly to obtain a gelatin-glycerol solution;

[0009] (2) Add graphene oxide to the gelatin-glycerol solution obtained in step (1), disperse and blend by the first ultrasonic treatment, and stir evenly for the first time to obtain a pre-composite gelatin film solution; then add gallic acid, disperse by the second ultrasonic treatment, and stir evenly for the second time to obtain a composite gelatin film solution;

[0010] (3) Pour the composite gelatin film solution obtained in step (2) into a flat plate to dry into a film, and then place it in a desiccator containing silica gel to balance to obtain a fish gelatin composite film;

[0011] (4) Irradiate the fish gelatin composite film obtained in step (3) to obtain an irradiated modified fish gelatin composite film.

[0012] The fish gelatin described in step (1) is at least one of fish skin gelatin, fish scale gelatin, and fish bone gelatin.

[0013] The water described in step (1) is preferably ultrapure water.

[0014] The swelling conditions described in step (1) are preferably swelling at room temperature for 0.5 - 1.5 h; more preferably swelling at room temperature for 1 h.

[0015] The so-called room temperature refers to 15 - 35 °C; more preferably 20 - 30 °C; most preferably 24 - 26 °C.

[0016] The stirring temperature for stirring until dissolved in step (1) is preferably 55 - 65 °C; more preferably 60 - 65 °C.

[0017] The concentration of the gelatin solution described in step (1) is preferably 4.5 - 5.5% (g:mL) of mass-to-volume ratio; more preferably 5% of mass-to-volume ratio.

[0018] The addition amount of glycerol described in step (1) is calculated according to 30% - 35% (v / w) of fish gelatin; more preferably calculated according to 32% - 35% (v / w) of fish gelatin.

[0019] The conditions for the continued stirring in step (1) are preferably as follows: the temperature is 55 - 65 °C, the stirring speed is 300 - 400 r / min, and the time is 0.5 - 1 h; more preferably as follows: the temperature is 60 - 65 °C, the stirring speed is 350 - 400 r / min, and the time is 0.5 - 1 h.

[0020] The concentration of graphene oxide in the pre-compounded gelatin film solution described in step (2) is 0.3 - 0.5 mg / mL; more preferably 0.4 - 0.5 mg / mL.

[0021] The conditions of the first ultrasonic treatment described in step (2) are preferably as follows: power is 400 - 600 W, temperature is 40 - 50 °C, and time is 15 - 30 min; more preferably as follows: power is 450 - 550 W, temperature is 45 - 50 °C, and time is 15 - 20 min.

[0022] The conditions of the first stirring described in step (2) are preferably as follows: temperature is 60 - 65 °C, stirring speed is 400 - 500 r / min, and time is 1.5 - 2.5 h; more preferably as follows: temperature is 60 - 65 °C, stirring speed is 450 - 500 r / min, and time is 1.5 - 2 h.

[0023] The addition amount of gallic acid described in step (2) is calculated as 10 - 20% (w / w) of fish gelatin; more preferably calculated as 10 - 15% (w / w) of fish gelatin.

[0024] The conditions of the second ultrasonic treatment described in step (2) are preferably as follows: power is 500 - 600 W, temperature is 45 - 55 °C, and time is 30 - 50 min; more preferably as follows: power is 550 - 600 W, temperature is 45 - 55 °C, and time is 30 - 45 min.

[0025] The conditions of the second stirring described in step (2) are preferably as follows: temperature is 60 - 70 °C, stirring speed is 500 - 600 r / min, and time is 2 - 3 h; more preferably as follows: temperature is 60 - 65 °C, stirring speed is 550 - 600 r / min, and time is 2 - 3 h.

[0026] The plate described in step (3) is preferably a square or rectangular plate; more preferably a square or rectangular plate with a specification of 10 - 50 cm × 10 - 50 cm. At this time, the amount of the film solution poured into the plate before film formation is preferably 20 - 500 mL.

[0027] The drying method described in step (3) is preferably air-blowing drying.

[0028] The temperature of the air-blowing drying is preferably 45 - 55 °C; more preferably 50 ± 2 °C.

[0029] The time of the air-blowing drying is preferably 22 - 26 h; more preferably 24 h.

[0030] The radiation source for the irradiation treatment described in step (4) is electron beam rays, X-rays or 60 Co - γ rays.

[0031] The irradiation dose for the irradiation treatment described in step (4) is 1 - 12 kGy, and the irradiation is carried out at normal temperature and normal pressure; more preferably, 60 Co - γ rays are used for irradiation, the irradiation dose is 1 - 10 kGy, and the irradiation is carried out at normal temperature and normal pressure.

[0032] An irradiated modified fish gelatin composite film is obtained by the above preparation method.

[0033] The application of the above irradiated modified fish gelatin composite film in biomedical materials, wound healing dressings and beauty products.

[0034] The present invention has the following advantages and effects compared with the prior art:

[0035] (1) The present invention uses fish gelatin extracted from fishery waste as raw material to prepare fish gelatin film. The operation steps are simple and easy to implement, and can be carried out in industrial production, achieving the purpose of environmental protection. The pre-treatment of the present invention is convenient, and the production process flow is simple and easy to operate. The present invention can not only significantly improve the added value of aquatic product processing, but also reduce the environmental pollution caused by aquatic product processing by-products, and greatly improve the comprehensive utilization value and economic benefits of fishery waste.

[0036] (2) The production cost of the process of the present invention is low, green, safe, efficient, reduces environmental pollution, does not involve complex reaction equipment or devices and cumbersome process flows, and has good environmental protection. The present invention uses irradiation to replace traditional chemical cross-linking agents, overcomes the problems of relying on modifiers with special chemical structures and chemical substance residues in conventional chemical modification methods, and is suitable for large-scale production. Irradiation technology has the advantages of strong controllability of equipment operation, reliable safety control of devices, no harmful substance residues, thorough and effective irradiation sterilization, low cost and high benefit.

[0037] (3) The present invention comprehensively introduces the raw material compounding process and irradiation technology. Adding gallic acid and performing irradiation has a synergistic effect on improving the mechanical properties and antibacterial properties of the film. The effect is better than that of adding gallic acid alone or irradiating alone. The fish gelatin film can be modified in a shorter time, and a modified product with improved performance can be obtained. The present invention improves the application performance of the fish gelatin composite film, has good biocompatibility, ensures the product quality, and has a wide application prospect in the field of biomedical membrane materials. Description of the Drawings

[0038] Figure 1 It is the mechanical property diagram of the films obtained in the examples and comparative examples of the present invention.

[0039] Figure 2It is the antibacterial property diagram of the films obtained in the embodiments and comparative examples of the present invention against Escherichia coli and Staphylococcus aureus.

[0040] Figure 3 It is the release curve diagram of gallic acid in the composite films obtained in the embodiments and comparative example 1 of the present invention.

[0041] Figure 4 It is the ultraviolet-visible light transmittance diagram of the films obtained in the embodiments and comparative example 1 of the present invention. Detailed implementation manners

[0042] The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the implementation manners of the present invention are not limited thereto. For those not specified in the embodiments in terms of specific technologies or conditions, they are carried out according to the technologies or conditions described in the literature in this field. For those reagents or instruments not specified in terms of the manufacturer, they are all conventional products that can be obtained through regular channels.

[0043] Example 1

[0044] (1) Dissolve 6 g of fish gelatin in 120 mL of ultrapure water, swell it at room temperature for 1 h, and then stir it at 65 °C until dissolved to obtain a 5% (w / v) gelatin solution. During this process, continuously seal the port of the container with plastic wrap to prevent the evaporation of the solution water during the long-term heating process and affect the concentration of gelatin in the solution. Add 2 mL of glycerol, and continue to stir at 400 r / min at the above temperature for 30 min to mix evenly to obtain a gelatin-glycerol solution.

[0045] (2) Add a certain mass of graphene oxide to the gelatin-glycerol solution obtained in step (1) to make its concentration 0.5 mg / mL, ultrasonicate it for 15 min under the conditions of a power of 500 W and a temperature of 50 °C, and stir it with a magnetic stirrer at 60 °C and 500 r / min for 90 min to obtain a pre-composite gelatin film solution.

[0046] (3) Add gallic acid accounting for 10% of the mass of gelatin to the pre-composite gelatin film solution obtained in step (2), ultrasonicate it for 40 min under the conditions of a power of 600 W and a temperature of 52 °C, and then stir it with a magnetic stirrer at 60 °C and 600 r / min for 120 min to obtain a composite gelatin film solution.

[0047] (4) Pour 20 mL of the composite gelatin film solution obtained in step (3) into a 10 cm × 10 cm square plate, place it in a blast drying oven at 50 °C for 24 h to form a film. Touch the surface of the film with your hand. After it is dry and has no wet feeling, the film can be peeled off. Take the sample and place it in a desiccator filled with silica gel to balance for 48 h for standby.

[0048] (5) The fish gelatin composite film obtained in step (4) was irradiated using a 60Co - γ ray irradiation device at normal temperature and pressure with an irradiation dose of 1 kGy to obtain an irradiated - modified fish gelatin composite film.

[0049] The results are as Figures 1 to 4 shown. The diameters of the antibacterial zones of the prepared irradiated - modified fish gelatin composite film against Escherichia coli and Staphylococcus aureus were 27.7 mm and 28.0 mm respectively, the tensile strength (TS) was 3.84 MPa, and the elongation at break (EAB) was 136.5%; it had a certain sustained - release effect on gallic acid. The irradiation controlled the slow release of gallic acid from the polymer matrix. The sustained release of the drug could maintain the continuous delivery of the drug, which was beneficial to the effective release of the drug at the wound site, prevented the rapid clearance of the drug from the wound bed, and could effectively accelerate the wound - healing treatment. Compared with Comparative Example 1, the light transmittance of the irradiated film was significantly reduced in the ultraviolet absorption range of 200 nm - 400 nm.

[0050] Example 2

[0051] (1) 6 g of fish gelatin was dissolved in 120 mL of ultrapure water and swollen at room temperature for 1 h, then stirred at 60 °C until dissolved to obtain a 5% (w / v) gelatin solution. During this period, the port of the container was continuously sealed with plastic wrap to prevent the evaporation of the solution moisture during the long - term heating process, which would affect the concentration of gelatin in the solution. 2 mL of glycerol was added, and the mixture was continuously stirred at 390 r / min for 45 min at the above temperature to obtain a gelatin - glycerol solution.

[0052] (2) A certain mass of graphene oxide was added to the gelatin - glycerol solution obtained in step (1) to make its concentration 0.5 mg / mL. It was ultrasonicated for 20 min at a power of 450 W and a temperature of 50 °C, and then stirred with a magnetic stirrer at 60 °C and 500 r / min for 90 min to obtain a pre - composite gelatin film solution.

[0053] (3) 10% of gallic acid relative to the mass of gelatin was added to the pre - composite gelatin film solution obtained in step (2). It was ultrasonicated for 45 min at a power of 550 W and a temperature of 50 °C, and then stirred with a magnetic stirrer at 60 °C and 580 r / min for 150 min to obtain a composite gelatin film solution.

[0054] (4) 20 mL of the composite gelatin film solution obtained in step (3) was poured into a 10 cm × 10 cm square plate and placed in a blast drying oven at 50 °C for 24 h to form a film. After touching the surface of the film with hand and feeling dry without a wet feeling, the film could be peeled off. The sample was taken and placed in a desiccator containing silica gel to equilibrate for 48 h for standby.

[0055] (5) The fish gelatin composite film obtained in step (4) is irradiated with a 60 Co-γ-ray irradiator at room temperature and pressure, with an irradiation dose of 3 kGy, to obtain an irradiation-modified fish gelatin composite film.

[0056] The results are as follows Figures 1 to 4 The results show that the diameters of the inhibition zones of the prepared irradiation-modified fish gelatin composite film against Escherichia coli and Staphylococcus aureus are 26.3 mm and 26.5 mm, respectively, the tensile strength (TS) is 3.60 MPa, and the elongation at break (EAB) is 99.0%. It also has a sustained-release effect on gallic acid. Compared with comparative example 1, the wavelength range that the film can completely shield is increased, and its light barrier performance is optimal. Irradiation can make the film have stronger UV-visible light blocking performance. The composite film is non-toxic and harmless and has good biocompatibility. The composite film has good film formation, clear texture, and dense surface.

[0057] Example 3

[0058] (1) Dissolve 6 g of fish gelatin in 120 mL of ultrapure water and swell at room temperature for 1 h. Stir at 65°C until dissolved to obtain a 5% (w / v) gelatin solution. During this period, the port of the container is continuously sealed with plastic wrap to prevent the long-term heating process from causing the water in the solution to evaporate and affect the concentration of gelatin in the solution. Add 2 mL of glycerol and continue stirring at 400 r / min for 30 min at the above temperature. Mix well to obtain a gelatin-glycerol solution.

[0059] (2) Add a certain mass of graphene oxide to the gelatin-glycerol solution obtained in step (1) to make its concentration 0.5 mg / mL, ultrasonicate for 15 min at a power of 550 W and a temperature of 50° C., and stir with a magnetic stirrer at 60° C. and 500 r / min for 100 min to obtain a pre-composite gelatin film solution.

[0060] (3) Add 10% gallic acid relative to the mass of gelatin to the pre-composite gelatin film liquid obtained in step (2), ultrasonicate for 45 min at a power of 600 W and a temperature of 48° C., and then stir with a magnetic stirrer at 60° C. and 600 r / min for 150 min to obtain a composite gelatin film liquid.

[0061] (4) Pour 20 mL of the composite gelatin film solution obtained in step (3) into a 10 cm × 10 cm square plate and place it in a 50°C forced air drying oven for 24 h to form a film. Touch the surface of the film with your hand. When it is dry and no longer wet, remove the film. Place the sample in a desiccator filled with silica gel for 48 h for standby use.

[0062] (5) The fish gelatin composite film obtained in step (4) was irradiated using a 60Co - γ ray irradiation device under normal temperature and pressure with an irradiation dose of 6 kGy to obtain an irradiated and modified fish gelatin composite film.

[0063] The results are as Figures 1 to 4 shown. The diameters of the antibacterial zones of the prepared irradiated and modified fish gelatin composite film against Escherichia coli and Staphylococcus aureus were 30.0 mm and 27.2 mm respectively, the tensile strength (TS) was 3.13 MPa, and the elongation at break (EAB) was 106.6%; it also had a sustained release effect on gallic acid. Compared with Comparative Example 1, the light transmittance of the irradiated film was significantly reduced in the ultraviolet absorption range of 200 nm - 400 nm, and the light barrier performance of the film could be improved. The composite film was non-toxic and harmless and had good biocompatibility. The composite film had no cracks, clear texture, and a dense structure. More wrinkles would lead to an increase in both the strength and toughness of the material, indicating that irradiation was beneficial to improving the microscopic morphology of the film and thus improving the film's properties.

[0064] Example 4

[0065] (1) 6 g of fish gelatin was dissolved in 120 mL of ultrapure water and swollen at room temperature for 1 h, then stirred at 65°C until dissolved to obtain a 5% (w / v) gelatin solution. During this process, the port of the container was continuously sealed with plastic wrap to prevent the evaporation of water in the solution during the long heating process and affect the concentration of gelatin in the solution. 2 mL of glycerol was added, and stirring continued at 390 r / min at the above temperature for 40 min to mix evenly to obtain a gelatin - glycerol solution.

[0066] (2) A certain mass of graphene oxide was added to the gelatin - glycerol solution obtained in step (1) to make its concentration 0.5 mg / mL, and it was sonicated for 15 min at a power of 500 W and a temperature of 48°C, and then stirred with a magnetic stirrer at 60°C and 500 r / min for 90 min to obtain a pre - composite gelatin film solution.

[0067] (3) 10% of gallic acid relative to the mass of gelatin was added to the pre - composite gelatin film solution obtained in step (2), sonicated for 35 min at a power of 600 W and a temperature of 50°C, and then stirred with a magnetic stirrer at 60°C and 580 r / min for 150 min to obtain a composite gelatin film solution.

[0068] (4) 20 mL of the composite gelatin film solution obtained in step (3) was poured into a 10 cm × 10 cm square plate and placed in a blast drying oven at 50°C for 24 h to form a film. After touching the surface of the film with the hand and it was dry and had no moist feeling, the film could be peeled off. The sample was taken and placed in a desiccator containing silica gel to equilibrate for 48 h for standby.

[0069] (5) The fish gelatin composite film obtained in step (4) was irradiated by a 60Co - γ ray irradiation device at normal temperature and pressure, and the irradiation dose was 9 kGy to obtain an irradiated and modified fish gelatin composite film.

[0070] The results are as Figures 1 to 4 shown that the diameters of the antibacterial zones of the prepared irradiated and modified fish gelatin composite film against Escherichia coli and Staphylococcus aureus are 30.5 mm and 28.3 mm respectively, the tensile strength (TS) is 3.93 MPa, and the elongation at break (EAB) is 153.9%; it also has a sustained release effect on gallic acid. Compared with Comparative Example 1, the light transmittance of the irradiated film in the ultraviolet absorption range of 200 nm - 400 nm is significantly reduced, and the light barrier performance of the film can be improved.

[0071] Example 5

[0072] (1) Dissolve 6 g of fish gelatin in 120 mL of ultrapure water and swell it at room temperature for 1 h, then stir it until dissolved at 65 °C to obtain a 5% (w / v) gelatin solution. During this period, continuously seal the port of the container with plastic wrap to prevent the evaporation of the solution moisture during the long heating process and affect the concentration of gelatin in the solution. Add 2 mL of glycerol and continue to stir at 400 r / min for 30 min at the above temperature to mix evenly to obtain a gelatin - glycerol solution.

[0073] (2) Add a certain mass of graphene oxide to the gelatin - glycerol solution obtained in step (1) to make its concentration 0.4 mg / mL, ultrasonicate it for 15 min at a power of 450 W and a temperature of 50 °C, and stir it with a magnetic stirrer at 60 °C and 500 r / min for 90 min to obtain a pre - composite gelatin film solution.

[0074] (3) Add 10% of the mass of gallic acid relative to gelatin to the pre - composite gelatin film solution obtained in step (2), ultrasonicate it for 35 min at a power of 600 W and a temperature of 50 °C, and then stir it with a magnetic stirrer at 62 °C and 590 r / min for 120 min to obtain a composite gelatin film solution.

[0075] (4) Pour 20 mL of the composite gelatin film solution obtained in step (3) into a 10 cm × 10 cm square plate, place it in a blast drying oven at 50 °C for 24 h to form a film. Touch the surface of the film with your hand. After it is dry and has no wet feeling, the film can be peeled off. Take the sample and place it in a desiccator containing silica gel to equilibrate for 48 h for standby.

[0076] (5) The fish gelatin composite film obtained in step (4) was irradiated using a 60Co - γ ray irradiation device at normal temperature and pressure with an irradiation dose of 12 kGy to obtain an irradiated and modified fish gelatin composite film.

[0077] The results are as Figures 1 to 4 shown that the diameters of the antibacterial zones of the prepared irradiated and modified fish gelatin composite film against Escherichia coli and Staphylococcus aureus are 30.7 mm and 27.7 mm respectively, the tensile strength (TS) is 3.41 MPa, and the elongation at break (EAB) is 102.5%; it also has a sustained release effect on gallic acid.

[0078] Comparative Example 1

[0079] The difference from Example 1 is that the composite film is not irradiated.

[0080] (1) Dissolve 6 g of fish gelatin in 120 mL of ultrapure water and swell it at room temperature for 1 h, then stir it at 65 °C until dissolved to obtain a 5% (w / v) gelatin solution. During this process, continuously seal the port of the container with plastic wrap to prevent the evaporation of water in the solution during the long heating process, which may affect the concentration of gelatin in the solution. Add 2 mL of glycerol and continue to stir at 400 r / min at the above temperature for 30 min to mix evenly to obtain a gelatin - glycerol solution.

[0081] (2) Add a certain mass of graphene oxide to the gelatin - glycerol solution obtained in step (1) to make its concentration 0.5 mg / mL, ultrasonicate it for 15 min at a power of 500 W and a temperature of 50 °C, and then stir it with a magnetic stirrer at 60 °C and 500 r / min for 90 min to obtain a pre - composite gelatin film solution.

[0082] (3) Add gallic acid equivalent to 10% of the mass of gelatin to the pre - composite gelatin film solution obtained in step (2), ultrasonicate it for 40 min at a power of 600 W and a temperature of 52 °C, and then stir it with a magnetic stirrer at 60 °C and 600 r / min for 120 min to obtain a composite gelatin film solution.

[0083] (4) Pour 20 mL of the composite gelatin film solution obtained in step (3) into a 10 cm × 10 cm square plate, place it in a blast drying oven at 50 °C for 24 h to form a film. After touching the surface of the film with your hand and it is dry and has no wet feeling, the film can be peeled off. Take the sample and place it in a desiccator containing silica gel to equilibrate for 48 h to obtain a fish gelatin composite film.

[0084] The results are as Figures 1 to 4As shown, the diameters of the inhibition zones of the prepared fish gelatin composite film against Escherichia coli and Staphylococcus aureus are 18.0 mm and 17.0 mm respectively, the tensile strength (TS) is 1.75 MPa, and the elongation at break (EAB) is 93.8%.

[0085] Comparative Example 2

[0086] The difference from Example 1 is that gallic acid is not added to the composite gelatin film solution obtained in Step 2.

[0087] (1) Dissolve 6 g of fish gelatin in 120 mL of ultrapure water and swell it at room temperature for 1 h, then stir it at 65 °C until dissolved to obtain a 5% (w / v) gelatin solution. During this process, continuously seal the port of the container with plastic wrap to prevent the water in the solution from evaporating during the long heating process, which may affect the concentration of gelatin in the solution. Add 2 mL of glycerol and continue to stir at the above temperature at 400 r / min for 30 min to mix evenly to obtain a gelatin-glycerol solution.

[0088] (2) Add a certain mass of graphene oxide to the gelatin-glycerol solution obtained in Step (1) to make its concentration 0.5 mg / mL, ultrasonicate it for 15 min under the conditions of a power of 500 W and a temperature of 50 °C, and stir it with a magnetic stirrer at 60 °C and 500 r / min for 90 min to obtain a composite gelatin film solution.

[0089] (3) Pour 20 mL of the composite gelatin film solution obtained in Step (2) into a 10 cm × 10 cm square plate and place it in a blast drying oven at 50 °C for 24 h to form a film. Touch the surface of the film with your hand. After it is dry and has no moist feeling, the film can be peeled off. Take the sample and place it in a desiccator containing silica gel to balance for 48 h to obtain a fish gelatin composite film.

[0090] (4) Irradiate the fish gelatin composite film obtained in Step (3) with a 60Co - γ ray irradiation device at normal temperature and pressure, and the irradiation dose is 1 kGy to obtain an irradiated and modified fish gelatin composite film.

[0091] The results are as Figures 1 to 2 shown. The diameters of the inhibition zones of the prepared fish gelatin composite film against Escherichia coli and Staphylococcus aureus are 16.0 mm and 15.0 mm respectively, the tensile strength (TS) is 2.09 MPa, and the elongation at break (EAB) is 96.1%.

[0092] Comparative Example 3

[0093] The difference from Example 1 is that gallic acid is not added to the composite gelatin film solution obtained in Step 2, and the composite film is not subjected to irradiation treatment.

[0094] (1) Dissolve 6 g of fish gelatin in 120 mL of ultrapure water and let it swell at room temperature for 1 h. Then stir it at 65 °C until dissolved to obtain a 5% (w / v) gelatin solution. During this process, continuously seal the port of the container with plastic wrap to prevent the evaporation of water in the solution during the long heating process, which may affect the concentration of gelatin in the solution. Add 2 mL of glycerol and continue to stir at 400 r / min for 30 min at the above temperature to mix evenly and obtain a gelatin-glycerol solution.

[0095] (2) Add a certain mass of graphene oxide to the gelatin-glycerol solution obtained in step (1) to make its concentration 0.5 mg / mL. Ultrasonic it for 15 min at a power of 500 W and a temperature of 50 °C, and then stir it with a magnetic stirrer at 60 °C and 500 r / min for 90 min to obtain a composite gelatin film solution.

[0096] (3) Pour 20 mL of the composite gelatin film solution obtained in step (2) into a 10 cm × 10 cm square plate and place it in a forced-air drying oven at 50 °C for 24 h to form a film. Touch the surface of the film with your hand. After it is dry and has no moist feeling, the film can be peeled off. Take the sample and place it in a desiccator filled with silica gel to equilibrate for 48 h to obtain a fish gelatin composite film.

[0097] The results are as Figures 1 to 2 shown. The diameters of the antibacterial zones of the prepared fish gelatin composite film against Escherichia coli and Staphylococcus aureus are 13.0 mm and 12.0 mm respectively, the tensile strength (TS) is 1.08 MPa, and the elongation at break (EAB) is 80.4%.

[0098] Test method

[0099] Detect the mechanical strength, light barrier property, slow-release property, and antibacterial property of the film samples prepared according to the examples and comparative examples. The specific methods are as follows:

[0100] (1) Antibacterial property

[0101] Conduct antibacterial experiments using Gram-negative bacterium Escherichia coli ATCC25922 and Gram-positive bacterium Staphylococcus aureus ATCC29213 respectively. Use the samples treated with the composite film at different irradiation doses as the antibacterial experiment materials. Culture the bacteria in LB medium and activate them at 30 °C for 12 - 18 h. Dilute the bacterial solution 100 times and take 25 μL to coat the plate. Then place a film with a diameter of 12 mm on the corresponding medium. After culturing at 37 °C for 24 h, use a caliper to measure the diameter (mm) of the antibacterial zone, and use the diameter of the antibacterial zone as the evaluation index for antibacterial activity.

[0102] (2) Light barrier property

[0103] Cut the membrane into rectangles with dimensions of 10 mm × 50 mm. Make 3 parallels for each sample and attach them to the inner side of the cuvette. Using an empty cuvette as a control, scan from 200 - 800 nm with a UV - visible spectrophotometer to measure the transmittance.

[0104] (3)Mechanical properties

[0105] Use a universal material testing machine Instron 5967 to measure the tensile strength (TS) and elongation at break (EAB) of the membrane. The tensile rate is 10 mm / min. Cut the specimens into strips with a width of 20 mm and a length of 50 mm. Repeat the measurement 3 times for each group of samples and take the average value.

[0106] (4)Sustained - release rate of gallic acid

[0107] Determination of the in vitro sustained - release curve: Take 30 mg of the drug - loaded sustained - release membrane sample and place it in a conical flask. Add 10 mL of PBS solution with a pH of 7.4 to the flask. Seal the bottle mouth with plastic wrap and place it in a water bath at 37℃. Take out 100 μL of the solution at the set time points. Repeat the above operation at the next time point. Calculate the cumulative drug release amount at different time periods according to the obtained absorbance values through the standard curve. Taking the cumulative release amount as the Y - axis and time as the X - axis, plot the time - drug cumulative release rate curve and calculate the release rate.

[0108] Release rate = M1 / M2 * 100

[0109] Where: M1: The mass of the drug released from the drug - loaded membrane at different times in the buffer solution (g).

[0110] M2: The total mass of the drug in the drug - loaded membrane (g).

[0111] Determination of gallic acid content: Take 100 μL of the sample solution, add 50 μL of Folin - Ciocalteu reagent, let it stand in the dark for 5 min, add 150 μL of saturated Na 2 CO 3 solution, make up the volume to 1 mL with distilled water, centrifuge for 5 min, take 200 μL of the supernatant to the microplate, and measure the absorbance at 760 nm. Calculate the gallic acid content according to the standard curve, with the unit of μg / mL (y = 0.0168x + 0.0544, R 2 = 0.9959).

[0112] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A preparation method of an irradiated modified fish gelatin composite film, characterized in that it comprises the following steps: (1) Swell fish gelatin in water, stir until dissolved to obtain a gelatin solution; then add glycerol, continue stirring, and mix evenly to obtain a gelatin-glycerol solution; (2) Add graphene oxide to the gelatin-glycerol solution obtained in step (1), disperse and blend by the first ultrasonic treatment, and stir evenly for the first time to obtain a pre-composite gelatin film solution; then add gallic acid, through the second ultrasonic dispersion, and stir evenly for the second time to obtain a composite gelatin film solution; (3) Pour the composite gelatin film solution obtained in step (2) into a flat plate to dry into a film, and then place it in a dryer containing silica gel to balance to obtain a fish gelatin composite film; (4) Irradiate the fish gelatin composite film obtained in step (3) to obtain an irradiated modified fish gelatin composite film; The concentration of the gelatin solution described in step (1) is 4.5-5.5% in mass-volume ratio; The addition amount of the glycerol described in step (1) is calculated as 30%-35% v / w of the fish gelatin; The concentration of graphene oxide in the pre-composite gelatin film solution described in step (2) is 0.3-0.5 mg / mL; The addition amount of the gallic acid described in step (2) is calculated as 10%-20% of the mass of the fish gelatin.

2. The preparation method of the irradiated modified fish gelatin composite film according to claim 1, characterized in that: The fish gelatin described in step (1) is at least one of fish skin gelatin, fish scale gelatin and fish bone gelatin; The water described in step (1) is ultrapure water.

3. The preparation method of the irradiated modified fish gelatin composite film according to claim 1, characterized in that: The swelling condition in step (1) is swelling at room temperature for 0.5-1.5 h; The stirring temperature for stirring until dissolved in step (1) is 55-65 °C; The conditions for the continued stirring in step (1) are as follows: the temperature is 55-65 °C, the stirring speed is 300-400 r / min, and the time is 0.5-1 h.

4. The preparation method of the irradiated modified fish gelatin composite film according to claim 1, characterized in that: The concentration of the gelatin solution described in step (1) is 5% in mass-volume ratio; The addition amount of the glycerol described in step (1) is calculated as 32%-35% v / w of the fish gelatin; The concentration of graphene oxide in the pre-composite gelatin film solution described in step (2) is 0.4-0.5 mg / mL; The addition amount of the gallic acid described in step (2) is calculated as 10%-15% of the mass of the fish gelatin.

5. The preparation method of the irradiated modified fish gelatin composite film according to claim 1, characterized in that: The conditions for the first ultrasonic treatment in step (2) are as follows: the power is 400-600 W, the temperature is 40-50 °C, and the time is 15-30 min; The conditions for the first stirring in step (2) are as follows: the temperature is 60-65 °C, the stirring speed is 400-500 r / min, and the time is 1.5-2.5 h; The conditions of the second ultrasonic treatment described in step (2) are as follows: the power is 500 - 600 W, the temperature is 45 - 55 °C, and the time is 30 - 50 min; The conditions of the second stirring described in step (2) are as follows: the temperature is 60 - 70 °C, the stirring speed is 500 - 600 r / min, and the time is 2 - 3 h.

6. The preparation method of the irradiated modified fish gelatin composite film according to claim 1, characterized in that: the plate described in step (3) is a square or rectangular plate; the drying method described in step (3) is air drying; The radiation source for the irradiation treatment described in step (4) is an electron beam, an X-ray or 60 Co - γ rays; the irradiation dose of the irradiation treatment described in step (4) is 1 - 12 kGy.

7. The preparation method of the irradiated modified fish gelatin composite film according to claim 6, characterized in that: the plate described in step (3) is a square or rectangular plate with a size of 10 - 50 cm × 10 - 50 cm; the dosage of the composite gelatin film solution described in step (3) is 20 - 500 mL; the temperature of the air drying is 45 - 55 °C; the time of the air drying is 22 - 26 h.

8. An irradiated modified fish gelatin composite film, characterized in that: it is obtained by the preparation method described in any one of claims 1 - 7.

9. The application of the irradiated modified fish gelatin composite film described in claim 8 in the preparation of biomedical materials and beauty products.

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