Zein / polyethylene oxide / dihydroquercetin nanofiber fresh-keeping film, preparation method and application thereof

Abstract

The embodiment of the present application relates to a zein / polyethylene oxide / dihydroquercetin nanofiber cling film and its preparation method and application, which belongs to the technical field of bio-based polymer composite materials. The preparation method of the zein / polyethylene oxide / dihydroquercetin nanofiber cling film of the embodiment of the present application comprises the following steps: dissolving zein in an acetic acid solution, then adding polyethylene oxide to obtain a zein / polyethylene oxide blended solution, adding dihydroquercetin to the zein / polyethylene oxide blended solution, mixing evenly to obtain a spinning solution; and subjecting the spinning solution to a solution blow spinning process. The nanofiber cling film provided in the embodiment of the present application has good hydrophobicity and antioxidant capacity, and at the same time has the advantages of good flexibility, hydrophobicity, antioxidant capacity, antibacterial property, biocompatibility, and environmental degradation.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of bio-based polymer composite materials, and in particular to a zein / polyethylene oxide / dihydroquercetin nanofiber cling film and a preparation method and application thereof. Background Art

[0002] Solution blown spinning (SBS) is an emerging method for rapidly producing nanofibers with high surface area, good loading capacity, and high porosity. SBS utilizes a high-speed airflow to draw a polymer solution into filaments, with some solvent volatilization occurring during the drawing process. The filaments are then collected by a rolling receiver, forming a nanofiber film. Compared to electrospinning, the most popular nanofiber production technique, SBS offers advantages such as high production efficiency, low cost, and the absence of a high voltage supply.

[0003] Nanofiber cling film, as a nanomaterial, is a fibrous network structure formed by hydrophilic macromolecules or polymers through molecular interactions such as hydrogen bonds, hydrophobic interactions or van der Waals forces. Its nanometer diameter can increase the loading rate of drugs, and it has a high specific area and high porosity.

[0004] Zein is a renewable, natural, high-molecular-weight protein extracted from corn. Found primarily in the corn endosperm, it is a byproduct of corn processing and widely available. Zein exhibits excellent film-forming, antioxidant, and gelling properties, and has been used as a surface coating material and pharmaceutical protective material. Furthermore, zein's polypeptide structure offers unique advantages in biodegradability and biocompatibility.

[0005] Using technologies such as solution blown spinning, nanofilms with various structures and functions can be designed and constructed. Examples include pH-responsive nanofilms, CO2-responsive nanofilms, and antibacterial nanofilms. The addition of polyethylene oxide improves fiber formability while also addressing the inherent brittleness of zein, enhancing its mechanical properties and flexibility, and broadening its application areas.

[0006] Dihydroquercetin (DHQ), also known as taxol, is an extract from larch and an important flavonoid compound. It exhibits antibacterial, anticancer, anti-inflammatory, antiviral, antioxidant, anti-fibrotic, blood sugar-lowering, immune-regulating, melanin-removing, and cardiovascular disease-fighting properties. In recent years, flavonoids such as luteolin and apigenin have been studied and incorporated into nanofiber plastic wrap to enhance its bioactivity. However, dihydroquercetin, known as the "king of cleansing agents" among flavonoids, has not been incorporated into nanofiber plastic wrap to explore its effects on meat preservation.

[0007] Therefore, it is of great significance to introduce dihydroquercetin, which has antioxidant and antibacterial properties, into the renewable zein raw material in combination with polyethylene oxide, which has good biocompatibility and easy processability, to prepare a nanofiber cling film with good biocompatibility and good mechanical properties, while also having multifunctional properties such as hydrophobicity, antioxidant, antibacterial, and UV resistance. Summary of the Invention

[0008] In view of this, the embodiments of the present application provide a zein / polyethylene oxide / dihydroquercetin nanofiber cling film, a preparation method and application thereof. The nanofiber cling film has good hydrophobicity and antioxidant capacity, and at the same time has the advantages of good flexibility, hydrophobicity, antioxidant, antibacterial property, biocompatibility and environmental degradation. It can be widely used in food packaging materials and biomedicine and other fields. Therefore, it has good application prospects and can effectively overcome the defects of the above-mentioned existing technologies.

[0009] A first aspect of the present invention provides a method for preparing a zein / polyethylene oxide / dihydroquercetin nanofiber cling film, comprising the following steps:

[0010] Zein is dissolved in an acetic acid solution, and then polyethylene oxide is added to obtain a zein / polyethylene oxide blend solution. Dihydroquercetin is added to the zein / polyethylene oxide blend solution, and the mixture is evenly mixed to obtain a spinning solution. The spinning solution is subjected to a solution blow spinning process to obtain a zein / polyethylene oxide / dihydroquercetin nanofiber cling film.

[0011] The polyethylene oxide (PEO) polymer chain interacts with the amino and carboxyl groups in zein through intermolecular hydrogen bonds, increasing the viscosity and stability of the spinning solution, making the nanofibers more stable and uniform during the spinning process, while also increasing the mechanical strength, toughness and flexibility of the film; the addition of dihydroquercetin (DHQ) improves the antioxidant properties of the nanofiber cling film, and its good antibacterial properties can reduce the growth of microorganisms on the surface of the nanofiber cling film.

[0012] In some embodiments that may include the above embodiments, the specific process of the solution blowing spinning process is:

[0013] Transfer part of the spinning solution into the injection container, bend the needle head into 90° and install it on the micro-injection pump, adjust the solution propulsion speed, turn on the air compressor for blowing, adjust the spinning air pressure and receiving distance, and stick a circle of release paper on the receiver for subsequent separation, adjust the receiver speed, click the start button on the injection pump, and start spinning.

[0014] In some embodiments, which may include the above embodiments, the parameters of the solution blow spinning process are:

[0015] The injection container is a 5 mL syringe, the needle model is 30G, the solution advancing speed is 1 mL / h, the spinning air pressure is 0.020 MPa, the receiving distance is 50 cm, and the receiver speed is 100 r / min.

[0016] In some embodiments including the aforementioned embodiments, the mass ratio of zein, polyethylene oxide, and dihydroquercetin is 2:0.1:(0.1-0.4).

[0017] In some embodiments that may include the above embodiments, the specific preparation process of the spinning solution is: after preparing the acetic acid solution, first add zein in proportion, stir for 3 minutes until there is no lumpy powder, then add polyethylene oxide, mix evenly until there are no obvious lumpy particles, then add dihydroquercetin, add while stirring, stir at room temperature overnight until it is completely dissolved, to obtain a spinning solution.

[0018] In some embodiments, which may include the above embodiments, the volume ratio of acetic acid to water in the acetic acid solution is 8:2.

[0019] Preferably, the preparation method of the zein / polyethylene oxide / dihydroquercetin nanofiber cling film of the present application specifically comprises the following steps:

[0020] (1) Preparation of zein / polyethylene oxide / dihydroquercetin spinning solution: In a 20 mL beaker, first add 8 mL of acetic acid, then add 2 mL of deionized water, mix well and start stirring on a stirrer, then add 2 g of zein, add while stirring, then add 0.1 g of polyethylene oxide, add while stirring, after it is completely dispersed, add 0.1-0.4 g of dihydroquercetin, also add while stirring, stir at room temperature overnight until dissolved, to obtain a spinning solution;

[0021] (2) Preparation of zein / polyethylene oxide / dihydroquercetin nanofiber cling film: Transfer part of the prepared spinning solution into a 5 mL syringe, use a 30G needle, bend its head into 90°, install it on a micro-injection pump, adjust the solution propulsion speed to 1 mL / h, turn on the air compressor for blowing, and adjust the spinning air pressure to 0.020 MPa, adjust the receiving distance to 50 cm, and stick a circle of release paper on the receiver to facilitate subsequent separation, adjust the receiver speed to 100 r / min, click the start button on the injection pump to start spinning, and obtain zein / polyethylene oxide / dihydroquercetin nanofiber cling film.

[0022] It should be noted that in the preparation method of the present application, zein is added first and then polyethylene oxide is added, so that the first two can interact with each other first, increasing the viscosity and spinnability of the solution, and then dihydroquercetin is added and stirred thoroughly. By utilizing the self-sealing property of zein, part of the dihydroquercetin can be embedded therein. In addition, the addition of dihydroquercetin enhances the antioxidant, antibacterial and other biological activities of the nanofiber cling film.

[0023] A second aspect of the present invention further provides a zein / polyethylene oxide / dihydroquercetin nanofiber cling film, produced using the aforementioned method. The zein / polyethylene oxide / dihydroquercetin nanofiber cling film exhibits excellent flexibility, hydrophobicity, antioxidant properties, antibacterial properties, biocompatibility, UV resistance, and environmentally friendly degradability.

[0024] In some embodiments, which may include the aforementioned embodiments, the fibers in the nanofiber cling film are uniformly distributed and have a diameter of 360 nm.

[0025] The third aspect of the embodiments of the present application also provides applications of the above-mentioned zein / polyethylene oxide / dihydroquercetin nanofiber preservative film in food packaging materials and biomedicine.

[0026] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0027] (1) The reaction conditions of the preparation method of the present application are room temperature, the required equipment is simple, the preparation efficiency is high and the controllability is strong;

[0028] (2) The preparation method of the present application is a nanofiber cling film system, which provides a larger specific surface area and extremely fine nanofibers, and increases the amount of dihydroquercetin loaded thereon. In addition, the polymer chain of polyethylene oxide interacts with the amino and carboxyl groups in zein through hydrogen bonds, which increases the viscosity and stability of the solution, making the nanofibers more stable and uniform during the spinning process, and to a certain extent improves the brittleness problem of zein, giving the nano packaging film a wider range of applications;

[0029] (3) This application constructs a novel multifunctional antibacterial, antioxidant, and hydrophobic nanofiber cling film that integrates multiple functional components by blending zein and polyethylene oxide with the drug dihydroquercetin system. The nanofiber cling film has good biocompatibility and has broad application prospects as a food packaging material. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 The scanning electron microscope image and diameter distribution diagram of the nanofiber cling film prepared in Comparative Example 1;

[0032] Figure 2 The water contact angle diagrams of the nanofiber cling film prepared in Comparative Example 1 and Examples 1-4;

[0033] Figure 3 The UV transmittance graph of the nanofiber cling film prepared in Comparative Example 1 and Examples 1-4;

[0034] Figure 4 DPPH free radical and ABTS free radical scavenging rate graphs of the nanofiber cling film prepared in Comparative Example 1 and Examples 1-4;

[0035] Figure 5 (a) is a graph showing the antibacterial performance of the nanofiber cling film obtained in Examples 1-4. Figure 5 (b) is a photo of the antibacterial zone test of the nanofiber cling film prepared in Examples 1-4. DETAILED DESCRIPTION

[0036] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0037] Unless otherwise specified, the experimental methods used in the examples of this application are all conventional methods.

[0038] In the following examples and comparative examples, unless otherwise specified, all raw materials can be purchased commercially or prepared by conventional methods.

[0039] Example 1

[0040] (1) Preparation of zein / polyethylene oxide / dihydroquercetin spinning solution:

[0041] Weigh 2 g of zein and dissolve it in a mixed solution of 8 ml of acetic acid and 2 ml of deionized water. Then add 0.1 g of polyethylene oxide while stirring. After it is completely dispersed, add 0.1 g of dihydroquercetin and stir at room temperature overnight until it dissolves. The spinning solution of zein / polyethylene oxide / dihydroquercetin can be obtained.

[0042] (2) Preparation of Zein / Polyethylene Oxide / Dihydroquercetin Nanofiber Fresh-keeping Film:

[0043] Transfer the prepared spinning solution into a 5mL syringe, use a 30G needle, bend its head into 90°, install it on a micro-injection pump, adjust the solution propulsion speed to 1mL / h, turn on the air compressor for blowing, and adjust the spinning air pressure to 0.020MPa, adjust the receiving distance to 50cm, and stick a circle of release paper on the receiver to facilitate subsequent separation, adjust the receiver speed to 100r / min, click the start button on the injection pump, spinning starts, and wait for 5h to obtain a nanofiber cling film with a thickness of about 0.10mm, recorded as ZPD-1%.

[0044] Example 2

[0045] The zein / polyethylene oxide / dihydroquercetin nanofiber fresh-keeping film and its preparation method of this embodiment can refer to Example 1, except that 0.2 g of dihydroquercetin is added, which is recorded as ZPD-2%.

[0046] Example 3

[0047] The zein / polyethylene oxide / dihydroquercetin nanofiber fresh-keeping film and its preparation method of this embodiment can refer to Example 1, except that 0.3 g of dihydroquercetin is added, which is recorded as ZPD-3%.

[0048] Example 4

[0049] The zein / polyethylene oxide / dihydroquercetin nanofiber fresh-keeping film and its preparation method of this embodiment can refer to Example 1, except that 0.4 g of dihydroquercetin is added, which is recorded as ZPD-4%.

[0050] Comparative Example 1

[0051] (1) Weigh 2 g of zein and dissolve it in a mixture of 8 ml of acetic acid and 2 ml of deionized water. Then add 0.1 g of polyethylene oxide while stirring. Stir at room temperature overnight until dissolved to obtain a zein / polyethylene oxide spinning solution.

[0052] (2) Transfer the prepared spinning solution into a 5 ml syringe, use a 30G needle, bend its head into 90 degrees, install it on a micro-injection pump, adjust the solution propulsion speed to 1 mL / h, turn on the air compressor for blowing, and adjust the spinning pressure to 0.020 MPa. Adjust the receiving distance to 50 cm, and stick a circle of release paper on the receiver to facilitate subsequent separation. Adjust the receiver speed to 100 r / min, click the start button on the injection pump, and the spinning starts. Wait for 5 hours to get a nanofiber cling film with a thickness of about 0.10 mm, recorded as ZP.

[0053] (3) After the zein / polyethylene oxide nanofiber cling film was woven, the film surface was observed by scanning electron microscopy and photographed at 20.00K× magnification. The results are as follows: Figure 1 shown.

[0054] Depend on Figure 1 It can be seen that the fiber diameter is uniform, the distribution is consistent, and the fibers are tightly interwoven with good directionality. This structure is conducive to loading more drugs and enhancing the functionality of the membrane.

[0055] Test Example 1

[0056] The hydrophobicity test of the nanofiber cling film in Examples 1-4 and Comparative Example 1 was performed

[0057] Water contact angle test: Take three 1.0cm×1.0cm samples of each of the five nanofiber cling films and place them on a test plate. Use an interfacial tension analyzer to perform contact angle tests. Then, gently drop 0.005ml of distilled water on the film surface. Use a video monitor to measure the contact angle change within 2s after dripping water. Select pictures with representative changes to determine the wettability of the sample. The results are as follows: Figure 2 shown.

[0058] Figure 2 is the water contact angle diagram, through Figure 2 It can be seen that the contact angle of the zein / polyethylene oxide film (abbreviated as ZP) in Comparative Example 1 is 128.2°, while after adding different masses of dihydroquercetin, the contact angles of the zein / polyethylene oxide / dihydroquercetin films in Examples 1-4 are 121.3°, 116.5°, 118.2°, and 111.9°, respectively. The contact angle has changed, but is still greater than 90°. Therefore, the nanofiber cling film of Examples 1-4 has excellent hydrophobic properties.

[0059] Test Example 2

[0060] Light transmittance test of the nanofiber cling film in Examples 1-4 and Comparative Example 1

[0061] Light transmittance test: Cut the above five nanofiber cling films into 1.0 cm × 5.0 cm size, place them in a quartz cuvette, and scan the films using an ultraviolet spectrophotometer within the range of 200-700 nm. The calculation formula is: Light transmittance T (%) = 10 -A , where A is the measured UV-visible spectrophotometric value, the result is as follows Figure 3 shown.

[0062] Figure 3 is the ultraviolet transmittance diagram of the film, through Figure 3 It can be seen that the transmittance in the UV-C (200-275nm), UV-B (275-320nm) and UV-A (320-420nm) regions is close to 0%, while in the visible light region, the transmittance of the ZP film is the lowest. This is because zein is an optically opaque polymer. With the increase of DHQ (dihydroquercetin), the transmittance gradually increases, but the maximum transmittance is only about 0.8%, which proves that the nanofilms of Examples 1-4 have good UV barrier properties.

[0063] Test Example 3

[0064] Antioxidant performance test of the nanofiber cling film in Examples 1-4 and Comparative Example 1

[0065] DPPH free radical scavenging ability test: Weigh 0.01g of different nanofiber membranes and dissolve them in 10mL of anhydrous ethanol to prepare a 1mg / mL fiber membrane sample solution. 2mL of sample is mixed with 2mL of 0.1mM DPPH dissolved in anhydrous ethanol, 2mL of sample solution is mixed with 2mL of anhydrous ethanol solution, and the absorbance value of 2mL of anhydrous ethanol solution and 2mL of DPPH solution is measured to make them fully mixed and stored in the dark for 40min. The DPPH free radical scavenging ability of the nanofiber cling film is calculated by the absorbance at 517nm. The specific results are shown in Figure 4 .

[0066] ABTS free radical scavenging ability test: ABTS (0.0384g) and K2S2O8 (0.0134g) were dissolved in 10mL of deionized water to obtain ABTS and K2S2O8 solutions, respectively. The two reagents were then mixed in a 1:1 ratio and protected from light for 12h. The two reagents were then diluted with PBS at pH 7.4 to an absorbance of 0.70±0.02, i.e., the ABTS working solution. 5mg of different nanofiber membranes were weighed and dissolved in anhydrous ethanol as sample solutions. 0.8mL of ABTS working solution and 0.2mL of anhydrous ethanol were taken, mixed and shaken for 10s, allowed to stand for 6min, and A1 was measured at 734nm. 0.8mL of ABTS working solution and 0.2mL of sample solution were taken, mixed and shaken for 10s, allowed to stand for 6min, and A2 was measured at 734nm. The calculation formula is:

[0067] ABTS clearance rate (%) = (A1-A2) / A1×100%. Figure 4 .

[0068] Figure 4 This is the antioxidant effect test chart, Figure 4 It can be seen that after adding dihydroquercetin, the zein / polyethylene oxide / dihydroquercetin nanofiber packaging film has good antioxidant properties, the DPPH free radical scavenging rate is above 90%, and the ABTS free radical scavenging rate increases with the increase of concentration, and the scavenging rate is as high as 91.22%.

[0069] Test Example 4

[0070] Antibacterial performance test of the nanofiber cling film in Examples 1-4 and Comparative Example 1

[0071] Antibacterial performance test of dihydroquercetin: The inhibitory activity of dihydroquercetin against was determined by agar plate punching method. The four foodborne bacteria tested were specifically Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Vibrio parahaemolyticus. Dihydroquercetin was solubilized with 20% (volume fraction, the same below) of DMSO and added to sterile water to make the concentrations of dihydroquercetin 1% (10 mg / mL), 2% (20 mg / mL), 3% (30 mg / mL), and 4% (40 mg / mL) (corresponding to Examples 1-4, respectively). Take 0.5 ml of a concentration of 10 6 The bacterial suspensions of different strains with CFU / mL were spread on LB solid medium. After the plate was dried, a 0.2ml pipette tip was used to punch holes in the medium. After picking out the holes with a needle, 0.1ml of different concentrations of drug solution was added to each well. 20% DMSO solution was used as a blank control. The results are shown below. Figure 5 (a), (b).

[0072] Figure 5 (a) and (b) are the antibacterial performance test diagrams of dihydroquercetin. Figure 5 (a) It can be seen that dihydroquercetin has strong antibacterial activity against the four foodborne bacteria. Among them, the inhibitory activity against Vibrio parahaemolyticus (V. parahaemolyticus) is the strongest, followed by Staphylococcus aureus (S. aureus), and the results against Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) are similar. Figure 5 (b) The antibacterial effect can be compared more intuitively by the diameter of the transparent circle. Figure 5 (a) The results are consistent.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a zein / polyethylene oxide / dihydroquercetin nanofiber fresh-keeping film, characterized in that: The following steps are involved: dissolving zein in an acetic acid solution, then adding polyethylene oxide to obtain a zein / polyethylene oxide blend solution, adding dihydroquercetin to the zein / polyethylene oxide blend solution, and mixing uniformly to obtain a spinning solution; The spinning solution is subjected to a solution blowing spinning process to obtain a zein / polyethylene oxide / dihydroquercetin nanofiber fresh-keeping film; The specific process of solution blowing spinning is: Transfer part of the spinning solution into the injection container, bend the needle head into 90 degrees and install it on the micro-injection pump, adjust the solution propulsion speed, turn on the air compressor for blowing, and adjust the spinning air pressure and receiving distance. Stick a circle of release paper on the receiver for subsequent separation, adjust the receiver speed, click the start button on the injection pump, and start spinning; The parameters of the solution blowing spinning process are: The injection container was a 5 mL syringe, the needle type was 30G, the solution advancing speed was 1 mL / h, the spinning gas pressure was 0.020 MPa, the receiving distance was 50 cm, and the receiver speed was 100 r / min; The mass ratio of zein, polyethylene oxide, and dihydroquercetin is 2: 0.1: (0.1-0.4); The specific preparation process of the spinning solution is as follows: after preparing the acetic acid solution, first add zein in proportion, stir for 3 minutes until there is no lumpy powder, then add polyethylene oxide, mix evenly until there are no obvious lumps, then add dihydroquercetin, stir while adding, and stir at room temperature overnight until it is completely dissolved to obtain the spinning solution; The volume ratio of acetic acid to water in the acetic acid solution is 8:2; The fibers in the nanofiber cling film are uniformly distributed and have a diameter of 360 nm.

2. A zein / polyethylene oxide / dihydroquercetin nanofiber fresh-keeping film, characterized in that: The method according to claim 1 is used to prepare the present invention.

3. Use of the zein / polyethylene oxide / dihydroquercetin nanofiber preservative film according to claim 2 in food packaging materials.

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