Starch-based dual-network antibacterial hydrogel loaded with aloe extract as well as preparation method and application of starch-based dual-network antibacterial hydrogel

Abstract

The invention provides starch-based dual-network antibacterial hydrogel loaded with aloe extract as well as a preparation method and application of the starch-based dual-network antibacterial hydrogel, and belongs to the field of hydrogel. The aloe extract is prepared by adopting an ultrasonic-assisted alcohol extraction method, and the aloe extract is embedded into a physicochemical dual-network of the amylose-polyvinyl alcohol-borax hydrogel prepared by adopting a retrogradation freeze-thawing method; the starch-based dual-network antibacterial hydrogel loaded with the aloe extract, which is strong in antibacterial ability, high in biological safety and compatibility and good in mechanical property, is obtained. The hydrogel has the advantages of simple preparation method and low cost, and is widely applicable to the fields of biomedicine and daily chemicals with the requirements of hemostasis, antibiosis, drug administration and the like.

Description

Technical Field

[0001] The invention relates to the field of hydrogels, and in particular to a starch-based double-network antibacterial hydrogel loaded with aloe extract, and a preparation method and application thereof. Background Art

[0002] Traditional trauma dressings such as gauze, bandages, sponges, etc. are prone to induce bacterial infection, delay wound healing, and even cause chronic complications that cause secondary damage to the wound due to poor thermal insulation, breathability, and hemostasis. Therefore, people have long been committed to developing medical dressings with high biocompatibility, better thermal insulation and breathability.

[0003] Hydrogel is a hydrophilic three-dimensional network polymer formed by chemical or physical crosslinking of hydrophilic polymer chains. Its mechanical properties are easy to control and can also load different functional materials. Hydrogel can maintain its original structure without being dissolved after absorbing a large amount of water and swelling significantly. It has good biocompatibility, water permeability and appropriate gas permeability. It can provide a temporary protective barrier and a good moist environment for skin wounds, and will not adhere to the wound. At the same time, it can also release drugs and promote rapid healing of wounds. It is an extremely ideal medical dressing.

[0004] As a hydrophilic natural polymer material that is widely present in organisms and inexpensive, starch has extremely high biocompatibility and biodegradability, and is suitable as a raw material for medical hydrogels. Polyvinyl alcohol (PVA) is an artificial polymer material, and its various degradation products and monomers are non-biotoxic, and have good film-forming properties and flexibility, which help to improve the mechanical properties of starch-based hydrogels and form a uniform and stable membrane structure. Chinese invention patent CN109354719A discloses a starch double cross-linked network hydrogel and a preparation method thereof, wherein a mixed sol of starch, PVA and borax is regenerated by freeze-thawing to form a double cross-linked network hydrogel with high mechanical strength, self-healing properties and water resistance. The hydrogel described in the invention has swelling and water absorption properties and excellent tensile toughness, but its water retention in a dry environment is insufficient, resulting in a short duration of flexibility. In addition, since the hydrogel described in the invention is not specifically used in the biomedical field, there is a lack of improvements to further improve the biocompatibility of the hydrogel, as well as the combined application of the hydrogel with drugs. In other patent documents, starch-based hydrogels are loaded with specific functional substances, such as drugs that require sustained release, conductive ionic liquids, etc., but there are no examples of further improving the mechanical strength and biocompatibility of the hydrogels at the same time.

[0005] In summary, the prior art lacks a starch-based hydrogel loaded with functional substances that has excellent mechanical properties and biocompatibility. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a starch-based double-network antibacterial hydrogel loaded with aloe extract, and a preparation method and application thereof. The mechanical properties of the hydrogel are significantly improved through the double-crosslinked network structure, and the hydrogel has excellent biocompatibility.

[0007] One of the purposes of the present invention is to provide a starch-based double-network antibacterial hydrogel loaded with aloe extract, comprising the following components in parts by weight: 2 to 3 parts of amylose, 1.5 to 2 parts of polyvinyl alcohol (PVA), 1 to 2 parts of aloe extract, 9 to 12 parts of glycerol, 0.04 to 0.08 parts of initiator, 0.01 to 0.03 parts of cross-linking aid, 0.05 to 0.15 parts of borax, and the balance is deionized water.

[0008] Another object of the present invention is to provide a method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract, comprising the following steps:

[0009] Wash the fresh aloe vera leaves, cut them into small pieces, freeze-dry them, and grind them into powder to obtain dry aloe vera powder.

[0010] The dried aloe powder is soaked in an ethanol solution and ultrasonicated, extracted by Soxhlet extraction, and the extract is filtered, concentrated, vacuum dried, and sterilized by ultraviolet to obtain the aloe extract.

[0011] The amylose and deionized water are mixed, heated and stirred until completely gelatinized to obtain a starch gelatinization solution.

[0012] The polyvinyl alcohol, deionized water and glycerin are mixed, heated and stirred to obtain a polyvinyl alcohol homogeneous solution.

[0013] The starch gelatinization solution and the polyvinyl alcohol homogenized solution are quickly mixed, and the aloe extract, borax and cross-linking aid are added, and finally the initiator is added, and the mixture is heated and stirred evenly, and then poured into a mold after ultrasonic defoaming.

[0014] The mixture in the mold is subjected to regeneration and cyclic freeze-thaw treatment to obtain the starch-based double-network antibacterial hydrogel loaded with aloe extract.

[0015] Furthermore, the freeze-drying time is 12 hours.

[0016] Furthermore, the mass ratio of the dry aloe powder to the ethanol solution is 1:5, wherein the concentration of the ethanol solution is 75% (volume).

[0017] Further, the aloe vera is one or more of Aloe vera, Aloe arborescens, and Aloe vera. Preferably, the aloe vera is Aloe vera.

[0018] Furthermore, the heating for preparing the starch gelatinization solution is 85° C. water bath heating.

[0019] Furthermore, the heating for preparing the homogeneous polyvinyl alcohol solution is 95° C. water bath heating, wherein the model of the polyvinyl alcohol is PVA-124.

[0020] Furthermore, the heating after adding the initiator is heating in a water bath at 60° C., wherein the crosslinking aid is N,N′-methylenebisacrylamide (MBA), and the initiator is ammonium persulfate.

[0021] Furthermore, the regeneration and freeze-thaw cycle treatment process is:

[0022] (1) Regeneration: The mold containing the mixture is regenerated at 4°C for 6 hours;

[0023] (2) Freeze-thaw: transfer the mold containing the mixture to -20 °C and freeze for 12 h, then thaw at 25 °C for 12 h;

[0024] The freeze-thaw step was cycled 3 times.

[0025] The last object of the present invention is to provide the application of the starch-based double-network antibacterial hydrogel loaded with aloe extract in the fields of biomedicine and daily chemicals.

[0026] The technical solution of the present invention has the following beneficial effects:

[0027] 1. The hydrogel system of the present invention adopts a water-glycerol dual solvent, in which the glycerol molecules not only generate a large number of hydrogen bonds with water molecules to hinder the evaporation of water molecules, thereby enhancing the flexibility and water retention capacity of the hydrogel, but also form physical cross-links with the macromolecular chains of starch and PVA through hydrogen bonds, thereby improving the mechanical strength and biocompatibility of the hydrogel.

[0028] 2. In the hydrogel system of the present invention, the hydrogen bonding between PVA and starch forms a physical cross-linked network, and the borax and starch and PVA molecular chains form chemical cross-linked networks respectively. The double network structure greatly improves the mechanical properties of the hydrogel. The starch is specifically amylose, which has a higher tensile strength than amylopectin.

[0029] 3. In the hydrogel system of the present invention, in addition to borax, a small amount of crosslinking aid (such as N,N'-methylenebisacrylamide) is involved in chemical crosslinking, which crosslinks with starch and PVA by another mechanism, significantly improving the pore size of the hydrogel, which is beneficial to improving its water absorption and water retention and the loading of aloe extract, while reducing the crystallinity of the hydrogel and improving its thermal stability. The hydrogel has excellent swelling and water retention properties in PBS buffer, with a balanced swelling rate of up to 600%, and still retains more than 20% water content after being out of water for 30 hours.

[0030] 4. The hydrogel of the present invention has low cytotoxicity (cell survival rate is above 94%), low hemolysis rate (below 2%), no adverse reactions in human patch tests, and extremely high biocompatibility and safety. At the same time, the hydrogel has excellent antibacterial effects on Escherichia coli and Staphylococcus aureus (the width of the inhibition zone is 10.17 mm and 11.05 mm respectively). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a scanning electron micrograph of the starch-based double-network antibacterial hydrogel loaded with aloe extract prepared in Example 1 of the present invention.

[0032] Figure 2 These are photos of human patch experiments of the hydrogels prepared in Examples 1-3 and Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0033] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments and drawings. Obviously, the described embodiments are only part of the implementation methods of the present invention, and are an explanation of the technical solution of the present invention rather than a limitation.

[0034] The invention provides a starch-based double-network antibacterial hydrogel loaded with aloe extract, comprising the following components in parts by weight: 2 to 3 parts of amylose, 1.5 to 2 parts of polyvinyl alcohol (PVA), 1 to 2 parts of aloe extract, 9 to 12 parts of glycerol, 0.04 to 0.08 parts of initiator, 0.01 to 0.03 parts of cross-linking aid, 0.05 to 0.15 parts of borax, and the balance being deionized water.

[0035] The present invention provides a method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract, comprising the following steps:

[0036] Wash the fresh aloe vera leaves, cut them into small pieces, freeze-dry them, and grind them into powder to obtain dry aloe vera powder.

[0037] The dried aloe powder is soaked in an ethanol solution and ultrasonicated, extracted by Soxhlet extraction, and the extract is filtered, concentrated, vacuum dried, and sterilized by ultraviolet to obtain the aloe extract.

[0038] The amylose and deionized water are mixed, heated and stirred until completely gelatinized to obtain a starch gelatinization solution.

[0039] The polyvinyl alcohol, deionized water and glycerin are mixed, heated and stirred to obtain a polyvinyl alcohol homogeneous solution.

[0040] The starch gelatinization solution and the polyvinyl alcohol homogenized solution are quickly mixed, and the aloe extract, borax and cross-linking aid are added, and finally the initiator is added, and the mixture is heated and stirred evenly, and then poured into a mold after ultrasonic defoaming.

[0041] The mixture in the mold is subjected to regeneration and cyclic freeze-thaw treatment to obtain the starch-based double-network antibacterial hydrogel loaded with aloe extract.

[0042] Furthermore, the freeze-drying time is 12 hours.

[0043] Furthermore, the mass ratio of the dry aloe powder to the ethanol solution is 1:5, wherein the concentration of the ethanol solution is 75% (volume).

[0044] Further, the aloe vera is one or more of Aloe vera, Aloe arborescens, and Aloe vera. Preferably, the aloe vera is Aloe vera.

[0045] Furthermore, the heating for preparing the starch gelatinization solution is 85° C. water bath heating.

[0046] Furthermore, the heating for preparing the homogeneous polyvinyl alcohol solution is 95° C. water bath heating, wherein the polyvinyl alcohol model is PVA-124; this model of PVA has a high viscosity of 54-66 cps, a degree of alcoholysis of 98-99 mol%, a pH value between 5 and 7, and a molecular weight of more than 100 kDa. As an alternative, PVA-1788, PVA-1797 and other models can also be used according to product application requirements.

[0047] Furthermore, the heating after adding the initiator is 60°C water bath heating, wherein the crosslinking aid is N,N'-methylenebisacrylamide (MBA), and the initiator is ammonium persulfate. MBA is commonly used for crosslinking polymers such as polyacrylamide, and can also react with hydroxyl-containing polymers such as starch and PVA. The specific process is as follows:

[0048] (1) The initiator ammonium persulfate decomposes under heat to produce free radicals SO4 - ·;

[0049] (2) Free radical SO4 - Attack starch and PVA to produce carbon free radicals -·CHOH, which further produce hydroxyl free radicals ·OH;

[0050] (3) The above-mentioned free radicals combine with each other and are captured by MBA, which is very easy to combine with free radicals, to complete the further cross-linking modification of the hydrogel.

[0051] Correspondingly, the mechanism of borax participating in cross-linking is: the borate in borax reacts with the hydroxyl groups OH in starch, PVA and glycerol. -The reaction generates borate esters. The borate group has a very high affinity for hydroxyl groups, so this reaction is the main cross-linking reaction for preparing the hydrogel of the present invention, and can quickly form a starch / PVA gel network.

[0052] Furthermore, the regeneration and freeze-thaw cycle treatment process is:

[0053] (1) Regeneration: The mold containing the mixture is regenerated at 4°C for 6 hours;

[0054] (2) Freeze-thaw: transfer the mold containing the mixture to -20 °C and freeze for 12 h, then thaw at 25 °C for 12 h;

[0055] The freeze-thaw step was cycled 3 times.

[0056] Retrogradation refers to the process of naturally cooling and dehydrating gelatinized starch at a relatively low temperature, so that the hydrogen bonds destroyed during gelatinization can be re-combined in an orderly manner; in the present invention, the retrogradation operation involves hydrogen bonding of various hydroxyl-containing compounds such as starch, PVA, borax, water and glycerol to form a strong physical cross-linking network and improve the mechanical strength of the hydrogel. For amylose, the completely gelatinized starch can complete the retrogradation process within a few hours.

[0057] Freeze-thaw is the most commonly used physical cross-linking method in the preparation of starch / PVA-based gels. During the freezing-thawing process, microcrystalline areas will be formed inside the gel system as physical cross-linking points, thereby obtaining a PVA hydrogel with a three-dimensional network structure; the presence of initiator anions in the system promotes this process.

[0058] The present invention is described in detail below with reference to the examples. The experimental methods are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0059] Example 1

[0060] The starch-based double-network antibacterial hydrogel loaded with aloe extract of the present invention is prepared according to the following steps:

[0061] Take fresh whole leaves of Aloe vera, wash them with anhydrous ethanol and deionized water, cut them into small pieces, freeze-dry them for 12 hours, and then grind them into powder.

[0062] Weigh 100 g of dry aloe powder, soak it in 500 mL of 75% ethanol solution for 2 hours and ultrasonicate it for 30 minutes. The obtained aloe-ethanol solution is extracted by Soxhlet extraction, and the extract is filtered, concentrated, vacuum dried, and sterilized by ultraviolet to obtain aloe extract.

[0063] 2 g of amylose and 6 g of deionized water were mixed and stirred in a water bath at 85° C. until completely gelatinized to obtain a starch gelatinized solution.

[0064] 2 g of PVA-124, 9 g of deionized water and 9 g of glycerol were mixed, heated and stirred in a 95° C. water bath to obtain a homogeneous polyvinyl alcohol solution.

[0065] The starch gelatinization solution and the polyvinyl alcohol homogenized solution were quickly mixed, and 2 g of aloe extract, 0.067 g of borax and 0.016 g of N,N'-methylenebisacrylamide were added and stirred evenly. Finally, 0.06 g of ammonium persulfate was added, stirred evenly in a 60°C water bath, and poured into a mold after ultrasonic defoaming.

[0066] The mixture in the mold was placed in an environment of 4°C for 6 hours to allow the starch to retrograde and form a network structure.

[0067] Then, the mixture was transferred to a -20°C environment and frozen for 12 hours, and then thawed in a 25°C environment for 12 hours. The freeze-thaw process was repeated 3 times to obtain the starch-based double-network antibacterial hydrogel loaded with aloe extract.

[0068] The scanning electron microscope photo of the hydrogel prepared in this example is attached. Figure 1 It can be seen that the pore diameter can reach about 5μm, providing a huge space for water absorption and drug loading.

[0069] Example 2

[0070] The only difference between this embodiment and embodiment 1 is that the amount of aloe extract used in step S4 is 1 g, and correspondingly the amount of deionized water used in step S2 is 7 g.

[0071] Example 3

[0072] The only difference between this embodiment and embodiment 1 is that the amount of glycerol used in step S3 is 12 g, and correspondingly the amount of deionized water used in this step is 6 g.

[0073] Comparative Example 1

[0074] The only difference between this comparative example and Example 1 is that no aloe extract is added in step S4, and accordingly, the amount of deionized water used in step S2 is 8 g.

[0075] Comparative Example 2

[0076] The only difference between this comparative example and Example 1 is that N,N'-methylenebisacrylamide and ammonium persulfate are not added in step S4.

[0077] Comparative Example 3

[0078] The only difference between this comparative example and Example 1 is that no glycerol is added in step S3, and accordingly the amount of deionized water used in this step is 18 g.

[0079] The following is a performance test of the hydrogels in the embodiments and comparative examples.

[0080] (1) The hydrogels obtained in Examples 1 to 3 and Comparative Example 1 were subjected to in vitro antibacterial experiments:

[0081] The target pathogenic bacteria were cultured in an agar medium to a certain concentration, and then evenly spread on a plate; each group of hydrogels of the same size were cut and scattered on the plate; after a period of time, the size of the sterile area (inhibition zone diameter) of each group was measured; the results are shown in Table 1.

[0082] Table 1 Hydrogel inhibition zone size (mm):

[0083] Bacteria species\group Example 1 Example 2 Example 3 Comparative Example 1 Escherichia coli 10.17 7.42 10.45 0 Staphylococcus aureus 11.05 6.28 10.48 0

[0084] From the above experimental results, it can be seen that the hydrogel with aloe extract has obvious antibacterial activity against Escherichia coli and Staphylococcus aureus, among which the hydrogel with a higher aloe extract content (accounting for 6.7% of the raw material mass) has a significantly stronger antibacterial activity than the hydrogel with a lower aloe extract content (accounting for 3.3% of the raw material mass); within the scope disclosed in the present invention, the ratio of solvent water to glycerol basically does not affect the antibacterial activity.

[0085] (2) The hydrogels obtained in Examples 1 to 3 were subjected to cytotoxicity experiments:

[0086] The same concentration of L929 cells were cultured in the 6×4 wells in the center of a 96-well plate, and PBS buffer was added to the remaining part; the same amount of hydrogels of Examples 1 to 3 and PBS buffer were added to the above 4 columns of wells containing cells (i.e., each group was repeated 6 times), and after culturing for 24 hours, MTT solution was added and stored in the dark, and DMSO was added after a period of time, and the plate was placed in an ELISA reader after shaking, and the absorbance value was measured at a wavelength of 490 nm; the PBS group was used as a benchmark, and the cell survival rate calculated accordingly is shown in Table 2.

[0087] Table 2 Cell survival rate in the presence of hydrogel for 24 hours:

[0088] Group Example 1 Example 2 Example 3 Cell viability 96％ 95％ 94％

[0089] It can be seen from the above experimental results that the starch-based double-network antibacterial hydrogel loaded with aloe extract within the scope of the present invention has good biocompatibility, and the cell survival rate in the 24h in vitro cytotoxicity experiment is above 94%.

[0090] (3) The hydrogels obtained in Examples 1 to 3 and Comparative Example 1 were subjected to human patch tests:

[0091] Take a small piece of each of the hydrogels prepared in Examples 1 to 3 and Comparative Example 1, place them on a patch with a diameter of 1 cm made of several layers of gauze, and stick the side with the hydrogel on human skin and fix it with a plastic film; remove the patch after 0.5h, 24h and 48h, and observe the local reaction of the skin with the naked eye; the final test results after 48h are shown in the attached figure. Figure 2 .

[0092] All skin patch test ratings were 0 (negative), that is, each group of hydrogels did not cause skin itching or redness at each time point, proving that the starch-based double-network antibacterial hydrogel loaded with aloe extract of the present invention has high safety.

[0093] (4) The hydrogels obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to a water absorption and water retention test:

[0094] Take small pieces of hydrogel from each group of the same size and shape, wipe off the surface moisture, weigh them and record them as m i ;

[0095] The hydrogel block was placed in PBS buffer for 2 h, taken out and the surface water was wiped dry, and the weight was recorded as m. f ;

[0096] Place the hydrogel block in air for 30 hours and weigh it to obtain m d ;

[0097] Calculate the equilibrium swelling ratio of each group = (m f -m i ) / m i ×100%, 30h water retention rate

[0098] =(m d -m i ) / (m f -m i )×100%;

[0099] The results are shown in Table 3.

[0100] Table 3 Equilibrium swelling rate and 30h water retention rate of hydrogel:

[0101] Project\Group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Equilibrium swelling ratio 618％ 612％ 634％ 613％ 477％ 394％ 30h water retention rate 22％ 21％ 24％ 22％ 17％ 8％

[0102] From the above experimental results, it can be seen that the addition of glycerol greatly improves the water absorption and water retention effect of the hydrogel of the present invention, the addition of cross-linking aids and initiators also affects the water absorption and water retention effect, and the aloe extract has basically no effect on the water absorption and water retention performance of the hydrogel.

[0103] (5) The hydrogels obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to tensile strength tests:

[0104] Take one dumbbell-shaped hydrogel obtained in Examples 1 to 3 and Comparative Examples 1 to 3 of the same size, test it on a tensile tester, and record its breaking elongation (the ratio of the elongated length to the length before stretching when subjected to gradually increasing tensile force until breaking), as shown in Table 4.

[0105] Table 4 Elongation at break of hydrogel

[0106] Project\Group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Elongation at break 2160％ 2130％ 2380％ 2150％ 2310％ 1420％

[0107] From the above experimental results, it can be seen that the addition of glycerol significantly improves the mechanical strength of the hydrogel of the present invention, the addition of cross-linking aids and initiators increases the pore size of the hydrogel, and the mechanical strength is slightly reduced, while the aloe extract has little effect on the mechanical properties of the hydrogel.

[0108] The starch-based double-network antibacterial hydrogel loaded with aloe extract of the present invention has good mechanical strength, excellent biocompatibility, safety and strong antibacterial ability against common pathogens, can be used as wound dressings, drug carriers, skin care products, etc., and is widely used in the fields of biomedicine and daily chemicals.

[0109] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description, and the obvious changes or modifications derived therefrom should still be considered as the protection scope of the present invention.

Claims

1. A starch-based double-network antibacterial hydrogel loaded with aloe extract, characterized in that: The invention comprises the following ingredients in parts by weight: 2 to 3 parts of amylose, 1.5 to 2 parts of polyvinyl alcohol, 1 to 2 parts of aloe extract, 9 to 12 parts of glycerol, 0.04 to 0.08 parts of initiator, 0.01 to 0.03 parts of cross-linking auxiliary agent, 0.05 to 0.15 parts of borax, and the balance is deionized water.

2. A method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract as claimed in claim 1, characterized in that: The steps include: Wash the whole fresh aloe vera leaves, cut them into small pieces, freeze-dry them and grind them into powder to obtain dry aloe vera powder; The dried aloe vera powder is immersed in an ethanol solution and ultrasonicated, extracted by Soxhlet extraction, and the extract is filtered, concentrated, vacuum dried, and sterilized by ultraviolet to obtain the aloe vera extract; The amylose and deionized water are mixed, and heated and stirred until completely gelatinized to obtain a starch gelatinization solution; The polyvinyl alcohol, deionized water and glycerol are mixed, and heated and stirred to obtain a polyvinyl alcohol homogeneous solution; The starch gelatinization solution and the polyvinyl alcohol homogenized solution are quickly mixed, and the aloe extract, borax and cross-linking aid are added, and finally the initiator is added, heated and stirred evenly, and the obtained mixture is ultrasonically defoamed and poured into a mold; The mixture in the mold is subjected to regeneration and cyclic freeze-thaw treatment to obtain the starch-based double-network antibacterial hydrogel loaded with aloe extract.

3. The method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 2, characterized in that: The freeze drying time is 12 hours.

4. The method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 2, characterized in that: The mass ratio of the dry aloe powder to the ethanol solution is 1:5, wherein the concentration of the ethanol solution is 75% (volume).

5. The method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 2, characterized in that: The aloe vera is one or more of Aloe vera, Aloe arborescens, and Aloe arborescens.

6. The method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 2, characterized in that: The heating for preparing the starch gelatinization solution is 85° C. water bath heating.

7. The method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 2, characterized in that: The heating for preparing the homogeneous polyvinyl alcohol solution is 95° C. water bath heating, wherein the type of the polyvinyl alcohol is PVA-124.

8. The method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 2, characterized in that: The heating after adding the initiator is 60° C. water bath heating, wherein the cross-linking aid is N,N′-methylenebisacrylamide, and the initiator is ammonium persulfate.

9. The method for preparing the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 2, characterized in that: The regeneration and freeze-thaw cycle treatment process is as follows: (1) Regeneration: The mold containing the mixture is regenerated at 4°C for 6 hours; (2) Freeze-thaw: transfer the mold containing the mixture to -20 °C and freeze for 12 h, then thaw at 25 °C for 12 h; The freeze-thaw step was cycled 3 times.

10. Application of the starch-based double-network antibacterial hydrogel loaded with aloe extract according to claim 1 in the fields of biomedicine and daily chemicals.

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