Preparation method of magnetic self-oxygen-supply hydrogel dressing and dressing

Abstract

The invention relates to a preparation method of a magnetic self-oxygen-supply hydrogel dressing, which comprises the following steps: firstly, mixing PVA and water, sealing, carrying out two-stage heating-type water bath heating, and then carrying out magnetic stirring at the highest temperature to obtain a pasty PVA solution; meanwhile, mixing CMCS and water, sealing, and magnetically stirring to obtain a CMCS solution; the preparation method comprises the following steps: preparing Fe3O4-CaO2 nano particles from Fe3O4-CaO2 nano particles, then mixing a PVA solution and a CMCS solution to obtain a primary mixed solution, adding the Fe3O4-CaO2 nano particles into the primary mixed solution to obtain a secondary mixed solution, introducing the secondary mixed solution into a mold, sealing the mold, and repeatedly freezing and unfreezing to obtain the magnetic self-oxygen-supply hydrogel dressing. According to the design, dissolved oxygen can be automatically generated, oxygen therapy can be directly provided to facilitate angiogenesis, humidity balance can be carried out on a wound, the magnetic therapy effect can be provided, and the wound healing effect is good.

Description

Technical Field

[0001] The invention relates to a medical dressing, belonging to the technical field of diabetic wound healing, and in particular to a preparation method of a magnetic self-oxygenating hydrogel dressing and the dressing. Background Art

[0003] Diabetes can cause many complications, and diabetic foot ulcers are currently the most common diabetic complication that requires hospitalization. Among them, 20% of diabetic foot patients require amputation, and the overall mortality rate of diabetic foot ulcers within 5 years of onset is as high as 50%.

[0004] The fundamental reason why diabetic foot ulcers have such a high disability and mortality rate is that ischemia of the wound surface delays its healing. Solving ischemia requires solving the problem of angiogenesis, and the core of solving the problem of angiogenesis is to solve the problem of hypoxia in the wound. Therefore, in order to shorten the healing time of diabetic foot ulcers and reduce mortality and amputation rates, many new auxiliary technologies have emerged in the clinic, and oxygen therapy is one of them.

[0005] Existing oxygen therapy technologies include hyperbaric oxygen therapy and topical oxygen therapy (TOT). Hyperbaric oxygen therapy requires a hyperbaric oxygen chamber and has high requirements for the environment. Patients can only go to the hospital for treatment, which is not only very inconvenient but also very expensive. Topical oxygen therapy is to pressurize humidified pure oxygen to 10-50MB in a cycle of 20s and deliver it to the oxygen bag around the affected limb to provide oxygen to the wound. The treatment needs to last 90 minutes a day, 4-5 times a week, and a lot of financial and energy resources are consumed during the treatment. At the same time, because TOT acts on the wound through gaseous oxygen, not only is the oxygen utilization rate low, but it will also cause the wound to dry and shrink, deepen the ulcer wound, and is not conducive to wound healing.

[0006] The invention patent application with application number 202110811536.1 and application date July 19, 2021 discloses an antibacterial hydrogel dressing for diabetic wound repair and its preparation method, which first prepares a TiO2 / Ag3PO4 phosphate suspension, then prepares a polyacrylic acid aqueous solution, a calcium chloride aqueous solution and a glucose oxidase aqueous solution, and then mixes the polyacrylic acid aqueous solution, the calcium chloride aqueous solution and the glucose oxidase aqueous solution, and adds the TiO2 / Ag3PO4 phosphate suspension under vigorous stirring to obtain an antibacterial hydrogel dressing. Although the design can respond to phosphate in a physiological environment, causing the escape of Ca2+, inducing gel degradation, and releasing TiO2 / Ag3PO4 and GOx, among which Gox can decompose glucose in the wound and reduce local blood glucose concentration, while TiO2 catalyzes H2O2 to generate reactive oxygen species (ROS) under light, cooperates with Ag+ to kill bacteria, and then reduces the blood glucose concentration in the wound to promote the healing of diabetic wounds, but the design still has the following defects: The design focuses primarily on lowering local blood sugar concentrations, and secondarily on sterilization. It does not consider the relationship between oxygen therapy and angiogenesis, and cannot directly address wound healing. Instead, it can only affect wound healing by lowering blood sugar, resulting in poor healing effects.

[0007] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the application, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to ordinary technicians in this field. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects and problems of the prior art that oxygen therapy cannot be directly provided to facilitate angiogenesis and the wound healing effect is poor, and to provide a preparation method and dressing of a magnetic self-oxygenating hydrogel dressing that can directly provide oxygen therapy to facilitate angiogenesis and has a better wound healing effect.

[0009] To achieve the above objectives, the technical solution of the present invention is: a method for preparing a magnetic self-oxygenating hydrogel dressing, the preparation method comprising the following steps: Step 1: first add PVA into a beaker, then add water, then seal the beaker, and heat them in a water bath until they reach temperature A, then keep them warm until the PVA swells significantly, then heat them to temperature B, and then at temperature B, stir the beaker magnetically until the PVA is fully dissolved to obtain a paste-like PVA solution, and the mass percentage concentration of PVA in the solution is 8%-10%; Step 2: First, add the powdered CMCS into a beaker, then add water, and then seal the beaker, and then stir the beaker magnetically until the CMCS is fully dissolved to obtain a CMCS solution, and the mass percentage concentration of CMCS in the solution is 5%-8%; Step 3: firstly mix the above-mentioned PVA solution and CMCS solution to obtain a primary mixed solution, in which the mass ratio of PVA solution in the primary mixed solution is 30%-50%, and then add Fe3O4-CaO2 nanoparticles to the primary mixed solution to obtain a secondary mixed solution, in which the mass of Fe3O4-CaO2 nanoparticles is 1%-5% of the primary mixed solution, and then introduce the evenly dispersed secondary mixed solution into a mold, and then seal the mold, and then freeze and thaw, and this freezing and thawing process is repeated 6-8 times, and then the seal of the mold is removed to obtain the magnetic self-oxygenating hydrogel dressing.

[0010] In the third step, the freezing temperature is -20°C to -30°C.

[0011] In the third step, the freezing time is 20 hours, and the thawing is carried out at room temperature.

[0012] In the third step, the uniform dispersion refers to ultrasonic dispersion of the secondary mixed liquid, and the dispersion time is 30 minutes.

[0013] In the third step, after obtaining the primary mixed solution, the mixed solution is first allowed to stand for defoaming, and then the Fe3O4-CaO2 nanoparticles are added; At the same time, before the secondary mixed liquid is introduced into the mold, the uniformly dispersed secondary mixed liquid is first allowed to stand and defoam.

[0014] In the first step, the temperature of step A is 60°C, and the temperature of step B is 90°C.

[0015] In the first step, the mass percentage concentration of PVA in the PVA solution is 10%; In the second step, the mass percentage concentration of CMCS in the CMCS solution is 5%; In the third step, the mass proportion of the PVA solution in the primary mixed solution is 50%.

[0016] In the first step, the beaker is not stirred during the entire process from the start of water bath heating to the obvious swelling of PVA.

[0017] In the third step, the Fe3O4-CaO2 nanoparticles refer to composite particles formed by physically binding Fe3O4 and CaO2 by HA.

[0018] A magnetic self-oxygenating hydrogel dressing is a dressing prepared by the method for preparing the magnetic self-oxygenating hydrogel dressing.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. In the preparation method and dressing of a magnetic self-oxygenating hydrogel dressing of the present invention, a paste-like PVA solution and a CMCS solution are first prepared, and then the PVA solution and the CMCS solution are mixed to obtain a primary mixed solution, in which the mass ratio of the PVA solution in the primary mixed solution is 30%-50%, and then Fe3O4-CaO2 nanoparticles are added to the primary mixed solution to obtain a secondary mixed solution, and the mass of the Fe3O4-CaO2 nanoparticles is 1%-5% of the primary mixed solution, and then the uniformly dispersed secondary mixed solution is introduced into a mold, and then the mold is sealed, and then the freezing and thawing operations are repeatedly performed, and then the seal of the mold is removed, and the final dressing is removed from the mold to obtain the magnetic self-oxygenating hydrogel dressing. The advantages of this design include: First point: the Fe3O4-CaO2 nanoparticles introduced during the preparation process can provide Fe3O4 and CaO2 for the final product. At the same time, water is stored in the hydrogel, and calcium peroxide reacts with water to generate hydrogen peroxide and calcium hydroxide. Hydrogen peroxide decomposes to produce oxygen, and ferroferric oxide can catalyze the process of hydrogen peroxide producing oxygen, as shown below: CaO2+2H2O → H2O2+Ca(OH)2; H2O2+2Fe 3+ → 2Fe 2+ +O 2 +2H + ; Fe 2+ + H2O2→ Fe 3+ +(OH) - +OH· ; As a result, the decomposition of free hydrogen peroxide becomes more active and faster in the hydrogel network, minimizing the possibility of releasing free hydrogen peroxide from the microsystem. It can not only generate oxygen autonomously, but also dissolve oxygen in water through catalytic reactions. The final product is dissolved oxygen, which can penetrate into the wound through liquid exchange, thus penetrating into the deep layer of the wound of diabetic patients (dissolved oxygen can penetrate human skin with a thickness greater than 700μm, while local gaseous oxygen can only penetrate the dermis layer of 300μm), providing an oxygen-rich environment for wound recovery, directly facilitating angiogenesis and improving wound healing. Second point: The internal structure of the hydrogel is a three-dimensional network structure with strong water retention capacity. On the one hand, it can support the self-oxygenation reaction and ensure the smooth generation of dissolved oxygen. On the other hand, it can absorb the tissue fluid exuded from the wound, which can be used to supplement the raw materials for the generation of dissolved oxygen and improve the oxygen supply efficiency. After saturation, the water can be discharged from the hydrogel in a free state, thereby balancing the humidity of the wound, so as to ensure the humidity of the wound healing and avoid the dryness of the wound surface, which leads to wound adhesion (such as local oxygen therapy in the prior art), and avoid excessive humidity, which hinders wound healing. Third point: Fe3O4 in Fe3O4-CaO2 nanoparticles has its own magnetism, which can provide a magnetic field for chronic wounds, allowing magnetic lines to penetrate deep into human tissues, accelerate cell resurrection and renewal, enhance the vitality of blood cells, purify blood, improve microcirculation, and enhance wound healing effects; Therefore, the present invention can not only autonomously generate dissolved oxygen and directly provide oxygen therapy to facilitate angiogenesis, but also balance the moisture of the wound and provide magnetic therapy, thereby achieving better wound healing effect.

[0020] 2. In the preparation method and dressing of a magnetic self-oxygenating hydrogel dressing of the present invention, PVA and CMCS together construct the framework structure of the hydrogel, realizing a three-dimensional double network structure. The advantages of this design include: First point: The double network hydrogel structure allows the network structures generated by PVA and CMCS to interpenetrate with each other. Compared with a single network, the double network hydrogel is not only more stable in structure and can improve the overall mechanical properties, but also because the two molecules are interpenetrated, the distance between the same molecules can be expanded, the gaps inside the hydrogel are increased, the space for water molecules to move is larger, and the overall water content of the hydrogel is improved. At the same time, in the subsequent repeated freezing and thawing process, the two molecules will produce different scaling rates, further generating more pores. In addition, the two have different attractions for water, which makes the cavities between different molecules more, thereby improving the water content as a whole and being more conducive to the efficient generation of dissolved oxygen. Second point: CMCS is an important water-soluble chitosan derivative. It not only has the functions of promoting wound healing, hemostasis, scar inhibition, analgesia, and antibacterial, but more importantly, it has good biocompatibility and biodegradability, and will not cause wound infection, discomfort, or adhesion, thereby improving the biocompatibility and antibacterial properties of the entire product; Third point: PVA is mainly responsible for constructing the polyvinyl alcohol network. The internal functional groups are more hydrophilic, which can significantly increase the overall water content of the entire hydrogel. At the same time, the molecular weight of PVA is relatively large compared to CMCS, so the overall mechanical properties will also be improved. In addition, PVA is an extremely safe macromolecular organic substance, non-toxic to the human body, has no side effects, and has good biocompatibility; Therefore, the present invention can not only construct a double-network hydrogel structure and improve the overall water content, but also has good biocompatibility and strong antibacterial performance.

[0021] 3. In the preparation method and dressing of a magnetic self-oxygenating hydrogel dressing of the present invention, after adding Fe3O4-CaO2 nanoparticles to a primary mixed solution to obtain a secondary mixed solution and uniformly dispersing the nanoparticles, the secondary mixed solution needs to be introduced into a mold, the mold is then sealed, and then the "freezing and thawing" operation is repeated to generate a magnetic self-oxygenating hydrogel dressing. This design can promote the generation of a gel with a network structure. The reason is (taking PVA as an example, CMCS is similar to it): In a homogeneous PVA aqueous solution, PVA molecular chains are randomly distributed in the aqueous phase, the relative fluidity between the molecular chains is large, the contact time between each other is short, and it is difficult to achieve tight bonding. At this time, the freezing process can "freeze" the molecular motion state of the PVA aqueous solution at a certain moment, so that the molecular chains in contact with each other can interact with each other and are tightly bound by van der Waals forces and hydrogen bonds. Even some molecular chain segments in a certain micro-region can form an ordered structure, making the bonding stronger, so that after thawing at room temperature, these tightly bound ordered micro-regions no longer separate and become entanglement points. Subsequently, when refrozen, some new tightly bound ordered micro-regions are formed, new entanglement points are obtained, and even the entanglement points can be connected to form physical cross-linking points. The physical cross-linking points formed under freezing conditions are relatively stable, and their disintegration requires the absorption of a large amount of energy, so that the structure can still be maintained during subsequent thawing, and so on, repeatedly, thereby obtaining more physical cross-linking points, and then obtaining a more stable three-dimensional network structure. Therefore, the present invention can not only generate hydrogels through repeated freezing and thawing, but also improve the stability of the three-dimensional network structure of the hydrogel and enhance the mechanical strength of the double-network hydrogel structure.

[0022] 4. In the preparation method and dressing of a magnetic self-oxygenating hydrogel dressing of the present invention, the Fe3O4-CaO2 nanoparticles preferably refer to composite particles obtained by physically binding Fe3O4 and CaO2 by HA, wherein the connection between the two nanoparticles of Fe3O4 and CaO2 by hyaluronic acid is a physical connection, which sticks the two substances together through their own viscosity so as to stably exist in the subsequent hydrogel. At the same time, the hyaluronic acid molecule HA is a polymer material containing a large number of carboxyl and hydroxyl groups, which can form hydrogen bonds within and between molecules in an aqueous solution. The hydrogel has a strong water-retaining effect, and can bind at least 400 times more water than itself. It can not only bind strongly with the water contained in the hydrogel to fix the two nanoparticles of Fe3O4 and CaO2 more stably, but also absorb additional water in addition to the effect of the hydrogel containing water, so as to facilitate the generation of dissolved oxygen. In addition, the generation of dissolved oxygen depends on the two nanoparticles of Fe3O4 and CaO2, and these two nanoparticles are bound by hyaluronic acid that can bind more water, so that water can be provided in time at the beginning of the generation of dissolved oxygen, ensuring the efficient generation of dissolved oxygen. Therefore, the present invention can not only improve the firmness of the fixation of nanoparticles in the hydrogel, but also generate dissolved oxygen in time, and the generation efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a SEM image of the surface of the hydrogel in the present invention at a resolution of 150 um.

[0024] Figure 2 Schematic diagram of the double network structure of the hydrogel in the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0026] See also Figure 1 — Figure 2 , a method for preparing a magnetic self-oxygenating hydrogel dressing, the preparation method comprising the following steps: Step 1: first add PVA into a beaker, then add water, then seal the beaker, and heat them in a water bath until they reach temperature A, then keep them warm until the PVA swells significantly, then heat them to temperature B, and then at temperature B, stir the beaker magnetically until the PVA is fully dissolved to obtain a paste-like PVA solution, and the mass percentage concentration of PVA in the solution is 8%-10%; Step 2: First, add the powdered CMCS into a beaker, then add water, and then seal the beaker, and then stir the beaker magnetically until the CMCS is fully dissolved to obtain a CMCS solution, and the mass percentage concentration of CMCS in the solution is 5%-8%; Step 3: firstly mix the above-mentioned PVA solution and CMCS solution to obtain a primary mixed solution, in which the mass ratio of PVA solution in the primary mixed solution is 30%-50%, and then add Fe3O4-CaO2 nanoparticles to the primary mixed solution to obtain a secondary mixed solution, in which the mass of Fe3O4-CaO2 nanoparticles is 1%-5% of the primary mixed solution, and then introduce the evenly dispersed secondary mixed solution into a mold, and then seal the mold, and then freeze and thaw, and this freezing and thawing process is repeated 6-8 times, and then the seal of the mold is removed to obtain the magnetic self-oxygenating hydrogel dressing.

[0027] In the third step, the freezing temperature is -20°C to -30°C.

[0028] In the third step, the freezing time is 20 hours, and the thawing is carried out at room temperature.

[0029] In the third step, the uniform dispersion refers to ultrasonic dispersion of the secondary mixed liquid, and the dispersion time is 30 minutes.

[0030] In the third step, after obtaining the primary mixed solution, the mixed solution is first allowed to stand for defoaming, and then the Fe3O4-CaO2 nanoparticles are added; At the same time, before the secondary mixed liquid is introduced into the mold, the uniformly dispersed secondary mixed liquid is first allowed to stand and defoam.

[0031] In the first step, the temperature of step A is 60°C, and the temperature of step B is 90°C.

[0032] In the first step, the mass percentage concentration of PVA in the PVA solution is 10%; In the second step, the mass percentage concentration of CMCS in the CMCS solution is 5%; In the third step, the mass proportion of the PVA solution in the primary mixed solution is 50%.

[0033] In the first step, the beaker is not stirred during the entire process from the start of water bath heating to the obvious swelling of PVA.

[0034] In the third step, the Fe3O4-CaO2 nanoparticles refer to composite particles formed by physically binding Fe3O4 and CaO2 by HA.

[0035] A magnetic self-oxygenating hydrogel dressing is a dressing prepared by the method for preparing the magnetic self-oxygenating hydrogel dressing.

[0036] The supplementary technical features of the present invention are as follows: In the present invention, PVA refers to polyvinyl alcohol, CMCS refers to carboxymethyl chitosan, and HA refers to hyaluronic acid.

[0037] The basic purpose of the present invention is to provide dissolved oxygen to the wound to promote angiogenesis at the wound and improve the wound healing effect. The main functions of oxygen in the wound recovery process include: Regulating oxygen receptors: The involvement of oxygen receptors in the transduction of hypoxic cells is a complex and diverse process. Once cells are hypoxic, wound healing is delayed. Although hyperbaric oxygen therapy can increase the oxygen partial pressure of tissue cells throughout the body, excessive oxygen partial pressure will produce too much ROS, causing the body to produce lipid peroxidation reactions, causing damage to tissues and organs, and bringing many adverse reactions to patients. Local oxygen therapy can provide appropriate oxygen partial pressure for the wound, promote wound healing by regulating oxygen receptors, and avoid the occurrence of systemic complications; Anti-infection effect: The bactericidal effect of oxygen is mainly to increase the activity of white blood cells, kill cells and necrotic tissues, thereby inhibiting bacterial growth and accelerating wound healing; Promote cell growth: Wound healing mainly relies on the generation of fibroblasts, synthesis of collagen cells and filling of granulation tissue. When the wound is severely hypoxic, the proliferation of fibroblasts will slow down or stop, and the quality and quantity of collagen will decrease, affecting wound healing. Oxygen can promote the synthesis of wound collagen and angiogenesis, and promote energy metabolism and the expression of various growth factors. The role of promoting microcirculation: Tissue edema and blood stasis can lead to microcirculation disorders, which prevent local tissues from obtaining the nutrients they need. This is an important reason for non-healing wounds. Local oxygen therapy can effectively reduce tissue edema and is beneficial to the normal growth of endothelial cells and capillaries.

[0038] Embodiment 1: A method for preparing a magnetic self-oxygenating hydrogel dressing, the method comprising the following steps: Step 1: first add PVA into a beaker, then add water, then seal the beaker, and then heat them in a water bath until they reach temperature A (preferably 60°C), then keep them warm until the PVA swells significantly, then heat them to temperature B (preferably 90°C), and then at temperature B, magnetically stir the beaker until the PVA is fully dissolved to obtain a paste-like PVA solution, and the mass percentage concentration of PVA in the solution is 8%-10%; Step 2: First, add the powdered CMCS into a beaker, then add water, and then seal the beaker, and then stir the beaker magnetically until the CMCS is fully dissolved to obtain a CMCS solution, and the mass percentage concentration of CMCS in the solution is 5%-8%; Step 3: firstly mix the above-mentioned PVA solution and CMCS solution to obtain a primary mixed solution, in which the mass ratio of PVA solution in the primary mixed solution is 30%-50%, and then add Fe3O4-CaO2 nanoparticles to the primary mixed solution to obtain a secondary mixed solution, in which the mass of Fe3O4-CaO2 nanoparticles is 1%-5% of the primary mixed solution, and then introduce the evenly dispersed secondary mixed solution into a mold, and then seal the mold, and then freeze and thaw, and this freezing and thawing process is repeated 6-8 times, and then the seal of the mold is removed to obtain the magnetic self-oxygenating hydrogel dressing.

[0039] A magnetic self-oxygenating hydrogel dressing is a dressing prepared by the method for preparing the magnetic self-oxygenating hydrogel dressing.

[0040] like Figure 1 As shown, this figure is a SEM image of the surface of the magnetic self-oxygenating hydrogel dressing of the present invention at a resolution of 150 um. The figure shows an obvious network structure, showing a multiple honeycomb structure that is staggered inside and outside.

[0041] like Figure 2 As shown, the figure is a schematic diagram of the double network structure of the magnetic self-oxygenating hydrogel dressing in the present invention. In the figure, the green lines are the molecular chains of CMCS, the yellow dots are the points where CMCS contacts each other during the formation of hydrogel, the black lines are the molecular chains of PVP, and the red dots are the points where PVP contacts each other during the formation of hydrogel.

[0042] After obtaining the magnetic self-oxygenating hydrogel dressing, if it is not needed immediately, the self-oxygenating hydrogel needs to be frozen first until the water contained inside it is frozen, and then it can be stored. At this time, the water in the self-oxygenating hydrogel has been frozen into ice, the molecular thermal motion has basically stopped, and it will basically no longer react.

[0043] Embodiment 2: The basic content is the same as that of Example 1, except that: In the third step, the freezing temperature is -20°C to -30°C, the freezing time is 20 hours, and the thawing is carried out at room temperature.

[0044] Embodiment 3: The basic content is the same as that of Example 1, except that: In the first step, the mass percentage concentration of PVA in the PVA solution is 10%; In the second step, the mass percentage concentration of CMCS in the CMCS solution is 5%; In the third step, the mass proportion of the PVA solution in the primary mixed solution is 50%.

[0045] Embodiment 4: The basic content is the same as that of Example 1, except that: In the first step, accurately weigh 5g of polyvinyl alcohol (PVA), add 45ml of sterile ultrapure water to a clean beaker, heat to 60°C in a constant temperature water bath, do not stir, and after 1 hour, the PVA can be seen to be obviously swollen. Then heat the constant temperature water bath to 90°C, seal the beaker, and stir repeatedly for about 3 hours to fully dissolve the PVA. It can be seen that the PVA is completely dissolved into a paste, and no particles are seen in the solution, so as to obtain a PVA aqueous solution with a mass percentage concentration of 10%; In the second step, 20 g of carboxymethyl chitosan (CMCS) powder was weighed into a clean beaker, and then a 5% carboxymethyl chitosan solution was prepared, and the mixture was stirred on a magnetic stirrer for 1 h to fully dissolve the carboxymethyl chitosan powder to obtain a CMCS solution; In the third step, the PVA aqueous solution and the CMCS solution are mixed in a mass ratio of 5:5, and then allowed to stand for defoaming to obtain a primary mixed solution.

[0046] The static defoaming means that since the solution is a relatively thick colloid, air will enter the liquid during stirring and produce bubbles. Therefore, this design will let the stirred liquid stand for a period of time. The bubbles in the liquid will float to the surface of the solution due to their own buoyancy, leaving no bubbles in the lower layer of colloid.

[0047] Embodiment 5: The basic content is the same as that of Example 1, except that: In the third step, 0.5 g of Fe3O4-CaO2 nanoparticles are first added to 50 ml of the primary mixed solution, and then ultrasonically treated for 30 minutes, and then allowed to stand for defoaming to obtain a secondary mixed solution, and then the secondary mixed solution is introduced into a mold, and then the mold is sealed and frozen, and the freezing temperature is -20°C, and then taken out and thawed at room temperature for 8 hours to thaw, and this freezing and thawing process is repeated 7 times, and then the mold seal is removed to obtain the PVA-CMCS-based magnetic self-oxygenating hydrogel.

[0048] Embodiment 6: The basic contents are the same as those of Example 5, except that: In the third step, the Fe3O4-CaO2 nanoparticles are prepared according to the following steps: first, 0.4g of anhydrous calcium chloride and 150mg of hyaluronic acid (HA) are added to 20ml of anhydrous ethanol, and then ultrasonically dissolved for 10 minutes, and then placed in a magnetic stirrer for magnetic stirring. During the stirring process, 2ml of ammonia solution and 3ml of hydrogen peroxide solution (mass percentage concentration is 30%) are added dropwise in sequence. When the solution is observed to gradually turn milky white, the stirring is stopped, and then centrifuged at 10000rpm for 10min using a centrifuge, and then the solid dressing is collected, and then the solid dressing is dissolved in 20ml of anhydrous ethanol and stirred for 24h, and finally centrifuged at 12000rpm for 10min to obtain Fe3O4-CaO2 nanoparticles.

[0049] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.

Claims

1. A method for preparing a magnetic self-oxygenating hydrogel dressing, characterized in that: The preparation method comprises the following steps: Step 1: first add PVA into a beaker, then add water, then seal the beaker, and heat them in a water bath until they reach temperature A, then keep them warm until the PVA swells significantly, then heat them to temperature B, and then at temperature B, stir the beaker magnetically until the PVA is fully dissolved to obtain a paste-like PVA solution, and the mass percentage concentration of PVA in the solution is 8%-10%; Step 2: First, add the powdered CMCS into a beaker, then add water, and then seal the beaker, and then stir the beaker magnetically until the CMCS is fully dissolved to obtain a CMCS solution, and the mass percentage concentration of CMCS in the solution is 5%-8%; Step 3: firstly mix the above-mentioned PVA solution and CMCS solution to obtain a primary mixed solution, in which the mass ratio of PVA solution in the primary mixed solution is 30%-50%, and then add Fe3O4-CaO2 nanoparticles to the primary mixed solution to obtain a secondary mixed solution, in which the mass of Fe3O4-CaO2 nanoparticles is 1%-5% of the primary mixed solution, and then introduce the evenly dispersed secondary mixed solution into a mold, and then seal the mold, and then freeze and thaw, and this freezing and thawing process is repeated 6-8 times, and then the seal of the mold is removed to obtain the magnetic self-oxygenating hydrogel dressing.

2. The method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 1, characterized in that: In the third step, the freezing temperature is -20°C to -30°C.

3. The method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 2, characterized in that: In the third step, the freezing time is 20 hours, and the thawing is carried out at room temperature.

4. A method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 1, 2 or 3, characterized in that: In the third step, the uniform dispersion refers to ultrasonic dispersion of the secondary mixed liquid, and the dispersion time is 30 minutes.

5. A method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 1, 2 or 3, characterized in that: In the third step, after obtaining the primary mixed solution, the mixed solution is first allowed to stand for defoaming, and then the Fe3O4-CaO2 nanoparticles are added; At the same time, before the secondary mixed liquid is introduced into the mold, the uniformly dispersed secondary mixed liquid is first allowed to stand and defoam.

6. A method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 1, 2 or 3, characterized in that: In the first step, the temperature of step A is 60°C, and the temperature of step B is 90°C.

7. A method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 1, 2 or 3, characterized in that: In the first step, the mass percentage concentration of PVA in the PVA solution is 10%; In the second step, the mass percentage concentration of CMCS in the CMCS solution is 5%; In the third step, the mass proportion of the PVA solution in the primary mixed solution is 50%.

8. A method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 1, 2 or 3, characterized in that: In the first step, the beaker is not stirred during the entire process from the start of water bath heating to the obvious swelling of PVA.

9. A method for preparing a magnetic self-oxygenating hydrogel dressing according to claim 1, 2 or 3, characterized in that: In the third step, the Fe3O4-CaO2 nanoparticles refer to composite particles formed by physically binding Fe3O4 and CaO2 by HA.

10. A magnetic self-oxygenating hydrogel dressing, characterized in that: The magnetic self-oxygenating hydrogel dressing is a product of the preparation method of the magnetic self-oxygenating hydrogel dressing according to claim 1, 2 or 3.

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