Pulsed magnetic field porous liquid metal conductive dressing and applications thereof

Abstract

The scheme discloses a pulse magnetic field porous liquid metal conductive dressing in the technical field of medical wound repair materials, which comprises a flexible porous substrate and a conductive functional layer, the flexible porous substrate is a polyurethane porous foam, and the conductive functional layer is gallium-based liquid metal; the gallium-based liquid metal adheres to a three-dimensional network framework of the polyurethane porous foam to form interconnected small closed loops, thereby constituting a continuous three-dimensional conductive network; the dressing is used in cooperation with an external low-frequency pulse magnetic field generator, and the magnetic flux of the closed loop is changed through the pulse magnetic field to generate an induced micro-current; the dressing has good biocompatibility, flexible fitting and air permeability and liquid absorption, can generate a mild induced micro-current noninvasively without external power supply, can effectively promote wound cell proliferation, migration and collagen deposition, significantly accelerates the healing process of chronic wounds such as diabetic foot and pressure sores, and is simple in preparation process, controllable in cost, and suitable for batch production and clinical transformation.

Description

Technical Field

[0001] This invention relates to the field of medical wound repair materials, and in particular to pulsed magnetic field porous liquid metal conductive dressings and their applications. Background Technology

[0002] Skin wound healing is a complex and orderly process involving stages such as coagulation, inflammatory response, granulation tissue growth, epithelial and vascular regeneration, and tissue remodeling. Chronic wounds, however, suffer from severely impaired healing processes, making it difficult to enter the normal repair cycle and posing a significant challenge in clinical nursing. This is especially true for patients with metabolic diseases such as diabetes, whose abnormal metabolism further reduces their wound healing ability, increases the risk of bacterial infection, exacerbates their existing condition, and in severe cases, can even lead to amputation or death. Therefore, developing efficient, safe, and convenient materials to promote chronic wound healing is of significant clinical importance.

[0003] Electrical stimulation therapy, as a non-invasive physical therapy, can effectively promote tissue repair by simulating the endogenous electric field of damaged skin tissue, thereby promoting tissue cell proliferation and differentiation, accelerating keratinocyte migration, and achieving wound re-epithelialization, thus speeding up the healing process. Among them, low-frequency pulsed electrical stimulation has good application prospects in the field of wound repair due to its simple operation, painless and non-invasive nature, and high safety.

[0004] However, traditional dressings commonly used in clinical practice can only achieve basic protective functions such as wound isolation and exudate absorption, without conductive or electrically stimulated wound repair functions. Existing externally powered conductive dressings need to be connected to an external power source through wires, which is not convenient to use. The wires can easily cause secondary damage to the wound, and patients have low compliance with long-term use. They are difficult to meet the clinical repair needs of chronic wounds in terms of efficiency, safety and comfort. Summary of the Invention

[0005] The present invention aims to provide a pulsed magnetic field porous liquid metal conductive dressing and its application, in order to solve the problems of traditional dressings lacking electrical stimulation repair function and external power supply conductive dressings being inconvenient to use and prone to causing secondary damage to the wound.

[0006] The pulsed magnetic field porous liquid metal conductive dressing in this solution includes a flexible porous substrate and a conductive functional layer. The flexible porous substrate is polyurethane (PU) porous foam, which is used to support the formation of a three-dimensional conductive network. The conductive functional layer is gallium-based liquid metal, which is adhered to the three-dimensional network skeleton formed by the polyurethane porous foam to form several interconnected micro closed loops. The micro closed loops constitute a continuous and interconnected three-dimensional conductive network.

[0007] A skin tissue repair device includes a low-frequency pulsed magnetic field generator and a pulsed magnetic field porous liquid metal conductive dressing. The low-frequency pulsed magnetic field generator generates an induced microcurrent on the surface of the dressing to promote wound healing by changing the magnetic flux of a tiny closed loop.

[0008] Furthermore, the polyurethane porous foam is a flexible material with interconnected open cells, and its apparent density is 30~60 kg / m³. 3 The pore size is 100~500μm. Polyurethane porous foam can absorb wound exudate and maintain the breathability of the wound.

[0009] Furthermore, the gallium-based liquid metal is a gallium-based alloy that is liquid at room temperature. It exhibits no significant cytotoxicity, is chemically stable, and has good biocompatibility.

[0010] Furthermore, the dressing has a flexible structure overall. The generated induced microcurrent is a low-frequency, gentle microcurrent.

[0011] Furthermore, the low-frequency pulsed magnetic field generator includes a pulse power supply and a solenoid coil; the pulse power supply is used to supply pulsed current with adjustable frequency, intensity, and duration. The low-frequency pulsed magnetic field generator changes the magnetic field strength by adjusting the number of turns of the solenoid coil to adapt to the magnetic field requirements of different wounds. After a pulsed current is applied to the solenoid coil, a stable low-frequency pulsed magnetic field is generated.

[0012] Furthermore, the gallium-based liquid metal is loaded in the following manner: the gallium-based liquid metal is ultrasonically dispersed in an ethanol solution, then drop-coated onto a polyurethane porous foam substrate. After drying, the gallium-based liquid metal adheres to the inner wall of the pores of the polyurethane porous foam, forming a continuous three-dimensional conductive network.

[0013] Application of the pulsed magnetic field porous liquid metal conductive dressing in the treatment of diabetic foot and pressure sores.

[0014] The working principle and beneficial effects of this solution are as follows: After cleaning the wound, apply the dressing to the wound surface and secure it firmly. Turn on the low-frequency pulsed magnetic field generator, and set the frequency, intensity, and duration of the pulsed current according to the wound type to generate a corresponding low-frequency pulsed magnetic field in the solenoid coil. The three-dimensional conductive network inside the dressing generates an induced microcurrent under the influence of the low-frequency pulsed magnetic field. This induced microcurrent stimulates cell proliferation, migration, and collagen deposition in the wound, while the porous structure of the dressing absorbs wound exudate and maintains breathability, synergistically accelerating wound healing.

[0015] 1. This invention utilizes a composite of polyurethane porous foam and gallium-based liquid metal to form a three-dimensional conductive network. Gallium-based liquid metal exhibits high biocompatibility and no significant cytotoxicity, while polyurethane porous foam demonstrates good biocompatibility. The composite of these two materials enables long-term safe coverage of the wound, while simultaneously providing favorable conditions for wound microenvironment repair and tissue regeneration. An external low-frequency pulsed magnetic field generator non-invasively generates an induced microcurrent, eliminating the need for an external power source and wires. This completely avoids secondary damage to the wound caused by wire traction, making it safe and convenient to use, and resulting in high patient compliance with long-term wear. The induced microcurrent effectively promotes wound cell proliferation, migration, and collagen deposition, significantly shortening the healing cycle and greatly improving the repair effect of chronic, difficult-to-heal wounds. This addresses the pain points of traditional electrical stimulation dressings, such as the susceptibility to infection and inconvenience of wearing wires. 2. The dressing of the present invention has a flexible porous structure. The flexibility of polyurethane porous foam allows the dressing to fit closely to the skin and adapt to wounds on different parts of the body. The porous structure has both high exudate absorption capacity and good breathability, which can effectively optimize the wound healing microenvironment, reduce the risk of infection, and solve the problems of poor adhesion and easy dampness of traditional rigid dressings. 3. The gallium-based liquid metal loading process of the present invention is simple, and the polyurethane porous foam is a conventional medical material with readily available raw materials. The overall preparation process is simple and cost-controllable, making it suitable for mass production and clinical transformation. It solves the industry problems of complex preparation, high cost, and difficulty in large-scale application of traditional conductive dressings. 4. The low-frequency pulsed magnetic field generator of the present invention can flexibly adjust the frequency, intensity and duration of the pulsed current, and can also change the magnetic field intensity by adjusting the number of turns of the solenoid coil. It can be customized according to different wound types and healing stages, with strong adaptability, realizing precise and personalized treatment for wound repair, and breaking through the limitations of traditional electrical stimulation schemes with fixed parameters that cannot adapt to different wound needs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the pulsed magnetic field porous liquid metal conductive dressing of the present invention; Figure 2 This is a schematic diagram of the cross-sectional pores and conductive network of the dressing according to the present invention; Figure 3 This is a schematic diagram of the pulse magnetic field generator of the present invention.

[0017] The reference numerals in the accompanying drawings include: 1. Polyurethane porous foam substrate; 2. Gallium-based liquid metal conductive layer; 3. Wound contact surface; 4. Exudate absorption pores; 5. Solenoid coil; 6. Pulse power supply; 7. Induction microcurrent region. Detailed Implementation

[0018] The following detailed explanation illustrates the specific implementation methods: Pulsed magnetic field porous liquid metal conductive dressing, such as Figures 1-3 As shown, 1. Dressing preparation (1) Select open-cell polyurethane porous foam with an apparent density of 30~60kg / m³ and a pore size of 100~500μm, cut it to the size that fits the wound, and use it as a flexible porous substrate; (2) The gallium-based liquid metal was ultrasonically dispersed in anhydrous ethanol solution to form a uniform liquid metal dispersion. (3) The liquid metal dispersion is uniformly drop-coated onto the surface and pores of the polyurethane porous foam substrate 1. After natural drying, the gallium-based liquid metal conductive layer 2 firmly adheres to the inner wall of the pores of the polyurethane foam, forming interconnected micro-closed loops and constituting a continuous three-dimensional conductive network, thus obtaining a porous liquid metal conductive dressing under a pulsed magnetic field. There are exudate absorption pores 4 between the polyurethane porous foam substrate 1 and the wound contact surface 3.

[0019] 2. Supporting equipment The dressing of the present invention is used in conjunction with an external low-frequency pulse magnetic field generator. The device consists of a pulse power supply 6 and a solenoid coil 5. The pulse power supply 6 can adjust the frequency, intensity and duration of the output pulse current. After the pulse current is applied to the solenoid coil 5, a stable low-frequency pulse magnetic field is generated. The magnetic field intensity can be adjusted by changing the number of coil turns. The low-frequency pulse magnetic field generator generates a magnetic field, causing the dressing to induced a micro-current region 7 inside.

[0020] 3. How to use (1) Perform routine cleaning and disinfection of the wound to remove necrotic tissue and secretions; (2) Apply the wound contact surface 3 of the dressing of the present invention to the treated wound surface, and use medical tape or dressing fixation tape to properly fix the dressing to ensure that the dressing is in close contact with the wound surface; (3) Place the solenoid coil 5 of the external low-frequency pulse magnetic field generator on the outside of the dressing, turn on the pulse power supply 6, and set the appropriate pulse frequency, magnetic field strength and action time according to the wound type and healing stage. (4) Under the action of a low-frequency pulsed magnetic field, the three-dimensional conductive network inside the dressing generates a gentle induced microcurrent through changes in magnetic flux, which acts on the wound to promote cell proliferation, epithelial migration and collagen deposition. At the same time, the porous structure of the dressing continuously absorbs wound exudate and keeps the wound breathable, thus accelerating wound healing in a synergistic way. (5) Change dressings regularly in accordance with clinical nursing guidelines, and adjust the working parameters of the pulse magnetic field generator according to the wound healing status.

[0021] 4. Experimental verification To verify the practical application effect of the dressing of the present invention, an animal experiment was conducted using a diabetic chronic wound model in SD rats. (1) Experimental model establishment: A diabetic model of SD rats was established by inducing streptozotocin (STZ). A full-thickness skin defect with a diameter of 15 mm was created on the back of the rats to simulate the clinical chronic diabetic foot ulcer.

[0022] (2) Grouping and treatment: The model rats were randomly divided into three groups of 10 rats each, and each group was treated with different methods: Group A (blank control group): The wound was covered with commercially available sterile gauze, with no other treatment; Group B (Ordinary Dressing Group): The wound is covered with pure polyurethane foam dressing, without magnetic field application; Group C (Experimental Group): The wound was covered with the porous liquid metal conductive dressing of the present invention, and treated with an external low-frequency pulse magnetic field generator. The parameters were set as follows: frequency 50Hz, magnetic field strength 10mT, and treatment time 30 minutes per day.

[0023] (3) Experimental results: The wound healing rate of rats in each group was counted on the 3rd, 7th and 14th days of treatment, and pathological observation was performed. The results are shown in the table below: Time points: Blank control group (wound healing rate), ordinary dressing group (wound healing rate), this patented dressing + pulsed magnetic field group (wound healing rate). Pathological observation results. On day 3, the wound exudate in the experimental groups (15.2%, 18.5%, and 30.4%) was significantly reduced, with no obvious accumulation of inflammatory cells and a mild inflammatory response. On day 7, in the experimental groups (38.6%, 45.1%, and 72.8%), the collagen fibers in the wounds were neatly arranged, the number of new blood vessels was significantly higher than that in the control group, and granulation tissue growth was good. On day 14, 63.3%, 78.3%, and 95.9% of the experimental groups showed complete epithelialization of the wound, with skin appendages beginning to regenerate and the newly formed skin tissue approaching the structure of normal skin.

[0024] Experimental results show that the porous liquid metal conductive dressing of the present invention, when used in conjunction with a low-frequency pulsed magnetic field generator, can significantly improve the healing rate of chronic wounds, shorten the healing cycle, and improve the repair effect of chronic refractory wounds. It has significant therapeutic advantages compared with traditional sterile gauze and pure polyurethane foam dressings.

[0025] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A pulsed magnetic field porous liquid metal conductive dressing, characterized in that: It includes a flexible porous substrate and a conductive functional layer; the flexible porous substrate is polyurethane porous foam, which is used to support the formation of a three-dimensional conductive network; the conductive functional layer is gallium-based liquid metal, which is adhered to the three-dimensional network skeleton formed by the polyurethane porous foam to form a number of interconnected micro closed loops, which constitute a continuous three-dimensional conductive network.

2. The pulsed magnetic field porous liquid metal conductive dressing according to claim 1, characterized in that: The polyurethane porous foam is a flexible material with interconnected open cells, and its apparent density is 30~60 kg / m³. 3 The pore size is 100~500μm.

3. The pulsed magnetic field porous liquid metal conductive dressing according to claim 2, characterized in that: The gallium-based liquid metal is a gallium-based alloy that is liquid at room temperature.

4. The pulsed magnetic field porous liquid metal conductive dressing according to claim 3, characterized in that: The dressing has a flexible structure as a whole.

5. The pulsed magnetic field porous liquid metal conductive dressing according to claim 4, characterized in that: The low-frequency pulsed magnetic field generator includes a pulse power supply and a solenoid coil; the pulse power supply is used to supply pulsed current with adjustable frequency, intensity and duration.

6. The pulsed magnetic field porous liquid metal conductive dressing according to claim 5, characterized in that: The gallium-based liquid metal is loaded in the following manner: the gallium-based liquid metal is ultrasonically dispersed in an ethanol solution and then drop-coated onto a polyurethane porous foam substrate. After drying, the gallium-based liquid metal adheres to the inner wall of the pores of the polyurethane porous foam, forming a continuous three-dimensional conductive network.

7. The application of the pulsed magnetic field porous liquid metal conductive dressing according to claim 6 in the treatment of diabetic foot and pressure ulcers.

8. A skin tissue repair device, comprising a low-frequency pulsed magnetic field generator and the pulsed magnetic field porous liquid metal conductive dressing of claim 1, wherein the low-frequency pulsed magnetic field generator generates an induced microcurrent on the dressing surface to promote wound healing by changing the magnetic flux of a tiny closed loop.

9. A skin tissue repair device according to claim 8, characterized in that: The low-frequency pulsed magnetic field generator has a frequency of 50Hz and a magnetic field strength of 10mT.

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