A heat-insulating anti-leakage flexible burn modeling patch as well as a preparation method and application thereof

Abstract

The application discloses a heat-insulating anti-leakage flexible burn modeling patch and a preparation method and application thereof, and relates to the technical field of burn experiment.The burn modeling patch comprises a sandwich layer structure and an RTV silicone seal edge structure, wherein the sandwich layer structure comprises, from outside to inside, a medical-grade silicone rubber sheet, a hydrophobic silica aerogel felt and a medical silicone double-sided adhesive tape; the burn modeling patch is provided with a wounding window, and the inner wall of the wounding window is coated with RTV silicone to form a continuous seal edge protection ring.The application adopts the sandwich layer composite structure and the RTV silicone seal edge structure, combines the super heat-insulating property of the hydrophobic silica aerogel and the micro conformal sealing property of the composite structure, and solves the technical problems of uneven contact pressure, hot liquid side leakage, edge thermal damage and mechanical skin damage in the traditional modeling method.

Description

Technical Field

[0001] This invention relates to the field of burn experimental technology, and in particular to a heat-insulating, leak-proof, flexible burn molding patch, its preparation method, and its application. Background Technology

[0002] Animal models of burns are a crucial foundation for studying the pathophysiological mechanisms of burns, evaluating drug efficacy, and assessing dressing performance. Currently, various methods for creating burn models are publicly available, including hot water scalding, steam scalding, hot metal scalding, flame burns, electric light source burns, electrical burns, radiation burns, and chemical burns. Among these, hot water scalding suffers from problems such as easy flow of hot liquids, rapid temperature drop, and poor depth control; steam scalding is difficult to control the burn area and requires sophisticated equipment; hot metal scalding has limited control over contact pressure and poor uniformity of burn depth, making it difficult to meet the needs of constructing standardized large-area burn animal models; flame burns have poor repeatability and high safety risks; electric light source burns are difficult to control burn depth and have relatively low technological maturity; electrical and radiation burns suffer from drawbacks such as expensive equipment, complex injury mechanisms, and difficulty in standardization. Overall, existing burn animal model preparation technologies generally have the following shortcomings: (1) The scope of injury is uncontrollable and the edges are irregular: Due to the fluidity and diffusion of liquid / gas media (such as hot water or steam scalding method), it is difficult to accurately define the contact area and it is easy to leak laterally, resulting in the actual burn area being larger than the preset area, and the edges appearing as irregular "map-like" shapes, lacking model consistency.

[0003] (2) Contact pressure is difficult to standardize, resulting in uneven burn depth: Solid contact modeling (such as hot metal scalding method) heavily depends on the operator's pressure and is difficult to adapt to the curved surface structure of the animal's body, resulting in large differences in burn depth within the same group.

[0004] (3) Thermal conduction effect leads to accidental damage to surrounding normal tissues: Traditional mold materials (such as ordinary plastics and metals) will absorb heat and conduct it laterally at high temperatures, causing non-lethal thermal damage (heat halo effect) to the normal skin around the opening, thereby interfering with the clarity of the pathological boundary of the burn edge.

[0005] (4) Poor biocompatibility and introduction of additional mechanical damage: Traditional fixation methods (such as strong adhesive tape and mechanical clamps) are prone to peeling off the animal's keratin layer or causing skin traction injury when removing the animal. These non-thermal factors-induced inflammatory reactions can become confounding variables that interfere with the experimental results.

[0006] Therefore, developing a standardized burn model that can accurately locate the injured area, ensure uniform burn depth, protect surrounding normal tissues, and has good biocompatibility is a technical problem that urgently needs to be solved. Summary of the Invention

[0007] To address the shortcomings of the existing technologies, this invention provides a heat-insulating, leak-proof, flexible burn molding patch, its preparation method, and its application.

[0008] The technical problem to be solved by this invention can be achieved through the following technical solution: A heat-insulating, leak-proof, flexible burn molding patch, the burn molding patch comprising a sandwich layered structure and an RTV silicone edge sealing structure; The sandwich layered structure comprises, from the outside to the inside, a medical-grade silicone rubber sheet, a hydrophobic silica aerogel felt, and a medical-grade silicone double-sided tape. The burn molding patch is provided with a wound-causing window; The inner wall of the wound window is coated with RTV silicone to form a continuous edge-sealing protective ring.

[0009] Furthermore, the thickness of the medical-grade silicone rubber sheet is 0.5 mm. The medical-grade silicone rubber sheet has excellent high temperature resistance (>200℃), flexibility, and hydrophobicity. It can provide overall skeletal support and basic thermal insulation for the material, block the lateral conduction of heat, prevent hot water from directly contacting the middle aerogel, and also provide good feel and fit.

[0010] Furthermore, the thickness of the hydrophobic silica aerogel felt is 1-2 mm.

[0011] Furthermore, the hydrophobic silica aerogel felt has a hydrophobicity of ≥99%.

[0012] Furthermore, the thermal conductivity of the hydrophobic silica aerogel felt is 0.015-0.030 W / m·K.

[0013] Hydrophobic silica aerogel felt has a nanoporous structure and extremely low thermal conductivity, which can serve as an efficient thermal barrier layer to block the vertical transfer of heat to the skin below. Furthermore, after hydrophobic modification, it can be ensured that it will not absorb moisture and fail when accidentally exposed to water.

[0014] Furthermore, the medical-grade silicone double-sided tape is 3M™ 2477 tape. The silicone side of the 3M™ 2477 tape has low surface energy, is gentle and harmless to the skin, leaves no residue upon removal, adheres firmly to the skin surface to form a watertight seal, and does not peel off the stratum corneum during removal, thus avoiding mechanical damage.

[0015] Furthermore, the thickness of the medical silicone double-sided tape is 0.1-0.15mm.

[0016] Furthermore, the RTV silicone is used to form an integrated sealing structure on the inner wall of the injury window through a coating-room temperature vulcanization process. The inner wall of the injury window is coated with RTV silicone to form a continuous waterproof protective ring, preventing aerogel powder from falling off and hydrothermal liquid from laterally penetrating the interlayer.

[0017] Furthermore, the method for preparing the burn molding patch includes the following steps: Step 1, Lamination and Composite: Apply one side of medical silicone double-sided tape to one side of the hydrophobic silica aerogel felt, keeping the silicone side in place to adhere to the skin. Spray 3M Super 77 adhesive onto the other side of the hydrophobic silica aerogel felt and attach the outer medical-grade silicone rubber sheet. Compact the layers with rollers to form a three-layer composite patch. Step 2, Cutting out the molding window: Use a hole punch to make through holes in the composite patch as needed to create the damage window; Step 3, RTV sealing: Apply RTV silicone evenly to the inner wall of the through hole and wait for it to fully cure to ensure that the aerogel felt is not exposed, forming a continuous waterproof protective ring to prevent aerogel powder from falling off and hot liquid from seeping into the interlayer laterally. Step 4, Sterilization: After the material is packaged, it is sterilized with ethylene oxide or ultraviolet light and then set aside for later use.

[0018] The beneficial effects of this invention are: (1) The inner layer of the burn molding patch of the present invention uses medical silicone double-sided tape. The silicone side perfectly fits the animal skin. Combined with the RTV silicone sealing process, an absolute airtight barrier is formed around the wound window, which completely eliminates the lateral leakage of hot liquid. The burn wound shape is highly regular (such as high roundness) and the area is basically consistent with the preset cutting area, achieving precise area control with zero leakage. It has the characteristics of micro-conformal sealing.

[0019] (2) The present invention combines the conformability of the outer flexible silicone sheet, so that the heat source can be applied evenly to the skin whether it is on a flat back or a curved side, eliminating the depth difference caused by different pressure and poor contact surface adhesion, effectively overcoming contact pressure error, significantly reducing the standard deviation of samples within and between groups, and greatly improving the repeatability of the experiment.

[0020] (3) The core layer of this invention uses a hydrophobic silica aerogel felt with nanopores, whose extremely low thermal conductivity can effectively block vertical heat transfer, and the outer silicone sheet further blocks lateral heat diffusion. This composite thermal insulation structure ensures that the skin temperature in the covered area is maintained within a safe range (<45°C) except for the wound window, achieving full-thickness burns in the target area while leaving the surrounding tissues undamaged, and ensuring the clarity of the damage boundary in pathological sections.

[0021] (4) The present invention uses medical silicone double-sided tape with mild adhesion and non-destructive peeling properties to apply the silicone side to the skin, so that the material will not peel off the stratum corneum or cause mechanical redness and swelling when it is removed, unlike acrylic glue. This ensures that the inflammation and healing response of the burn model wound is entirely due to thermal damage, eliminating the confounding variable of mechanical damage, and making the pathological score and molecular biological test results more reliable.

[0022] (5) The burn modeling patch provided by the present invention is a sheet-like flexible composite material, which can be cut into different shapes (circles, squares, etc.) and sizes of wound windows according to the experimental animal species (rats, mice, pigs, etc.) and experimental requirements. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a heat-insulating, leak-proof, flexible burn molding patch. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 This embodiment provides a heat-insulating, leak-proof, flexible burn molding patch, referring to... Figure 1 The burn molding patch includes a sandwich layered structure and an RTV silicone edge sealing structure; The sandwich layered structure comprises, from the outside to the inside, a medical-grade silicone rubber sheet, a hydrophobic silica aerogel felt, and a medical-grade silicone double-sided tape. The burn molding patch is provided with a wound-causing window; The inner wall of the wound window is coated with RTV silicone to form a continuous edge-sealing protective ring.

[0026] The preparation method of the heat-insulating, leak-proof, flexible burn molding patch includes the following steps: Step 1, Lamination: Apply the acrylic adhesive side of 3M™ 2477 tape (0.1mm thick) to one side of hydrophobic silica aerogel felt (1mm thick, hydrophobicity ≥99%, thermal conductivity 0.02W / m·K). Spray 3M Super 77 adhesive onto the other side and attach the outer medical-grade silicone rubber sheet (0.5mm thick). Compact the layers with rollers to form a three-layer composite patch.

[0027] Step 2, Cutting out the molding window: Based on the required 2cm diameter circular burn area on the rat's back, use a punch to make a 2cm diameter circular through hole on the composite patch.

[0028] Step 3, RTV sealing: Use a cotton swab to apply RTV silicone evenly to the inner wall of the through hole. Wait for it to fully cure to ensure that the aerogel felt is not exposed, forming a continuous waterproof protective ring to prevent aerogel powder from falling off and hot liquid from seeping into the interlayer laterally.

[0029] Step 4, Sterilization: After the material is packaged, it is sterilized with ultraviolet light and set aside for later use.

[0030] Example 2 Applications of burn molding patches: (1) Animal skin pretreatment: 1. Anesthesia and skin preparation: After intraperitoneal injection anesthesia, the hair on the back of the rat was shaved.

[0031] 2. Chemical hair removal: Use hair removal cream for 2-3 minutes to completely remove the hair shaft and expose smooth skin (residual hair stubs will damage the silicone seal).

[0032] 3. Degreasing and cleaning: Wash off the hair removal cream with warm water, wipe dry with a gauze, and then gently wipe with an alcohol swab to remove the grease.

[0033] (2) Implementation of burn molding and patching: 1. Application: Remove the release paper from the acrylic adhesive side of 3M™ 2477, align the wound window with the predetermined site, and apply it to the rat's back.

[0034] 2. Negative pressure: Press firmly around the edge of the wound with your fingers, using body temperature and pressure to allow the 3M™ 2477 silicone to fully penetrate the skin texture.

[0035] 3. Thermal injury: The rat was placed upside down and pressed against the opening of a constant temperature water bath (100℃).

[0036] 4. Timing and Termination: Once the predetermined time is reached, immediately remove the heat source.

[0037] 5. Remove the patch: After blotting the wound with sterile gauze, gently peel off the patch.

[0038] Example 3 Thermodynamic properties and sealing performance of burn molding patches (in vitro experiments): 1. Experimental objective: Verify the thermal insulation performance (protecting surrounding tissues) and waterproof sealing performance (preventing side leakage) of the material of the present invention in a 100°C water bath environment.

[0039] 2. Experimental Groups: Experimental patch (Example 1 of this invention): 0.5mm silicone sheet + 1mm hydrophobic silica aerogel felt (hydrophobicity ≥99%, thermal conductivity 0.02W / m·K) + 0.1mm 3M™ 2477 tape + 2cm diameter circular through hole + RTV silicone sealing edge.

[0040] Control group A patch (traditional aluminum foil): 0.05mm single-layer aluminum foil + 0.16mm 3M™ 1522 medical acrylic double-sided tape + 2cm diameter circular through hole.

[0041] Control group B patch (ordinary plastic): 1mm thick polypropylene (PP) sheet + 0.13mm 3M™ 468MP double-sided adhesive tape + 2cm diameter circular through hole.

[0042] 3. Experimental methods: (1) Thermal insulation test: The patch was applied to a 37°C constant-temperature thermosensitive color-changing plate (or simulated skin), and a thermocouple was attached to the back. The front was exposed to boiling water at 100°C for 30 seconds, and the temperature change curve and thermal infrared image of the back were recorded.

[0043] (2) Sealing test: The patch is applied to a textured biomimetic silicone skin and immersed in 100°C boiling water dyed with methylene blue for 20 seconds. After removal, the material is peeled off, and the diameter and roundness of the dyed area are measured.

[0044] 4. Experimental Results: (1) Thermal insulation data: Experimental group: After contact with boiling water for 30 seconds, the temperature on the back of the material only rose to 41.5℃±0.8℃ (not reaching the burn threshold of 45℃), and the thermal infrared image showed no thermal halo diffusion around the through hole (the injury window).

[0045] Control group A: The temperature on the back exceeded 85°C after 30 seconds of contact, indicating significant lateral heat conduction.

[0046] (2) Sealing data: Experimental group: The edge of the dyed area is sharp, with no dye leakage, and the error between the dyed diameter and the preset opening diameter is <0.5mm.

[0047] Control group B: The staining solution seeped outward along the texture, forming a burr-like edge. The actual stained area was 15-30% larger than the preset area.

[0048] The above experimental results show that the burn molding patch provided by the present invention has excellent heat insulation properties, can effectively block the transfer of heat to non-target areas, and the adhesive layer achieves perfect sealing at the microscopic level, eliminating hot liquid leakage and solving the problem of uncontrollable injury area.

[0049] Example 4 Consistency evaluation of the rat model of deep second-degree burns on the back using burn patch (in vivo experiment): 1. Experimental objective: The differences between the material of this invention and traditional modeling methods in terms of burn area consistency, depth uniformity, and repeatability are compared.

[0050] 2. Laboratory animals and grouping: (1) Thirty SPF-grade SD rats (250-300g) were randomly divided into three groups (n=10).

[0051] Group 1 (Example 1 of the present invention: patch + water bath): burn molding patch is applied and then contacted with a 100°C water bath for 12 seconds.

[0052] Group 2 (Metal Rod): Use a heated copper rod with a diameter of 2cm (100℃) + 500g pressure for 12 seconds.

[0053] Group 3 (Traditional Water Bath): Using a standard perforated plastic tube + 100℃ water bath for 12 seconds.

[0054] 3. Detection indicators: (1) General morphology: Take a picture 1 hour after the injury and use ImageJ software to analyze the wound area and roundness (the closer the value is to 1, the rounder it is).

[0055] (2) Pathological histology: 24 hours after the injury, wound tissue was taken for H&E staining and the depth from the epidermis to the bottom of the necrotic tissue was measured under a microscope.

[0056] (3) Statistical analysis: Calculate the coefficient of variation (CV = standard deviation / mean × 100%) for each group of data. The smaller the CV value, the better the repeatability.

[0057] 4. Experimental results: as shown in Table 1.

[0058] Table 1

[0059] As can be seen from Table 1, Group 2 has a deep center and shallow edges due to uneven contact pressure, resulting in a large coefficient of variation in depth; Group 3 has a significantly larger and irregular area due to side leakage.

[0060] Therefore, this invention group significantly outperforms the traditional water bath group in terms of burn area control precision and the metal rod group in terms of burn depth uniformity. The extremely low coefficient of variation (CV < 5%) demonstrates that the model has a very high degree of standardization and repeatability, making it suitable for demanding scientific research experiments.

[0061] Example 5 Biocompatibility and Mechanical Damage Assessment Experiment: 1. Experimental objective: To verify whether the inner layer of medical-grade silicone double-sided tape (3M™ 2477) causes additional mechanical damage to normal skin upon removal.

[0062] 2. Experimental Methods: The following were applied to the left and right sides of the back of the same rat: the burn modeling patch of this invention was applied to the left side, and the traditional strong adhesive tape (0.16mm 3M™1522 medical acrylic double-sided tape) was applied to the right side. After 30 minutes, the patches were removed at the same angle and speed.

[0063] 3. Observation indicators: (1) Skin erythema score: Observe the redness of the skin immediately after tearing. The specific scoring criteria are shown in Table 2.

[0064] Table 2

[0065] (2) Amount of stratum corneum peeling: A peeling test was conducted using adhesive tape, and the amount of skin flakes adhering to the surface of the tape was observed under a microscope.

[0066] (3) Transepidermal water loss (TEWL value): Skin barrier function was detected using a water loss meter.

[0067] 4. Experimental Results: (1) Skin erythema score: After the burn modeling patch of the present invention was removed, the skin surface was smooth, the color was normal, and there was no erythema (score 0). After the traditional strong adhesive tape in the control group was removed, the skin showed obvious redness and slight bleeding in some areas (score 2-3).

[0068] (2) TEWL value: Before application, the baseline TEWL values ​​of the skin on the left and right sides were (8.7±1.1) g / m² / h and (8.9±1.0) g / m² / h, respectively. After the burn modeling patch of the present invention was removed, the TEWL value was (9.2±1.3) g / m² / h, which was relatively small compared with the baseline. After the traditional strong adhesive tape in the control group was removed, the TEWL value was (26.4±3.7) g / m² / h, which was significantly higher (>25 g / m² / h). 2 / h) indicates damage to the stratum corneum barrier.

[0069] (3) Observation of the amount of stratum corneum peeling: After the burn modeling patch of the present invention was removed, the adhesive surface under the microscope was relatively clean, while the traditional strong adhesive tape in the control group had a large number of white stratum corneum fragments adhering to the adhesive surface under the microscope.

[0070] As can be seen from the above, the medical silicone interface used in this invention has excellent biocompatibility and achieves non-destructive peeling. This design ensures that all tissue damage and inflammatory responses observed in the experiment are entirely due to thermal burns, eliminating the important confounding variable of mechanical damage.

[0071] Based on the above experimental results, the burn modeling patch prepared by this invention has a burn area error of less than 5% compared to the preset window, which is very precise. The coefficient of variation (CV) of the burn depth within the group is low. The patch does not damage the stratum corneum or cause redness and swelling when removed, and the temperature rise of adjacent tissues is small, with no accidental burns. At the same time, the silicone is odorless and non-toxic, not easily chewed by rats, has good biocompatibility, and is soft enough to fit curved areas such as limbs and flanks.

[0072] This invention successfully constructs a flexible barrier that combines high thermal insulation with microscopic sealing through a sandwich structure and RTV sealing technology, solving the problems of side leakage and thermal halo in traditional liquid burn models. It also eliminates mechanical skin damage interference, providing a highly controllable, standardized, and data-pure ideal experimental platform for research on burn wound healing mechanisms, drug screening, and tissue-engineered skin transplantation.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heat-insulating, leak-proof, flexible burn molding patch, characterized in that, The burn molding patch includes a sandwich layered structure and an RTV silicone edge sealing structure; The sandwich layered structure comprises, from the outside to the inside, a medical-grade silicone rubber sheet, a hydrophobic silica aerogel felt, and a medical-grade silicone double-sided tape. The burn molding patch is provided with a wound-causing window; The inner wall of the wound window is coated with RTV silicone to form a continuous edge-sealing protective ring.

2. The heat-insulating, leak-proof, flexible burn molding patch according to claim 1, characterized in that, The thickness of the medical-grade silicone rubber sheet is 0.5 mm.

3. The heat-insulating, leak-proof, flexible burn molding patch according to claim 1, characterized in that, The thickness of the hydrophobic silica aerogel felt is 1-2 mm.

4. The heat-insulating, leak-proof, flexible burn molding patch according to claim 1, characterized in that, The hydrophobic silica aerogel felt has a hydrophobicity of ≥99%.

5. The heat-insulating, leak-proof, flexible burn molding patch according to claim 1, characterized in that, The thermal conductivity of the hydrophobic silica aerogel felt is 0.015-0.030 W / m·K.

6. The heat-insulating, leak-proof, flexible burn molding patch according to claim 1, characterized in that, The medical-grade silicone double-sided tape is 3M™ 2477 tape.

7. The heat-insulating, leak-proof, flexible burn molding patch according to claim 1, characterized in that, The thickness of the medical silicone double-sided tape is 0.1-0.15mm.

8. The heat-insulating, leak-proof, flexible burn molding patch according to claim 1, characterized in that, The RTV silicone is coated and cured at room temperature to form an integrated sealing structure on the inner wall of the injury window.

9. A method for preparing a heat-insulating, leak-proof, flexible burn molding patch, characterized in that, The preparation of the burn molding patch as described in any one of claims 1-8 includes the following steps: Step 1, Lamination and Composite: One side of medical silicone double-sided tape is attached to one side of the hydrophobic silica aerogel felt, leaving the silicone side exposed to the skin. The other side of the hydrophobic silica aerogel felt is sprayed with 3M Super 77 adhesive and bonded to the outer medical-grade silicone rubber sheet. The layers are then compacted using rollers to form a three-layer composite patch. Step 2, Cutting out the molding window: Use a hole punch to make through holes in the composite patch as needed to create a damage window; Step 3, RTV sealing: Apply RTV silicone evenly to the inner wall of the through hole and wait for it to fully cure to ensure that the aerogel felt is not exposed, forming a continuous waterproof protective ring to prevent aerogel powder from falling off and hot liquid from seeping into the interlayer laterally. Step 4, Sterilization: After the material is packaged, it is sterilized with ethylene oxide or ultraviolet light and then set aside for later use.

10. An application of a heat-insulating, leak-proof, flexible burn molding patch, characterized in that, The burn molding patch as described in any one of claims 1-8 can be used in conjunction with the hot water scalding method for burn molding.

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