Hemostatic dressing with Janus hydrophilic and hydrophobic composite interface and preparation method thereof

Abstract

The invention discloses a hemostatic dressing with a Janus hydrophilic and hydrophobic composite interface and a preparation method of the hemostatic dressing, and belongs to the technical field of medical dressings. The hemostatic dressing comprises a three-layer structure, the innermost layer is a super-hydrophobic medicine layer, the middle layer is a super-hydrophilic liquid absorption layer, the outermost layer is a super-hydrophobic protection layer, and a functional gradient structure is constructed through layered modification; the inner-layer super-hydrophobic medicine layer and the outer-layer super-hydrophobic protection layer are the same in structure and composition, PDMS modification and CuS + TA loading processes are adopted, and an inner-layer and outer-layer double-hydrophobic symmetrical structure is formed; the middle layer is a super-hydrophilic liquid absorption layer formed by PVA and boric acid; the inner layer and the middle layer are connected in a discontinuous sewing mode through medical hydrophilic cotton threads, and the middle layer and the outer layer are bonded through an acrylic ester medical adhesive. Through the gradient design of the super-hydrophobic medicine layer, the super-hydrophilic liquid absorption layer and the super-hydrophobic protection layer, the synergistic functions of rapid hemostasis, efficient antibiosis and wound surface secondary injury prevention are achieved, and good biological safety is achieved.

Description

Technical Field

[0001] This invention belongs to the field of medical dressing technology, and relates to a hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface that has the functions of rapid hemostasis, antibacterial properties and prevention of secondary damage, as well as its preparation method. Background Technology

[0002] As a key medical consumable for wound healing, wound dressings directly affect the wound healing rate, infection risk, and patient comfort. They have evolved from simply "covering the wound" in the early stages to a multi-dimensional synergistic approach that includes "hemostasis, antibacterial properties, promoting healing, and preventing damage."

[0003] Medical cotton dressings are still widely used for basic care of low-exudate and chronic wounds due to their readily available raw materials, low cost, and good biocompatibility. However, in cases of acute trauma and postoperative bleeding, their technical shortcomings have become a core bottleneck restricting clinical application. Traditional cotton dressings rely on capillary adsorption between fibers for absorption, but their fiber surfaces lack targeted hydrophilic design, resulting in a low initial absorption rate of wound exudate. Furthermore, after absorption, fiber swelling can cause blockage of the gaps, hindering the rapid concentration of wound clotting factors and making it difficult to achieve a synergistic "compression-absorption-clotting" effect through physical structure. Traditional cotton dressings rely solely on physical barrier effects, lacking active antibacterial components. The porous structure of cotton fibers easily absorbs wound secretions, creating a breeding ground for bacteria. They have no significant antibacterial effect against common wound pathogens such as Staphylococcus aureus and Escherichia coli, especially in moist wound environments where bacterial reproduction can increase 3-5 times, further exacerbating the risk of infection. Traditional cotton dressings have inherent defects in their interaction mechanism with wounds: on the one hand, after the dressing absorbs exudate, the cotton fibers easily form physical adhesions with the newly formed granulation tissue and fibrin membrane of the wound; on the other hand, the dressing lacks a hydrophobic interface design, and red blood cells and platelets in the blood easily adhere to the fiber surface and coagulate, resulting in the dressing being tightly bound to the wound. When removing the dressing, it is very easy to cause tearing of granulation tissue and re-rupture of capillaries, which not only causes severe pain to the patient, but also leads to secondary bleeding and aggravated inflammatory response, prolonging the healing period by 30%-50%.

[0004] Nie et al. (Wei Nie, Xinyi Dai, Dejian Li, et al. One-Pot Synthesis of Silver Nanoparticle Incorporated Mesoporous Silica Granules for Hemorrhage Control and Antibacterial Treatment [J]. ACS Biomaterials Science & Engineering, 2018, 4, 10) achieved antibacterial function by introducing metallic Ag nanoparticles, but did not optimize the liquid absorption and anti-adhesion properties, and the long-term release of metal ions could easily cause cytotoxicity; Jin et al. (Chunfeng Jin, Xiaobao Gong, Wenling Jiao, et al. Superhydrophobic polyvinylidene fluoride nanofibrous membranes with stable hierarchical structures for protective textiles [J]. Composites Communications, 2023, 38, 101500) used polyvinylidene fluoride to achieve superhydrophobicity in textiles, which could reduce dressing adhesion, but the fluoride was prone to residual toxicity, posing a biosafety hazard. Summary of the Invention

[0005] Addressing the three core shortcomings of existing cotton wound dressings—low hemostatic efficiency, weak antibacterial ability, and severe wound adhesion—this invention provides a hemostatic dressing based on medical cotton fabric with a Janus hydrophilic-hydrophobic composite interface, suitable for wound care in acute trauma and post-surgical procedures. This invention achieves synergistic functionality—rapid hemostasis, efficient antibacterial effect, and prevention of secondary injury—through a gradient functional design of a superhydrophobic drug layer, a superhydrophilic absorbent layer, and a superhydrophobic protective layer, combined with the synergistic effect of material components and process innovation. Simultaneously, it considers the dressing's biocompatibility, mechanical stability, and feasibility for large-scale production, overcoming the technical limitations of existing single-function dressings.

[0006] This invention provides a hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface, comprising a three-layer structure: an innermost superhydrophobic drug layer, a middle superhydrophilic absorbent layer, and an outermost superhydrophobic protective layer. Each layer uses medical cotton fabric as the substrate, and a functional gradient structure is constructed through layered modification. The layers are connected by an innovative process to form a holistic system of "functional complementarity and synergistic effect." The specific technical solution and innovative mechanism are as follows: 1. Functional design of each layer (1) Innermost layer (superhydrophobic drug layer): Overcoming the limitations of traditional cotton fabrics that are "non-hydrophobic and prone to adhesion," this layer uses medical cotton fabric as the substrate and polydimethylsiloxane (PDMS) to modify the surface of the cotton fabric, constructing a PDMS coating on the surface of the cotton fibers. During the curing process, in order to minimize the surface energy of the system, the molecular chains of PDMS spontaneously orient the nonpolar methyl groups (-CH3) outward on the fiber surface. This orientation structure is then permanently fixed by the cross-linking network, thereby forming a stable low surface energy interface, making the water contact angle of the coating ≥150°, achieving a superhydrophobic state. This not only avoids direct adhesion between wound blood, exudate and dressing fibers, but also reduces irritation to the wound through the bio-inertness of PDMS, solving the core pain point of "secondary damage after dressing removal." This layer is loaded with CuS nanospheres and tannic acid (TA) to construct a composite antibacterial system. The CuS nanospheres release Cu through slow release of Cu 2+ It disrupts the integrity of bacterial cell membranes; tannic acid binds to bacterial surface proteins through hydrogen bonds via phenolic hydroxyl groups, leading to protein denaturation; the two form a synergistic antibacterial effect of "physical disruption-chemical inhibition".

[0007] (2) Intermediate layer (superhydrophilic absorbent layer): To address the shortcomings of traditional cotton fabrics in terms of slow absorption rate and low absorption volume, polyvinyl alcohol (PVA) and boric acid (H3BO3) are used for synergistic modification. By utilizing the cross-linking reaction between H3BO3 and the hydroxyl groups (-OH) in the PVA molecular chain, a "network of hydrophilic groups" is constructed on the surface of the cotton fabric fibers, making the surface of the cotton fabric hydrophilic and significantly improving the absorbency. It can quickly absorb wound exudate and blood, concentrate clotting factors, and accelerate prothrombin activation, providing a physical basis for "rapid hemostasis".

[0008] (3) Outermost layer (superhydrophobic protective layer): The outermost and innermost layers use the same PDMS modification and CuS+TA loading process to form a symmetrical structure with double hydrophobicity between the inner and outer layers. The superhydrophobicity of the outer layer can isolate external dust and liquids from entering the wound and avoid secondary contamination; at the same time, the CuS+TA composite system loaded on the outer layer can pre-treat bacteria that come into contact with the outside world, forming a double antibacterial barrier; in addition, the superhydrophobicity of the outer layer prevents the dressing from sticking to external objects such as clothing and sheets, further improving the comfort and ease of use.

[0009] 2. Interlayer connection process (1) The innermost and middle layers are intermittently sutured with medical hydrophilic cotton thread. This eliminates the drawback of traditional adhesives that can easily block the liquid absorption channels in the middle layer; the hydrophilicity of the cotton thread is compatible with the hydrophilic properties of the middle layer, so it does not hinder liquid conduction and avoids skin irritation that may be caused by adhesives.

[0010] (2) The intermediate layer and the outermost layer are bonded together with an acrylic medical adhesive. The adhesive forms a thin film only on the fiber surface of the intermediate layer and the outermost layer, without penetrating into the interior of the intermediate layer, ensuring that the liquid absorption performance of the intermediate layer is not affected; at the same time, the acrylic adhesive does not chemically react with PDMS and PVA, and does not damage the functional structure of each layer.

[0011] The inner superhydrophobic drug layer and the outer superhydrophobic protective layer have the same structure and composition. The composition is as follows: using medical cotton cloth as the substrate, the surface of the cotton cloth is modified with polydimethylsiloxane (PDMS) to construct a PDMS coating on the surface of the cotton cloth fibers; and CuS nanospheres and tannic acid (TA) are loaded to construct a composite antibacterial system.

[0012] The intermediate layer, namely the superhydrophilic absorbent layer, is composed of: medical cotton fabric as the base material, polyvinyl alcohol (PVA) and boric acid (H3BO3) are used for synergistic modification, and the cross-linking reaction of H3BO3 with the hydroxyl groups (-OH) in the PVA molecular chain is used to construct a "network of hydrophilic groups" on the surface of the cotton fabric fibers, so that the surface of the cotton fabric reaches a hydrophilic state.

[0013] The inner layer and the middle layer are connected by interrupted sutures using medical hydrophilic cotton thread, and the middle layer and the outer layer are bonded together using acrylic medical adhesive. In this invention, PDMS is a two-component product purchased from Dow Corning, model number dc184, comprising a main agent and a corresponding crosslinking agent; the acrylate medical adhesive is purchased from Shenzhen Mingde Chemical Co., Ltd.; the medical cotton cloth is medical-grade degreased cotton cloth, and the medical cotton thread is medical-grade degreased cotton thread.

[0014] This invention provides a method for preparing the above-mentioned hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface, comprising the following steps: (1) Cu(NO3)2·3H2O, PVP and thioacetamide were added to DMSO and magnetically stirred until all components were completely dissolved. The mixture was then transferred to a polytetrafluoroethylene reactor for hydrothermal reaction. After the reaction was completed, the mixture was centrifuged, washed and vacuum dried to obtain CuS nanospheres. (2) Add the product from step (1) together with TA to deionized water, adjust the pH of the solution with dilute hydrochloric acid, stir magnetically and then freeze dry. (3) Cut the medical cotton cloth and cotton thread to the preset specifications, immerse them in NaOH solution to remove the surface wax, wash them with deionized water, and dry them in an oven; (4) Take the product from step (2) and add it into EA. Use ultrasound to make the particles evenly dispersed in EA. Add PDMS main agent and corresponding crosslinking agent to EA dispersion and stir magnetically to make PDMS completely dissolved in EA dispersion. (5) Immerse the cotton cloth and cotton thread treated in step (3) into the PDMS-EA dispersion in step (4), remove them after full immersion, and dry them in an oven to obtain inner and outer dressings; (6) Dissolve PVA powder in deionized water, heat and stir to prepare PVA solution; dissolve H3BO3 powder in deionized water to prepare H3BO3 solution, mix PVA solution and H3BO3 solution, heat and stir magnetically; (7) Immerse the cotton cloth and cotton thread treated in step (3) into the PVA-H3BO3 mixed solution in step (6), perform a two-dip and two-roll process under water bath heating, and then place them in an oven for heat treatment. After curing, rinse with deionized water and dry. (8) Take the cotton fabric products processed in steps (5) and (7) respectively, cut them into the same size, and sew them together with the cotton thread processed in step (7); (9) Use an acrylic medical adhesive to bond the hydrophilic surfaces of the cotton fabric product from step (5) and the product from step (8) to obtain a three-layer composite dressing.

[0015] The above preparation method is further explained as follows: In step (1), the ratio of Cu(NO3)2·3H2O, PVP, thioacetamide and DMSO is 0.4-0.6 g:0.3-0.5 g:0.2-0.4 g:20-40 mL. The magnetic stirring speed is 500-600 rpm, the magnetic stirring time is 20-30 min, the hydrothermal reaction temperature is 100-140 ℃, the hydrothermal reaction time is 20-28 h, the centrifuge speed is 7000-9000 rpm, the centrifugation time is 5-10 min, the anhydrous ethanol washing is 3-5 times, the vacuum drying oven temperature is 50-80 ℃, and the vacuum drying time is 10-16 h.

[0016] In step (2), the mass ratio of the product from step (1) to tannic acid is 0.9-1.1:1. The amount of deionized water used is: 40-60 mL of deionized water for 50-100 mg of tannic acid. The concentration of dilute hydrochloric acid is 0.1 mol / mL. The pH of the solution is adjusted to 5.5-6. The magnetic stirring speed is 500-600 rpm and the magnetic stirring time is 20-30 min.

[0017] In step (3), the concentration of NaOH solution is 0.8 g / mL-1.2 g / mL, the dewaxing time is 20-30 min, the number of times of washing with deionized water is 3-5, the oven temperature is 50-80 ℃, and the drying time is 10-15 min.

[0018] In step (4), the ratio of the product from step (2) to EA is 40-60 mg: 15-25 mL, the sonication time is 5-10 min, the amount of PDMS agent is 6-9 g of PDMS agent per 100 mL of EA dispersion, the mass ratio of PDMS agent to crosslinking agent is 8-12:1, the magnetic stirring speed is 500-600 rpm, and the magnetic stirring time is 20-30 min.

[0019] In step (5), the size of the cotton cloth after step (3) is (80~120) mm × (80~120) mm × 1 mm, the immersion time is 10-20 min, the oven temperature is 60-80 ℃, and the drying time is 3-5 h.

[0020] In step (6), the mass concentration of the PVA solution is 3-7%, the heating and stirring temperature is 80-95 ℃, the stirring time is 2-3 h, and the magnetic stirring speed is 500-600 rpm; the mass concentration of the H3BO3 solution is 1-3%, the stirring time is 10-15 min, and the magnetic stirring speed is 500-600 rpm; the volume ratio of the PVA solution to the H3BO3 solution is 4-6:1, the stirring time after mixing is 10-15 min, the heating and stirring temperature is 80-95 ℃, and the magnetic stirring speed is 500-600 rpm.

[0021] In step (7), the size of the cotton fabric after step (3) is (80~120) mm × (80~120) mm × 1 mm, and the water bath heating temperature is 60-80 ℃; in the two-dip and two-pinch process: the first dip time is 3-5 min, the puffing rate is 70-90%, and the cotton fabric is turned over and dipped for 3-5 min during the second dip, with a puffing rate of 70-90%; the oven heat treatment temperature is 120-150 ℃, the heat treatment time is 3-5 min, the number of deionized water rinsings is 3-5, the drying temperature after rinsing is 40-60 ℃, and the drying time is 2-3 h.

[0022] In step (8), the suturing is done using a flat stitch technique with a stitch length of 3-5 mm and the stitches are evenly distributed.

[0023] In step (9), the amount of adhesive applied is 2-4 mg / cm³. 2 .

[0024] This invention provides the application of the above-mentioned hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface in wound care.

[0025] When using the dressing of this invention, the innermost layer (superhydrophobic drug layer) of the dressing can be directly placed towards the wound surface to completely cover the bleeding wound, ensuring that the edge of the dressing extends at least 3mm beyond the edge of the wound to ensure that the wound surface is completely covered; after covering, apply uniform pressure to the surface of the outermost layer (superhydrophobic protective layer) of the dressing and press continuously for 3-5 minutes until the bleeding from the wound completely stops.

[0026] The beneficial effects of this invention are: (1) Rapid hemostasis function. The superhydrophilic properties of the middle layer can quickly absorb wound exudate and blood, and accelerate the coagulation cascade reaction by concentrating coagulation factors; the superhydrophobic properties of the innermost layer prevent blood from adhering to the dressing fibers and reduce the interfacial resistance during the coagulation process. The two work together to shorten the hemostasis time by more than 70% compared with traditional cotton dressings, which can effectively reduce the risk of acute traumatic hemorrhagic shock.

[0027] (2) Highly effective antibacterial function. An innovative synergistic antibacterial system combining CuS nanospheres and TA through "physical disruption-chemical inhibition" is employed. The CuS nanospheres slowly release Cu... 2+ It disrupts the integrity of bacterial cell membranes; TA binds to bacterial proteins through phenolic hydroxyl groups, causing protein denaturation. The two work synergistically to achieve an antibacterial rate of ≥99.99% against Staphylococcus aureus, which is 20%-30% higher than that of a single antibacterial component.

[0028] (3) Prevent secondary damage. The inner and outer double-layer superhydrophobic design forms a "two-way anti-adhesion barrier". The innermost superhydrophobic surface is in direct contact with the wound, avoiding adhesion between granulation tissue and fibrin membrane; the outermost superhydrophobic surface isolates external clothing, sheets and other objects from adhering, so that there is no pulling pain or tissue tearing when removing it, which solves the problem of secondary bleeding and aggravation of inflammation when removing traditional dressings.

[0029] (4) Excellent biosafety. All components meet medical biosafety standards. PDMS has good bioinertness and does not irritate the skin. The cross-linked products of PVA and H3BO3 can be slowly metabolized by the human body. CuS nanospheres and TA have low loading and no risk of heavy metal accumulation.

[0030] (5) Clinical convenience and suitability. The dressing base material is medical cotton cloth, which has excellent flexibility and can closely fit joints, trunk and other active parts without affecting the patient's daily activities; it supports cutting as needed and is suitable for various wound types such as acute trauma, post-surgical, and burns; no additional solvent is needed when changing the dressing, it can be directly peeled off, which is simple to operate and leaves no fiber residue, reducing the risk of foreign body reaction.

[0031] (6) Environmental sustainability and economic efficiency. The base material is renewable medical cotton fabric, and the preparation process does not require the use of toxic solvents or high-energy-consuming equipment. After disposal, the cotton fabric and cotton thread base material can be naturally degraded, and the PDMS and PVA coating can be harmlessly disposed of through conventional medical waste treatment processes, meeting environmental protection requirements. At the same time, the raw material cost is low, the production process is simple, and it is easy to achieve large-scale mass production, which can meet the needs of primary medical institutions and public health emergency response. Attached Figure Description

[0032] Figure 1 The images show SEM images of CuS powder (a), TA powder (b), and CuS+TA composite powder (c) under the conditions of Example 1, as well as XRD patterns (d) and FTIR patterns (e) of the three powders. Figure 2 The results are the contact angle test results of each layer of the composite hemostatic dressing under the conditions of Example 1 (unmodified cotton cloth, PDMS modified cotton cloth, CuS modified cotton cloth, TA modified cotton cloth, CuS+TA modified cotton cloth, PVA-H3BO3 modified cotton cloth). Figure 3 The results of antibacterial, antibacterial adhesion, and antibacterial penetration tests of the composite hemostatic dressing under the conditions of Example 1 are as follows: (a) Plate counting test results of each group of samples under light / contact conditions; (b) Plate test results of antibacterial adhesion and antibacterial penetration of each group of samples; (c) Antibacterial rate of each group of samples under light / contact conditions; (d) Antibacterial adhesion rate of each group of samples. Figure 4 The results are from the mouse liver single-incision bleeding model experiment under the conditions of Example 1, including (a) bloodstain images of unmodified cotton cloth, CuS+TA cotton cloth, PVA-H3BO3 hydrophilic cotton cloth and HHH three-layer structure cotton cloth of the present invention after hemostasis; (b) blood loss of each material group; and (c) hemostasis time of each material group. Detailed Implementation

[0033] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments.

[0034] To better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, the scope of protection of the present invention is not limited to the scope described in the following embodiments. Example 1

[0035] A hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface is provided, and a method for preparing the same is described. The preparation method is carried out according to the following steps: Step 1: Add 0.5 g Cu(NO3)2·3H2O, 0.4 g PVP and 0.3 g thioacetamide to 30 mL DMSO, and stir magnetically at 500 rpm for 30 min until completely dissolved. Then transfer to a polytetrafluoroethylene reactor and carry out hydrothermal reaction at 120℃ for 24 h. After the reaction is completed, centrifuge at 8000 rpm for 10 min, wash 4 times with anhydrous ethanol, and vacuum dry at 60℃ for 12 h.

[0036] Step 2: After vacuum drying, add 50 mg of the product from Step 1 and 50 mg of tannic acid to 50 mL of deionized water, adjust the pH of the solution to 5.5 with 0.1 mol / mL dilute hydrochloric acid, stir magnetically at 500 rpm for 20 min, and then freeze dry. Step 3: Cut the medical cotton cloth and cotton thread, immerse them in a 1 g / mL NaOH solution for 20 min to remove the surface wax, then wash them 3 times with deionized water and dry them in a 60 ℃ oven for 15 min.

[0037] Step 4: After freeze-drying, add 50 mg of the product from Step 2 to 20 mL of EA and sonicate for 15 min to disperse the particles evenly in EA. Then add 1.5 g of PDMS main agent and 0.15 g of crosslinking agent to the EA dispersion and magnetically stir at 500 rpm for 20 min to completely dissolve the PDMS in the EA dispersion.

[0038] Step 5: Cut the cotton cloth and cotton thread treated in Step 3 to 100×100×1 mm, then immerse them in the PDMS-EA dispersion in Step 4 for 15 min until fully impregnated. After that, take them out and place them in an oven at 60 ℃ for 4 h to dry.

[0039] Step 6: Dissolve 2.5 g of PVA powder in 50 mL of deionized water and heat to 90 °C. Stir magnetically at 500 rpm for 2 h to prepare a PVA solution. Dissolve 0.2 g of boric acid powder in 10 mL of deionized water and stir magnetically at 500 rpm for 10 min to prepare a boric acid solution. Mix the prepared PVA solution and boric acid solution and stir magnetically at 90 °C and 500 rpm for 10 min to prepare a PVA-boric acid mixed solution.

[0040] Step 7: Cut the cotton fabric treated in Step 3 to 100×100×1 mm and the cotton thread to 1 m in length. Immerse them in the PVA-boric acid mixed solution from Step 5 for 5 min while heating in a water bath to 80 ℃. Then perform a rolling operation, controlling the roll-off rate to 80%. Repeat the immersion-rolling operation once, then place them in an oven at 130 ℃ for 5 min. After that, rinse them three times with deionized water and dry them in an oven at 60 ℃ for 2 h.

[0041] Step 8: Take the cotton fabrics from Step 5 and Step 7, each cut to 100×100×1 mm in size. Using 30 cm of cotton thread from Step 7, sew the fabrics from Step 4 and Step 7 together with a flat stitch, controlling the stitch length to 3 mm and keeping the stitches evenly distributed.

[0042] Step Nine: Use an acrylic medical adhesive to bond the hydrophilic surfaces of the cotton fabric product from Step Five and the product from Step Eight, controlling the adhesive application rate to be 4 mg / cm². 2 A composite hemostatic dressing with a size of approximately 100×100 mm was obtained.

[0043] The prepared hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface is used in the care of acute trauma, postoperative surgical wounds, etc. When using the dressing of this invention, the innermost layer (superhydrophobic drug layer) of the dressing is placed directly towards the wound, so as to completely cover the bleeding wound, ensuring that the edge of the dressing extends at least 3 mm beyond the edge of the wound to ensure that the wound is completely covered; after covering, uniform pressure is applied to the surface of the outermost layer (superhydrophobic protective layer) of the dressing, and the pressure is maintained for 3-5 minutes until the bleeding from the wound stops completely.

[0044] The microstructure, hydrophobic properties, antibacterial properties, and hemostatic ability of the composite hemostatic dressings prepared in the above embodiments were tested, and the experimental results are attached. Figures 1-4 As shown.

[0045] Figure 1SEM images of CuS powder, TA powder, and CuS+TA composite powder, along with their XRD and FTIR spectra, are presented. SEM shows that CuS powder exhibits a regular spherical structure with a uniform particle size distribution, ranging from 150 to 200 nm in diameter; TA powder displays a unique spherical shell morphology. After TA modification, CuS particles are uniformly loaded onto the spherical shell surface of TA without significant agglomeration. XRD analysis shows that the diffraction peaks of CuS powder match the characteristic diffraction peaks of its standard card, with no impurity peaks, indicating high purity and good crystallinity of the prepared CuS phase. Due to its natural amorphous morphology, TA's XRD pattern shows no obvious characteristic diffraction peaks. The CuS+TA composite powder retains the characteristic diffraction peaks of CuS without introducing new impurity peaks due to the introduction of TA. The FTIR spectrum of the CuS+TA composite powder shows three types of characteristic absorption peaks, corresponding to the stretching vibrations of C=O, C=C, and CO bonds, respectively. This confirms the successful grafting of CuS onto the TA surface.

[0046] Figure 2 The results show the contact angles of each layer of the composite hemostatic dressing. Unmodified medical cotton fabric, due to residual natural waxes on its surface, exhibited a contact angle of 122.2±2°, showing hydrophobicity, but not meeting the superhydrophobicity standard (water contact angle >150°). After modification with PDMS, CuS, or TA alone, the contact angles were 141.8±2°, 143.1±3°, and 143.7±3°, respectively. This indicates that simply coating the cotton fabric surface with materials such as PDMS, CuS, or TA only provides limited hydrophobicity; the contact angles do not reach the superhydrophobic threshold, thus failing to achieve superhydrophobic functionality. The contact angle of CuS+TA composite modified cotton fabric increased to 152.5±2°, meeting the criteria for superhydrophobicity. This is because the composite structure formed by CuS nanospheres and TA shells creates a micro / nano-scale rough structure on the surface of the cotton fabric, which, combined with low surface energy, significantly improves hydrophobicity. The contact angle of PVA-H3BO3 modified cotton fabric is 36.9±4°, exhibiting strong hydrophilicity. This is because the hydroxyl groups (-OH) in the PVA molecular chain crosslink with H3BO3 to form a hydrophilic network structure on the surface of the cotton fabric, greatly enhancing the adsorption capacity for water molecules.

[0047] Figure 3The results show the antibacterial, antibacterial adhesion, and antibacterial penetration experiments of each layer of the composite hemostatic dressing. The results indicate that neither the unmodified cotton cloth group nor the PDMS-modified cotton cloth group showed significant antibacterial activity under any of the three experimental conditions, proving that simple physical barrier or hydrophobic modification has no active antibacterial effect. Under light exposure of only 10 min, the antibacterial effect of the TA-modified cotton cloth group was not significant, while the antibacterial rates of the CuS-modified cotton cloth group and the CuS+TA composite modified cotton cloth group reached 70.85% and 70.74%, respectively, due to the photocatalytic antibacterial effect of CuS under light exposure. Under light exposure of only 12 h, the antibacterial activity of the CuS-modified cotton cloth group was negligible, while the antibacterial rates of the TA-modified cotton cloth group and the CuS+TA composite modified cotton cloth group reached 82.09% and 82.61%, respectively, because TA can achieve contact antibacterial effects by binding to bacterial proteins through phenolic hydroxyl groups. Under conditions of 12 hours of continued contact after 10 minutes of light exposure, the CuS+TA composite modified cotton fabric group achieved an antibacterial rate of 99.99%, exhibiting excellent antibacterial activity. This demonstrates a synergistic effect between the photocatalytic antibacterial properties of CuS and the contact antibacterial properties of TA. The antibacterial adhesion rate of the material increased with the enhanced hydrophobicity of the cotton fabric surface, showing a positive correlation with the water contact angle. The anti-adhesion rate of the CuS+TA composite modified cotton fabric group reached 99.23%. All hydrophobic surface groups (PDMS modified, CuS modified, TA modified, and CuS+TA composite modified) exhibited excellent antibacterial penetration performance, with the number of bacteria penetrating to the back of the dressing being <10 CFU / cm², far lower than that of the unmodified cotton fabric (>1000 CFU / cm²), verifying the physical barrier effect of the hydrophobic surface on bacterial migration.

[0048] Figure 4This study presents the results of a mouse liver single-incision hemorrhage model experiment using unmodified cotton cloth, CuS+TA modified cotton cloth, PVA-H3BO3 modified cotton cloth, and HHH composite hemostatic dressing. The results showed that the CuS+TA modified cotton cloth group, due to its superhydrophobic surface, had difficulty in effective adhesion of platelets and erythrocytes, thus inhibiting platelet aggregation and coagulation function to some extent, resulting in the highest blood loss. However, because the CuS+TA composite antibacterial agent it contained could activate coagulation factors in the blood, the hemostasis time was actually shorter than that of the unmodified cotton cloth group. The PVA-H3BO3 modified cotton cloth showed comparable blood loss and hemostasis time to the unmodified cotton cloth, indicating that simple hydrophilic modification only improves absorbency but does not create a synergistic "absorption-coagulation" effect, thus limiting the hemostatic effect. HHH composite hemostatic dressing demonstrated optimal hemostatic performance, reducing blood loss by 57.17% (from 0.481 g to 0.206 g) compared to the unmodified cotton cloth group, and shortening the hemostasis time to 31.67 s, approximately one-sixth that of the blank cotton cloth group. Its core mechanism is: the strong hydrophilic properties of the middle layer rapidly absorb blood from the wound, concentrating coagulation factors; the superhydrophobic properties of the inner layer reduce ineffective adhesion between fibers and the wound, accelerating the coagulation cascade reaction. These results indicate that HHH composite hemostatic dressing exhibits significant hemostatic effects in the bleeding model. Example 2

[0049] A hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface is provided, and a method for preparing the same is described. The preparation method is carried out according to the following steps: Step 1: Add 0.4 g Cu(NO3)2·3H2O, 0.3 g PVP and 0.4 g thioacetamide to 35 mL DMSO, and stir magnetically at 500 rpm for 30 min until completely dissolved. Then transfer to a polytetrafluoroethylene reactor and carry out hydrothermal reaction at 130℃ for 20 h. After the reaction is completed, centrifuge at 8000 rpm for 8 min, wash three times with anhydrous ethanol, and vacuum dry at 70℃ for 10 h.

[0050] Step 2: After vacuum drying, 90 mg of the product from Step 1 and 100 mg of tannic acid were added to 50 mL of deionized water. The pH of the solution was adjusted to 5.7 using 0.1 mol / mL dilute hydrochloric acid. The solution was then lyophilized after magnetic stirring at 500 rpm for 30 min. Step 3: Cut the medical cotton cloth and cotton thread, immerse them in 0.8 g / mL NaOH solution for 30 min to remove the surface wax, then wash them 3 times with deionized water and dry them in an oven at 60 ℃ for 10 min.

[0051] Step 4: After freeze-drying, add 40 mg of the product from Step 2 to 20 mL of EA and sonicate for 10 min to disperse the particles evenly in EA. Then add 1.2 g of PDMS main agent and 0.11 g of crosslinking agent to the EA dispersion and magnetically stir at 500 rpm for 20 min to completely dissolve the PDMS in the EA dispersion.

[0052] Step 5: Cut the product from Step 3 to a size of 120×120×1 mm, then immerse it in the PDMS-EA dispersion from Step 4 for 20 min until it is fully impregnated. After that, take it out and place it in an oven at 70 ℃ for 3 h to dry.

[0053] Step 6: Dissolve 2 g of PVA powder in 50 mL of deionized water and heat to 85 °C. Stir magnetically at 500 rpm for 2 h to prepare a PVA solution. Dissolve 0.1 g of boric acid powder in 10 mL of deionized water and stir magnetically at 500 rpm for 10 min to prepare a boric acid solution. Mix the prepared PVA solution and boric acid solution and stir magnetically at 85 °C and 500 rpm for 10 min to prepare a PVA-boric acid mixed solution.

[0054] Step 7: Cut the cotton fabric product from Step 3 to 120×120×1 mm and the cotton thread product to 1 m in length. Immerse them in the PVA-boric acid mixed solution from Step 5 for 3 min under water bath heating to 85 ℃. Then perform a rolling operation, controlling the roll residue rate to 90%. Repeat the immersion-rolling operation once. Then place them in an oven at 120 ℃ for 5 min. After that, rinse them 4 times with deionized water and dry them in an oven at 50 ℃ for 2 h.

[0055] Step 8: Take the cotton fabric products from Step 4 and Step 7, each cut to 120×120×1 mm in size. Using 20 cm of cotton thread from Step 7, sew the cotton fabric products from Step 4 and Step 7 together using a flat stitch technique, controlling the stitch length to 5 mm and keeping the stitches evenly distributed.

[0056] Step Nine: Use an acrylic medical adhesive to bond the hydrophilic surfaces of the cotton fabric product from Step Five and the product from Step Eight, controlling the adhesive application rate to be 3 mg / cm². 2 A composite hemostatic dressing with a size of approximately 120×120 mm was obtained. Example 3

[0057] A hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface is provided, and a method for preparing the same is described. The preparation method is carried out according to the following steps: Step 1: Add 0.6 g Cu(NO3)2·3H2O, 0.5 g PVP and 0.3 g thioacetamide to 40 mL DMSO, and stir magnetically at 500 rpm for 30 min until completely dissolved. Then transfer to a polytetrafluoroethylene reactor and carry out hydrothermal reaction at 140℃ for 24 h. After the reaction is completed, centrifuge at 7000 rpm for 10 min, wash three times with anhydrous ethanol, and vacuum dry at 50℃ for 12 h.

[0058] Step 2: After vacuum drying, 110 mg of the product from Step 1 and 100 mg of tannic acid were added to 50 mL of deionized water. The pH of the solution was adjusted to 6 using 0.1 mol / mL dilute hydrochloric acid. The solution was then lyophilized after magnetic stirring at 500 rpm for 20 min. Step 3: Cut the medical cotton cloth and cotton thread, immerse them in a 1.2 g / mL NaOH solution for 20 min to remove the surface wax, then wash them 5 times with deionized water and dry them in a 70 ℃ oven for 10 min.

[0059] Step 4: After freeze-drying, add 60 mg of the product from Step 2 to 20 mL of EA and sonicate for 10 min to disperse the particles evenly in EA. Then add 1.5 g of PDMS main agent and 0.15 g of crosslinking agent to the EA dispersion and magnetically stir at 500 rpm for 25 min to completely dissolve the PDMS in the EA dispersion.

[0060] Step 5: Cut the product from Step 3 to a size of 80×80×1 mm, then immerse it in the PDMS-EA dispersion from Step 4 for 15 min until it is fully impregnated. After that, take it out and place it in an oven at 60 ℃ for 5 h to dry.

[0061] Step 6: Dissolve 3 g of PVA powder in 50 mL of deionized water and heat to 80 °C. Stir magnetically at 500 rpm for 2 h to prepare a PVA solution. Dissolve 0.3 g of boric acid powder in 10 mL of deionized water and stir magnetically at 500 rpm for 10 min to prepare a boric acid solution. Mix the prepared PVA solution and boric acid solution and stir magnetically at 80 °C and 500 rpm for 10 min to prepare a PVA-boric acid mixed solution.

[0062] Step 7: Cut the cotton fabric product from Step 3 to 80×80×1 mm and the cotton thread product to 1 m in length. Immerse them in the PVA-boric acid mixed solution from Step 5 for 4 min under water bath heating to 80 ℃. Then perform a rolling operation, controlling the roll residue rate to 70%. Repeat the immersion-rolling operation once. Then place them in an oven at 140 ℃ for 3 min. After that, rinse them 3 times with deionized water and dry them in an oven at 40 ℃ for 3 h.

[0063] Step 8: Take the cotton fabric products from Step 5 and Step 7, each cut to 80×80×1 mm in size. Using 40cm of cotton thread from Step 7, sew the cotton fabric products from Step 4 and Step 7 together with a flat stitch, controlling the stitch length to 3 mm and keeping the stitches evenly distributed.

[0064] Step Nine: Use an acrylic medical adhesive to bond the hydrophilic surfaces of the cotton fabric product from Step Four and the product from Step Eight, controlling the adhesive application rate to be 2 mg / cm². 2 A composite hemostatic dressing with a size of approximately 80×80 mm was obtained.

Claims

1. A hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface, characterized in that... The device comprises a three-layer structure: an innermost superhydrophobic drug layer, a middle superhydrophilic absorbent layer, and an outermost superhydrophobic protective layer. Each layer uses medical cotton fabric as the substrate and is constructed through layered modification to create a functional gradient structure. The inner superhydrophobic drug layer and the outer superhydrophobic protective layer have the same structure and composition, and are modified with PDMS and loaded with CuS+TA to form a symmetrical structure with double hydrophobicity between the inner and outer layers. The middle layer is composed of PVA and boric acid to form a superhydrophilic absorbent layer. The inner and middle layers are connected by interrupted sutures using medical hydrophilic cotton thread, and the middle and outer layers are bonded together using acrylic medical adhesives.

2. The hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface according to claim 1, characterized in that, The structure of the inner superhydrophobic drug layer and the outer superhydrophobic protective layer is as follows: using medical cotton cloth as the substrate, the surface of the cotton cloth is modified with PDMS, and a PDMS coating is constructed on the surface of the cotton cloth fibers. The water contact angle of the coating is ≥150°. CuS nanospheres and TA are loaded on the coating to construct a composite antibacterial system. The CuS+TA composite system loaded on the outer layer pre-treats the bacteria that come into contact with the outside world, forming a double antibacterial barrier. The middle layer uses medical cotton fabric as the base material and is modified by polyvinyl alcohol and boric acid. By utilizing the cross-linking reaction between H3BO3 and the hydroxyl groups in the PVA molecular chain, a network of hydrophilic groups is constructed on the surface of the cotton fabric fibers, making the surface of the cotton fabric hydrophilic.

3. A method for preparing a hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface as described in any one of claims 1 to 2, characterized in that... Includes the following steps: (1) Add Cu(NO3)2·3H2O, PVP and thioacetamide to DMSO, stir magnetically until all components are completely dissolved, transfer to polytetrafluoroethylene reactor for hydrothermal reaction, centrifuge, wash and vacuum dry after reaction. Obtain CuS nanospheres; (2) Add the product from step (1) together with TA to deionized water, adjust the pH of the solution with dilute hydrochloric acid, stir magnetically and then freeze dry. (3) Cut the medical cotton cloth and cotton thread to the preset specifications, immerse them in NaOH solution to remove the surface wax, wash them with deionized water, and dry them in an oven; (4) Take the product from step (2) and add it into EA. Use ultrasound to make the particles evenly dispersed in EA. Add PDMS main agent and corresponding crosslinking agent to EA dispersion and stir magnetically to make PDMS completely dissolved in EA dispersion. (5) Immerse the cotton cloth and cotton thread treated in step (3) into the PDMS-EA dispersion in step (4), remove them after full immersion, and dry them in an oven to obtain inner and outer dressings; (6) Dissolve PVA powder in deionized water, heat and stir to prepare PVA solution; dissolve H3BO3 powder in deionized water to prepare H3BO3 solution, mix PVA solution and H3BO3 solution, heat and stir magnetically; (7) Immerse the cotton cloth and cotton thread treated in step (3) into the PVA-H3BO3 mixed solution in step (6), perform a two-dip and two-roll process under water bath heating, and then place them in an oven for heat treatment. After curing, rinse with deionized water and dry. (8) Take the cotton fabric products processed in steps (5) and (7) respectively, cut them into the same size, and sew them together with the cotton thread processed in step (7); (9) Use an acrylic medical adhesive to bond the hydrophilic surfaces of the cotton fabric product from step (5) and the product from step (8) to obtain a three-layer composite dressing.

4. The method for preparing the hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface according to claim 3, characterized in that, In step (1), the ratio of Cu(NO3)2·3H2O, PVP, thioacetamide and DMSO is 0.4-0.6 g:0.3-0.5 g:0.2-0.4 g:20-40 mL. The magnetic stirring speed is 500-600 rpm, the magnetic stirring time is 20-30 min, the hydrothermal reaction temperature is 100-140 ℃, the hydrothermal reaction time is 20-28 h, the centrifuge speed is 7000-9000 rpm, the centrifugation time is 5-10 min, the number of times of washing with anhydrous ethanol is 3-5, the temperature of the vacuum drying oven is 50-80 ℃, and the vacuum drying time is 10-16 h.

5. The method for preparing the hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface according to claim 3, characterized in that, In step (2), the mass ratio of the product from step (1) to tannic acid is 0.9-1.1:

1. The amount of deionized water used is: 40-60 mL of deionized water for 50-100 mg of tannic acid. The concentration of dilute hydrochloric acid is 0.1 mol / mL. The pH of the solution is adjusted to 5.5-6. The magnetic stirring speed is 500-600 rpm and the magnetic stirring time is 20-30 min. In step (3), the concentration of NaOH solution is 0.8 g / mL-1.2 g / mL, the dewaxing time is 20-30 min, the number of times of washing with deionized water is 3-5, the oven temperature is 50-80 ℃, and the drying time is 10-15 min.

6. The method for preparing the hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface according to claim 3, characterized in that, In step (4), the ratio of the product from step (2) to EA is 40-60 mg: 15-25 mL, the sonication time is 5-10 min, the amount of PDMS agent is 6-9 g of PDMS agent per 100 mL of EA dispersion, the mass ratio of PDMS agent to crosslinking agent is 8-12:1, the magnetic stirring speed is 500-600 rpm, and the magnetic stirring time is 20-30 min; In step (5), the size of the cotton cloth after step (3) is (80~120) mm × (80~120) mm × 1 mm, the immersion time is 10-20 min, the oven temperature is 60-80 ℃, and the drying time is 3-5 h.

7. The method for preparing the hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface according to claim 3, characterized in that, In step (6), the mass concentration of the PVA solution is 3-7%, the heating and stirring temperature is 80-95 ℃, the stirring time is 2-3 h, and the magnetic stirring speed is 500-600 rpm; the mass concentration of the H3BO3 solution is 1-3%, the stirring time is 10-15 min, and the magnetic stirring speed is 500-600 rpm; the volume ratio of the PVA solution to the H3BO3 solution is 4-6:1, the stirring time after mixing is 10-15 min, the heating and stirring temperature is 80-95 ℃, and the magnetic stirring speed is 500-600 rpm.

8. The method for preparing the hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface according to claim 3, characterized in that, In step (7), the size of the cotton fabric after step (3) is (80~120) mm × (80~120) mm × 1 mm, and the water bath heating temperature is 60-80 ℃; in the two-dip and two-pinch process: the first dip time is 3-5 min, the puffing rate is 70-90%, and the cotton fabric is turned over and dipped for 3-5 min during the second dip, with a puffing rate of 70-90%; the oven heat treatment temperature is 120-150 ℃, the heat treatment time is 3-5 min, the number of deionized water rinsings is 3-5, the drying temperature after rinsing is 40-60 ℃, and the drying time is 2-3 h.

9. The method for preparing the hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface according to claim 3, characterized in that, In step (8), the suturing is done using a flat stitch technique with a stitch spacing of 3-5 mm and evenly distributed stitches; in step (9), the adhesive application amount is 2-4 mg / cm². 2 .

10. The application of a hemostatic dressing with a Janus hydrophilic-hydrophobic composite interface as described in any one of claims 1 to 2 in wound care.

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