Hemostatic composite material as well as preparation method and application thereof

Abstract

The invention discloses a hemostatic composite material as well as a preparation method and application thereof, and the hemostatic composite material is prepared from the following raw materials in parts by weight: hexamethylene diisocyanate, kaolin, an organic silicon surfactant, inorganic alkali, a nonionic surfactant and water. The hemostatic material obtained under the synergistic effect of all the component raw materials realizes rapid and effective hemostasis of rat abdominal liver injury and femoral artery, vein and nerve disjunction massive hemorrhage.

Description

Technical Field

[0001] The invention relates to the technical field of biomedical hemostatic materials, and in particular to a hemostatic composite material and a preparation method and application thereof. Background Art

[0002] 75% of casualties in modern warfare are caused by explosive fragments and gunshot wounds, and bleeding is still the main cause of death from battlefield trauma. More than 18% of deaths can be avoided by effective hemostasis. Among them, penetrating injuries are severe injuries caused by high-speed sharp objects penetrating human tissues, which are common in battlefields, traffic accidents and violent incidents. Since penetrating injuries usually cause rupture of large blood vessels or damage to important organs, causing massive bleeding, they have a very high mortality rate. At present, the main methods for emergency treatment of penetrating wounds with massive bleeding include direct compression hemostasis, packing hemostasis, and tourniquet hemostasis. The tourniquet is used to block blood supply by compression to stop bleeding. It is only suitable for severe bleeding and amputation of limbs. It has no procoagulant effect. Existing studies recommend the use of tourniquets in applicable parts, and new hemostatic materials are recommended for bleeding in other parts. Among them, Combat Gauze and self-expanding polyurethane foam are the main hemostatic materials for penetrating wound packing. Combat Gauze is a gauze containing a hemostatic agent that can quickly promote coagulation, but its hemostatic effect is limited when facing massive bleeding or deep wounds. Polyurethane foam hemostatic materials can expand rapidly in the wound, seal the bleeding site, and prevent blood from flowing out. However, these methods have certain problems in the application process, such as incomplete hemostasis, complicated operation, and possible secondary injury and infection, especially when dealing with complex, multi-site penetrating injuries, which show obvious limitations.

[0003] As a new type of hemostatic material, the expansion speed and degree of in-situ polymerization of polyurethane foam hemostatic sponge are difficult to accurately control, which may cause excessive compression of surrounding healthy tissues. The in-situ polymerization reaction process generates high heat and even causes secondary injury. In addition, when facing massive arterial bleeding, the physical hemostasis effect of polyurethane foam sponge alone is limited, and there will be poor hemostatic effect or secondary bleeding problems. At the same time, polyurethane materials may cause foreign body reactions and infection risks due to biodegradability issues.

[0004] Therefore, in order to meet the challenge of massive bleeding from penetrating injuries, it is urgent to design and develop safer hemostatic materials. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a hemostatic composite material, which can achieve rapid and effective hemostasis of rat abdominal liver injury, femoral artery, vein and nerve severance bleeding through synthesis of raw materials.

[0006] The invention also provides a method for preparing the hemostatic composite material.

[0007] The present invention also proposes an application of the above-mentioned hemostatic composite material in preparing materials for treating hemorrhage caused by liver injury, femoral artery, vein and nerve rupture.

[0008] According to one aspect of the present invention, a hemostatic composite material is provided, which comprises the following raw materials by weight: hexamethylene diisocyanate, kaolin, an organic silicon surfactant, an inorganic base, a nonionic surfactant and water.

[0009] In some embodiments of the present invention, the hemostatic composite material includes the following raw materials, measured by weight: 70-90 parts of hexamethylene diisocyanate, 1-20 parts of kaolin, 0.05-0.5 parts of silicone surfactant, 0.02-0.5 parts of inorganic base, 0.5-2 parts of nonionic surfactant and 10-30 parts of water.

[0010] The embodiments according to the first aspect of the present invention have at least the following beneficial effects:

[0011] 1. The raw materials for preparing the hemostatic composite material of the present invention avoid the use of organic amines and organic tin catalysts, and the raw materials are highly safe. The hemostatic material prepared thereby meets the safety requirements of the blood system;

[0012] 2. In the present invention, by adding kaolin, the formed blood components can be absorbed and retained in the interface space of the polyurethane foam sponge formed by hexamethylene diisocyanate, while the chemical activation of the coagulation system can be initiated, thereby further rapidly amplifying the thrombin chain reaction, accelerating hemostasis, and stabilizing the thrombus.

[0013] 3. The pore structure of the hemostatic composite material of the present invention is uniform, and pores of uniform size can be formed through the synergistic effect of non-ionic surfactant and other raw materials, and the process is simple.

[0014] 4. The hemostatic material obtained by the synergistic action of various component raw materials of the present invention, on the one hand, after the hemostatic sponge contacts the wound surface, immediately absorbs concentrated blood through the pore structure, enriches the red blood cells, platelets, coagulation-related factors and proteins in the concentrated blood, and rapidly amplifies the thrombin-linked reaction rate; on the other hand, when the highly concentrated coagulation-related components contact the kaolin stably loaded on the interface of the hemostatic sponge, they can directly contact and activate FⅪ or FⅫ, accelerate the initiation of the endogenous coagulation pathway, and further amplify the thrombin-linked reaction rate; further, the specific pore structure can jointly construct a large thrombus network with the formed elements of the blood, thereby accelerating wound sealing.

[0015] In some embodiments of the present invention, the weight ratio of the hexamethylene diisocyanate, the silicone surfactant, the inorganic base, the nonionic surfactant and the water is 85-90:0.4-0.5:0.4-0.5:1-2:20-30.

[0016] The above ratio achieves uniformity of the mixture of isocyanate prepolymer, kaolin and silicone surfactant, as well as control of the pore structure of the material.

[0017] In some embodiments of the present invention, the organosilicon surfactant includes at least one of a polysiloxane surfactant, a silanol surfactant, a silane ester surfactant, a silane ether surfactant and a silanol ester surfactant.

[0018] The above-mentioned silicone surfactants generally have good biocompatibility and can provide good wetting and emulsifying properties.

[0019] The addition of the above-mentioned organosilicon surfactant effectively improves the dispersibility of the isocyanate prepolymer and the inorganic salt in the system.

[0020] In some embodiments of the present invention, the nonionic surfactant includes at least one of polyoxyethylene-polyoxypropylene block copolymers, fatty alcohol polyoxyethylene ethers and alkylphenol polyoxyethylene ethers.

[0021] The above nonionic surfactants synergistically exhibit good wettability and stability in the system with other components, and can effectively adjust the microstructure of the polyurethane foam and promote the cell opening effect of the foam.

[0022] In some embodiments of the present invention, the inorganic base includes at least one of sodium bicarbonate, sodium carbonate, potassium carbonate and potassium bicarbonate.

[0023] The inorganic base provides an alkaline environment and acts as a catalyst, which can increase the reaction rate of the system, regulate the structure of the hemostatic composite material so that the pores in the obtained structure are uniform and improve the biological safety of the material. Hexamethylene diisocyanate has low reactivity, low foaming efficiency at room temperature, and the product is easy to shrink. The foaming efficiency is improved under the above catalyst.

[0024] In some embodiments of the present invention, the particle size of the kaolin is 1 to 10 μm.

[0025] Kaolin with the above particle size can prevent particle sedimentation and improve the uniformity and stability of the system.

[0026] The second aspect of the present invention provides a method for preparing a hemostatic composite material, comprising the following steps:

[0027] S1. The polyurethane prepolymer, kaolin and silicone surfactant are mixed to obtain liquid A, and the inorganic base, water and 0.5 nonionic surfactant are heated and mixed to obtain liquid B;

[0028] S2. After mixing liquid A and liquid B, apply them on a silicone release paper, foam and solidify, and then remove the release paper to obtain a hemostatic composite material.

[0029] The hemostatic composite material proposed by the present invention is synthesized by a two-step method of raw material compounding, which improves the biocompatibility of the polyurethane foam material, and can avoid the yellowing and core burning caused by the material heating up too fast, and realizes the emergency hemostasis treatment of the hemostatic material with controllable pore structure and stable organic and inorganic composite in the first aid of massive bleeding, especially the scenes of abdominal penetrating injury and massive groin bleeding. On the one hand, after the hemostatic sponge contacts the wound surface, it immediately absorbs the concentrated blood through the pore structure, enriches the red blood cells, platelets, coagulation-related factors and proteins in the concentrated blood, and rapidly amplifies the thrombin-linked reaction rate; on the other hand, when the highly concentrated coagulation-related components contact the kaolin stably loaded on the interface of the hemostatic sponge, they can directly contact and activate FⅪ or FⅫ, accelerate the initiation of the endogenous coagulation pathway, and further amplify the thrombin-linked reaction rate; further, the specific pore structure can jointly construct a large thrombus block network with the formed elements of the blood to accelerate the wound closure.

[0030] In some embodiments of the present invention, in step S2, the parameters of the mixing step are: mixing at 1000-5000 r / min for 5s-15s.

[0031] In some embodiments of the present invention, in step S2, the temperature of the foaming step is not higher than 60°C.

[0032] The reaction temperature is less than 60℃ to ensure uniform pores of the material.

[0033] In some embodiments of the present invention, in step S2, the curing parameters are: curing at 25° C. to 60° C. for 10 to 30 min.

[0034] In the polymerization process of the polyurethane foam in the present invention, the pore structure and size can be controlled by adjusting the formula (such as isocyanate prepolymer and water, silicone surfactant, non-ionic surfactant), raw material precooling temperature, reaction temperature, stirring rate, etc., which can affect the bubble generation, expansion and stability of the foam, thereby controlling its final pore size and structure.

[0035] In some embodiments of the present invention, the silicone release paper includes polysilicone release paper.

[0036] The present invention adopts polysilicone release paper to effectively prevent adhesion with its hemostatic composite material, thereby avoiding bottom closure and ensuring the integrity and controllability of the pore structure.

[0037] The third aspect of the present invention proposes the use of the hemostatic composite material in the preparation of materials for treating hemorrhage caused by liver injury, femoral artery, vein and nerve rupture.

[0038] In some embodiments of the invention, the material comprises a hemostatic sponge. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0040] Figure 1 This is the appearance diagram of the composite hemostatic material;

[0041] Figure 2 This is a scanning electron microscope image of the bottom of the composite hemostatic material;

[0042] Figure 3 This is a scanning electron microscope image of the cross section of the composite hemostatic material;

[0043] Figure 4 The hemostasis of the composite hemostatic material on the femoral artery, vein and nerve of SD rats;

[0044] Figure 5 The blocking performance of the composite hemostatic material to liquid;

[0045] Figure 6 Activation of the coagulation system by composite hemostatic materials;

[0046] Figure 7 The adhesion of the composite hemostatic material to blood cells;

[0047] Figure 8 The stability of kaolin powder in the solution of the composite hemostatic material;

[0048] Fig. 9 Blood compatibility of composite hemostatic materials;

[0049] Fig.10 Cytotoxicity of composite hemostatic materials. DETAILED DESCRIPTION

[0050] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0051] In the embodiment, the silane ether surfactant is Dowsil 556, the silanol ester surfactant is SilresBS 94, the silane ester surfactant is Geniosil STP-E, and the silanol surfactant is BS 605, polysiloxane surfactants are BS100;

[0052] Polyoxyethylene-polyoxypropylene-polyoxyethylene is BASF Pluronic PE (BASF);

[0053] The fatty alcohol polyoxyethylene ether is AEO-9;

[0054] The alkylphenol polyoxyethylene ether is OP-10.

[0055] Example 1

[0056] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0057] S1. 70 parts of HDI polyurethane prepolymer (Baymedix FP504), 1 part of kaolin and 0.05 parts of silanol surfactant BS 605 was quickly mixed to obtain liquid A; then 0.02 parts of sodium bicarbonate, 10 parts of deionized water, and 0.5 parts of PEO-PPO-PEO pore opener (BASF Pluronic PE) were heated and mixed to obtain liquid B;

[0058] S2. Mix liquid A and liquid B at 1500 r / min for 15 seconds, pour the mixed liquid onto a silicone release paper, smooth it with a scraper, foam it at room temperature, and cure it at 40°C for 30 minutes, remove the release paper, and obtain the hemostatic composite material 1.

[0059] The appearance of the hemostatic composite material is shown in the figure Figure 1 shown.

[0060] Example 2

[0061] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0062] S1. 80 parts of HDI polyurethane prepolymer, 10 parts of kaolin and 0.2 parts of polysiloxane surfactant BS100 is mixed quickly to obtain liquid A; then 0.2 parts of sodium carbonate, 20 parts of deionized water, and 1 part of PEO-PPO-PEO pore opening agent are heated and mixed evenly to obtain liquid B;

[0063] S2. Mix liquid A and liquid B at 2000 r / min for 10 seconds, pour the mixed liquid onto a silicone release paper, smooth it with a scraper, foam it at room temperature, and cure it at 40°C for 20 minutes, remove the release paper, and obtain a composite hemostatic material 2.

[0064] Example 3

[0065] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0066] S1. 90 parts of HDI polyurethane prepolymer, 20 parts of kaolin and 0.5 parts of silane ester surfactant Geniosil STP-E were quickly mixed to obtain liquid A; then 0.5 parts of potassium carbonate, 30 parts of deionized water, and 2 parts of PEO-PPO-PEO pore opening agent were heated and mixed to obtain liquid B;

[0067] S2. Mix liquid A and liquid B at 5000 r / min for 5 seconds, pour the mixed liquid onto a silicone release paper, smooth it with a scraper, foam it at room temperature, and cure it at 60°C for 10 minutes, remove the release paper, and obtain a composite hemostatic material 3.

[0068] Example 4

[0069] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0070] S1. 90 parts of HDI polyurethane prepolymer, 20 parts of kaolin and 0.5 parts of silanol surfactant BS 605 is quickly mixed to obtain liquid A; then 0.5 parts of potassium bicarbonate, 30 parts of deionized water, and 2 parts of PEO-PPO-PEO pore opening agent are heated and mixed evenly to obtain liquid B;

[0071] S2. Mix liquid A and liquid B at 5000 r / min for 5 seconds, pour the mixed solution onto a silicone release paper, smooth it with a scraper, foam it at room temperature, and cure it at 40°C for 20 minutes, remove the release paper, and obtain a hemostatic composite material 4.

[0072] Example 5

[0073] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0074] S1. 90 parts of HDI polyurethane prepolymer, 20 parts of kaolin and 0.5 parts of silanol surfactant BS 605 is quickly mixed to obtain liquid A; then 0.5 parts of sodium bicarbonate, 30 parts of deionized water, and 2 parts of PEO-PPO-PEO pore opening agent are heated and mixed evenly to obtain liquid B;

[0075] S2. Mix liquid A and liquid B at 2000 r / min for 5 seconds, pour the mixture onto a silicone release paper, smooth it with a scraper, foam it at room temperature, and cure it at 25°C for 20 minutes. Remove the release paper to obtain a hemostatic composite material 5 (20PK).

[0076] Example 6

[0077] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0078] S1. 90 parts of HDI polyurethane prepolymer, 5 parts of kaolin and 0.5 parts of silanol surfactant BS 605 is quickly mixed to obtain liquid A; then 0.5 parts of sodium bicarbonate, 30 parts of deionized water, and 2 parts of PEO-PPO-PEO pore opening agent are heated and mixed evenly to obtain liquid B;

[0079] S2. Mix liquid A and liquid B at 5000 r / min for 5 seconds, pour the mixture onto a silicone release paper, scrape it flat with a scraper, foam it at room temperature, and cure it at 25°C for 20 minutes, then remove the release paper to obtain a hemostatic composite material 6 (5PK). Figure 2 and Figure 3 It can be seen that the pores of the hemostatic sponge are clear, without collapse, and the pore diameter is 50-200 μm.

[0080] Comparison of the SEM images of 5PK and 20PK shows that this preparation method can still maintain a stable pore structure as the amount of kaolin increases.

[0081] Example 7

[0082] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0083] S1. 90 parts of HDI polyurethane prepolymer, 10 parts of kaolin and 0.5 parts of silanol surfactant BS 605 is quickly mixed to obtain liquid A; then 0.5 parts of sodium bicarbonate, 30 parts of deionized water, and 2 parts of PEO-PPO-PEO pore opening agent are heated and mixed evenly to obtain liquid B;

[0084] S2. Mix liquid A and liquid B at 5000 r / min for 5 seconds, pour the mixture onto silicone release paper, scrape it flat with a scraper, foam at room temperature, cure at 25°C for 20 minutes, remove the release paper, and obtain material 7 (10PK). Figure 2 and Figure 3 It can be seen that the pores of the hemostatic sponge are clear, without collapse, and the pore diameter is 50-200 μm.

[0085] Example 8

[0086] This embodiment provides a method for preparing a hemostatic composite material, specifically:

[0087] S1. 90 parts of HDI polyurethane prepolymer, 15 parts of kaolin and 0.5 parts of silanol surfactant BS 605 is quickly mixed to obtain liquid A; then 0.5 parts of sodium bicarbonate, 30 parts of deionized water, and 2 parts of PEO-PPO-PEO pore opening agent are heated and mixed evenly to obtain liquid B;

[0088] S2. Mix liquid A and liquid B at 5000 r / min for 5 seconds, pour the mixture onto a silicone release paper, smooth it with a scraper, foam at room temperature, and cure at 25°C for 20 minutes, remove the release paper, and obtain a hemostatic composite material 8 (15PK). Figure 2 and Figure 3 It can be seen that the pores of the hemostatic sponge are clear, without collapse, and the pore diameter is 50-200 μm.

[0089] Comparative Example 1

[0090] This comparative example provides a method for preparing a hemostatic composite material. The difference between this comparative example and the embodiment is that a TDI type polyurethane prepolymer is used, specifically:

[0091] S1. 90 parts of TDI polyurethane prepolymer, 20 parts of kaolin and 0.5 parts of silicone surfactant were quickly mixed to obtain liquid A; then 0.5 parts of sodium bicarbonate, 30 parts of deionized water, and 2 parts of PEO-PPO-PEO pore opening agent were heated and mixed to obtain liquid B;

[0092] S2. Mix liquid A and liquid B at 5000 r / min for 5 seconds, pour the mixed liquid onto silicone release paper, smooth it with a scraper, foam at room temperature, and cure at room temperature for 20 minutes, remove the release paper, and obtain material C1.

[0093] Compared with Example C1, it is yellow and hard, and is not suitable as a hemostatic composite material. The PU foam starting with TDI is prone to yellowing due to the presence of the benzene ring. The large π bond on the benzene ring forms a conjugate with the adjacent NCO, which will cause the urethane bond to decompose under the action of light, heat, oxygen, especially ultraviolet rays, to generate aromatic amines. The benzene nucleus on the aromatic amine is oxidized and rearranged to generate quinone-type structure and other chromophores, so the produced PU product is easy to yellow and cannot maintain water white color for a long time.

[0094] Comparative Example 2

[0095] This comparative example provides a method for preparing a hemostatic composite material. The difference between this comparative example and the example is that montmorillonite is used to replace the kaolin in the example, and the other conditions are the same.

[0096] Compared with the embodiment, the hemostatic composite material has poor biocompatibility and is prone to cause distal embolism, and is not suitable as a hemostatic composite material.

[0097] Comparative Example 3

[0098] This comparative example provides a method for preparing a hemostatic composite material. The difference between this comparative example and the example is that triethylamine is used to replace the sodium bicarbonate in the example, and the other conditions are the same.

[0099] Compared with the examples, the organic amine catalyst in the hemostatic composite material is irritating to the eyes and skin, and the hemostatic composite material prepared by the organic amine catalyst leads to uneven pores and is not suitable as a hemostatic composite material.

[0100] Test Example 1

[0101] This test example tests the effects of different materials on the hemostasis of the liver and femoral artery, vein, and nerve of SD rats. The experimental animals are male SD rats (Sprague-Dawley) weighing about 400g. The experimental animals are randomly divided into a gauze group (blank control group), a combat gauze group, and a material group, with 4 rats in each group.

[0102] (1) SD rat liver hemostasis experiment The hemostatic properties of the material were evaluated by a liver injury model. The material was sterilized by ultraviolet one day before the operation. The SD rats were anesthetized using a small animal gas anesthesia machine and isoflurane. The rats were placed in a supine position to expose their abdomens. The rat abdomens were opened with surgical scissors to expose one lobe of the liver. The liver was rinsed with a small amount of saline and the excess fluid was wiped off with gauze. The filter paper was placed under the liver, and a cross incision (1.5 cm × 1.5 cm) was made in the liver tissue with a scalpel. The material was then immediately laid on and a timer was started to count down for 6 minutes. After the end, the amount of blood loss was recorded and photographed. After the experiment was completed, the SD rats were euthanized. As can be seen from Table 1, with the increase of kaolin, liver injury bleeding was significantly reduced, and PK20 was significantly better than the positive control group.

[0103] Table 1. Effects of Examples and Comparative Examples on Hemostasis of Liver and Femoral Artery, Vein and Nerve Dissection in SD Rat

[0104]

[0105] (2) Hemostasis experiment of femoral artery, vein and nerve severance in SD rats

[0106] The hemostatic ability of the material for massive bleeding was evaluated by the inguinal hemorrhage model. The material was sterilized by ultraviolet one day before the operation. SD rats were generally anesthetized using a small animal gas anesthesia machine and isoflurane, and the rats were placed in a supine position. Depilation was performed around the left lower limb. After disinfection, the skin of the left lower limb of the SD rat was cut open with surgical scissors to expose the groin area as much as possible. The femoral artery, vein and nerve at the root of the groin of the left leg of the SD rat were cut open simultaneously using a scalpel, the material was immediately spread, and a 100g weight was placed above the material for 30s (simulated compression hemostasis). After 10min, the amount of blood loss was recorded and photographed for record. After the experiment was completed, the SD rats were euthanized. The results are shown in Table 2.

[0107] Table 2. Hemostasis experiment of femoral artery, vein and nerve severance in SD rats

[0108]

[0109]

[0110] Test Example 2

[0111] This test case tests the effect of different materials on water contact angle to verify that the polyurethane kaolin composite hemostatic sponge has spatial blocking and micro-expansion effects on liquids. The water contact angle of the sample is measured using a contact angle meter, and photos are taken to record and observe the shape changes of the droplets and materials. Figure 5 It can be seen that with the addition of kaolin, the hydrophobicity of the interface of the polyurethane foam sponge gradually increases within a few seconds. It is based on this change in properties that when blood comes into contact with the hemostatic composite sponge, the sponge has a spatial barrier effect on the microenvironment of the blood, especially its formed components ( Figure 6 ), a large number of blood cells adhere and aggregate at the interface ( Figure 6 ), which significantly reduces the amount of bleeding in major hemorrhage (Tables 1 and 2) and enables faster thrombus formation ( Figure 4 As shown in Table 2, with the increase of kaolin, the bleeding of femoral artery, vein and nerve rupture was significantly reduced, and PK20 was significantly better than the positive control group.

[0112] Test Example 3

[0113] This test case tests the effect of different materials on blood cell adhesion.

[0114] Take New Zealand rabbit ear vein blood and put it in a sodium citrate anticoagulation blood collection tube. Mix 8mL of fresh anticoagulated New Zealand rabbit ear vein blood with 10mL of normal saline in a container to obtain diluted blood. Cut the material into 1.5cm×1.5cm squares in a 12-well plate and divide it into two groups for treatment. Incubate in a 37°C shaker for 10 minutes, then add 500μL of fresh anticoagulated blood and 500μL of the aforementioned diluted blood to the top of the sample. Continue to incubate in a 37°C shaker for 5 minutes, then wash 3 times with phosphate buffered saline (PBS) to remove free blood cells, and fix overnight with 2.5% glutaraldehyde. After fixation, the excess glutaraldehyde solution was removed and the samples were dehydrated in a series of anhydrous ethanol concentration gradients, including 30%, 50%, 70%, 90%, and 100% anhydrous ethanol. Each dehydration lasted for 15 minutes. The samples were allowed to dry naturally and then gold-sprayed. The cell adhesion state on the surface of the material was observed using a scanning electron microscope (SEM). Figure 6 It can be seen that compared with Figure 6 a) pure polyurethane foam material, Figure 6 The pore structure of the 20PK hemostatic sponge in b) can aggregate and adhere to a larger number of blood cells, further proving that the spatial barrier and capillary action of the hemostatic sponge help the formed elements of blood to stay at the interface of the hemostatic sponge, and to adhere and aggregate more strongly, which helps to form a more stable thrombus and prevent secondary bleeding.

[0115] Test Example 4

[0116] This test example tests the effects of different materials on the activation of endogenous and exogenous coagulation pathways (APTT and PT) through chemical reactions. After the sample is sterilized by ultraviolet light, 0.5 g of material and 10 mL of PBS are added to the centrifuge tube, and the tube is placed in a 37°C constant temperature shaker for 24 hours. The material is discarded to obtain an extract. (1) Activated partial thromboplastin time (APTT) test: The APTT reagent and CaCl2 solution in the kit are placed in the 37°C preheating tank of the coagulation analyzer and preheated for more than 5 minutes and less than 15 minutes. 50 μL of extract, 50 μL of plasma, and 50 μL of APTT reagent (preheated) are sequentially drawn into the sample cup, and magnetic beads are added, and incubated at 37°C for 5 minutes. Afterwards, 100 μL of CaCl2 solution (preheated) is added, and the coagulation analyzer is triggered to measure and obtain the measurement results. (2) Prothrombin time (PT) test: Place the PT reagent in the 37°C preheating tank of the coagulation analyzer and preheat for 5 minutes to 15 minutes. Pipette 50 μL of extract and 50 μL of plasma into the sample cup, add magnetic beads, and incubate at 37°C for 3 minutes. Then, add 100 μL of PT reagent (preheated) and trigger the coagulation analyzer to measure and obtain the measurement results.

[0117] APTT (activated partial thromboplastin time) is a screening indicator for the intrinsic coagulation pathway, and PT (plasma prothrombin time) is a screening indicator for the extrinsic coagulation pathway. Figure 7 The results show that the addition of kaolin can activate the intrinsic coagulation pathway and accelerate plasma coagulation, and within the dosage range of the present invention, as the amount of kaolin added increases, the plasma coagulation becomes faster.

[0118] Test Example 5

[0119] This test example tests the influence of different materials on the stability of kaolin powder in aqueous solution. The material is soaked in phosphate buffer solution (PBS) at a ratio of 0.3g / 10mL and placed in a 37℃ constant temperature oscillating box. Photos are taken at 0h and 24h for comparison to observe whether there is any precipitation in the liquid. Figure 8 It can be seen that compared with the reference product CombatGauze, the loading stability of kaolin is greatly improved after the prepolymer and kaolin are evenly mixed and polymerized, which can effectively prevent kaolin from entering the human blood system through blood circulation, effectively avoid the occurrence of distal embolism, and have better biosafety.

[0120] Test Example 6

[0121] This test case tests the effect of different materials on blood compatibility.

[0122] According to the YY / T 1651.1-2019 standard, the material was tested for hemolysis. 8 mL of fresh anticoagulated New Zealand rabbit ear vein blood was mixed with 10 mL of normal saline in a container and mixed thoroughly to prepare diluted blood. The indirect contact method was used for testing. Due to the strong water absorption of the material, the extract was prepared at a ratio of 0.03 g / mL of the material to the extraction medium, that is, 0.3 g of the material was added to 10 mL of normal saline, and then placed in a shaker at 37°C for (72±2) h to ensure that the extract was fully mixed. 2 mL of the extract was transferred to a new centrifuge tube for standby use, and 3 parallel samples were prepared at the same time. 2 mL of normal saline was added to another centrifuge tube as a control. 2 mL of normal saline and 5 mL of distilled water were added to the tubes of the negative and positive control groups, respectively, and 3 parallel samples were prepared at the same time. Place these centrifuge tubes in a 37°C 100 rpm constant temperature shaker and incubate for 0.5 h. Then add diluted blood to each centrifuge tube at a ratio of 0.2 mL of diluted blood / 10 mL of normal saline, mix gently, and then incubate in a 37°C 100 rpm constant temperature shaker for 1 h. Finally, centrifuge at low temperature (800g, 5 min). Pipette 100 μL of supernatant into a 96-well plate and use an enzyme reader to measure the absorbance at a wavelength of 545 nm. Calculate the hemolysis rate (HI) according to formula (3-3). By Fig. 9It can be seen that the prepared polyurethane foam kaolin composite hemostatic sponges meet the national standard requirements for hemolysis rate (≤5%) and have excellent blood compatibility.

[0123] Test Example 7

[0124] This test case tests the effect of different materials on cytotoxicity profile.

[0125] After UV sterilization, the material was soaked in a ratio of 0.3 g material / 10 mL culture medium, placed in a 37°C constant temperature shaker for 24 hours, the material was discarded, and then filtered with a 0.22 μm filter to obtain an extract. The culture medium used for L929 cell culture is α-MEM culture medium containing 1% double antibody and 10% fetal bovine serum. L929 cells were seeded in a 96-well plate at a rate of 5,000 cells per well. After 24 hours, the cells were allowed to adhere to the wall, the culture medium was aspirated, and the culture medium to be tested was added, and the plate was placed in an incubator for culturing for 24 hours. The upper culture medium was removed, and the CCK-8 reagent was added under light-proof conditions, and incubated for half an hour in the dark. The absorbance was measured at a wavelength of 450 nm using an enzyme reader. Fig.10 It can be seen that the prepared polyurethane foam kaolin composite sponges meet the national standard requirements for cytotoxicity (cell survival rate ≥ 75%) and have excellent cell safety.

Claims

1. A hemostatic composite material, characterized in that: The preparation method comprises the following raw materials by weight: hexamethylene diisocyanate, kaolin, an organic silicon surfactant, an inorganic base, a nonionic surfactant and water.

2. The hemostatic composite material according to claim 1, characterized in that: The hemostatic composite material comprises the following raw materials by weight: 70-90 parts of hexamethylene diisocyanate, 1-20 parts of kaolin, 0.05-0.5 parts of organic silicon surfactant, 0.02-0.5 parts of inorganic base, 0.5-2 parts of nonionic surfactant and 10-30 parts of water.

3. The hemostatic composite material according to claim 1, characterized in that: In terms of weight ratio, the hexamethylene diisocyanate, the organosilicon surfactant, the inorganic base, the nonionic surfactant and the water are 85 to 90: 0.4～0.5：0.4～0.5：1～2：20～30。 4. The hemostatic composite material according to claim 1, characterized in that: The organosilicon surfactant comprises: At least one of polysiloxane surfactants, silanol surfactants, silane ester surfactants, silane ether surfactants and silanol ester surfactants.

5. The hemostatic composite material according to claim 1, characterized in that: The nonionic surfactant comprises at least one of polyoxyethylene-polyoxypropylene block copolymer, fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

6. The hemostatic composite material according to claim 1, characterized in that: The inorganic base includes at least one of sodium bicarbonate, sodium carbonate and potassium carbonate.

7. The hemostatic composite material according to claim 1, characterized in that: The particle size of the kaolin is 1 to 10 μm.

8. A method for preparing the hemostatic composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. The polyurethane prepolymer, kaolin and silicone surfactant are mixed to obtain liquid A, and the inorganic base, water and 0.5 nonionic surfactant are heated and mixed to obtain liquid B; S2. After mixing liquid A and liquid B, apply them on a silicone release paper, foam and solidify, and then remove the release paper to obtain a hemostatic composite material.

9. The preparation method according to claim 8, characterized in that: The organic silicone release paper includes polysilicone release paper.

10. Use of the hemostatic composite material according to any one of claims 1 to 7 in the preparation of materials for treating hemorrhage caused by liver injury, femoral artery, vein and nerve rupture.

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