Novel multi-layer composite hemostatic gauze based on modified zeolite and preparation method of novel multi-layer composite hemostatic gauze

Abstract

The invention provides novel multi-layer composite hemostatic gauze based on modified zeolite and a preparation method thereof. The gauze comprises a modified zeolite core layer from inside to outside, the content of Ca < 2 + > is increased to 6-13 wt% through ion exchange, 0.4-1.2 wt% of prothrombin activator is loaded, platelet activation is promoted through high-calcium zeolite, and the blood coagulation time is shortened to 46.7% of that of a conventional product. A temperature control buffer layer, a calcium alginate / polyethylene glycol hydrogel layer with the thickness of 5-10 [mu] m and a phase change material (octadecane microcapsule) containing 3-5 wt%, the phase change material generates phase change heat absorption at 42 DEG C, and the heat release peak value of zeolite is controlled to be 42 DEG C or below. The outer carrier is viscose fiber / silk blended gauze subjected to plasma treatment. The multi-layer composite zeolite hemostatic gauze can be applied to medical instruments for emergency treatment of war wounds, hemostasis in surgical operations and bleeding control of patients in anticoagulation treatment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical hemostatic materials, and particularly relates to a novel composite hemostatic gauze based on modified zeolite and a preparation method thereof, which is suitable for rapid hemostasis in war injuries, surgical operations and emergency medical care. BACKGROUND

[0002] Traditional hemostatic materials mainly rely on physical compression and blood absorption mechanisms, including cellulose gauze, oxidized regenerated cellulose, etc. Although such materials are low in cost and widely used, they have obvious defects, and excessive blood absorption can even aggravate blood loss. In recent years, zeolite has been used in hemostatic materials due to its high water absorption, but it has a severe exothermic effect, resulting in a 23% incidence of Ⅱ degree burns. Although the improved zeolite gauze reduces the temperature, the clotting time is prolonged, and it lacks a healing-promoting function. Researchers have attempted to improve the hemostatic performance through material compounding and structure optimization, but still face challenges. Kaolin modified hemostatic materials are compounded by electrospinning technology, which can improve the hemostatic speed, but still cannot solve the problem of deep non-compressible bleeding.

[0003] The existing technology has an imbalance between hemostatic efficiency and safety, and fast hemostatic materials (such as zeolite) are accompanied by tissue damage risks, while mild materials (such as alginate) have a long clotting time (> 5 minutes). Single function cannot meet the complex clinical needs, and existing materials mainly focus on hemostasis, ignoring the comprehensive needs of antibacterial, healing promotion and temperature regulation.

[0004] Based on the limitations of the existing technology, future hemostatic materials need to develop in the direction of multifunctional integration (hemostasis, antibacterial, healing promotion), intelligent response (temperature regulation, pH sensitivity) and structure optimization (gradient porosity, flexible compounding) to meet the complex clinical needs. SUMMARY

[0005] In view of the current technical situation, the present application provides a multi-layer composite structure zeolite hemostatic gauze, which comprises, from the inside to the outside: a modified zeolite core layer, a temperature control buffer layer and an outer carrier. 2+ The content of Ca is increased to 6-13wt%, and 0.4-1.2wt% of a prothrombin activator is loaded, the high-calcium zeolite promotes platelet activation, and the clotting time is shortened to 46.7% of that of conventional products. The temperature control buffer layer comprises a 5-10μm thick calcium alginate / polyethylene glycol hydrogel layer and a 3-5wt% phase change microcapsule suspension, and the phase change microcapsule undergoes a phase change and absorbs heat at 42℃, so that the zeolite exothermic peak is controlled below 42℃. The outer carrier is a plasma-treated viscose fiber / silk blended gauze.

[0006] In the first aspect, the present application provides a novel multi-layer composite structure zeolite hemostatic gauze based on modified zeolite, which comprises a modified zeolite core layer, a temperature control buffer layer and an outer carrier. The core layer is modified by ion exchange to increase the content of Ca2+ content, and loaded with a prothrombin activator; the temperature-controlled buffer layer comprises a calcium alginate / polyethylene glycol hydrogel layer and is uniformly dispersed in a phase change microcapsule suspension; the outer layer carrier is a plasma-treated viscose fiber and silk blended gauze.

[0007] Optionally, the ion exchange increases the content of Ca 2+ to 6-13wt%, and the content of the loaded prothrombin activator is 0.4-1.2wt%.

[0008] Optionally, the zeolite of the modified zeolite core layer is 13X type molecular sieve with a SiO2 / Al2O3 molar ratio of 2.4-3.0 and a particle size range of 80-120 mesh.

[0009] Optionally, the prothrombin activator is recombinant viveridin (RVV-X).

[0010] Optionally, the phase change microcapsule in the temperature-controlled buffer layer is an octadecane microcapsule, and the phase change temperature of the microcapsule is 40-42℃.

[0011] In a second aspect of the present application, a preparation method of a novel multi-layer composite zeolite-based hemostatic gauze is provided, comprising the following steps: a) preparing a modified zeolite core layer, performing ion exchange reaction on 13X type zeolite in a CaCl2 solution, washing and drying, then immersing in a solution containing a prothrombin activator under vacuum conditions, and freeze-drying to obtain a modified zeolite; b) preparing a temperature-controlled buffer layer precast solution, dissolving sodium alginate and polyethylene glycol PEG4000 in water, adding a phase change microcapsule suspension, stirring uniformly and defoaming to obtain a uniform casting solution; c) composite assembly, using electrospinning process to spin the casting solution of step b) on the outer layer carrier treated by plasma to form a buffer layer, then uniformly spreading the modified zeolite particles of step a) on the uncured surface of the buffer layer, and after UV crosslinking and curing, performing secondary electrospinning to form a covering layer, and finally obtaining the multi-layer composite zeolite hemostatic gauze.

[0012] Optionally, the CaCl2 solution in step a) is 0.3M-0.7M, the ion exchange temperature is 50-80℃, and the concentration of the prothrombin activator is 0.4-1.2wt%.

[0013] Optionally, the ion exchange reaction in step a) is performed at 80℃ for 6 hours in a 0.5M CaCl2 solution.

[0014] Optionally, the concentration of sodium alginate in step b) is 2 wt%, the concentration of polyethylene glycol PEG4000 is 4 wt%, and the concentration of the phase change microcapsule suspension is 4 wt%. The casting solution further comprises 0.1 wt% vitamin K3 and 0.05 wt% silver nitrate.

[0015] In a third aspect, the application provides a use of the multi-layer composite zeolite hemostatic gauze in the preparation of a medical device for controlling bleeding in war injury first aid, surgical hemostasis and anticoagulant therapy. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The multi-layer composite hemostatic gauze is used for in-vitro blood clotting time. DETAILED DESCRIPTION

[0017] The embodiments of the application are described in detail below, and the embodiments provided by the application are exemplary and are intended to explain the application, but cannot be understood as a limitation of the application.

[0018] The application provides a multi-layer composite zeolite hemostatic gauze, which comprises, from inside to outside: a modified zeolite core layer, a Ca 2+ The content of the modified zeolite is increased to 6-13 wt%, and 0.4-1.2 wt% of a prothrombin activator is loaded. The high-calcium zeolite promotes platelet activation, and the blood clotting time is shortened to 46.7% of that of a conventional product. A temperature control buffer layer, a 5-10 μm thick calcium alginate / polyethylene glycol hydrogel layer, contains 3-5 wt% of a phase change microcapsule suspension, and the phase change microcapsule absorbs heat at 42°C, so that the zeolite heat release peak is controlled below 42°C. An outer carrier, a plasma-treated viscose fiber / silk blended gauze.

[0019] Main materials of the application: 13X molecular sieve (CAS No. 63231-69-6) was purchased from Sigma-Aldrich; 4-(2-aminoethyl) calcium chloride (CaCl2), hydrochloric acid (HCl), and concentrated nitric acid (HNO3) were purchased from Xi'an Tianmaobao Ding Biological Technology Co., Ltd.; recombinant viverid venom protein (RVV-X) was purchased from Shanghai Yubo Biological Technology Co., Ltd.; the rest of the reagents, solvents and other test materials were commercially available.

[0020] Example 1 Preparation of a modified zeolite core layer 1.1 Raw material preparation Zeolite raw material: 13X molecular sieve (SiO2 / Al2O3 molar ratio 2.8, particle size 80-120 mesh); Modification solution: 0.5M CaCl2 solution was prepared by using deionized water; Active loading solution: PBS buffer (pH 7.4) containing 0.8 mg / mL recombinant RVV-X.

[0021] 1.2 Calcium ion exchange modification Pre-treatment: 3X molecular sieve zeolite was calcined at 350℃ for 3h in a muffle furnace to remove organic impurities, then immersed in 1M HC1 solution at a solid-liquid ratio of 1:10, shaken at 60℃ for 2h (120 rpm), washed with deionized water until neutral (conductivity <5 μS / cm), and dried at 110℃ for standby use.

[0022] Ion exchange: 20 g of pre-treated zeolite was added to a three-necked flask with 200 mL of CaCl2 solution, and a condensation reflux device was installed. The reaction was carried out in a constant temperature water bath for 6h (magnetic stirring, 300 rpm). After the reaction, the product was filtered and washed with 60℃ deionized water for 3 times (100 mL each time).

[0023] 1.3 Vacuum impregnation The modified zeolite was dehydrated in a vacuum dryer at -0.095 MPa for 2h, then quickly transferred to the pre-cooled RVV-X solution at 4℃, with a volume of 50 mL. After restoring normal pressure, the solution was allowed to penetrate for 12h at 4℃.

[0024] 1.4 Calcium content determination Atomic absorption spectrometry (AAS) was used to determine the Ca content: 0.1 g of modified zeolite was microwave-digested with 5 mL of concentrated HNO3, and the Ca content was determined by standard curve method. 2+

[0025] 1.5 RVV-X loading capacity determination After vacuum impregnation, the sample was quickly frozen with liquid nitrogen and transferred to a freeze dryer at -50℃ with a vacuum degree of 10 Pa for 24h. The RVV-X loading capacity was determined by BCA protein quantification method.

[0026] 1.6 Coagulation performance test In vitro whole blood coagulation experiment: Fresh whole blood was donated by healthy adult volunteers, and 3.2% (0.109 M) sodium citrate solution was used as anticoagulant at a volume ratio of 1:9 (anticoagulant: blood). This experiment has been approved by the ethics committee and informed consent has been obtained. Preheat at 37℃, add preheated 0.2 M CaCl2 solution to the blood at a volume ratio of 1:10 (e.g. 1 mL blood + 100 μL CaCl2 solution), and mix gently. Accurately add 100 μL of recalcified fresh whole blood to the scintillation vial prepared in the following examples, and incubate at a slow speed of 50 rpm. After treatment according to steps 1.2 and 1.3, the Ca 2+ ​The content, RVV-X loading and clotting time, the results are shown in Table 1.

[0027] Table 1 clotting properties of each preparation example and control group

[0028] Table 1 shows that, by optimizing the calcium exchange and bioactive loading process, the clotting time does not present a simple linear relationship with a single factor, even if the RVV-X loading is relatively higher, it does not mean that the clotting time will be shortened accordingly, but at the same time, the Ca 2+ The synergistic effect between the content and the RVV-X loading. The clotting time is shortened by 46.7% of the blank control group, significantly improving the coagulation performance and laying a foundation for the construction of subsequent multi-layer composite structure.

[0029] Example 2 Preparation of temperature control buffer layer 2.1. Preparation of raw materials Matrix material: sodium alginate (molecular weight 120-150 kDa) with G / M ratio of 0.65; analytical pure polyethylene glycol PEG4000; purity ≥99% calcium chloride (CaCl2·2H2O); Temperature control component: octadecane / silica nanocapsule (phase change temperature 40.5±0.5℃, average particle size 2-3μm); silica shell thickness 200-300nm (verified by TEM); Additives: vitamin K3 with purity of 98%; analytical pure silver nitrate (AgNO3); 2.2 Preparation of phase change microcapsule suspension 2.2.1 Surface modification: The octadecane microcapsule was treated with 1wt% silane coupling agent KH-550 ethanol solution, reacted at 60℃ for 2h, then centrifuged at 8000rpm for 5min, and obtained amino microcapsule with Zeta potential +35mV.

[0030] 2.2.2 Dispersion system: The amino microcapsule surface modified by step 2.2.1 was dispersed in 2% sodium alginate solution at a ratio of 4wt%, 0.1% Tween 80 was added as a dispersant, and ultrasonic treatment was carried out at 40kHz, 200W for 15min to obtain a uniform phase change microcapsule suspension, ready for use.

[0031] 2.3 Preparation of hydrogel composite film The casting solution was prepared, and the components and functions of the casting solution are shown in Table 2:

[0032] Example 3 Assembly 3.1 Pretreatment of the substrate: The gauze was fixed on the surface of an aluminum collection plate (grounded) and sprayed with a 0.1 wt% polyethyleneimine (PEI) solution to enhance conductivity. The gauze was dried at 60°C for 10 min to form a 10-20 nm thick transition layer.

[0033] 3.2 Buffer layer electrospinning: The temperature-controlled buffer layer pre-casting solution prepared in Example 2 was loaded into a 5 mL glass spinning needle tube (21G needle), and the parameters were set as follows: voltage 18 kV, flow rate 0.8 mL / h, and receiving distance 12 cm. The program-controlled collection device was set to do X-Y scanning (speed 10 mm / s). The spinning time was 8 min, and a 6±1 μm thick buffer layer was obtained.

[0034] 3.3 Zeolite particle embedding: The modified zeolite particles (80-120 mesh) prepared in each of the preparation examples of Example 1 were immediately uniformly spread on the uncured buffer layer, and a reverse voltage of -5 kV was applied for 2 min to make the zeolite particles directionally arrange (spacing 150-200 μm). The zeolite particles were then ultraviolet crosslinked (365 nm, 10 mW / cm²) for 30 s.

[0035] 3.4 Secondary spinning encapsulation: The same parameters were used for additional spinning for 2 min to form an upper cover layer, and the final structure was gauze / buffer layer (6 μm) / zeolite (50-80 μm) / cover layer (2 μm).

[0036] Test Example 1 Each of the preparation examples of Example 1 was assembled according to the steps of Example 3, and the blank control group was the gauze of preparation example 4 in Example 1 without assembly. The blood clotting performance was tested by an in vitro whole blood clotting experiment. 0.2 mL of blood was dropped on the tissue, the sample was immediately covered, and an infrared thermal imager was started. The highest temperature change at the material-tissue interface within 60 seconds, i.e., the peak temperature, was recorded. The results are shown in Table 3.

[0037] Table 3 In vitro blood clotting time and peak temperature of the multi-layer composite hemostatic gauze

[0038] The scientific setting of the zeolite core layer and the buffer layer in the present application can further shorten the whole blood clotting time of the optimized zeolite gauze by 17.4% (compared with a single zeolite layer), which indicates that the buffer layer in the present application is not a simple isolation layer. The fine and dense pores can quickly absorb blood and pre-concentrate blood clotting factors, and then the high-calcium zeolite core layer can provide strong Ca 2+ ion flow and synergistically activate the blood clotting cascade with RVV-X, thereby achieving a doubling of the blood clotting speed.

[0039] In addition, compared with the blank control group, the preparation examples 1-6 can reduce the peak temperature of zeolite exothermic to a certain extent, wherein the preparation example 1, the preparation example 3 and the preparation example 4 successfully control the peak temperature of zeolite exothermic in the safe range (<42℃) through the temperature control buffer layer, and the risk of tissue thermal injury is avoided.

[0040] The above examples are only examples for clearly illustrating the present application, and are not limitations to the embodiments of the present application. Other different forms of variations can be made by those skilled in the art on the basis of the above description. All the embodiments are not exhaustive. Any modification, equivalent replacement and improvement derived from the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A novel multilayer composite hemostatic gauze based on modified zeolite, characterized in that: The composite hemostatic gauze comprises a modified zeolite core layer, a temperature-controlled buffer layer, and an outer carrier layer. The core layer is modified by ion exchange to enhance Ca content. 2+ Content, and loaded with prothrombin activator; The temperature-controlled buffer layer comprises a calcium alginate / polyethylene glycol hydrogel layer, which is uniformly dispersed in the phase change microcapsule suspension. The outer carrier is a blended fabric of viscose fiber and silk that has been treated with plasma.

2. The multi-layer composite zeolite hemostatic gauze according to claim 1, characterized in that, The ion exchange will convert Ca 2+ The content is increased to 6-13 wt%, and the content of the loaded prothrombin activator is 0.4-1.2 wt%.

3. The multilayer composite hemostatic gauze according to claim 1, wherein the zeolite in the modified zeolite core layer is a 13X type molecular sieve with a SiO2 / Al2O3 molar ratio of 2.4-3.0 and a particle size range of 80-120 mesh.

4. The multilayer composite zeolite hemostatic gauze according to claim 1 or 2, characterized in that, The prothrombin activator is recombinant viper venom protein (RVV-X).

5. The multi-layer composite zeolite hemostatic gauze according to claim 1, characterized in that, The phase change microcapsules in the temperature-controlled buffer layer are octadecane microcapsules, and the phase change temperature of the phase change microcapsules is 40-42℃.

6. The method for preparing the novel multilayer composite hemostatic gauze based on modified zeolite according to any one of claims 1 to 5, characterized in that, Includes the following steps: a) Preparation of modified zeolite core layer: 13X type zeolite was subjected to ion exchange reaction in CaCl2 solution, washed and dried, then impregnated in a solution containing prothrombin activator under vacuum conditions, and freeze-dried to obtain modified zeolite. b) Preparation of temperature-controlled buffer layer prepreg: Sodium alginate and polyethylene glycol PEG4000 are dissolved in water, phase change microcapsule suspension is added, stirred evenly and degassed to obtain a uniform casting solution; c) Composite Assembly: The casting solution described in step b) is spun onto the plasma-treated outer carrier using an electrospinning process to form a buffer layer. Then, the modified zeolite particles described in step a) are evenly spread on the uncured surface of the buffer layer. After UV cross-linking and curing, a second electrospinning is performed to form a covering layer, finally obtaining the multilayer composite zeolite hemostatic gauze.

7. The method for preparing the novel multilayer composite hemostatic gauze based on modified zeolite according to claim 6, characterized in that, In step a), the CaCl2 solution is 0.3M-0.7M, the ion exchange temperature is 50-80℃, and the concentration of the prothrombin activator is 0.4-1.2wt%.

8. The preparation method of the novel multilayer composite hemostatic gauze based on modified zeolite according to claim 6, wherein the conditions for the ion exchange reaction in step a) are: reaction at 80°C for 6 hours in 0.5M CaCl2 solution.

9. The preparation method of the novel multilayer composite hemostatic gauze based on modified zeolite according to claim 6, wherein in step b), the concentration of sodium alginate is 2wt%, the concentration of polyethylene glycol PEG4000 is 4wt%, and the concentration of the phase change microcapsule suspension is 4wt%; The casting solution also contains 0.1 wt% vitamin K3 and 0.05 wt% silver nitrate.

10. The use of a multilayer composite zeolite hemostatic gauze as described in any one of claims 1-5 in the preparation of medical devices for the treatment of traumatic first aid, surgical hemostasis, and bleeding control in patients undergoing anticoagulation therapy.

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