Double network structure sponge material and its preparation method and application

Abstract

A double-network structure sponge material and its preparation method and application, construct a double-network structure, improve the mechanical strength and procoagulant activity of the sponge, and show a significantly improved hemostatic effect at a specific ratio. It still maintains excellent mechanical properties in the fully swollen state, can enhance the strength of the blood clot, and at the same time, can directly activate coagulation factor XII, increase thrombin activity, and show a high procoagulant ability. The 3D printability of the sponge under this formula was verified by DIW and freeze-drying technology, and customized porous sponges with excellent mechanical properties and enhanced procoagulant potential were printed. It is a very promising hemostatic material for the treatment of acute bleeding. The proposed 3D printing strategy for hemostatic sponges will change its processing method and provide the possibility for personalized customization and manufacturing of complex hemostatic materials.

Description

Technical Field

[0001] The present invention relates to the technical field of biomaterials, and in particular to a double-network structure sponge material and a preparation method and application thereof. Background Art

[0002] Uncontrolled acute bleeding caused by severe trauma is a global health problem and the main cause of death among injured people in wars, traffic accidents or other accidents. Excessive bleeding often increases the risk of hemorrhagic shock, coagulopathy, infection and multiple organ failure. Studies have reported that some hemostatic materials can prolong the initial rescue time of bleeding, thereby reducing mortality. Deep or penetrating wounds caused by small-caliber weapons and explosions are often accompanied by pulsating or spurting bleeding, which cannot be treated by conventional hemostatic agents or hemostatic devices. This type of bleeding may be the target of a series of developments in trauma resuscitation. It is necessary to develop new hemostatic materials to quickly and effectively control non-compressible (internal organs) and compressible (areas of the neck and head close to the heart and brain) bleeding.

[0003] To date, highly absorbent macroporous hemostatic sponges / foams composed of polyvinyl alcohol, cellulose, starch, and chitosan have been reported for the treatment of uncontrollable and non-compressible bleeding. Upon contact with blood within the wound cavity, the material rapidly absorbs water from the blood, concentrating its components. Furthermore, the compressed sponges can rapidly expand or return to their original shape to fill the wound, exert pressure on the wound, and seal the bleeding site. However, these macroporous sponges constructed with single cross-linked networks exhibit a typical swelling-weakening phenomenon, resulting in a lack of sufficient mechanical strength to exert pressure on the wound surface after absorbing fluid. Furthermore, sponges with high cross-link density generate rigid compressive forces upon expansion, potentially damaging surrounding tissue or nerves. A series of swellable macroporous gels based on carbon nanotube (CNT)-reinforced and polydopamine-crosslinked polymer networks have been reported, demonstrating excellent mechanical properties and providing a robust physical barrier at the bleeding site. Animal studies have demonstrated that these gels have strong hemostatic potential for non-compressible wounds. However, the CNTs are non-degradable, and residual CNTs may be inherently toxic, leading to the risk of thrombosis. Furthermore, the prepared materials lack strong procoagulant activity, such as activation of endogenous or exogenous coagulation factors, and the ability to generate thrombin or fibrin. Therefore, the active hemostatic effect of these materials is limited.

[0004] Although a large number of hydrogels / foams / sponges have been developed for non-compressible bleeding, we found that the manufacturing process of these materials always adopts the traditional molding and mold route, which is complicated and expensive. Based on the principles of energy saving and high efficiency, new methods for manufacturing hemostatic foams / sponges are needed. Additive manufacturing, also known as 3D printing, is a promising mold-free manufacturing technology that can be used to manufacture precise scaffolds with customized morphology and structure. Various tissue engineering scaffolds and wound dressings printed by 3D direct ink writing (DIW) technology have been widely studied to adapt to the needs of wounds. Existing printed scaffolds have limited porosity or poor water absorption capacity and may not be suitable for the control of acute bleeding. Summary of the Invention

[0005] In order to address the technical defects of the existing technology, the present invention provides a double-network structure sponge material and its preparation method and application, which has excellent mechanical properties and enhanced coagulant potential. It is a very promising hemostatic material for the treatment of acute bleeding. The proposed 3D printing strategy for hemostatic sponge will change its processing method and provide the possibility for personalized customization and manufacturing of complex hemostatic materials.

[0006] The technical solution adopted by the present invention is: a double network structure sponge material, wherein the double network structure sponge material is a gas foam solution made of modified starch St-Nor, bis-mercapto polyethylene glycol HS-PEG-SH, sodium alginate SA and a photoinitiator, and after being irradiated with ultraviolet light, Ca 2+ The secondary cross-linking obtains a sponge material having a double cross-linked network structure and a through-hole macroporous structure.

[0007] The mass concentration of sodium alginate SA in the gas foam solution is 3-5% w / v.

[0008] The UV light intensity is 15 mW·cm −2 , the irradiation time is 60s.

[0009] A method for preparing a double-network structure sponge material, characterized by comprising the following steps:

[0010] (1) Preparation of gas foam solution: Modified starch St-Nor was dissolved in PBS containing photoinitiator PI 2959. HS-PEG-SH was dissolved in PBS at room temperature and mixed with the St-Nor solution. Then, sodium alginate solution was mixed with the above solution. Then, sodium dodecyl sulfate (SDS) solution was added and stirred at high speed to obtain a gas foam solution.

[0011] (2) Preparation of double-network hemostatic sponge material: The gas foam solution was placed into a cylindrical mold using a syringe and exposed to 15 mW·cm −2The foamed material was then immersed in 1% CaCl2 under ultraviolet light to form a second cross-linked network. Finally, it was washed three times with distilled water and freeze-dried to obtain the double-network sponge material.

[0012] The modified starch St-Nor has a mass concentration of 10% w / v.

[0013] A method for preparing a double-network structure sponge material comprises the following steps:

[0014] (1) Preparation of gas foam solution: Modified starch St-Nor was dissolved in PBS containing photoinitiator PI 2959. HS-PEG-SH was dissolved in PBS at room temperature and mixed with the St-Nor solution. Then, sodium alginate solution was mixed with the above solution. Then, sodium dodecyl sulfate (SDS) solution was added and stirred at high speed to obtain a gas foam solution.

[0015] (2) Preparation of double-network structure hemostatic sponge material: The gas foam solution was used as 3D printing foam ink for 3D printing. The prepared foam ink was printed with a needle with a nozzle size of 0.63 mm. A 10 mm × 10 mm × 5 mm cubic bracket and a specially designed cubic grid were printed layer by layer on a plastic plate. After printing one layer, the bracket was exposed to 15 mW·cm −2 Under ultraviolet light, the next layer continues to be printed. After printing is completed, the scaffold is immersed in a 1% CaCl2 solution, washed and freeze-dried to obtain the final double-network structure sponge material.

[0016] The modified starch St-Nor has a mass concentration of 10% w / v.

[0017] The needle moving speed is 7.5 mm·s −1 , the extrusion pressure is 0.5 bar.

[0018] Application of a double-network structure hemostatic sponge material in the preparation of hemostatic materials.

[0019] A gas foam solution is used in preparing foam ink for 3D printing hemostatic sponge materials. The gas foam solution is made of modified starch St-Nor, bis-mercapto polyethylene glycol HS-PEG-SH, sodium alginate SA, and a photoinitiator.

[0020] The beneficial effects of the present invention are: the present invention provides a double-network structure sponge material and its preparation method and application, constructs a double-network structure, improves the mechanical strength and procoagulant activity of the sponge, and exhibits a significantly improved hemostatic effect under specific proportions, and still maintains excellent mechanical properties in a fully swollen state, which can enhance the strength of the blood clot. At the same time, it can directly activate coagulation factor XII, increase thrombin activity, and exhibit higher procoagulant ability. The 3D printability of the sponge under this formula is verified by DIW and freeze-drying technology, and a porous sponge with customized shape is printed, which has excellent mechanical properties and enhanced procoagulant potential. It is a very promising hemostatic material for the treatment of acute bleeding, and the proposed 3D printing strategy of hemostatic sponge will change its processing method and provide the possibility for personalized customization and manufacturing of complex hemostatic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 (a) Microscopic pore structure of sponges in different embodiments; (b) Maximum liquid absorption ratio of different sponges to PBS and blood; (c) Liquid absorption rate of different sponges to PBS and blood; (d) Expansion rate of compressed sponges in PBS and blood; (e, f) Shape recovery of compressed sponges under PBS and blood triggering; (g) Shape recovery of sponges of different shapes under PBS triggering after compression.

[0022] Figure 2 The mechanical properties of the sponge; (a) schematic diagram of the uniaxial compression test of the sponge; (b) compressive stress-strain curves of different sponges; (c) statistical results of the maximum compressive stress of different sponges at a strain of 60%; the mechanical strength (maximum compressive stress) of the sponge increases with the increase of the amount of sodium alginate added.

[0023] Figure 3 The procoagulant ability of the sponge; (a) statistical results of whole blood clotting time of different sponges; (b) statistical results of the ability of different sponges to activate factor XII on a coagulometer; (c) statistical results of the effect of different sponges on thrombin activity; (d, e) statistical results of whole blood coagulation index of different sponges; (f) scanning electron microscopy images of the adhesion of different sponges to platelets and red blood cells.

[0024] Figure 4 The 3D printability of the material; (a) Image of the sponge printing process. (b) Macro and micro images of the printed sponge. Figure 5This is an animal model hemostasis experiment; including (a) surgical process diagram of the liver volume defect model and femoral artery rupture bleeding model of SD rats; (b) statistical results of hemostasis time of several groups of materials in the SD rat liver bleeding model; (c) statistical results of bleeding volume of several groups of materials in the SD rat liver bleeding model; (d) statistical results of hemostasis time of several groups of materials in the SD rat femoral artery bleeding model; (e) statistical results of bleeding volume of several groups of materials in the SD rat femoral artery bleeding model. Figure 6 This is a blood and cell compatibility experiment of sponges; (a) the statistical results of hemolysis rates of different sponges; (b) the statistical results of cell survival rates of different sponges. DETAILED DESCRIPTION

[0025] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] Example 1

[0027] First, modified starch St-Nor (0.1 g, 10% w / v) was dissolved in PBS (pH = 7.4, 0.01 M) containing PI 2959 (0.1 wt%). At room temperature, 0.02 g HS-PEG-SH was dissolved in 100 μl PBS and mixed with the St-Nor solution. Then, 500 μl of sodium alginate solution (1%, 3%, 5%, 7% w / v) was mixed with the above solution. Then, 50 μl of SDS solution (10 mg / mL) was added and stirred at high speed (1500 rpm) to obtain a foam solution. In particular, the foaming height of the solutions in different groups was the same. Afterwards, the foam solution was placed into a polytetrafluoroethylene cylindrical mold using a syringe and exposed to ultraviolet light (15 mW·cm −2 ) for 60 seconds. The resulting foam was then immersed in 1% CaCl2 for 24 hours to form a second cross-linked network. Finally, it was washed three times with distilled water (DW) and freeze-dried.

[0028] Example 2

[0029] First, modified starch St-Nor (0.1 g, 10% w / v) was dissolved in PBS (pH 7.4, 0.01 M) containing PI 2959 (0.1 wt%). At room temperature, 0.02 g of HS-PEG-SH was dissolved in 100 μl of PBS and mixed with the St-Nor solution. 500 μl of sodium alginate solution (1%, 3%, 5%, or 7% w / v) was then mixed with the above solution. 50 μl of SDS solution (10 mg / mL) was then added, and the mixture was stirred at high speed (1500 rpm) to obtain a foam solution. A gas foam solution containing St-Nor, HS-PEG-SH, and SA was prepared as the printing ink. 3D printing was performed using an Envision TEC direct ink writer, the 3D-bioplotter® system. The prepared foam ink was printed using a needle with a nozzle size of 0.63 mm. Based on preliminary optimization, the needle travel speed was 7.5 mm·s. −1 , with an extrusion pressure of 0.5 bar. A 10 mm × 10 mm × 5 mm cubic support and a specially designed cubic grid were printed layer by layer on a plastic disk at 20°C. After printing one layer, the support was exposed to ultraviolet light (15 mW·cm −2 ) for 10 s, and the next layer continued to print. After printing, the scaffold was soaked in 1% CaCl2 solution for 24 hours. After washing and freeze-drying, the final 3D printed sponge (P-StCA) was obtained and characterized by scanning electron microscopy.

[0030] Example 3

[0031] SEM: The prepared sponge was stuck on the sample stage and sputtered with a thin layer of gold, and then analyzed and observed using a scanning electron microscope (SU8010, HITACHI, Japan).

[0032] Example 4

[0033] Maximum liquid absorption ratio: All sponges were freeze-dried and weighed before testing (W0). The sponges were soaked in PBS / blood and exposed to a vacuum (200 Pa). The sample was then removed and gently wiped on filter paper to remove excess liquid. The final weight of the maximum liquid absorbed by the sample was recorded as W1. The maximum liquid absorption ratio was calculated using the following formula:

[0034]

[0035] Example 5

[0036] The test instrument primarily consists of a separation funnel and a connected pipette. PBS / blood is pre-loaded into the instrument. By adjusting the height of the separation funnel, a small amount of fluid appears at the bottom of the funnel. Before testing, the initial value in the pipette is recorded as C0. Next, sponges of identical base area and height are placed into the funnel. The sponges absorb the liquid in the pipette until they stop moving. The end value C1 and duration t of this entire process are recorded. The fluid absorption rate is calculated using the following formula:

[0037]

[0038] Example 6

[0039] Shape Recovery (Swelling) Properties: The shape recovery properties of the sponges were qualitatively and quantitatively determined. First, all hydrated sponges were compressed to the same size and freeze-fixed. After freeze-drying, the dried sponges were soaked in PBS / blood. Upon contact with PBS / blood, the compressed sponges returned to their initial volume. The time required for the sponges to recover their shape was recorded. Three cycles were repeated for each sponge.

[0040] Example 7

[0041] Mechanical Strength: The compressive properties of the sponges were evaluated using a UTM2102 electronic universal testing machine at 25°C. In the compression tests, sponges with different water contents (5x, 10x, and maximum) were prepared into cylindrical shapes with a height of 6 mm and a diameter of 8 mm and compressed at a rate of 10 mm / min to a maximum strain of 60%.

[0042] Example 8

[0043] 3D Printability: A gas foam solution containing St-Nor, HS-PEG-SH, and SA was prepared as a printing ink. 3D printing was performed using Envision TEC's direct ink writer, the 3D-Bioplotter® system. The prepared foam ink was printed using a needle with a nozzle size of 0.63 mm. Based on preliminary optimization, the needle traveled at a speed of 7.5 mm / s. −1 , the extrusion pressure was 0.5 bar. A 10 mm × 10 mm × 5 mm cubic support and a specially designed cubic grid were printed layer by layer on a plastic disk at 20°C. After printing one layer, the support was exposed to ultraviolet light (15 mW·cm −2 ) for 10 s, and the next layer continued to print. After printing, the scaffold was soaked in 1% CaCl2 solution for 24 hours. After washing and freeze-drying, the final 3D printed sponge (P-StCA) was obtained and characterized by scanning electron microscopy.

[0044] Example 9

[0045] Cytotoxicity: L929 fibroblasts were maintained in DMEM at 37°C and 5% CO2, with the medium refreshed every 2–3 days. Prior to testing, all samples were sterilized by UV irradiation for 4 h. Sample extracts were prepared at a concentration of 500 μg / ml (24 h post-incubation). 100 μL of a cell suspension containing 5 × 103 cells was added to each well of a 96-well plate and incubated at 37°C in a 5% CO2 atmosphere for 24 h to allow cell attachment. The medium was then replaced with 100 μL of the sample extract and incubated for 24 and 48 h, respectively. CCK-8 solution was then added to each well and incubated at 37°C and 5% CO2 for 2 h. Finally, absorbance was measured at 450 nm using a microplate reader (Varioskan LUX, ThermoFisher).

[0046] Example 10

[0047] Hemolysis rate: Prepare a 10 mg / mL sample solution in normal saline (NS). Add 50 μl of sodium citrate-anticoagulated whole blood from a healthy donor to 1 mL of the sample suspension. Use distilled water (DW) and NS as positive and negative controls. Incubate all solutions at 37°C for 24 h. Then, centrifuge the solution at 1500 rpm for 5 min, and measure the absorbance of the supernatant at 540 nm using a Microplate Reader (VarioskanLUX, ThermoFisher). The hemolysis rate is calculated using the following formula:

[0048]

[0049] Example 11

[0050] Whole Blood Clotting Time: Weigh 20 mg of sponge and place it in a plastic dish. Add 100 μl of sodium citrate anticoagulated whole blood and 10 μl of 0.2 M CaCl₂ solution (preheated at 37°C for 30 min) to the surface of the sample. Tilt the dish every 15 seconds to monitor blood flow. Record the time it takes for thrombus formation. Repeat the test three times.

[0051] Example 12

[0052] Whole blood coagulation index: 50 mg of sponge is added to 100 μl of sodium citrate anticoagulated whole blood and 10 μl of 0.2 M CaCl2 solution. The mixture is then incubated at 37°C for 30 minutes. Subsequently, 25 ml of deionized water is added to the culture dish to wash away any uncoagulated blood. Finally, the absorbance of the uncoagulated blood solution is measured at 540 nm (Abs1). The absorbance of 100 μl of citrated whole blood in 25 ml of deionized water is used as the blank control (Abs0). The blood coagulation index (BCI) is calculated using the following formula:

[0053]

[0054] Example 13

[0055] Activated Factor XII Assay: Sodium citrate anticoagulated whole blood was collected from healthy donors and centrifuged at 1500 rpm for 10 minutes at 37°C to obtain platelet-poor plasma (PPP). 10 mg of sponge was incubated with 100 μl of PPP for 30 minutes. Finally, FXIIa expression in PPP was measured using an FXIIa ELISA kit. The concentration of expressed FXIIa was calculated using a calibration curve using a standard. PPP without any material served as a control.

[0056] Example 14

[0057] Thrombin activity assay: 10 mg of sponge was incubated with 100 μl of platelet-rich plasma (PRP) in a tube at 37°C for 5–20 minutes. A blank control group was left untreated with plasma. After incubation, 10 μl of the suspension or plasma was mixed with 160 μl of HEPES buffer and 30 μl of thrombin chromogenic substrate solution (S-2238, Chromogenix). The reaction was incubated in a heat shock chamber at 37°C for 2 minutes. The absorbance of the supernatant was measured at 405 nm.

[0058] Example 15

[0059] Platelet and RBC Adhesion: Sodium citrate-anticoagulated whole blood was centrifuged at 1500 rpm for 10 min at 4°C to obtain platelet-rich plasma (PRP) and RBC suspensions. A 10 mg sponge was placed in a 24-well plate and incubated with 100 μL of PRP and RBC suspension for 30 min, respectively. The sponge was rinsed with PBS to remove non-adherent platelets and RBCs. The sponge was then fixed with 2 mL of PBS containing 2.5% glutaraldehyde and dehydrated with graded ethanol solutions (50%, 75%, 80%, 90%, and 100%). The dried sample was mounted on a stage, sputtered with a thin layer of gold, and analyzed using a scanning electron microscope (SU8010, HITACHI, Japan).

[0060] Example 16

[0061] Hemostasis experiment in the liver volume defect model of SD rats: The rats were randomly divided into five groups. The rats were anesthetized with a quantitative intramuscular injection of 10% chloral hydrate, and the abdominal hair was shaved. The abdominal cavity was opened to expose the liver, and a pre-weighed filter paper was placed at the bottom of the liver. A biopsy needle was then used to make a liver perforation volume defect with a diameter of 5 mm. The prepared sponge with a diameter of 10 mm and a height of 5 mm was fixed to a new size (diameter of 5 mm and height of 5 mm). The commercial sponges were cut into the same size. Each sample was then immediately placed in the wound. The intraoperative hemostasis time, bleeding volume and other data were recorded.

[0062] Example 17

[0063] Hemostasis experiment in a femoral artery transection model in SD rats: Rats were randomly divided into five groups. Rats were anesthetized with a quantitative intramuscular injection of 10% chloral hydrate, and their legs were shaved. The overlying inguinal muscles were incised to expose the femoral artery. The femoral artery was completely severed using surgical scissors. A compressed sponge sample (10 mm in diameter and 3 mm in height) was applied to the bleeding site using an injectable device. The time to hemostasis and the amount of bleeding were recorded.

[0064] Experimental results analysis

[0065] like Figure 1 (a) The microscopic pore structure of the sponge under different embodiments shows that as the sodium alginate content increases, the pore distribution of the sponge becomes more uniform and the pore size becomes smaller. When the content increases to 7% (StCA7), the pores become uneven due to the high solid content. Figure 1 As shown in (b) the maximum absorption ratio of different sponges to PBS and blood and (c) the absorption speed of different sponges to PBS and blood, the absorption ratio and absorption speed of the sponges decreased with the increase of sodium alginate content, but still remained at a high level. Figure 1 As shown in (d) the expansion rate of the compressed sponge in PBS and blood, and (e, f) the shape recovery of the compressed sponge under PBS and blood triggering, the expansion rate of the sponge decreases with the increase of sodium alginate content, but StCA3 and StCA5 still maintain a high level. As shown in (g) the shape recovery of sponges of different shapes under PBS triggering after compression, StCA3 can be prepared into different shapes and still maintain water-triggered shape recovery performance after compression. (Qualitative study) Figure 2 The mechanical properties of the sponge showed that the mechanical strength (maximum compressive stress) of the sponge increased with the increase of the amount of sodium alginate added.

[0066] like Figure 3(a) Statistical results of whole-blood clotting time for different sponges show that the whole-blood clotting time of the sponge decreases with increasing sodium alginate content, but increases again when the sodium alginate content reaches 7%. This may be due to the decreased liquid absorption performance of the sponge, resulting in insufficient blood contact with the sponge.

[0067] like Figure 3 As shown in (b), (c), and (f), sponges containing sodium alginate can activate coagulation factor XII; sponges containing sodium alginate can increase thrombin activity in the blood; and sponges containing sodium alginate can significantly enhance the sponge's ability to enrich platelets and red blood cells. (Qualitative study)

[0068] like Figure 3 (d, e) The statistical results of the whole blood coagulation index of different sponges show that the sponge with the addition of sodium alginate can significantly reduce the whole blood coagulation index and improve the coagulation effect. Among them, StCA1 and StCA3 showed the best coagulation performance, which may be related to the sponge's liquid absorption and pro-coagulation properties. The statistical results of the whole blood coagulation index of different sponges show that the sponge with the addition of sodium alginate can significantly reduce the whole blood coagulation index and improve the coagulation effect. Among them, StCA1 and StCA3 showed the best coagulation performance, which may be related to the sponge's liquid absorption and pro-coagulation properties. Figure 4 As shown in Figure 3, the foam solution under the StCA5 formula can be 3D printed by direct ink writing technology, and the printed scaffold still has a through-hole macroporous structure. Figure 5 As shown, StCA5 has significantly improved hemostatic performance compared to St and commercially available gelatin sponges and polyvinyl alcohol sponges, both in the uncompressible bleeding model and the uncontrollable massive bleeding model. This is due to the introduction of a second network of sodium alginate / calcium ions into the sponge, which significantly improves the mechanical strength of the sponge without significantly affecting the sponge's fluid absorption performance, thereby enhancing the compression effect on the bleeding site. Secondly, by activating coagulation factors and affecting thrombin activity, it improves the active coagulation ability of the blood and accelerates thrombus formation.

[0069] like Figure 6 As shown, all sponges have good blood compatibility and cytocompatibility. The addition of the second network has no effect on the biosafety of the sponges.

[0070] in conclusion

[0071] The addition of a second network of sodium alginate / calcium ions improves the sponge's mechanical strength and procoagulant activity, and at a specific ratio, the two networks exhibit significantly enhanced hemostatic effects. The 3D printing performance of sponges with high liquid absorption capacity is rarely studied. This study investigated the printability of a solution after foaming, and experimental results demonstrated that the printed sponge retained a through-hole macroporous structure.

[0072] Technical personnel should note: Although the present invention has been described according to the above specific implementation methods, the inventive concept of the present invention is not limited to this invention. Any modification using the inventive concept will be included in the scope of protection of this patent.

[0073] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a double-network structure sponge material, characterized in that: The double network structure sponge material is a gas foam solution made of modified starch St-Nor, bis-mercapto polyethylene glycol HS-PEG-SH, sodium alginate SA and a photoinitiator. After being irradiated with ultraviolet light, Ca 2+ The sponge material having a double-crosslinked network structure and a through-hole macroporous structure obtained by secondary crosslinking specifically comprises the following steps: (1) Preparation of gas foam solution: 0.1 g of modified starch St-Nor was dissolved in PBS containing 0.1 wt% PI 2959 to form a 0.1 g / mL modified starch St-Nor solution. At room temperature, 0.02 g of HS-PEG-SH was dissolved in 100 μl of PBS and mixed with the St-Nor solution. Then, 500 μl of sodium alginate solution with a concentration of 0.01 g / mL, 0.03 g / mL, 0.05 g / mL, or 0.07 g / mL was mixed with the above solution. Then, 50 μl of 10 mg / mL SDS solution was added and stirred at high speed to obtain a gas foam solution. (2) Preparation of double-network structure hemostatic sponge material: A gas foam solution containing St-Nor, HS-PEG-SH and SA was prepared as printing ink for 3D printing. The prepared foam ink was printed with a needle with a nozzle size of 0.63 mm. Based on preliminary optimization, the needle movement speed was 7.5 mm·s −1 , the extrusion pressure was 0.5 bar, and a 10 mm × 10 mm × 5 mm cubic bracket and a specially designed cubic grid were printed layer by layer on a plastic disk at 20 ° C. After printing one layer, the bracket was exposed to ultraviolet light of 15 mw·cm −2 After 10 s, the next layer continued to be printed. After printing was completed, the scaffold was immersed in 1% CaCl2 solution for 24 hours, washed and freeze-dried to obtain the final double-network structure sponge material.

2. Use of the double-network structure sponge material prepared by the preparation method according to claim 1 in preparing hemostatic materials.

Images