A polydopamine-capped capillary channel agarose sponge composite hemostatic material assembled with magnetic fluid, and a preparation method and use thereof

Abstract

The application provides a polydopamine-capillary channel agarose sponge composite hemostatic material assembled with a magnetic fluid, a preparation method and application thereof, and belongs to the technical field of medical dressings. The composite hemostatic material comprises the following components: (1) a sponge loaded with polydopamine, and (2) a magnetic fluid; wherein the magnetic fluid is obtained by uniformly dispersing tannic acid-loaded magnetic nanoparticles in a eutectic solvent. The composite hemostatic material has controllable directional arrangement of capillary channels, and the material has significant shape memory and liquid absorption performance. In addition, the composite hemostatic material has good mechanical properties, good air permeability, strong recyclability, good biocompatibility, bacteriostatic function and procoagulant performance. The material has good magnetism, fluidity and stability, can rapidly react with a bleeding site under the action of a magnetic field, and has significant hemostatic effect, and is particularly suitable for hemostasis of incompressible and irregular wounds.

Description

Technical Field

[0001] This invention belongs to the field of medical dressing technology, specifically relating to a polydopamine-capillary agarose sponge composite hemostatic material assembled with magnetic fluid, its preparation method, and its uses. Background Technology

[0002] Bleeding is one of the major complications after trauma. In adults, bleeding exceeding 800-1000 ml can cause shock and endanger life. Uncontrollable bleeding after severe trauma and its complications have become a leading cause of high mortality, with an incidence rate exceeding 30%. Therefore, hemostasis is an extremely important measure in the rescue of bleeding victims. It must be performed quickly, accurately, and effectively, and it has special significance in saving lives.

[0003] Hemostatic products can be broadly categorized into inorganic and polymeric types. Traditional inorganic hemostatic products include inorganic clays such as kaolinite, montmorillonite, and lithium magnesium silicate. However, they present some potential risks, including uncontrollable leakage of certain substances (small molecules and inorganic nanoplatelets) and incomplete removal of residual fragments of the hemostatic agent, leading to infection and thrombosis. Polymer hemostatic products, such as gelatin sponges, absorbent cotton, gauze, and bandages, offer advantages such as being non-toxic, breathable, and having fewer side effects, and are widely used clinically.

[0004] Gelatin sponge is a non-toxic, non-antigenic protein hemostatic material with good biocompatibility and biodegradability. It is economical and easy to prepare, and is widely used in clinical hemostasis. However, gelatin sponge as a hemostatic material has the following problems: 1. Slow hemostasis speed; 2. Its complete degradation time in vivo is up to 3 months, far exceeding the tissue repair time, thus easily causing slow wound healing and chronic inflammation; 3. For deep, penetrating, and hollow wounds, gelatin sponge, under the impact of wound blood flow, has difficulty moving against the blood flow to the damaged blood vessel through the narrow and deep wound channel. Statistics show that deep, penetrating, and hollow wounds account for nearly 90% of all deaths caused by blood loss. Irregular wounds, deep and narrow wounds, and large artery damage, due to their incompressibility and the fact that blood loss originates within the cavity, pose a major challenge to controlling blood loss. To solve these problems, there is an urgent need to develop a multifunctional hemostatic material suitable for incompressible and irregular wounds. Summary of the Invention

[0005] The purpose of this invention is to provide a composite hemostatic material suitable for hemostasis of incompressible and irregular wounds, as well as its preparation method and uses.

[0006] The present invention provides a composite hemostatic material comprising the following components: (1) a sponge loaded with polydopamine, and (2) a magnetic fluid; wherein the magnetic fluid is obtained by uniformly dispersing tannic acid-loaded magnetic nanoparticles in a eutectic solvent.

[0007] Furthermore, the polydopamine-loaded sponge is a polydopamine-loaded agarose sponge.

[0008] Furthermore, the preparation method of the polydopamine-loaded agarose sponge includes the following steps: pouring an agarose aqueous solution into a 3D printed model containing microneedles, forming a gel through self-crosslinking, and freeze-drying to obtain an agarose sponge; adding the agarose sponge to a solution of dopamine or its salt, washing after 1-5 hours, and freeze-drying to obtain agarose sponge loaded with polydopamine.

[0009] Furthermore, wash after 2 hours.

[0010] Furthermore, the pore size of the microneedle is 0.2-0.5 mm, preferably 0.4 mm;

[0011] The mass ratio of the agarose sponge to dopamine or its salt is 1:(0.1-0.5), preferably 1:(0.2-0.25);

[0012] The concentration of the agarose aqueous solution is (3-5): 100 g / mL, preferably 1: 25 g / mL;

[0013] The concentration of the solution of dopamine or its salt is (0.1-0.5) g / mL, preferably (0.2-0.25):100 g / mL; the solvent in the solution of dopamine or its salt is a buffer solution with pH 7.5-9.5, preferably a Tris-HCl buffer solution with pH 8.5.

[0014] Furthermore, the eutectic solvent is a mixture of choline chloride and another component, wherein the other component is glycerol, citric acid or urea, and the molar ratio of choline chloride to the other component is 1:(0.5-2), preferably 1:1.

[0015] Furthermore, the mass-to-volume ratio of the tannic acid-loaded magnetic nanoparticles to the eutectic solvent is 1:(0.5-2) mg / mL, preferably 1:1 mg / mL;

[0016] The magnetic nanoparticles are Fe3O4 nanoparticles;

[0017] The method for achieving uniform dispersion is ultrasonic treatment.

[0018] Furthermore, the preparation method of the tannic acid-loaded magnetic nanoparticles includes the following steps: adding magnetic nanoparticles to an aqueous solution of tannic acid and stirring to obtain the final product.

[0019] The present invention also provides a method for preparing the above-mentioned composite hemostatic material, the method comprising the following steps: coating a magnetic fluid onto one side of a sponge loaded with polydopamine, thereby obtaining the material.

[0020] Furthermore, the amount of the magnetic fluid used is 0.5 mL / cm³. 2 .

[0021] The present invention also provides the use of the above-mentioned composite hemostatic material in the preparation of hemostatic products.

[0022] Furthermore, the hemostatic product is designed for use in non-compressible or irregular wounds that are bleeding.

[0023] The thickness or shape of the capillary channels in the composite hemostatic material of the present invention can be adjusted based on the mold depth or microneedle diameter according to the actual wound depth and shape. For example, the resulting capillary channel diameter can be 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm, 0.40 mm, 0.45 cm, 0.50 cm, 0.55 cm, etc.

[0024] The thickness range of the composite hemostatic material of the present invention includes, but is not limited to, 1.0-4.0 cm, preferably 1.0-2.0 cm.

[0025] The hemostatic material of the present invention can be used to stop bleeding in areas including but not limited to skin wounds, and can also be used to stop bleeding in incompressible wounds of other human tissues or organs.

[0026] The terms “comprising” or “including” used in this invention are open-ended terms and should therefore be interpreted as “including but not limited to”.

[0027] This invention utilizes a eutectic solvent (DES), tannic acid-loaded Fe3O4 nanoparticles (Fe3O4@TA), and polydopamine-capillary agarose (PDA-CAGA) sponge as raw materials to prepare a polydopamine-capillary agarose sponge composite hemostatic material assembled with magnetic fluid. The eutectic solvent is used as a dispersant, forming a magnetic fluid (DES-Fe3O4@TA) with Fe3O4@TA through physical interaction, exhibiting good magnetism, fluidity, and stability. The PDA-CAGA sponge, prepared using 3D printing technology, possesses controllable oriented capillary channels, endowing the material with significant shape memory and liquid absorption properties. Furthermore, this composite hemostatic material exhibits excellent mechanical properties, good air permeability, strong recyclability, and good biocompatibility, antibacterial function, and procoagulant properties. The material also possesses good magnetism, fluidity, and stability, and can react rapidly with the bleeding site under the influence of a magnetic field, exhibiting a significant hemostatic effect, making it particularly suitable for hemostasis of incompressible and irregular wounds.

[0028] This invention expands the application of green solvents in the field of clinical management.

[0029] The composite hemostatic material of this invention has comprehensive functions and is reusable. The preparation process involved is simple and low-cost, making it suitable for industrial production.

[0030] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0031] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the preparation process of the magnetic fluid DES-Fe3O4@TA of the present invention (a is the eutectic solvent (DES, in which the molar ratio of choline chloride to glycerol is 1:1); b is Fe3O4@TA);

[0033] Figure 2 The hysteresis loops of Fe3O4 and Fe3O4@TA particles (a) and the magnetic fluid DES-Fe3O4@TA (b) at room temperature;

[0034] Figure 3The images show the appearance of the polydopamine-capillary channel agarose sponge (unassembled magnetofluid) after freeze-drying according to the present invention (a is the agarose sponge with a capillary channel size of 200 μm and loaded with 2.0% polydopamine obtained in Example 4; b is the agarose sponge with a capillary channel size of 300 μm and loaded with 2.0% polydopamine obtained in Example 2; c is the agarose sponge with a capillary channel size of 400 μm and loaded with 2.0% polydopamine obtained in Example 5).

[0035] Figure 4 The image shows a scanning electron microscope (SEM) front view of the capillary channel longitudinal section of the three types of agarose sponges of the present invention (a is the agarose sponge obtained in Example 4; b is the agarose sponge obtained in Example 2; c is the agarose sponge obtained in Example 5).

[0036] Figure 5 The three types of agarose sponge PDAs obtained in Examples 4, 2, and 5 of this invention. 2％ -C 0.2mm AGA 4％ PDA 2％ -C 0.3mm AGA 4％ PDA 2％ -C 0.4mm AGA 4％ And GS water vapor transmission rate;

[0037] Figure 6 For sample (a) PDA 1.5％ -M 0.4mm AGA 4％ (b) PDA 2％ -M 0.4mm AGA 4％ (c) PDA 2.5％ -M 0.4 mm AGA 4％ (d) DES-Fe3O4@TA, (e) positive control GS and (f) blank group were respectively 1.0×10 4 Photograph of colony growth after co-incubation of CFU / mL Staphylococcus aureus for 24 hours;

[0038] Figure 7 The images show the state of the polydopamine-capillary agarose sponge composite hemostatic material (i.e., the novel hemostatic sponge in the figure) assembled with magnetic fluid and gelatin sponge obtained in Example 5 of this invention at 0s and 15s for hemostasis in a rat tail amputation model. Detailed Implementation

[0039] The raw materials and equipment used in this invention are all known products, obtained by purchasing commercially available products.

[0040] The preparation method of tannic acid-supported Fe3O4 nanoparticles (Fe3O4@TA) is as follows: 0.5g of magnetic iron oxide nanoparticles (Fe3O4) are added to 100mL of tannic acid aqueous solution with a concentration of 20mg / mL, and the solution is continuously mechanically stirred for 4h to obtain Fe3O4@TA.

[0041] Example 1

[0042] Agarose and deionized water were heated to a ratio of 3:100 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2 A 3D-printed metal model (0.3mm x 1.5 cm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.2g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 2％ -C 0.3mm AGA 3％ ;

[0043] 5.0 mg of Fe3O4@TA was weighed and dissolved in 5.0 mL of a eutectic solvent (a mixture of choline chloride and glycerol in a 1:1 molar ratio). The solution was then placed in a 400 W ultrasonic bath for 30 min. After standing for 15 days, the homogeneously mixed magnetic fluid DES-Fe3O4@TA was collected. The preparation process of magnetic fluid DES-Fe3O4@TA is as follows: Figure 1 As shown.

[0044] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.5cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0045] Example 2

[0046] Agarose and deionized water were heated to a ratio of 1:25 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2A 3D-printed metal model (0.3mm x 1.5 cm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.2g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 2％ -C 0.3mm AGA 4％ ;

[0047] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0048] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.5cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0049] Example 3

[0050] Agarose and deionized water were heated to a ratio of 1:20 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2 A 3D-printed metal model (0.3mm x 1.5 cm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.2g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 2％ -C 0.3mm AGA 5％ ;

[0051] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0052] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.5cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0053] Example 4

[0054] Agarose and deionized water were heated to a ratio of 1:25 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2 A 3D-printed metal model (0.2mm x 0.2mm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.2g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 2％ -C 0.2mm AGA 4％ ;

[0055] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0056] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.5cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0057] Example 5

[0058] Agarose and deionized water were heated to a ratio of 1:25 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2A 3D-printed metal model (0.4mm x 1.5 cm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.2g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 2％ -C 0.4mm AGA 4％ ;

[0059] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0060] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.5cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0061] Example 6

[0062] Agarose and deionized water were heated to a ratio of 1:25 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2 A 3D-printed metal model (0.4mm x 1.5 cm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.3g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 3％ -C 0.4mm AGA 4％ ;

[0063] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0064] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.5cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0065] Example 7

[0066] Agarose and deionized water were heated to a ratio of 1:25 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2 A 3D-printed metal model (0.4mm x 1.5mm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.4g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 4％ -C 0.4mm AGA 4％ ;

[0067] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0068] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.5cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0069] Example 8

[0070] Agarose and deionized water were heated to a ratio of 1:25 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2A 3D-printed metal model (0.4mm x 1.5 cm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.15g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 1.5％ -C 0.4mm AGA 4％ ;

[0071] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0072] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 1.0cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0073] Example 9

[0074] Agarose and deionized water were heated to a ratio of 1:25 (g / mL) and boiled until the solution became clear and homogeneous. After cooling to 60°C, the solution was poured into a container containing densely packed microneedles (density: 0.005 cm³) to a depth of 3.0 cm. 2 A 3D-printed metal model (0.4mm x 1.5mm) was created. After the hydrogel solidified, it was removed from the mold, freeze-dried, and the CAGA sponge was obtained for later use. 0.25g of dopamine hydrochloride was dissolved in 100mL of pH 8.5 Tris-HCl buffer solution, and 1.0g of CAGA sponge was added to load the buffer solution for 2.0h. The sponge was then washed with ultrapure water and freeze-dried to obtain PDA-CAGA sponge, named PDA. 2.5％ -C 0.4mm AGA 4％ ;

[0075] Weigh 5.0 mg of Fe3O4@TA and dissolve it in 5.0 mL of eutectic solvent (eutectic solvent is a mixture of choline chloride and glycerol in a molar ratio of 1:1). Place it in an ultrasonic bath with a power of 400 W for 30 min. After standing for 15 days, collect the uniformly mixed magnetic fluid DES-Fe3O4@TA.

[0076] Application of composite sponge: Before contact with the wound, apply magnetic fluid (0.5 mL / cm³). 2 Apply the coating to one side of a PDA-CAGA sponge (sponge thickness: 2.0cm) that does not come into contact with the wound; the PDA-CAGA sponge, in conjunction with an external magnetic field, can interact with irregular bleeding openings through the magnetic fluid in the sponge's capillary channels; the material used is washed with water 5 times, freeze-dried and sterilized, and then sealed for later use.

[0077] The following experimental examples demonstrate the beneficial effects of the present invention.

[0078] Experimental Example 1: Magnetic Performance Testing of Magnetohydrodynamics

[0079] 1. Experimental Samples

[0080] The magnetic fluid DES-Fe3O4@TA prepared in Examples 1-9 is identical. Fe3O4 and Fe3O4@TA are used as controls.

[0081] 2. Experimental Methods

[0082] The hysteresis loop of magnetic particles was determined using a vibrating sample magnetometer (VSM). The test conditions were: fast scan range: 25-30 Oe / s, magnetic field fast scan: ±2T, and temperature: 25℃.

[0083] 3. Experimental Results

[0084] The hysteresis loop of the sample is shown below. Figure 2In the figure, left figure a shows the hysteresis loops of Fe3O4 and Fe3O4@TA, and right figure b shows the hysteresis loop of the magnetic fluid DES-Fe3O4@TA. The hysteresis loops of both magnetic particles (Fe3O4 and Fe3O4@TA) and the magnetic fluid DES-Fe3O4@TA are "S"-shaped curves passing through the origin, indicating that both remanent magnetization and coercivity are zero. When this characteristic is present, Fe3O4, Fe3O4@TA, and the magnetic fluid DES-Fe3O4@TA exhibit magnetism and thus exhibit attraction when an external magnetic field is applied; when the magnetic field is absent, none of them exhibit magnetic activity. At room temperature, under a magnetic field strength of 2.0T, the saturation magnetization of Fe3O4@TA particles is 74.91 emu / g, slightly lower than the saturation magnetization of magnetic Fe3O4 nanoparticles (82.99 emu / g), indicating that Fe3O4 nanoparticles have modified non-magnetic tannic acid, thus successfully preparing Fe3O4@TA. Under the same magnetic field strength, the saturation magnetization of DES (choline chloride: glycerol = 1:1)-Fe3O4@TA particles is 0.125 emu / mL. Since the units of saturation magnetization for liquids and solid particles are different, comparing their absolute values ​​is meaningless. Actual observation shows that the magnetic strength of liquids is indeed somewhat weaker than that of magnetic particles. However, the magnetic strength of this magnetic fluid is sufficient for its application requirements.

[0085] Experiment Example 2: Air permeability test of polydopamine-capillary channel agarose sponge (unassembled magnetofluid)

[0086] 1. Experimental Samples

[0087] Examples 4, 2, and 5: Polydopamine-capillary channel agarose sponges (unassembled magnetic fluids) with different components: PDA 2％ -C 0.2mm AGA 4％ PDA 2％ -C 0.3mm AGA 4％ and PDA 2％ -C 0.4mm AGA 4％ Commercially available medical gelatin sponge (GS) was used as a control.

[0088] 2. Experimental Methods

[0089] The sponge sample to be tested (exposed surface area 1.13 × 10⁻⁶) -3 m 2The sample was sealed in a plastic cup containing 5.0 g of anhydrous calcium chloride (0% RH). The sample was placed in a desiccator containing a saturated sodium chloride solution (75% RH) at 25°C. For the first 8 hours, the weight change of the cup was recorded hourly, then every 24 hours until the anhydrous calcium chloride began to melt. The weights were plotted as a function of time, and the slope of each plot was determined by linear regression (R²). 2 >0.99). Water vapor transmission rate (WVTR) is calculated as the slope of a straight line (g / s) versus the material area (m²). 2 The ratio of WVP (g·m) of the thin film. -1 ·s -1 ·Pa -1 The calculation formula is: WVP=[WVTR / S×(R) 1 -R 2 )]×T. Where S is the saturated vapor pressure of water at a test temperature of 25℃; R 1 R represents the relative humidity of the dryer. 2 The relative humidity of the permeation tank is denoted as ; T is the film thickness. The experiments were conducted independently, in triplicate.

[0090] 3. Experimental Results

[0091] Figure 3 and Figure 4 The images show the appearance of the polydopamine-capillary channel agarose sponge after freeze-drying and the scanning electron microscope front view of the longitudinal section of the capillary channel prepared in Examples 4, 2 and 5 of this invention.

[0092] Different types of wounds and wound stages require different types of dressings to promote healing. Current technology indicates that the optimal WVTR value range for injured skin is 279 g·m³ for first-degree burns. -2 ·d -1 5138 g·m to granulation wound -2 ·d -1 Agarose sponge PDA 2％ -C 0.2mm AGA 4％ PDA 2％ -C 0.3mm AGA 4％ and PDA 2％ -C 0.4mm AGA 4％ See the water vapor transmission rate (WVTR) test results for commercially available medical gelatin sponge (GS) for comparison. Figure 5 In this test result, the PDA 2％ -C 0.2mm AGA 4％ PDA 2％ -C 0.3mm AGA 4％ and PDA 2％-C 0.4mm AGA 4％ WVTR of sponge sample at 1200 g·m -2 ·d -1 Up to 1600 g·m -2 ·d -1 Within this range, which falls in the middle of the skin damage loss rate, this WVTR range provides sufficient moisture permeability without the risk of wound dehydration.

[0093] The above results indicate that the microchannel sponge prepared in this invention possesses excellent water vapor permeability suitable for wound healing applications. This is closely related to the unique structure of the prepared PDA-CAGA sponge, which features dense pores and uniformly distributed microchannels.

[0094] Experimental Example 3: Overall Properties and Rabbit Whole Blood Absorption Test of Polydopamine-Capillary Channel Agarose Sponge (Unassembled Magnetofluid)

[0095] 1. Experimental Samples

[0096] Examples 1-9 show polydopamine-capillary channel agarose sponges with different components. Commercially available medical gelatin sponge (GS) was used as a positive control.

[0097] 2. Experimental Methods

[0098] Overall properties include capillary channel distribution, load-bearing capacity, and resilience. The testing method involves: examining the capillary channel distribution using an optical microscope; measuring the compression deformation of the sample under a 100g load for 5 minutes after freeze-drying to assess its shape recovery ability, thus evaluating its load-bearing capacity and resilience. Specifically, the sample height (in cm) is recorded before, during, and after the loading weight. This test is an important indicator for evaluating the mechanical properties and durability of polymeric medical materials.

[0099] The absorption capacity of rabbit whole blood is expressed using the saturated liquid absorption ratio (SLAR). The specific procedure for testing the SLAR value is as follows: Take a thoroughly dried sponge sample to eliminate the influence of the material's inherent moisture content. Immerse 2.0g of dried sponges of different sizes into beakers containing rabbit whole blood. After a specific period of time, remove the sponges from the beakers. Remove the liquid adsorbed on the sponge surface with filter paper and immediately weigh the sponge. The formula for calculating the liquid absorption ratio (LAR) of the sponge sample is: LAR(g / g) = (M... b -M a ) / M a To evaluate the liquid absorption rate of the sponge, instantaneous LAR values ​​were calculated at 1, 2, 3, 5, 7, 10, 30, 60, and 120 s. Where M... b The mass of the sponge after absorbing liquid is m; M adenoted as m, representing the dry mass of the sponge; saturated liquid absorbance ratio (SLAR) represents the LAR value at which the mass of liquid inside the sponge no longer increases.

[0100] 3. Experimental Results

[0101] Table 1. Comparison of the overall properties and rabbit whole blood absorption of polydopamine-capillary channel agarose sponge and gelatin sponge obtained in different examples.

[0102] Example 1 The capillary channels are evenly distributed, have poor load-bearing capacity, and exhibit good resilience. 25.32±0.38 Example 2 The capillary channels are evenly distributed, have good load-bearing capacity, and exhibit excellent resilience. 27.55±0.17 Example 3 The capillary channels are evenly distributed, have good load-bearing capacity, and exhibit excellent resilience. 27.80±0.22 Example 4 The capillary channels are evenly distributed, the load-bearing capacity is average, and the resilience is good. 22.55±0.71 Example 5 The capillary channels are evenly distributed, have good load-bearing capacity, and exhibit excellent resilience. 29.05±0.05 Example 6 The capillary channels are evenly distributed, resulting in good load-bearing capacity, but slightly poor resilience. 28.52±0.10 Example 7 The capillary channels are evenly distributed, have good load-bearing capacity, and moderate resilience. 29.01±0.15 Example 8 The capillary channels are evenly distributed, have good load-bearing capacity, and exhibit excellent resilience. 26.35±0.34 Example 9 The capillary channels are evenly distributed, have good load-bearing capacity, and exhibit excellent resilience. 31.22±0.28 Gelatin sponge The capillary channels are evenly distributed, have good load-bearing capacity, and exhibit excellent resilience. 25.43±0.12

[0103] The test results are shown in Table 1. It can be seen that the polydopamine-capillary agarose sponges prepared in Examples 2, 3, 5, 8, and 9 of this invention have uniform capillary channel distribution, good load-bearing capacity, good resilience, and better rabbit whole blood absorption effect than gelatin sponges; among them, the polydopamine-capillary agarose sponges prepared in Examples 5 and 9 also have a significantly improved rabbit whole blood absorption effect.

[0104] Experiment 4: Antibacterial Properties Test of Polydopamine-Capillary Channel Agarose Sponge (Unassembled Magnetorheological Fluid) and Magnetorheological Fluid

[0105] 1. Experimental Samples

[0106] Polydopamine-capillary channel agarose sponges with different components prepared in Examples 8, 5 and 9: PDA 1.5％ -M 0.4mm AGA 4％ PDA 2％ -M 0.4mm AGA 4％ PDA 2.5％ -M 0.4 mm AGA 4％ DES-Fe3O4@TA was used as a control, and commercially available medical gelatin sponge (GS) was used as a positive control.

[0107] 2. Experimental Methods

[0108] The antibacterial activity of the samples was determined using a colony assay. Specifically, Staphylococcus aureus (a Gram-positive bacterium) was selected as the target bacterium. For quantitative evaluation, 10... 5 300 μL of CFU / mL Staphylococcus aureus was transferred to 30 mL of sterile Luria-Bertani (LB) medium. The sterilized sample (3.0 g) was then immersed in the LB medium and incubated at 37 °C for 24 h in a shaker at 120 rpm. The solution was then diluted to 10 times the original bacterial concentration. -4After dilution, these bacterial suspensions (150 μL) were evenly spread onto the solid surface of the culture medium. After incubation at 37°C for 24 hours, the number of Staphylococcus aureus colonies (CFU) was counted, with each colony being measured at more than three independent time points. Bacterial suspensions without the composite polydopamine-capillary agarose sponge were used as blank controls, and gelatin sponges as positive controls. Bacterial growth viability R (%) was calculated using the following formula: R = λ t / λ0×100%, where λ0 is the average viable count after incubation with the blank sample, and λ t The average viable count is the number of colonies after incubation of the test sample.

[0109] 3. Experimental Results

[0110] The results of the inhibition of Staphylococcus aureus growth in each group are shown in the figure. Figure 6 The colonies in the petri dish in the image were formed after the sample and Staphylococcus aureus were co-incubated for 24 hours. A lower colony count indicates stronger antibacterial properties of the sample. The survival rate of Staphylococcus aureus in the samples was ranked as follows: blank control > gelatin sponge > PDA. 1.5％ -M 0.4mm AGA 4％ PDA 2％ -M 0.4mm AGA 4％ PDA 2.5％ -M 0.4mm AGA 4％ =DES-Fe3O4@TA. After co-culturing Staphylococcus aureus with three types of PDA-CAGA agarose sponges and magnetic fluid DES-Fe3O4@TA, few or almost no colonies were observed on the surface of the inoculated solid culture medium, a stark contrast to the large number of colonies grown in the positive control and blank group. The novel composite hemostatic sponge prepared in this invention exhibits significant inhibitory activity against Staphylococcus aureus. Among the three agarose sponges, the antibacterial effect gradually increased as the PDA content increased from 1.5% to 2.5%. This may be because the amino and phenolic hydroxyl groups on the surface of the loaded polydopamine interact with the sulfhydryl and amino groups of bacterial membrane surface proteins, inhibiting bacterial metabolism and thus inhibiting bacterial growth.

[0111] Experiment Example 5: Hemostatic Effect Test of Polydopamine-Capillary Channel Agarose Sponge Composite Hemostatic Material Assembled with Magnetorheological Fluid

[0112] 1. Experimental Samples

[0113] Example 5 describes the preparation of a polydopamine-capillary channel agarose sponge composite hemostatic material assembled with magnetic fluid. Commercially available medical gelatin sponge (GS) was used as a positive control.

[0114] 2. Experimental Methods

[0115] Fifteen SD rats were randomly divided into 5 groups and anesthetized with sodium pentobarbital. During tail amputation, the tail was cut off at 50% of its length using surgical scissors and exposed to air for 20 seconds to ensure bleeding. Then, 2.0 mL of DES-Fe3O4@TA was applied to the surface of a composite hemostatic sponge (2cm x 2cm x 0.5cm) and a hemostasis experiment was performed under a magnetic field. GS served as a positive control. Hemostasis time (s) and blood loss (mg) were collected after hemostasis. The control group only received gauze pressure. All animals were euthanized after the experiment. Bleeding sites were photographed at 0 and 15 seconds, and the weight of the filter paper (W) was measured until the blood clotted. t Blood loss is calculated as the increase in weight of the filter paper, ΔW: ΔW = W t -W0.

[0116] 3. Experimental Results

[0117] The composite hemostatic sponge prepared using this invention (component: PDA) 2％ -C 0.4mm AGA 4％ When using DES-Fe3O4@TA, 2.0 mL of the magnetic fluid DES-Fe3O4@TA is applied to one side of a PDA-CAGA sponge (length × width × thickness: 2.0 cm × 2.0 cm × 0.8 cm) that does not come into contact with the wound. Under the influence of the magnetic field, the fluid enters the capillary channels and interacts with the blood flowing from the wound after tail amputation in rats, promoting blood coagulation and achieving a combined hemostatic effect. Figure 7 It can be seen that the composite hemostatic sponge of this invention exhibits the best hemostatic performance, reducing the hemostasis time from 207±3.5s in the control group to 31±1.8s, which is lower than that of commercially available GS (the hemostasis time of the commercially available GS group was 125±0.9s). Correspondingly, the blood loss in rats decreased from 58.3±1.8mg in the control group to 1.7±0.1mg, and the blood loss of this composite sponge was less than that of commercially available GS in the rat tail-arrest model (the blood loss of the commercially available GS group was 15.0±1.2mg). This indicates that the novel composite sponge demonstrates excellent procoagulant and hemostatic properties in bleeding wounds.

[0118] In summary, this invention provides a magnetically driven composite hemostatic sponge with eutectic solvent (DES), tannic acid-loaded Fe3O4 nanoparticles (Fe3O4@TA), and polydopamine-capillary channel agarose (PDA-CAGA) sponge as the main components. It features a novel composition, simple process, comprehensive functions, reusability, and ease of large-scale preparation. Simultaneously, it solves the problems of incompressibility and irregular wound bleeding, improves the air permeability and antibacterial properties of drug carriers, and expands the new strategy of using rapid-response magnetic driving force for wound hemostasis, potentially meeting the needs of hemostasis and wound healing for various complex bleeding points.

Claims

1. A composite hemostatic material, characterized in that, The composite hemostatic material comprises the following components: (1) a sponge loaded with polydopamine, and (2) a magnetic fluid; wherein the sponge loaded with polydopamine has controllable directional arrangement of capillary channels, the sponge loaded with polydopamine is an agarose sponge loaded with polydopamine, and the magnetic fluid is obtained by uniformly dispersing tannic acid-loaded magnetic nanoparticles in a eutectic solvent; the preparation method of the composite hemostatic material includes the following steps: coating the magnetic fluid on one side of the sponge loaded with polydopamine, thereby obtaining the material.

2. The composite hemostatic material according to claim 1, characterized in that: The preparation method of the polydopamine-loaded agarose sponge includes the following steps: pouring an agarose aqueous solution into a 3D printed model containing microneedles, forming a gel through self-crosslinking, and freeze-drying to obtain an agarose sponge; adding the agarose sponge to a solution of dopamine or its salt, washing after 1-5 hours, and freeze-drying to obtain agarose sponge loaded with polydopamine.

3. The composite hemostatic material according to claim 2, characterized in that: The pore size of the microneedles is 0.2-0.5 mm; The mass ratio of the agarose sponge to dopamine or its salt is 1:(0.1-0.5). The concentration of the agarose aqueous solution is (3-5): 100 g / mL; The concentration of the solution of dopamine or its salt is (0.1-0.5) g / mL: 100 g / mL; the solvent in the solution of dopamine or its salt is a buffer solution with pH 7.5-9.

5.

4. The composite hemostatic material according to claim 3, characterized in that: The microneedle has a pore size of 0.4 mm; The mass ratio of the agarose sponge to dopamine or its salt is 1:(0.2-0.25). The concentration of the agarose aqueous solution is 1:25 g / mL; The concentration of the solution of dopamine or its salt is (0.2-0.25): 100 g / mL; the solvent in the solution of dopamine or its salt is a Tris-HCl buffer solution with pH 8.

5.

5. The composite hemostatic material according to claim 1, characterized in that: The eutectic solvent is a mixture of choline chloride and another component, wherein the other component is glycerol, citric acid or urea, and the molar ratio of choline chloride to the other component is 1:(0.5-2).

6. The composite hemostatic material according to claim 5, characterized in that: The molar ratio of choline chloride to the other component is 1:

1.

7. The composite hemostatic material according to claim 1, characterized in that: The mass-to-volume ratio of the tannic acid-loaded magnetic nanoparticles to the eutectic solvent is 1:(0.5-2) mg / mL; The magnetic nanoparticles are Fe3O4 nanoparticles; The method for achieving uniform dispersion is ultrasonic treatment.

8. The composite hemostatic material according to claim 7, characterized in that: The mass-to-volume ratio of the tannic acid-loaded magnetic nanoparticles to the eutectic solvent is 1:1 mg / mL.

9. A method for preparing the composite hemostatic material according to any one of claims 1-8, characterized in that, The method includes the following steps: coating a magnetic fluid onto one side of a sponge loaded with polydopamine, thus obtaining the desired product.

10. The method according to claim 9, characterized in that, The amount of magnetic fluid used is 0.5 mL / cm³. 2 .

11. Use of the composite hemostatic material according to any one of claims 1-8 in the preparation of hemostatic products.

12. The use according to claim 11, characterized in that, The hemostatic product is used for bleeding from incompressible or irregular wounds.

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