A rapid hemostatic sponge reinforced with sea squirt nanocellulose and having photothermal antibacterial effect and its preparation method

Abstract

The present invention belongs to the field of biomaterial preparation technology, and specifically relates to a sea squirt nanocellulose-enhanced rapid hemostatic sponge with photothermal antibacterial effect and a preparation method thereof. The present invention uses chitosan and oxidized konjac glucomannan as matrix materials, nano sea squirt cellulose and polydopamine nanoparticles as main reinforcing raw materials, firstly modifies konjac glucomannan into oxidized konjac glucomannan by oxidation, and constructs sea squirt nanocellulose / polydopamine polysaccharide-based scaffold material, which not only has a good infrared light response antibacterial effect, but also has a uniform three-dimensional macroporous structure that enables the sponge scaffold to achieve the function of rapid hemostasis, and can effectively scavenge free radicals and promote wound healing. The prepared sponge has good biocompatibility and no cytotoxicity, and is expected to become a new type of rapid hemostasis and effective antibacterial scaffold material.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomaterial preparation, and in particular relates to a quick hemostatic sponge reinforced with ascidian nanocellulose and having photothermal antibacterial effects, and a preparation method thereof. Background Art

[0002] According to statistics, uncontrolled bleeding and its complications caused by war, accidents, etc. are an important cause of death and a major challenge currently faced in clinical practice. Open wounds are susceptible to external bacterial infection, leading to severe inflammation, inhibiting wound healing, and even leading to death. New, fast and effective multifunctional wound dressings have always been a hot topic of research in the field of healthcare. However, most of the wound dressings currently available on the market are expensive and have disadvantages such as unstable hemostatic effects and easy to cause inflammatory reactions. Therefore, a low-cost hemostatic material with rapid hemostasis and excellent antibacterial properties is in urgent need of development.

[0003] Konjac glucomannan (KGM) is a water-soluble, high-molecular-weight polysaccharide with numerous properties, including excellent gelation, antibacterial properties, and immunomodulatory capabilities. Studies have shown that oxidized konjac glucomannan (OKGM), obtained by oxidizing KGM, can be cross-linked with chitosan (CS) via a Schiff base reaction. The resulting OKGM-CS hydrogel is safer and more durable than most wound dressings. However, this material lacks antibacterial properties and has poor mechanical strength, making its hemostatic properties difficult to meet clinical requirements.

[0004] Based on this, the present invention provides a rapid hemostatic sponge with photothermal antibacterial effect reinforced by tunicate nanocellulose and a preparation method thereof. The hemostatic sponge based on chitosan / oxidized konjac glucomannan is endowed with excellent mechanical strength, adhesion properties and photothermal antibacterial properties by incorporating tunicate nanocellulose and polydopamine nanoparticles, providing a new idea for constructing an ideal hemostatic material. Summary of the Invention

[0005] The present invention aims to provide a method for preparing a rapid, infrared-responsive, sea squirt nanocellulose / polydopamine polysaccharide-based hemostatic sponge. Konjac glucomannan is oxidized to oxidized konjac glucomannan by sodium periodate oxidation. The modified aldehyde groups react with amino groups in chitosan to achieve a Schiff base reaction, achieving a first crosslink. The addition of sea squirt nanocellulose significantly improves the mechanical properties of the sponge. After the introduction of polydopamine nanoparticles, their amino groups react with the aldehyde groups of the konjac glucomannan to achieve a second crosslink. The polydopamine nanoparticles not only act as a crosslinking agent but also provide the sponge with excellent antibacterial, antioxidant, and adhesive properties.

[0006] The oxidatively modified konjac glucomannan is cross-linked with chitosan, giving the sponge a uniform, macroporous structure that rapidly absorbs blood cells and provides a strong coagulation effect. The sponge scaffold possesses considerable compressive strength and shape memory, allowing it to rapidly absorb large amounts of blood when acting as a hemostatic agent. The swelling process exerts pressure on the wound, reducing bleeding. The polydopamine incorporated into the sponge exhibits excellent photothermal conversion capabilities, resulting in an excellent photothermal antibacterial effect, effectively preventing the development of drug-resistant bacteria caused by overuse and misuse of antibiotics. Polydopamine also scavenges free radicals, giving the sponge unique antioxidant properties. The sponge exhibits excellent biocompatibility, lacks cytotoxicity and hemolysis, and exhibits a low hemolysis rate, resulting in a high safety profile.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A quick hemostatic sponge reinforced with ascidian nanocellulose and having photothermal antibacterial effects and a preparation method thereof. Chitosan and oxidized konjac glucomannan are used as the skeleton materials of the sponge, ascidian nanocellulose is used as the reinforcing material, polydopamine nanoparticles are added thereto and freeze-dried to obtain the hemostatic sponge.

[0009] The method for preparing the ascidian nanocellulose-enhanced rapid hemostatic sponge with photothermal antibacterial effect specifically comprises the following steps:

[0010] (1) Preparation method of polydopamine nanoparticles;

[0011] (2) Preparation method of oxidized konjac glucomannan;

[0012] (3) Preparation method of ascidian nanocellulose;

[0013] (4) Different amounts of ascidian nanocellulose were added to deionized water and ultrasonically dispersed until completely dispersed. Chitosan and oxidized konjac glucomannan were then added. The mixture was stirred to form a uniform solution and freeze-dried to obtain a preliminary hemostatic sponge, namely, KCT sponge. The ascidian nanocellulose doping amount ranged from 0 wt % to 5 wt %. Mechanical testing determined that the optimal doping amount of ascidian nanocellulose was 2 wt %.

[0014] (5) The ascidian nanocellulose dispersion was added to chitosan and oxidized konjac glucomannan, stirred evenly, and then polydopamine nanoparticles were added. The mixture was stirred for 6 h and finally freeze-dried to obtain the final hemostatic sponge, namely KCP sponge, in which the doping amount of ascidian nanocellulose was 2 wt % and the doping amount of polydopamine nanoparticles was 0.5 wt %~2 wt %.

[0015] Furthermore, the mass ratio of chitosan to oxidized konjac glucomannan in steps (4) and (5) is 9:1.

[0016] Furthermore, the preparation method of polydopamine nanoparticles includes: stirring and uniformly mixing ammonia water, anhydrous ethanol, and deionized water, denoted as solution A. Then, dissolving dopamine in an appropriate amount of deionized water, denoted as solution B. Solution B is added dropwise to the mixed solution A. The mixture is stirred for 30 hours, centrifuged, washed three times with distilled water, and dried at 60°C to obtain polydopamine nanoparticles, namely PDA NPs.

[0017] Furthermore, the volume ratio of ammonia water, anhydrous ethanol and deionized water is 1:45:100, and the concentration of ammonia water is 25-28 wt %.

[0018] Furthermore, the preparation method of oxidized konjac glucomannan comprises the following steps: adding 5.0 g of konjac glucomannan to 500 ml of water, stirring to obtain a uniform aqueous dispersion, adding 5.0 g of sodium periodate, controlling the temperature at 30° C., reacting in the dark for 12 hours, then adding an appropriate amount of ethylene glycol and continuing the reaction for 2 hours to remove unreacted oxidant, followed by dialysis for 72 hours. After centrifugation, the supernatant is collected and dried to obtain oxidized konjac glucomannan.

[0019] Furthermore, the preparation method of the ascidian nanocellulose comprises the following steps:

[0020] 1) Clean the sea squirt and remove the internal organs, keeping the outer tunicate; cut the weeds on the back of the outer tunicate, remove the film attached to the inner side of the outer tunicate, and then wash it with water. Place it in an oven to dry, smash it with a hammer, and grind it into sea squirt powder with a grinder;

[0021] 2) Add ascidian powder to 5 wt% sodium hydroxide solution and stir in a water bath; repeat the alkaline soaking step 3-4 times to remove the lipid layer, and then wash with water until neutral;

[0022] 3) Prepare a bleaching solution with glacial acetic acid, sodium hypochlorite, and distilled water. Add the ascidian powder obtained after the alkaline soak to the bleaching solution and stir in a water bath. Continuously add glacial acetic acid and sodium hypochlorite until bleached.

[0023] 4) Filtering the bleached ascidian suspension, washing the ascidian powder with water until neutral, and then drying to obtain ascidian cellulose;

[0024] 5) Add the dried ascidian cellulose to a 60wt% sulfuric acid solution and stir mechanically in a water bath. After the hydrolysis is completed, add a large amount of ice-distilled water to terminate the reaction and centrifuge and wash twice. Remove the upper acid solution, collect the bottom precipitate, add an appropriate amount of distilled water and continue centrifugation. Collect the upper suspension, evaporate and concentrate, mix the concentrate evenly with an ultrasonic grinder, put it into a dialysis bag, dialyze it until neutral, and freeze-dry to obtain ascidian nanocellulose.

[0025] Furthermore, in step 2), the water bath temperature is 40°C.

[0026] Furthermore, in step 3), the water bath temperature is 60°C.

[0027] Furthermore, the drying temperature in step 4) is 60°C.

[0028] Furthermore, in step 5), the temperature of the water bath mechanical stirring is 55° C. and the time is 2 h.

[0029] Chitosan is rich in amino groups, which can form chemical crosslinks with aldehydes and strong hydrogen bonds with substances such as catechol. The positive amino groups can induce platelet adhesion and red blood cell aggregation, giving chitosan its excellent hemostatic properties. Therefore, chitosan and oxidized konjac glucomannan were used as the skeleton materials of the sponge to form a uniform and neat macroporous structure. Then, ascidian nanocellulose was used as the reinforcement material, and polydopamine nanoparticles were added to the structure and freeze-dried to obtain a sponge that can quickly stop bleeding and has photothermal antibacterial properties.

[0030] PDA NPs contain a large amount of catechol, which can produce reactive oxygen species or, through electrostatic effects, destroy bacterial cell walls and membrane structures to a certain extent, achieving antibacterial effects even without photothermal stimulation. Under photothermal stimulation, PDA NPs can respond to infrared light, and this light-to-heat conversion ability gives the sponge excellent antibacterial properties.

[0031] Furthermore, the catechol groups in PDA NPs have a strong chelating effect with trivalent iron ions in the blood. This addition allows the sponge to aggregate and concentrate blood cells, allowing them to tightly adhere to and wrap around the sponge, promoting the activation of coagulation factors and the formation of blood clots. Furthermore, the catechol groups can form chemical bonds with groups in tissues to enhance interfacial adhesion, thus enabling their application in hemostatic materials to achieve a wound-sealing effect.

[0032] As a wound dressing, the present invention exhibits excellent swelling properties and biocompatibility, highly absorbing wound exudate and facilitating the transport of medications, nutrients, and oxygen. The well-swelling dressing can keep the wound moist and accelerate blood coagulation. It also possesses antioxidant activity, scavenging excess free radicals and promoting wound healing.

[0033] The significant advantages of the present invention are:

[0034] (1) The present invention modifies konjac glucomannan into dialdehyde glucomannan, and cross-links it with chitosan using a Schiff base reaction to form a uniform three-dimensional network structure. The moderate pores enable the sponge to have a good blood absorption rate and facilitate cell growth on it.

[0035] (2) This invention is the first to incorporate ascidian cellulose into a polysaccharide-based system to create a material with excellent mechanical properties. This material can prevent the dressing from rupturing due to excessive blood pressure in the wound, which could cause residue to be left near the wound and cause adverse effects. It also provides toughness, avoiding excessive hardness that could increase pain in the affected area. The macroporous structure with interwoven fibers helps to trap blood cells, promote blood cell aggregation, and induce blood coagulation.

[0036] (3) The present invention adds polydopamine nanoparticles, the catechol structure of which promotes the adhesion of the sponge to the surface cells of the skin and liver, which can bring adhesion to the sponge and achieve a wound seal, ensuring that the sponge will not dislocate during application, and can achieve a packing effect similar to that of gauze. At the same time, the polydopamine nanoparticles added by the present invention have a unique light-to-heat conversion ability. Local hyperthermia causes irreversible damage to heat shock proteins, destroys the bacterial cell membrane, and causes the leakage of internal substances, threatening the normal physiological activities of bacteria, thereby achieving an antibacterial effect.

[0037] (5) The KCP sponge prepared by the present invention has shape adaptability. When stopping bleeding on a narrow wound, the sponge generates force to expand after contacting blood. The expanded sponge can exert pressure on the wound and reduce the amount of bleeding, which is similar to some manual compression hemostasis. It can also suppress the exudation of excess tissue fluid from the wound and provide a moist environment. Combined with the unique adhesive properties, it can well protect the wound and avoid infection.

[0038] (6) The KCP sponge prepared by the present invention has good biocompatibility, no cytotoxicity, and low hemolysis rate. It has good antioxidant activity, scavenges wound free radicals, and promotes wound healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the mechanical property curve of the KCT sponge prepared in Example 1;

[0040] Figure 2 This is a picture of the KCP sponge sample prepared in Example 2;

[0041] Figure 3 This is a microscopic electron microscope image of the KCP sponge prepared in Example 2;

[0042] Figure 4 The figure shows the mechanical properties test results of the KCP sponge prepared in Example 2;

[0043] Figure 5 FTIR spectrum of the KCP sponge prepared in Example 2;

[0044] Figure 6 The XRD pattern of the KCP sponge prepared in Example 2;

[0045] Figure 7is the porosity of the KCP sponge prepared in Example 2;

[0046] Figure 8 The blood absorption capacity of the KCP sponge prepared in Example 2;

[0047] Figure 9 is the hemolysis rate of the KCP sponge prepared in Example 2;

[0048] Figure 10 The antioxidant activity of the KCP sponge prepared in Example 2;

[0049] Figure 11 This is a diagram of colony formation on a plate after the KCP sponge prepared in Example 2 was cultured with Escherichia coli and Staphylococcus aureus and diluted;

[0050] Figure 12 The sterilization rate of the KCP sponge prepared in Example 2 under infrared light irradiation;

[0051] Figure 13 The sterilization rate of KCP sponge obtained in Example 2 under non-infrared light irradiation is

[0052] Figure 14 This is an electron micrograph of blood cell adhesion to the KCP sponge prepared in Example 2. DETAILED DESCRIPTION

[0053] In order to make the contents of the present invention easier to understand, the technical solutions of the present invention are further described below in conjunction with specific implementation methods. However, the following examples are merely examples of the present invention and do not represent the scope of protection of the rights defined by the present invention. The scope of protection of the rights of the present invention shall be subject to the claims.

[0054] Example 1 Preparation of KCT sponge

[0055] (1) Add 2 g of chitosan powder to 100 ml of 1% acetic acid solution and stir to dissolve in a constant temperature water bath at 60°C to form solution A.

[0056] (2) Take 0.2 g of oxidized konjac glucomannan, add it to 50 ml of deionized water, and stir until it is completely dissolved to form solution B;

[0057] (3) Mix 90 ml of solution A and 10 ml of solution B and stir to form a homogeneous solution, which is recorded as solution C;

[0058] (4) Take 0.072 g of ascidian nanocellulose, add it to 20 ml of deionized water, ultrasonicate until uniformly dispersed, add it to solution C, and stir until a uniform solution is formed;

[0059] (5) The solution obtained in step (4) was injected into a mold and placed at 4°C for 1 hour, -20°C for 4 hours, and -80°C for 12 hours to form solid A;

[0060] (6) The solid A obtained in step (5) was freeze-dried in a vacuum freeze dryer to remove moisture from the sample. The sample was taken out after 48 hours to finally obtain a composite sponge with a TCNCs doping amount of 2 wt%, numbered KCT2.

[0061] Example 2 Preparation of KCP sponge

[0062] (1) Add 2 g of chitosan powder to 100 ml of 1% acetic acid solution and stir to dissolve in a constant temperature water bath at 60°C to form solution A.

[0063] (2) Take 0.2 g of oxidized konjac glucomannan, add it to 50 ml of deionized water, and stir until it is completely dissolved to form solution B;

[0064] (3) Mix 90 ml of solution A and 10 ml of solution B and stir to form a homogeneous solution, which is recorded as solution C;

[0065] (4) Take 0.072 g of ascidian nanocellulose, add it to 20 ml of deionized water, ultrasonicate until uniformly dispersed, add it to solution C, stir until uniform, and record it as solution D;

[0066] (5) Add 0.036 g of polydopamine nanoparticles to solution D and stir until uniform;

[0067] (6) The solution obtained in step (5) was injected into a mold and placed at 4°C for 1 hour, -20°C for 4 hours, and -80°C for 12 hours to form solid A;

[0068] (7) The solid A obtained in step (6) was freeze-dried in a vacuum freeze dryer to remove moisture from the sample. The sample was taken out after 48 hours to finally obtain a chitosan / oxidized konjac glucomannan / polydopamine nanoparticle sponge reinforced with ascidian nanocellulose, wherein the TCNCs doping amount was 2 wt% and the PDA NPs doping amount was 1 wt%, numbered KCP1.

[0069] Example 3 Sponge scaffold material performance measurement

[0070] (1) Mechanical strength

[0071] By adjusting the amount of ascidian nanocellulose, the remaining operations were the same as in Example 1, so that the doping amounts of ascidian nanocellulose in the final KCT sponge were 0%, 1%, 2%, 3%, 4%, and 5%, respectively. The mechanical properties of the KCT sponge material with a TCNCs doping amount of 0%-5% were measured using a compression modulus tester. The sample was placed on the sample stage, the software parameters were set, and the sample was slowly compressed at a compression speed of 0.5 mm / min to obtain the force-deformation curve.

[0072] Results: As Figure 1 As shown, the maximum bearing capacity of the KCP composite sponge gradually increases with increasing TCNCs content. Because TCNCs carry a negative surface charge during extraction, excessive TCNC doping can lead to positive and negative charge flocculation with chitosan, exacerbating the brittleness of the KCP sponge and causing a sharp drop in mechanical strength. Based on comprehensive mechanical performance indicators, the present invention determined that a 2wt% TCNCs doping level was suitable for preparing the KCP composite sponge.

[0073] (2) Scanning electron microscopy (SEM)

[0074] By adjusting the dosage of polydopamine nanoparticles, the remaining operations were the same as in Example 2, so that the doping amounts of polydopamine nanoparticles in the final KCP sponge were 0%, 0.5%, 1%, and 2%, respectively. The four groups of KCP hemostatic sponge samples were cut into thin slices, and conductive double-sided tape was attached to the stage. A cotton swab was dipped in a small amount of sample on the surface of the double-sided tape. The samples were processed in sequence, and the cross-sectional morphology was observed using a field emission scanning electron microscope.

[0075] Results: As Figure 3 As shown in the figure, the microstructure of each KCP group was observed by scanning electron microscopy, and it was found that the KCP sponge formed a three-dimensional macroporous network structure. The pore size range of the four concentrations of KCP sponges was all within the range of 50-80μm, indicating that there was not much impact on the pore size; at the same time, by magnifying the image to 10μm, it can be clearly observed that dopamine nanoparticles are attached to the surface of the network pores. The attachment amount varies according to the doping concentration, and the pore structures of several groups of KCP sponges are similar; by magnifying the image to 1μm, it can be observed that various substances in the KCP sponge are cross-linked through chemical reactions to form pore peripheries, and filamentous cellulose tentacles are extended, which react with polydopamine nanoparticles at the same time. Therefore, the pore peripheries and tentacles wrap the polydopamine nanoparticles inside to form a tightly bound cross-linked structure.

[0076] (3) Mechanical properties

[0077] The sponges were soaked in PBS to reach swelling equilibrium and then manually compressed to maximum deformation to visually observe their compressive properties. The compressive properties of the sponges were further tested using a universal testing machine (TPA, FTC, USA). In a cyclic compression test model, the sponges were compressed at a speed of 1 mm / s to 50% deformation and then returned to 0% strain at the same speed. Three replicates were used for each group, and the results were repeated three times.

[0078] Results: As Figure 4 As shown in the figure, whether it is pressed by fingers or applied with a greater external pressure (press), once the stress is removed, KCP sponge can quickly recover its shape. When the compression reaches 50%, the corresponding forces of the four groups are 1.01N, 0.86N, 0.82N and 0.81N respectively. Compared with KCP0, KCP 0.5 The corresponding force of KCP1 and KCP2 decreased, indicating that the catechol structure of PDA NPs formed strong hydrogen bonds with the amino groups in chitosan, which enhanced the flexibility of the KCP composite sponge and improved the brittleness of the CS / OKGM sponge. These results prove that the sponge has good compressive resistance and rapid rebound, which can better provide a physical barrier for wounds.

[0079] (4) Infrared absorption spectroscopy (FTIR)

[0080] Four groups of KCP hemostatic sponge samples and OKGM, CS, PDA NPs, and TCNCs raw material samples were processed and ground into powders, pressed into tablets with potassium bromide, and measured using a Fourier transform infrared spectrometer.

[0081] Results: As Figure 5 As shown, 1647 cm in OKGM -1 The absorption peak of aldehyde group (C=OH) at 1610 cm in KCP sponge confirmed that KGM was successfully oxidized by sodium periodate. -1 The appearance of the amide bond enhancement peak indicates that the amino group in CS and the aldehyde group in OKGM did undergo a Schiff base reaction.

[0082] (5) X-ray diffraction (XRD)

[0083] Four groups of KCP hemostatic sponge samples and OKGM, CS, and PDA NPs raw material samples were processed and ground into powders, and then measured on an X-ray diffractometer. The X-ray diffraction intensity curve of the material at 2θ=5°~60° was recorded using a super energy detector.

[0084] Results: As Figure 6As shown in the figure, by performing XRD analysis on each component and KCP hemostatic sponge, the characteristic peaks of OKGM and CS disappeared, indicating that they were indeed involved in the system reaction; at the same time, the characteristic peaks corresponding to ascidian nanocellulose and PDA NPs could be observed at 16.4° and 22.6° in the KCP spectrum, indicating that the two had been successfully doped.

[0085] (6) Porosity and blood absorption rate

[0086] The porosity was tested by ethanol immersion method, and the blood absorption rate was determined by whole blood absorption method. The porosity and blood absorption rate were calculated by formula.

[0087] Results: As Figure 7 As shown in Figure 2, the addition of appropriate PDA NPs does not affect the porosity. The increase in the doping amount increases the amount of free amino groups in the sponge. The Schiff base bond formed by the aldehyde group and the amino group makes the structure of the sponge denser and the pores smaller. Figure 8 As shown, KCP1 sponge can absorb 3100% of its own weight of blood, further confirming that the macroporous uniform network structure and good blood cell adhesion ability of KCP sponge are conducive to rapid hemostasis.

[0088] (7) Hemolysis rate and antioxidant activity

[0089] 0.5 mL of 5% red blood cells was added to 0.5 mL of KCP sample dispersion at various concentrations. After incubation and centrifugation, the absorbance of the supernatant was measured. Deionized water and normal saline were used as positive and negative controls, respectively. The hemolysis rate was calculated using the formula.

[0090] The antioxidant activity of KCP sponges was assessed using an ABTS free radical assay kit, followed by measuring the absorbance of each group. The antioxidant activity was calculated using the formula.

[0091] Results: As Figure 9 As shown in the figure, the hemolysis rate of KCP sponge in each group was less than 5%, which proved that KCP sponge has good blood compatibility; Figure 10 As shown in the figure, with the increase of polydopamine doping amount, the free radical scavenging ability continues to increase.

[0092] (8) Sterilization rate

[0093] Four groups of KCP sponges were co-cultured with bacterial solution for 12 hours, and then coated and inoculated on plates after dilution. The antibacterial effect of KCP sponges was verified by visual observation; the bactericidal rate was then calculated by measuring the corresponding OD value.

[0094] Results: As Figure 11 As shown in Figure 2, in the case of polydopamine doping, the bacteria in the plate decreased significantly with the addition of light; Figure 12, 13, NIR illumination groups KCP0, KCP 0.5 The bacterial killing rates of KCP0, KCP1 and KCP2 were over 90%, and the killing rates for Escherichia coli were 7.8%, 95.6%, 98.5% and 98.6% respectively; the killing rates for Staphylococcus aureus were 12.4%, 96.2%, 98.1% and 99.0% respectively. 0.5 The bacterial killing rates of KCP1, KCP2 are only about 15%, and the killing rates of Escherichia coli are 7.1%, 15.5%, 15.0% and 16.9% respectively; the killing rates of Staphylococcus aureus are 8.0%, 14.0%, 13.7% and 15.1% respectively, which shows that KCP sponge has a good photothermal antibacterial effect.

[0095] (9) Blood cell adhesion

[0096] Fresh blood was dripped onto four sets of KCP discs and incubated at 37°C for 30 minutes. Red blood cells were then fixed with glutaraldehyde for 2 hours and dehydrated using various concentrations of ethanol. Finally, red blood cell adhesion was observed using scanning electron microscopy (SEM). A commercial gelatin sponge was used as a control group.

[0097] Results: As Figure 14 As shown in the figure, SEM electron microscopy of the KCP series sponges after blood absorption revealed that the KCP sponges can effectively promote blood cell adsorption, with the number of adhered blood cells far exceeding that of the control group. This shows that the KCP series sponges can achieve coagulation effects by enriching red blood cells and platelets. Based on the above results, the optimal doping level of polydopamine in the KCP sponge is 1%.

[0098] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for preparing a rapid hemostatic sponge reinforced with ascidian nanocellulose and having a photothermal antibacterial effect, characterized in that: The following steps are involved: (1) Add 2 g of chitosan powder to 100 mL of 1% acetic acid solution and stir to dissolve in a constant temperature water bath at 60 °C to form solution A. (2) Take 0.2 g of oxidized konjac glucomannan, add it to 50 mL of deionized water, and stir until it is completely dissolved to form solution B; (3) Mix 90 mL of solution A and 10 mL of solution B and stir to form a homogeneous solution, which is recorded as solution C; (4) Take 0.072 g of ascidian nanocellulose, add it to 20 mL of deionized water, ultrasonicate until uniformly dispersed, add it to solution C, and stir until uniform, which is recorded as solution D; (5) Add 0.036 g of polydopamine nanoparticles to solution D and stir until uniform; (6) The solution obtained in step (5) was injected into a mold and placed at 4°C for 1 hour, -20°C for 4 hours, and -80°C for 12 hours to form solid A; (7) The solid A obtained in step (6) was freeze-dried in a vacuum freeze dryer to remove moisture from the sample, and was taken out after 48 hours to finally obtain a chitosan / oxidized konjac glucomannan / polydopamine nanoparticle sponge reinforced with ascidian nanocellulose.

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