CN115089760B - Antibacterial hemostatic sponge for deep wound hemorrhage and preparation method thereof - Google Patents

Abstract

The invention provides an antibacterial hemostatic sponge for deep wound bleeding and a preparation method thereof. The preparation raw materials include: an oxidizing agent, a catalytic system, sodium alginate, dopamine and chitosan; the oxidizing agent is NaIO ₄ ; the catalytic system is selected from EDC/NHS , DMAP/HOBT, TEA/DIEA or EDCI/HOBT system. The hemostatic sponge has good shape memory performance and is of great significance for filling hemostasis in irregular and narrow deep wounds. Hemostatic cotton such as CS3/SA/DA1 showed good hemostatic ability, and significantly shortened the hemostatic time and blood loss compared with medical gauze and commercial gelatin sponge. Hemostatic sponges such as CS3/SA/DA1 can absorb blood after filling the wound after being compressed and quickly restore the original state to block the wound, quickly stop bleeding and have good biocompatibility; after compression, it is easy to carry, has good hemostasis and antibacterial properties, which can be used in battlefields, traffic accidents and daily life. There are broad application prospects in life.

Description

A kind of antibacterial hemostatic sponge for deep trauma massive bleeding and preparation method thereof

technical field

The invention belongs to the technical field of hemostatic sponges, and in particular relates to an antibacterial hemostatic sponge for deep wound hemorrhage and a preparation method thereof.

Background technique

In wars, natural disasters, and traffic accidents, uncontrolled hemorrhage has a fatal risk, accounting for more than 30% of the total number of trauma deaths worldwide. At present, there are many kinds of hemostatic agents such as cyanoacrylate, fibrin glue, oxidized cellulose, polysaccharide microspheres, etc., but these hemostatic agents have a high hemostatic effect on surface bleeding. Penetrating wounds caused by gunshots and sharp objects will inevitably bleed profusely, which makes it particularly important to prepare a hemostatic material that can be applied to deep and lethal massive incompressible hemorrhage.

Clinically, the treatment of massive bleeding from deep trauma is still based on simple gauze filling and blockage, which greatly increases the risk of death and also brings a burden to the medical blood supply. It is noteworthy that some new hemostatic agents have been developed and approved by FDA for deep massive bleeding wounds. The XStat device is filled with a large amount of compressed cellulose sponge, which rapidly expands, fills, and compresses deeply incompressible wounds, however, it takes more time to remove a single sponge from the wound after hemostasis is complete. In addition, cellulose sponge cannot be degraded, and the residue left after surgery may cause tissue damage and affect wound healing, and even require a second operation to clean the wound.

At present, calcium ions (such as calcium chloride, etc.) or aldehyde crosslinking agents (such as glutaraldehyde, etc.) are often used to prepare hemostatic sponges such as alginic acid or chitosan, which require the introduction of calcium ions or toxic Aldehyde cross-linking agent, which is not friendly to human blood and tissues.

Contents of the invention

In view of this, the object of the present invention is to provide an antibacterial hemostatic sponge for deep wound bleeding and a preparation method thereof, the hemostatic sponge has excellent hemostatic effect.

The invention provides an antibacterial hemostatic sponge for deep wound bleeding, the preparation raw materials include the following components:

Oxidizing agents, catalytic systems, sodium alginate, dopamine and chitosan;

The oxidizing agent is NaIO ₄ ;

The catalytic system is selected from EDC/NHS system, DMAP/HOBT system, TEA/DIEA system or EDCI/HOBT system.

In the present invention, the molar ratio of the carboxyl group of the sodium alginate to the amino group of the dopamine and the amino group of chitosan is 1:1;

The molar ratio of the carboxyl group of the sodium alginate to the amino group of the dopamine is (1-3): (0-3).

In the present invention, the molar ratio of the carboxyl _group of the sodium alginate to NaIO is 1:0.95～1.05;

The molar ratio of the carboxyl group of the sodium alginate to the catalyst system is 1:0.45-0.55.

In the present invention, the molar ratio of the chitosan amino group to the dopamine amino group is 3:1, 2:1, 1:1, 1:2 or 1:3.

The present invention provides a kind of preparation method of antibacterial hemostatic sponge described in above-mentioned technical scheme, comprises the following steps:

Sodium alginate is dissolved to obtain a sodium alginate solution;

Add the catalytic system to the sodium alginate solution, add dopamine after 30 to 60 minutes, and react for 3 to 5 hours to obtain a reaction solution;

adding chitosan solution into the reaction solution, reacting for 3-5 hours, cooling, adding oxidizing agent NaIO ₄ and NaOH solution to obtain cryogel precursor;

The cryogel precursor is polymerized at -18 to -23° C. for 40 to 50 hours, thawed, purified, and freeze-dried to obtain an antibacterial hemostatic sponge.

In the present invention, the concentration of the sodium alginate solution is 3-5wt%;

The chitosan solution is an acetic acid solution of chitosan; the pH value of the acetic acid is 5.5-6.5.

The invention provides a kind of antibacterial hemostatic sponge that is used for deep wound hemorrhage, and preparation raw material comprises following component: oxidizing agent, catalytic system, sodium alginate, dopamine and chitosan; Described oxidizing agent is NaIO ₄ ; Described catalyzing system selects From the EDC/NHS system, the DMAP/HOBT system, the TEA/DIEA system or the EDCI/HOBT system. The hemostatic sponge has good shape memory performance, which is of great significance for filling hemostasis in irregular and narrow deep wounds. In rat liver and leg vein injury models, hemostatic cotton such as CS3/SA/DA1 showed good hemostatic ability, and significantly shortened the hemostatic time and blood loss compared with medical gauze and commercial gelatin sponge. In the rabbit liver deep injury model, hemostatic sponges such as CS3/SA/DA1 can absorb blood and quickly restore the original state to block the wound and stop bleeding after compression and filling the wound. Hemostatic sponges such as CS3/SA/DA1 showed good biocompatibility in the rat back skin injury model. The above results indicate that hemostatic sponges such as CS3/SA/DA1 can be applied to hemostasis of incompressible deep wounds. The hemostatic sponge is easy to carry after compression, has good hemostatic performance and antibacterial performance, and has broad application prospects in battlefields, traffic accidents and daily life.

Description of drawings

Fig. 1 is the design schematic diagram of the antibacterial hemostatic sponge prepared by the present invention;

Figure 2 is the shape, compression, rebound and size of CS3/SA/DA1 hemostatic cotton;

Figure 3 shows the appearance, compression and shape recovery of CS3/SA/DA1 hemostatic cotton, CS2/SA/DA1 hemostatic cotton, CS1/SA/DA1 hemostatic cotton, CS1/SA/DA3 hemostatic cotton and CS1/SA/DA2 hemostatic cotton After the SEM image and the elemental analysis image of each hemostatic cotton;

Figure 4 is a picture of the CS3/SA/DA1 hemostatic cotton before and after being compressed by external forces such as lateral, vertical, and torsion, and after absorbing PBS and recovering the expanded shape of blood;

Figure 5 is the appearance of each group of hemostatic cotton after 1-4 weeks of in vitro degradation; A, B, C, D, and E are CS1/SA/DA2 hemostatic cotton, CS1/SA/DA3 hemostatic cotton, CS1/SA/DA1 Hemostatic cotton, CS2/SA/DA1 hemostatic cotton, CS3/SA/DA1 hemostatic cotton;

Fig. 6 is the statistical diagram of the weight loss of the in vitro degradation of each group of hemostatic cotton for 1 to 4 weeks;

Fig. 7 is the statistical diagram of the hemostatic rate of each group of hemostatic cotton;

Figure 8 is a comparison chart of the hemostatic index of each group of hemostatic cotton;

Fig. 9 is the photothermal performance diagram of each group of hemostatic cotton;

Fig. 10 is the antibacterial ability graph of each group of hemostatic cotton to Escherichia coli E.coli;

Figure 11 is a comparison chart of hemostasis time for hepatic bleeding with CS3/SA/DA1 hemostatic cotton;

Figure 12 is a comparison chart of the bleeding volume of CS3/SA/DA1 hemostatic cotton for venous bleeding and hemostasis;

Figure 13 is a comparison chart of liver cavity bleeding volume of CS3/SA/DA1 hemostatic cotton.

Detailed ways

The invention provides an antibacterial hemostatic sponge for deep wound bleeding, the preparation raw materials include the following components:

Oxidant, catalytic system, sodium alginate (SA), dopamine (DA) and chitosan (CS);

The oxidizing agent is NaIO ₄ ;

The catalytic system is selected from EDC/NHS system, 4-dimethylaminopyridine (DMAP)/1-hydroxybenzotriazole (HOBT) system, triethanolamine (TEA)/N,N-diisopropylethylamine ( DIEA) system or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI)/HOBT system.

Fig. 1 is the schematic diagram of the design of the antibacterial hemostatic sponge prepared by the present invention; As can be seen from Fig. 1: chitosan (CS), sodium alginate (SA), dopamine (DA) and EDC/NHS are mixed by one pot reaction to form a A series of chitosan/sodium alginate/dopamine (CS/SA/DA) polymers. In order to form a cross-linked network structure and realize the injectability of the wound, the present invention uses sodium periodate as an oxidant to oxidize the CS/SA/DA polymer, uses a 2ml syringe as a shaper, and prepares a CS/SA/DA polymer by polymerization at low temperature. SA/DA hemostatic sponge. CS/SA/DA hemostatic sponge has strong coagulation ability in the mouse liver injury model, and the important thing is that CS/SA/DA can show excellent hemostatic performance in the lethal incompressible hemorrhage model of rabbit liver defect. Meanwhile, the CS/SA/DA hemostatic sponge also showed effective antibacterial properties against Gram-positive and negative bacteria. The antibacterial effect of the hemostatic cotton may be due to the certain adhesion of polydopamine. When the bacteria come into contact with the material, the catechol groups on the dopamine stick the bacteria to the surface of the material. Subsequently, the positively charged amino groups on chitosan adhere to the bacterial cell wall through electrostatic adhesion, thereby destroying the bacterial cell wall and causing the release of intracellular fluid.

The present invention provides a kind of preparation method of antibacterial hemostatic sponge described in above-mentioned technical scheme, comprises the following steps:

Sodium alginate is dissolved to obtain a sodium alginate solution;

Add the catalytic system to the sodium alginate solution, add dopamine after 30 to 60 minutes, and react for 3 to 5 hours to obtain a reaction solution;

adding chitosan solution into the reaction solution, reacting for 3-5 hours, cooling, adding oxidizing agent NaIO ₄ and NaOH solution to obtain cryogel precursor;

The cryogel precursor is polymerized at -18 to -23°C, thawed, purified, and freeze-dried to obtain an antibacterial hemostatic sponge.

The invention does not need additional cross-linking agent, direct chemical reaction to form a cross-linking structure, freeze-drying molding, and can be shaped according to the shape of the mold during the freeze-drying molding process, and can restore the original shape after compression; suitable for narrow cavities , hemorrhoids, fistulas, and hemostatic packing of deep wounds of tissues and organs; it has good elasticity and shape memory properties, and is of great significance for filling and hemostasis of irregular and narrow deep wounds; the hemostatic sponge can absorb blood and quickly return to its original state after compression and filling the wound Block the wound, quickly stop bleeding, and antibacterial, biodegradable.

The present invention is preferably purified in DI water, and the purification time is 2-3 days.

In order to further illustrate the present invention, a kind of antibacterial hemostatic sponge for deep trauma hemorrhage provided by the present invention and its preparation method are described in detail below in conjunction with the examples, but they should not be interpreted as limiting the protection scope of the present invention.

Example 1

Using _NaIO4 as oxidant and EDC/NHS as catalyst system, the mixed aqueous solution of sodium alginate SA, dopamine DA and chitosan CS was copolymerized at -20℃ to prepare cryogels. The total moles of amino groups of CS and DA are equal to the moles of carboxyl groups of SA. The molar amount of sodium alginate is fixed. To determine the optimal gel ratio, the molar ratios of CS and DA were set at 3:1, 2:1, 1:1, 1:2, and 1:3, respectively.

First, 0.3 g SA was dissolved in 6 mL deionized water to form a 5 wt% SA solution. Then EDC and NHS were added in sequence, and the molar ratio of the carboxyl groups on the SA skeleton to EDC/NHS was 1:0.5. After 30 minutes, DA with different molar ratios was added to the SA solution and reacted for 5 hours respectively. Then the corresponding chitosan solution (chitosan dissolved in 3 mL of acetic acid solution with pH=5.5) was added to the above reaction solution, and reacted for 5 hours. Then, the mixture was placed in an ice bath for half an hour, and sodium _periodate NaIO solution ( _NaIO dissolved in 1 mL of deionized water) was added to the above mixture under rapid stirring, followed by 200 μL of 5M NaOH solution. The amount of _NaIO4 added was determined according to the molar ratio of carboxyl groups on SA to _NaIO4 being 1:1. Then, the cryogel precursor was transferred into the prepared mold (the shape of the cryogel depends on the shape of the mold) and placed in a -20 °C freezer. Polymerization was carried out for 48 hours and the resulting cryogel was thawed. The resulting CS-SA-DA cryogel was purified by immersion in DI water for 3 days to remove unreacted polymer and free DA. Then freeze dry. The final sample numbers obtained were designated as CSm/SA/DAn, where m and n represent the molar ratios of CS and DA in the cryogel precursor, respectively; for example, CS1/SA/DA1 represents a 1:1 molar ratio of CS to DA. The six sets of sponge samples all had a fixed 3 wt% SA concentration.

1. Volume expansion ratio test

Each sample was prepared as a 2-3 cm cylinder. The sample is compressed to fix the shape, and the diameter (D ₁ ) and height (L ₁ ) of the fixed-shape sample are measured. Subsequently, the shape-fixed samples were soaked in DI water to restore their shape. After the shape is restored, the diameter of the sample is measured as D ₂ and the height as L ₂ . Use the following formulas to calculate the immobilized volume, recovered volume, and water-absorbed volume expansion ratio. Five test replicates per sample.

V _f ＝(D ₁ /2) ² ×L ₁ ×π

Vr＝(D ₂ /2) ² ×L ₂ ×π

2. Shape recovery ratio test

Cut the dry sample into 2-3 cm cylinders, measure and record the initial height as L ₁ . Compress the sample with a compression instrument and keep it for 1 minute, measure the height of the sample after compression and record it as L ₂ . Then the compressed sample was left for 5 minutes, and the recovered height in the natural state was measured as L ₃ . Finally, the sample in the natural state was soaked in DI water for 5 minutes, and then the recovered height was measured as L ₄ . The shape recovery rate ε _SR of the sample was calculated according to the following equation. Each sample has at least five parallel samples.

ε _SR = (L ₄ -L ₃ )/(L ₁ -L ₃ )×100%

3. In vitro degradability test

Cut the dried sample into a 2 cm cylindrical shape, weigh its initial mass and record it as w0, and take pictures to record its morphology. The samples were then placed in 10 ml of PBS solution for incubation. The degradation test was carried out in a shaker at 37°C at 100 rpm. The testing time was 1 week, 2 weeks, 3 weeks and 4 weeks respectively. The samples were taken out at the specified time, soaked in DI water for 3 days to remove the residual phosphate in the samples, and the water was changed every 6 hours. The samples were then freeze-dried until repeated weighings kept the mass constant. After drying, the sample is recorded as wn (n is a different period) and photographed to record the shape change. Each group of samples had five parallel samples. The degradation rate is calculated as follows:

Degradation rate (%)=(w0-wn)/w0×100%

4. Blood compatibility test

Fresh blood was extracted from rabbit ear vein, and red blood cells were centrifuged (116 g, 10 min) from the blood. The obtained erythrocytes were washed three times with PBS and diluted to a concentration of 2% (V/V). The obtained dry samples were then ground into powders and dispersed in PBS water to form dispersions with concentrations of 7.5 mg/ml, 5 mg/ml, 2.5 mg/ml and 1.25 mg/ml, respectively. Add 500 μL of erythrocyte (5%) suspension to every 2 mL of sample dispersion, and gently blow and mix with a pipette gun. The mixture was incubated at 37°C for 1h. At the scheduled time, the sample tubes were centrifuged for 10 minutes (116Xg). Transfer 200 μL of supernatant from each sample to a 96-well cell culture plate. The absorbance of the supernatant was measured at 540 nm with a microplate reader. We set PBS as the negative control group and 1% Triton as the positive control group. Each sample has at least five parallel samples. The formula for calculating the hemolysis rate is as follows:

Hemolysis rate (%)=[(Ap-Ab)/(At-Ab)]×100%

Among them, Ap is the absorbance value of the supernatant, At is the absorbance value of the positive control Triton X-100, and Ab is the absorbance value of the negative control PBS.

5. Cytocompatibility test

The cell-sample contact co-culture experiment method was used to evaluate the cytocompatibility of the sample. The dried samples were cut into discs with a height of 1 mm and a diameter of 8 mm and transferred to 96-well cell culture plates, and then soaked in 75% alcohol and sterilized under ultraviolet irradiation for 3 hours. Subsequently, the samples were washed three times with sterile PBS in an ultra-clean bench to remove residual 75% ethanol. After the samples were washed, NIH ₃ T ₃ fibroblasts were seeded into 96-well cell culture plates at a cell density of 5×10 ³ cells (200 μL high glucose medium DMEM). Incubate for 1, 3 and 7 days at 37°C in a humidified environment of 95% air and 5% carbon dioxide. After the predetermined time, add 100 μL/mL CCK-8 solution to each well. After culturing for 2 h, 150 μL of the reaction solution was transferred to a new 96-well cell plate. Use a microplate reader to read the absorption wavelength at 450 nm. Five parallel samples for each sample.

NIH ₃ T ₃ fibroblasts were seeded into 24-well cell culture plates containing material samples at a cell density of 2 × ¹⁰⁴ cells per well. After culturing for 1 day, 3 days, and 5 days, respectively, the medium was discarded and washed with PBS. Subsequently, 200 μL of staining solution for live/dead cell staining was added to each well, incubated at 37°C for 10 minutes, and then washed 3 times with PBS. Afterwards, cell viability was observed with an inverted microscope.

NIH ₃ T ₃ fibroblasts were seeded into 48-well cell culture plates containing samples at a cell density of 3×10 ⁴ cells per well. Cell morphology was observed by SEM after 1, 3 and 5 days of culture respectively. Cells were fixed with 4% paraformaldehyde in PBS for 30 min and washed 3 times with PBS. Then sequentially use 50%, 60%, 70%, 80%, 90% and 100% ethanol to dehydrate the samples sequentially, add 500 μL of ethanol to each well, and dehydrate each gradient ethanol for 30 minutes. After the samples were dried at room temperature, the cell morphology was observed by SEM.

6. In vitro antibacterial performance test

Samples were prepared into disks with a diameter of 8 mm and a height of 5 mm, and then transferred to 48-well bacterial culture plates. Then soak it in 75% alcohol and irradiate it under ultraviolet light for 3h to sterilize. After disinfection, wash 3 times with PBS to remove residual 75% ethanol. The pre-cultured bacteria (Escherichia coli and Staphylococcus aureus) were inoculated into a 48-well bacterial culture plate, and 1 mL of suspended bacterial solution was added to each well, with a bacterial density of 1×10 ⁶ CFU/mL. Cultivate for 6, 12, 18, 24 and 30 hours at 37°C in a humidified environment of 95% air and 5% carbon dioxide. Transfer 200 μL of bacterial solution to a new 96-well plate at the scheduled time. Use a microplate reader to read the absorption wavelength at 600 nm. The group without material was used as the blank control group, with five parallel samples in each group, and the bacterial proliferation was observed.

7. Whole Blood Coagulation Test

The sample was prepared into a disc shape with a diameter of 10 mm and a height of 5 mm. The sample was preheated at 37° C. for 30 min, then 50 μL of fresh rabbit whole blood and 25 μL of CaCl ₂ solution (10 mM) were added. The mixture was incubated at 37°C for 30s, 60s, 90s, 120s and 150s, respectively. Medical gauze and commercial gelatin sponge were used as the control group, and no samples were added as the blank control group. After the specified time, the free blood was gently washed with 10ml DI water without destroying the formed blood clot. Take 200 μL of the washing solution and transfer it to a 96-well plate, and measure the absorbance of the supernatant at 540 nm by using a microplate reader. Each group carried out 5 parallel experiments.

The calculation formula of whole blood coagulation index (BCI) is as follows:

BCI%=[(Is-I0)-(Ir-I0)]×100%;

Is is the absorbance of the sample, Ir is the absorbance of the blank group, and I0 is the absorbance of primary water;

8. Adhesion observation of red blood cells and platelets;

The sample is prepared in the shape of a disc with a diameter of 10 mm and a height of 5 mm. The sample was immersed in PBS and incubated at 37°C for 1 h, and then 200 μL of pre-separated erythrocytes were dropped into the sample, and further placed at 37°C for 5 minutes. 200 μL of platelet-rich plasma (PRP) was dropped into the sample, and further placed at 37° C. for 1 hour. At the end of the time, samples were gently washed three times with PBS to remove non-adhered platelets and red blood cells. The samples were then fixed for 2 h using 2.5% glutaraldehyde solution. Afterwards, 50%, 60%, 70%, 80%, 90% and 100% ethanol were sequentially used to dehydrate the erythrocytes and platelets in the sample in gradient. SEM was used to observe the adhesion status of platelets and red blood cells in the samples.

9. In vivo hemostasis test

(1) SD rat liver hemostasis:

The hemostatic effect of CS3/SA/DA1 hemostatic cotton in vivo was studied by rat liver injury model. In this experiment, male SD rats (200 g, 6 weeks old) were used as animal models. SD rats were randomly divided into 4 groups, 6 rats in each group. Animals were anesthetized and mounted on a surgical board by injection of 10% chloral hydrate (0.3 ml/100 g body weight). The liver was exposed through abdominal dissection, and the tissue fluid around the liver was carefully wiped clean with medical gauze to prevent errors in the measurement of blood loss. The pre-weighed filter paper was placed under the liver, and a cross-cut injury with a depth of 0.3 cm was made in the liver with a scalpel. Block the pre-weighed medical gauze, gelatin sponge, and CS3/SA/DA1 hemostatic cotton at the liver injury site respectively. SD rats without any treatment after liver injury were used as the control group. During the hemostasis process, the wound hemostasis was observed every 10 seconds until the wound stopped bleeding, and the hemostasis time and bleeding volume were recorded.

Bleeding volume = Wx – Wy

Wx and Wy are the bleeding weight with or without hemostasis, respectively.

(2) Venous hemostasis

For the leg vein rupture model of SD rats, male SD rats (200 g, 6 weeks old) were divided into 4 groups, and each group was divided into 5 randomly. Rats were anesthetized by injection of 10% chloral hydrate and fixed to a surgical board. The SD rat leg was dissected to separate the vein, and the previously prepared filter paper was placed under the vein. The vein was broken with medical scissors, and the wound was subsequently covered with pre-weighed medical gauze, gelatin sponge and CS3/SA/DA1 under slight pressure. During the hemostasis process, the hemostasis time and bleeding volume were recorded. SD rats without any treatment after leg vein injury were used as the control group.

(3) Fatal incompressible bleeding hemostasis test (simulating deep cavity bleeding)

The hemostatic ability of CS3/SA/DA1 was evaluated by liver injury in New Zealand rabbits as a hemostatic model of lethal incompressible hemorrhage. Cut the dry CS3/SA/DA1 hemostatic cotton into a cylindrical shape with a diameter of 8mm and a height of 10mm, and compress the CS3/SA/DA1 hemostatic cotton into small particles. Male New Zealand rabbits (2.5kg) were divided into five groups with five parallel samples in each group.

Rabbits were anesthetized by injection of chloral hydrate and fixed to a surgical board. Afterwards, the rabbit was subjected to an abdominal incision to expose the liver, the serous fluid around the liver was carefully removed, and then a cross-incision injury with a depth of 0.8 cm was made in the liver with a scalpel. Then fill the pre-weighed and compressed CS3/SA/DA1 granules into the wound site until the wound is blocked. Afterwards, the small particles of CS3/SA/DA1 absorb blood and rapidly expand into the form before compression. The liver injury without any treatment was taken as the blank group, and the medical gauze was used as the control group. Record the hemostasis time, blood loss and vital status. Experiments were repeated five times for each group.

10. Histocompatibility test

Rats were anesthetized by injection of 10% chloral hydrate and fixed to a surgical board. The pre-sterilized CS3/SA/DA1 material was implanted into the back muscles of rats (n=5). At given time intervals (days 7, 14 and 21), 3 rats per group were sacrificed and tissue samples were taken and fixed with glutaraldehyde (4%). Fixed tissues were embedded in paraffin for sectioning. After gradient dehydration, tissue sections were stained with H&E.

Figure 2 is the shape, compression, rebound and size diagram of CS3/SA/DA1 hemostatic cotton; from Figure 2, it can be seen that the hemostatic sponge polymerized at low temperature has good elastic memory, and quickly returns to its original shape after compression and bending ; In addition, the CS/SA/DA dry hemostatic sponge expands in volume after absorbing water, so it can be used to fill hemostasis in deep wounds caused outdoors and on the battlefield.

Figure 3 shows the appearance, compression and shape recovery of CS3/SA/DA1 hemostatic cotton, CS2/SA/DA1 hemostatic cotton, CS1/SA/DA1 hemostatic cotton, CS1/SA/DA3 hemostatic cotton and CS1/SA/DA2 hemostatic cotton After the SEM image and the elemental analysis image of each hemostatic cotton;

Figure 4 is a picture of the CS3/SA/DA1 hemostatic cotton before and after being compressed by external forces such as lateral, vertical, and torsion, and after absorbing PBS and recovering the expanded shape of blood;

Figure 5 is the appearance of each group of hemostatic cotton after 1-4 weeks of in vitro degradation; A, B, C, D, and E are CS1/SA/DA2 hemostatic cotton, CS1/SA/DA3 hemostatic cotton, CS1/SA/DA1 Hemostatic cotton, CS2/SA/DA1 hemostatic cotton, CS3/SA/DA1 hemostatic cotton;

Fig. 6 is the statistical diagram of the weight loss of the in vitro degradation of each group of hemostatic cotton for 1 to 4 weeks;

Fig. 7 is the statistical diagram of the hemostatic rate of each group of hemostatic cotton;

Figure 8 is a comparison chart of the hemostatic index of each group of hemostatic cotton;

Fig. 9 is the photothermal performance diagram of each group of hemostatic cotton;

Fig. 10 is the antibacterial ability graph of each group of hemostatic cotton to Escherichia coli E.coli;

Figure 11 is a comparison chart of hemostasis time for hepatic bleeding with CS3/SA/DA1 hemostatic cotton;

Fig. 12 is a comparison chart of bleeding volume of CS3/SA/DA1 hemostatic cotton for venous bleeding and hemostasis; the present invention creates a fractured injury model in rat leg veins. The blood loss of CS3/SA/DA1 hemostatic cotton (0.12±0.05g) was much smaller than that of blank group (0.34±0.13g), medical gauze group (0.28±0.12g) and gelatin sponge group (0.27±0.10g);

Figure 13 is a comparison chart of liver cavity bleeding in CS3/SA/DA1 hemostatic cotton; it can be seen from Figure 13: the bleeding volume in the blank group was 1.18±0.07g, and the bleeding volume in the medical gauze group was 0.48±0.17g. The bleeding volume of the CS3/SA/DA1 hemostatic cotton prepared by the invention is 0.34±0.02g.

It can be seen from the above examples that the present invention prepares a hemostatic sponge for filling deep wounds with good biocompatibility, blood compatibility, antibacterial properties and degradability through a simple mixed chemical reaction. The hemostatic sponge has good shape memory performance, which is of great significance for filling hemostasis in irregular and narrow deep wounds. In rat liver and leg vein injury models, hemostatic cotton such as CS3/SA/DA1 showed good hemostatic ability, and significantly shortened the hemostatic time and blood loss compared with medical gauze and commercial gelatin sponge. In the rabbit liver deep injury model, hemostatic sponges such as CS3/SA/DA1 can absorb blood and quickly restore the original state to block the wound and stop bleeding after compression and filling the wound. Hemostatic sponges such as CS3/SA/DA1 showed good biocompatibility in the rat back skin injury model. The above results indicate that hemostatic sponges such as CS3/SA/DA1 can be applied to hemostasis of incompressible deep wounds. The hemostatic sponge is easy to carry after compression, has good hemostatic performance and antibacterial performance, and has broad application prospects in battlefields, traffic accidents and daily life.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (5)

1. A preparation method of an antibacterial hemostatic sponge comprises the following steps:

dissolving sodium alginate to obtain a sodium alginate solution;

adding a catalytic system into a sodium alginate solution, adding dopamine after 30-60 min, and reacting for 3-5 h to obtain a reaction solution; the catalytic system is selected from an EDC/NHS system, a DMAP/HOBT system, a TEA/DIEA system or an EDCI/HOBT system;

adding chitosan solution into the reaction solution, reacting for 3-5 h, cooling, adding oxidant NaIO ₄ And NaOH solution to obtain a frozen gel precursor;

and carrying out polymerization reaction on the frozen gel precursor at the temperature of between 18 ℃ below zero and 23 ℃ below zero for 40 to 50 hours, thawing, purifying, and freeze-drying to obtain the antibacterial hemostatic sponge.

2. The method according to claim 1, wherein the ratio of the number of moles of carboxyl groups in sodium alginate to the total number of moles of amino groups in dopamine and chitosan is 1:1;

the molar ratio of the carboxyl of the sodium alginate to the amino of the dopamine is (1-3): (0-3).

3. The method of claim 1, wherein the carboxyl group of sodium alginate and NaIO ₄ In a molar ratio of 1:0.95 to 1.05;

the molar ratio of the carboxyl of the sodium alginate to the catalyst system is 1.45-0.55.

4. The method according to claim 1, wherein the molar ratio of the amino group of chitosan to the amino group of dopamine is 3:1, 2:1, 1:1, 1:2 or 1:3.

5. The preparation method of claim 1, wherein the concentration of the sodium alginate solution is 3-5 wt%;

the chitosan solution is acetic acid solution of chitosan; the pH value of the acetic acid is 5.5-6.5.

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