Preparation method, product and application of a cationized alginic acid hemostatic material

Abstract

The present invention discloses a preparation method of a cationized alginic acid hemostatic material. Alginic acid or alginate is subjected to a one-pot reaction with epichlorohydrin and N,N-dimethylx-alkyl tertiary amine, where x = 10 - 14, the reaction temperature is 30 - 70 °C, and the reaction time is 10 - 60 hours; the molar ratio of epichlorohydrin to N,N-dimethylx-alkyl tertiary amine is 10:11 - 10:13; the feeding molar ratio of alginic acid or alginate to epichlorohydrin is 1:0.5 - 1:1.5; after the reaction, the precipitate obtained from the reaction is stirred with an electrolyte solution having a concentration of 50% - 80% to untangle the molecular chain entanglement, and the foamed product is obtained. It is precipitated and washed with absolute ethanol to obtain the cationized alginic acid hemostatic material. This material has good blood coagulation promoting performance while maintaining good blood compatibility, and can be more widely used in the field of medical hemostatic products. It can also be applied in the preparation of thermosensitive hemostatic gel products.

Description

Technical Field

[0001] The present invention belongs to the field of hemostatic materials, and relates to a preparation method, product and application of a cationized alginic acid hemostatic material. Background Art

[0002] Hemostatic materials and medical hemostatic products are crucial in dealing with traumatic bleeding caused by traffic accidents, natural disasters, surgical operations, etc. Alginic acid and alginates, as a kind of plant-derived polysaccharides, have become a hot research material due to their characteristics of green safety, strong water retention, cheap and easy availability, etc. The Chinese invention patent publication text with the publication number CN201910591877.5 discloses an alginate quaternary ammonium salt hemostatic and antibacterial agent, which is obtained by the method of grafting an alkyl chain quaternary ammonium salt onto alginate, and has a good hemostatic effect. Its feature is that a positively charged epoxyalkyl chain quaternary ammonium salt or haloalkyl quaternary ammonium salt is first synthesized, and then the quaternary ammonium salt is grafted onto the negatively charged alginate polysaccharide. However, this method requires the prior synthesis of the quaternary ammonium salt and then the grafting of the quaternary ammonium salt onto alginate, and the steps are relatively complex. Therefore, there is a need to provide an alginic acid material with a simple synthesis method and hemostatic performance. Summary of the Invention

[0003] In view of this, the present invention provides a preparation method, product and application of a cationized alginic acid hemostatic material. The present invention specifically provides the following technical solutions:

[0004] 1. A preparation method of a cationized alginic acid hemostatic material, and the preparation steps are as follows:

[0005] 1) Alginic acid or alginate is subjected to a one-pot reaction with epichlorohydrin and N,N-dimethylxalkyl tertiary amine, where x = 10 - 14, the reaction temperature of the one-pot reaction is 30 - 70 °C, and the reaction time is 10 - 60 hours; the molar ratio of epichlorohydrin to N,N-dimethylxalkyl tertiary amine is 10:11 - 10:13; the feeding molar ratio of alginic acid or alginate to epichlorohydrin is 1:0.5 - 1:1.5;

[0006] 2) After the reaction is completed, the precipitate obtained from the reaction is stirred with an electrolyte solution with a concentration of 50% - 80% to untangle the molecular chain entanglement, and the foamed product is obtained. It is precipitated and washed with absolute ethanol to obtain the cationized alginic acid hemostatic material.

[0007] Further, the product obtained in step 1) is alginic acid grafted with a long alkyl chain quaternary ammonium salt, and the grafting rate of the long alkyl chain quaternary ammonium salt is 3% - 10%.

[0008] Furthermore, the alginic acid or alginate described in step 1) needs to be prepared into an aqueous solution with a mass fraction of 2-10%, and after adding epichlorohydrin and N,N-dimethyl x-alkyl tertiary amine, react at 30-70° C. for 10-60 hours.

[0009] Furthermore, the precipitate described in step 2) is a sodium alginate quaternary ammonium salt product that is aggregated together due to electrostatic action.

[0010] Furthermore, the electrolyte solution in step 2) is a sodium chloride or potassium chloride solution.

[0011] 2. The product prepared according to the above-mentioned method for preparing a cationic alginate hemostatic material.

[0012] 3. The application of the above-mentioned cationic alginate hemostatic material in the preparation of a thermosensitive hemostatic gel product, the application method is: the thermosensitive polymer is configured into a solution with a concentration of 150-300 mg / mL, and then a solution of the cationic alginate hemostatic material with a concentration of 0.5-2 mg / mL is added to form a thermosensitive gel.

[0013] Furthermore, the temperature-sensitive polymer is poloxamer, a mixture of poloxamer and hydroxypropyl methylcellulose, a mixture of poloxamer and hydroxypropyl cellulose, or a mixture of poloxamer, hydroxypropyl methylcellulose and hydroxypropyl cellulose.

[0014] Furthermore, the solvent of the thermosensitive polymer solution is water, physiological saline, phosphate buffer or glucose solution, and the solvent of the solution of the cationic alginate hemostatic material is consistent with the solvent of the thermosensitive polymer solution.

[0015] The beneficial effects of the present invention are as follows: the present invention provides a method for preparing a cationized alginate hemostatic material, wherein epichlorohydrin and N,N-dimethyl x-alkyl tertiary amine (x=10-14) are reacted with alginate or alginate in an aqueous solution in a one-pot process under the condition of a molar ratio of 10:11-10:13, and the following process occurs:

[0016] 1) Epichlorohydrin and N,N-dimethyl x-alkyl tertiary amine (x=10-14) are prone to undergo a substitution reaction of alkyl halide on tertiary amine to generate long alkyl quaternary ammonium salt with epoxy group;

[0017] 2) In the above two reaction systems, the N,N-dimethyl x-alkyl tertiary amine with a molar excess of 0.1-0.3 times can capture hydrogen ions in water to form ligands through the tertiary amine, which will make the aqueous solution weakly alkaline, and then catalyze the reaction of hydroxyl and carboxyl groups in alginate or alginate with epoxy groups, so as to achieve the grafting of long alkyl quaternary ammonium salt with epoxy groups onto alginate;

[0018] 3) Thereafter, due to the hydrophobicity and positive charge of the excessive unreacted tertiary amine on N,N-dimethyl x-alkyl, and the large number of negatively charged carboxyl groups present in the cationic alginic acid, the electrostatic assembly of the two will cause the formation of water-insoluble precipitate in the system. This precipitate can still react with the aforementioned steps 1) and 2), and may even be accelerated due to the high local concentration (of course, there is also the negative impact of increased steric hindrance). More importantly, the appearance of this precipitate also realizes the rapid separation of the cationic alginic acid product from the aqueous solution, greatly reducing the use of precipitating agents. In the subsequent post-treatment process of the product, using electrolytes such as sodium chloride to post-treat the obtained precipitate and disassemble the electrostatic assembly can further accelerate the removal of unreacted raw materials, reduce the use of precipitating agents, and improve the yield.

[0019] For hemostatic applications, this preparation method limits the feeding ranges of epichlorohydrin (the molar ratio of alginic acid or alginate to epichlorohydrin is 1:0.5 - 1:1.5) and N,N-dimethyl x-alkyl tertiary amine (the molar ratio of epichlorohydrin to N,N-dimethyl x-alkyl tertiary amine is 10:11 - 10:13), grafting long alkyl chain quaternary ammonium salts with a relatively low grafting rate onto sodium alginate, so that the prepared cationic alginic acid material has good blood compatibility while having good procoagulant properties. (The procoagulant property comes from the promotion of blood component aggregation by a small amount of long alkyl quaternary ammonium salts, and the presence of a large number of carboxyl groups avoids the interference of too strong positive charge on coagulation factors), and it can be more widely used in the field of medical hemostatic products. Finally, by mixing a thermosensitive polymer solution with cationic alginic acid, the preparation and application of a thermosensitive hemostatic gel are demonstrated, and its hemostatic performance is superior to that of single cationic alginic acid (powder) and single thermosensitive gel (thermosensitive polymer solution). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To make the objectives, technical solutions, and beneficial effects of the present invention clearer, the present invention provides the following drawings:

[0021] Figure 1 Photograph of the precipitate obtained after the stirring reaction of 50% sodium chloride solution producing a large amount of foam

[0022] Figure 2 Photograph of the product obtained by precipitating the fully foamed product with absolute ethanol to obtain fine granular product for easy washing

[0023] Figure 3 Photograph of the granular cationic alginic acid obtained after washing

[0024] Figure 4 Photograph of the precipitate obtained after the stirring reaction of 10% sodium chloride solution producing foam SPECIFIC EMBODIMENTS

[0025] The preferred embodiments of the present invention will be described in detail below.

[0026] Example 1

[0027] 1) Take 4 g of sodium alginate (viscosity 1000 mPa·s), add it to 80 mL of deionized water, then add 1 mL of epichlorohydrin and 3.2 mL of N,N-dimethyldecylamine, and react in an N 2 atmosphere at 40 °C for 24 h.

[0028] 2) After the reaction is completed, stir the precipitate obtained by the reaction with a 50% sodium chloride solution. After a large amount of foam is generated in the system due to stirring (this process is called foaming) ( Figure 1 ), wash it three times with absolute ethanol (including the processes of precipitation, stirring and centrifugation, as Figure 2 and Figure 3 ), 2 h each time. After vacuum drying, cationic alginic acid X1 with a grafting rate of 4% is obtained.

[0029] In this example, the molar ratio of SA (sodium alginate): EP (epichlorohydrin): NH 2 (tertiary amine on N,N-dimethyldecylamine) = 1:0.619:0.681, and the number of carbon atoms on N,N-dimethyldecylamine is 10.

[0030] From Figure 1 it can be seen that when stirring in a 50% sodium chloride solution, a large amount of fine foam can be generated from the precipitate obtained after the reaction is completed.

[0031] From Figure 2 it can be seen that when using absolute ethanol precipitation, the product obtained after foaming can be evenly dispersed in the ethanol solution, which is convenient for removing unreacted raw materials during the washing process.

[0032] From Figure 3 it can be seen that the product obtained after washing is in a relatively dispersed state, proving that it has been washed sufficiently.

[0033] Example 2

[0034] 1) Take 4 g of sodium alginate (viscosity 1000 mPa·s), add it to 80 mL of deionized water, then add 1 mL of epichlorohydrin and 3.2 g of N,N-dimethyldodecylamine, and react in an N 2 atmosphere at 40 °C for 24 h.

[0035] 2) After the reaction is completed, stir the precipitate obtained by the reaction with a 50% sodium chloride solution. After a large amount of foam is generated in the system due to stirring, precipitate and wash it three times with absolute ethanol, 2 h each time. After vacuum drying, cationic alginic acid X2 with a grafting rate of 5% is obtained.

[0036] In this example, the molar ratio of SA (sodium alginate): EP (epichlorohydrin): NH 2 (tertiary amine on N,N-dimethyldodecylamine) = 1: 0.619: 0.681, and the number of carbon atoms on N,N-dimethyldodecylamine is 12.

[0037] Example 3

[0038] Poloxamer (F127) was configured into a solution with a concentration of 200 mg / mL using physiological saline, and the cationic alginic acid X1 in Example 1 was added to make its concentration in the solution 1 mg / mL, obtaining the gel X3 with hemostatic performance.

[0039] Example 4

[0040] Poloxamer (F127) was configured into a solution with a concentration of 240 mg / mL using physiological saline, and the cationic alginic acid X2 in Example 2 was added to make its concentration in the solution 1 mg / mL, obtaining the gel X4 with hemostatic performance.

[0041] Comparative Example 1

[0042] 1) 4 g of sodium alginate (viscosity 1000 mPa·s) was taken and added to 80 mL of deionized water, then 1 mL of epichlorohydrin and 3.2 mL of N,N-dimethylbutylamine were added, and the reaction was carried out for 24 h under the condition of 40 °C in the atmosphere of N 2 .

[0043] 2) After the reaction ended, the reaction system was a homogeneous system, and no precipitate could be obtained, and the cationic alginic acid could not be efficiently separated out.

[0044] In this scheme, there are only 4 carbons on the carbon chain of N,N-dimethylbutylamine, its hydrophobicity is lower than that of tertiary amines with 10 carbons, and due to its short carbon chain, the entanglement with alginate is less, so the electrostatic assembly of the positively charged tertiary amine and the negatively charged cationic alginic acid is greatly weakened, resulting in no precipitation precipitate in the system and the product cannot be obtained.

[0045] Comparative Example 2

[0046] 1) 4 g of sodium alginate (viscosity 1000 mPa·s) was taken and added to 80 mL of deionized water, then 4 mL of epichlorohydrin and 12.8 mL of N,N-dimethyldecylamine were added, and the reaction was carried out for 24 h under the condition of 40 °C in the atmosphere of N 2 .

[0047] 2) After the reaction ended, the precipitate obtained was stirred with 50% sodium chloride solution to untangle the molecular chains. After vigorous foaming, it was precipitated and washed three times with absolute ethanol for 2 hours each time. Then, it was dried under vacuum to obtain cationic alginic acid Y2 with a grafting amount of 15%.

[0048] In this scheme, the molar ratio of alginic acid or alginate to epichlorohydrin was 1:2.5. Outside the range of 1:0.5 to 1:1.5, the resulting product hemolyzed (the hemolysis rate was as high as 30.2%, see Table 1).

[0049] Comparative Example 3

[0050] 1) Take 4 g of sodium alginate (viscosity 1000 mPa·s), add it to 80 mL of deionized water, then add 0.5 mL of epichlorohydrin and 1.6 mL of N,N-dimethyldecylamine. In the atmosphere of N 2 , react at 40 °C for 24 hours.

[0051] 2) After the reaction ended, although there was a certain amount of precipitate, the yield of the separated cationic alginic acid was extremely low, about 2%, which could not support subsequent experiments.

[0052] In this scheme, the molar ratio of alginic acid to epichlorohydrin was 1:0.31 (outside the range of 1:0.5 to 1:1.5), and the molar ratio of epichlorohydrin to N,N-dimethyldecylamine was maintained at 10:11. Therefore, compared with epichlorohydrin, the slightly excessive N,N-dimethyldecylamine provided a weakly basic environment for the reaction to proceed. However, due to the low dosage of epichlorohydrin and N,N-dimethyldecylamine compared to alginic acid in the total system, the degree of reaction was low, the resulting precipitate was extremely small, and the yield was extremely low, without application value.

[0053] Comparative Example 4

[0054] 1) Take 4 g of sodium alginate (viscosity 1000 mPa·s), add it to 80 mL of deionized water, then add 1 mL of epichlorohydrin and 3.2 mL of N,N-dimethyldecylamine. In the atmosphere of N 2 , react at 40 °C for 24 hours.

[0055] 2) After the reaction ended, the precipitated product obtained was directly washed with absolute ethanol, precipitated and washed three times with absolute ethanol for 2 hours each time. Then, it was dried under vacuum to obtain cationic alginic acid Y4.

[0056] In this scheme, instead of stirring and foaming with sodium chloride solution, the product was directly washed with absolute ethanol, and the resulting product hemolyzed (the hemolysis rate was as high as 33.5%, see Table 1).

[0057] Comparative Example 5

[0058] 1) Take 4 g of sodium alginate (viscosity 1000 mPa·s), add it to 80 mL of deionized water, then add 1 mL of epichlorohydrin and 3.2 mL of N,N-dimethyldecylamine. React for 24 h at 40 °C under a nitrogen atmosphere.

[0059] 2) After the reaction, stir the precipitate obtained with a 10% sodium chloride solution. There are a small amount of foams in the system. Precipitate and wash three times with absolute ethanol, 2 h each time. Then, after vacuum drying, cationized alginic acid Y5 with a grafting amount of 4% is obtained.

[0060] In this scheme, when stirring the product with a low-concentration sodium chloride solution, the entanglement of molecular chains is not completely untied, which is not conducive to the removal of residual quaternary ammonium salts. The obtained product has hemolysis (hemolysis rate as high as 25.3%, see Table 1).

[0061] From Figure 4 it can be seen that stirring with a 10% sodium chloride solution gives a small amount of foams. This is because the concentration of the sodium chloride solution is low, and a product with sufficient foaming cannot be obtained, which is not conducive to the washing of the product.

[0062] Comparative Example 6

[0063] 1) Take 4 g of sodium alginate (viscosity 1000 mPa·s), add it to 80 mL of deionized water, then add 1 mL of epichlorohydrin and 1.4 mL of N,N-dimethyldecylamine. React for 24 h at 40 °C under a nitrogen 2 atmosphere.

[0064] 2) After the reaction, there are very few precipitated products. The yield of cationized alginic acid separated is extremely low and cannot support subsequent experiments.

[0065] In this scheme, the molar ratio of epichlorohydrin to N,N-dimethyldecylamine is 10:5, which is less than 10:11 - 10:13. The amount of N,N-dimethyldecylamine is too small to provide a weak alkaline environment, which is not conducive to catalyzing the reaction of hydroxyl and carboxyl groups in alginic acid or alginate with epoxy groups, resulting in a decrease in the reaction efficiency of grafting long-chain alkyl quaternary ammonium salts onto alginic acid and an extremely low yield, without application value.

[0066] Comparative Example 7

[0067] Prepare a solution of poloxamer (F127) with a concentration of 200 mg / mL in physiological saline, and add sodium alginate (viscosity 1000 mPa·s) to make its concentration in the solution 1.5 mg / mL to obtain gel Y7.

[0068] In this scheme, only ordinary sodium alginate (without cationic modification) is added.

[0069] Comparative Example 8

[0070] Prepare a solution of poloxamer (F127) with a concentration of 200 mg / mL using physiological saline, and add the cationized alginic acid X1 in Example 1 to make its concentration in the solution 0.1 mg / mL, obtaining gel Y8.

[0071] In this scheme, the concentration of the cationized alginic acid X1 is less than the range of 0.5 - 2 mg / mL.

[0072] Comparative Example 9

[0073] Prepare a solution of poloxamer (F127) with a concentration of 200 mg / mL using physiological saline, and add the cationized alginic acid X1 in Example 1 to make its concentration in the solution 5 mg / mL, obtaining gel Y9.

[0074] In this scheme, the concentration of the cationized alginic acid X1 is greater than 0.5 - 2 mg / mL.

[0075] Comparative Example 10

[0076] Prepare a solution of poloxamer (F127) with a concentration of 200 mg / mL using physiological saline, obtaining gel Y10.

[0077] This scheme only has poloxamer and does not add any other modified materials.

[0078] Test Example 1 Blood Compatibility Test

[0079] Detection conditions: Blood compatibility tests were carried out on Examples 1, 2, 3, 4, Comparative Examples 2, 4, and the alginate raw material (viscosity 1000 mPa·s). Detection method: Hemolysis rate test. The blood used for detection was fresh SD rat citrate anticoagulated blood. The test materials were prepared into a 1 mg / mL solution using physiological saline. Centrifuge the whole blood (3000 rpm, 10 min), take the blood cells, wash the blood cells twice with physiological saline, and then prepare the blood cells into a 4% solution using physiological saline. Mix the test material solution and the blood cell solution in equal volumes (250 μL each), and the final concentration is 2% blood cells and 1 mg / mL test material. Set positive and negative control groups. The negative control group is a physiological saline solution (250 μL) with the same volume as the blood cell solution, and the positive control group is a 4% Triton solution (250 μL) with the same volume as the blood cell solution. Incubate at 37 °C for 3 h, centrifuge (3000 rpm, 3 min), take 100 μL of the supernatant and add it to a 96-well plate, and use an enzyme-linked immunosorbent assay reader to read the absorbance Abs at 545 nm for each well. Finally, calculate the hemolysis rate through the following formula.

[0080] Hemolysis rate = (Abs material - Abs negative) / (Abs positive - Abs negative) × 100%................... Equation

[0081] Where: Abs material is the absorbance of the material group at 545 nm; Abs positive is the absorbance of the positive group at 545 nm; Abs negative is the absorbance of the negative group at 545 nm. The hemolysis rates of the examples and comparative examples are as follows in the table:

[0082] Table 1 Hemolysis rate test

[0083] Table 1 Hemolysis rate test

[0084] sample X1 X2 X3 X4 Y2 Y4 Y5 sodium alginate Hemolysis rate (%) 1.5 1.2 0.9 1.2 30.2 33.5 25.3 0.6

[0085] The hemolysis rate is used to characterize the red blood cell compatibility of blood contact materials. Hemolysis means that a large number of red blood cells are broken after the blood contacts the material, and a large amount of hemoglobin is released. Generally speaking, when the hemolysis rate is less than 5%, it indicates that the blood compatibility of the material is good; when the hemolysis rate is greater than 5%, it indicates that the material has certain toxicity, causing more red blood cells to rupture, which will damage the composition and function of the blood and is not suitable to be used as a blood contact material (the state stipulates that the hemolysis rate of any blood contact material should not exceed 5%), which limits its application in the field of hemostasis.

[0086] It can be seen from Table 1 that the hemolysis rates of X1, X2, X3 and sodium alginate are all lower than 5%. The above results show that sodium alginate itself has good blood compatibility, and the cationized sodium alginate (X1, X2) grafted with a small amount of quaternary ammonium salt within a certain ratio and the gels (X3, X4) prepared on this basis can also continue to maintain good blood compatibility. And in the process of preparing the X1 and X2 systems, the use of an electrolyte solution in the post-treatment weakens the positive and negative charge attraction between the negatively charged carboxyl groups of sodium alginate and tertiary amines and quaternary ammonium salts, so that in the washing process, the ungrafted / residual quaternary ammonium salts and tertiary amine impurities in the system can be removed to the greatest extent, which is beneficial to the removal of quaternary ammonium salts, with a low hemolysis rate and good blood compatibility.

[0087] The hemolysis rate of the comparative example Y2 is as high as 30.2%, indicating that the material has great biological toxicity. The reason is that an excessive amount of epichlorohydrin and excessive N,N-dimethyldecylamine are used in the reaction system for preparing the counter material, resulting in too many quaternary ammonium salts grafted on the cationized sodium alginate in the end. Due to the toxicity of the excessive quaternary ammonium salts, the cell membrane of red blood cells ruptures, resulting in an increased hemolysis rate and poor blood compatibility.

[0088] The hemolysis rate of Comparative Example Y4 was as high as 33.55%, indicating that the material had great biotoxicity. The reason was that sodium chloride was not added during the post-treatment of the reaction, and the precipitate was directly washed. Due to the positive-negative charge attraction between the negatively charged carboxyl groups of sodium alginate and tertiary amines and quaternary ammonium salts, it was difficult to effectively remove the ungrafted / residual quaternary ammonium salts and tertiary amine impurities, which was not conducive to the removal of quaternary ammonium salt residues, resulting in an increased hemolysis rate and poor blood compatibility.

[0089] The hemolysis rate of Comparative Example Y5 was also relatively high at 25.3%, indicating that the material had great biotoxicity. The reason was that although sodium chloride solution was added for dissociation during the post-treatment of the reaction, the concentration of the added sodium chloride solution was too low, and the dissociation of the precipitate was incomplete, so that the molecular chain entanglement was not completely opened, which was not conducive to subsequent washing, and the ungrafted / residual quaternary ammonium salts and tertiary amine impurities in the system were not completely removed, resulting in an increased hemolysis rate and poor blood compatibility.

[0090] Comparison of in vitro blood coagulation effects in Test Example 2

[0091] Detection conditions: In vitro blood coagulation effect tests were carried out on Examples 1, 2, 4 and Comparative Examples 7, 8, 9, 10 and sodium alginate raw material (viscosity 1000 mPa·s). Test method: The test samples (50 μL of gel and 5 mg of powder) were respectively placed in 2 mL plastic centrifuge tubes and incubated in a constant temperature water bath at 37 °C for 5 minutes; then 100 μL of fresh anticoagulant and 10 μL of calcium chloride solution (CaCl 2 ; 0.2 M) were mixed evenly to form about 100 μL of re-coagulated blood; the re-coagulated blood was added to the surface of the sample and incubated in a constant temperature water bath at 37 °C for 1 minute. Finally, 10 mL of deionized water was added to fully lyse the excess blood that did not form a blood clot, and incubation was continued for 3 minutes to release hemoglobin (HGB); 2 mL of the lysed liquid was aspirated for centrifugation (2500 rmp, 3 minutes), 100 μL of the centrifuged supernatant was taken, added to a 96-well plate, and the absorbance at 545 nm was measured with an enzyme-linked immunosorbent detector to calculate the hemoglobin content. The blank group was to directly add 100 μL of fresh anticoagulant to 10 mL of deionized water, incubate in a constant temperature water bath at 37 °C for 3 minutes, and aspirate 100 μL to measure the absorbance Abs at 545 nm. Finally, the blood coagulation index (BCI) was calculated by the following formula.

[0092] Blood coagulation index % (BCI) = (Abs material / Abs blank) × 100%................... formula

[0093] In the formula: Abs material is the absorbance of the material group at 545 nm; Abs blank is the absorbance of the blank group at 545 nm. The BCI indexes of the examples and comparative examples are as follows in the table:

[0094] Table 2 In vitro blood coagulation effect test

[0095]

[0096] BCI (Blood clotting index), which can characterize the blood clotting effect of materials. Generally, the smaller the value of BCI, the better the blood clotting effect of the material. It can be seen from Table 2 that:

[0097] The BCI indexes of the hemostatic materials X1 - X4 obtained in Examples 1, 2, 3, and 4 of the present invention are significantly lower than those of Comparative Examples 7, 8, 9, 10 and sodium alginate. Thus, it can be seen that after modifying sodium alginate by the preparation method of the present invention, that is, cationic sodium alginate (X1, X2) grafted with a small amount of quaternary ammonium salt within a certain ratio and the gels prepared on this basis (a certain concentration of cationic sodium alginate is added to the thermosensitive polymer solution, that is, X3, X4), hemostatic materials with excellent hemostatic performance can be obtained.

[0098] The hemostatic performance of sodium alginate powder is also lower than that of the corresponding Examples X1 and X2; Y7 is a gel added with unmodified alginic acid, and its hemostatic performance is lower than that of the corresponding Examples X3 and X4; this performance difference effectively illustrates the improvement of the hemostatic effect of alginic acid by cationic modification. In addition, the in vitro blood clotting performance of Comparative Examples Y8, Y9, and Y10 is poor because the gel preparation method is inappropriate. Specifically:

[0099] 1) The reason for the poor in vitro blood clotting performance of Y8 is that the concentration of cationic sodium alginate with hemostatic performance in the gel system is too low, only 0.1 mg / mL, which does not play an effective role in improving the blood clotting effect of the gel.

[0100] 2) The reason for the poor in vitro blood clotting performance of Y9 is that the concentration of cationic sodium alginate with hemostatic performance in the gel system is too high, 5 mg / mL. The excessive content of cationic sodium alginate will inhibit the activity of blood clotting-related factors when contacting with blood, which is also not conducive to the blood clotting effect.

[0101] 3) Y10 is a gel prepared by using poloxamer (F127) alone without adding any modified materials. The BCI results show that the hemostatic performance of the gel is not as good as that after adding cationic sodium alginate. Therefore, it shows that cationic sodium alginate can improve the hemostatic performance of the gel.

[0102] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. Preparation method of a cationized alginic acid hemostatic material, characterized in that, the preparation steps are as follows: 1) Alginate or alginic acid needs to be formulated into an aqueous solution with a mass fraction of 2-10%, and after adding epichlorohydrin and N,N-dimethylx alkyl tertiary amine, react at 30-70 °C for 10-60 hours; the molar ratio of epichlorohydrin to N,N-dimethylx alkyl tertiary amine is 10:11-10:13; the molar ratio of alginate or alginic acid to epichlorohydrin in the feed is 1:0.5-1:1.5; x = 10-14; 2) After the reaction is completed, stir the precipitate obtained from the reaction with an electrolyte solution of 50%-80% to untangle the molecular chain entanglement, obtain the foamed product, precipitate and wash with absolute ethanol to obtain the cationized alginic acid hemostatic material.

2. The preparation method of a cationized alginic acid hemostatic material according to claim 1, characterized in that, the product obtained in step 1) is alginic acid grafted with a long alkyl chain quaternary ammonium salt, and the grafting rate of the long alkyl chain quaternary ammonium salt is 3%-10%.

3. The preparation method of a cationized alginic acid hemostatic material according to claim 1, characterized in that, the precipitate in step 2) is a sodium alginate quaternary ammonium salt product aggregated together due to electrostatic interaction.

4. The preparation method of a cationized alginic acid hemostatic material according to claim 1, characterized in that, the electrolyte solution in step 2) is a sodium chloride or potassium chloride solution.

5. A product prepared by the preparation method of a cationized alginic acid hemostatic material according to any one of claims 1-4.

6. Application of the cationized alginic acid hemostatic material according to claim 5 in the preparation of a thermosensitive hemostatic gel product, characterized in that, the application method is: configure the thermosensitive polymer into a solution with a concentration of 150-300 mg / mL, and then add a solution of the cationized alginic acid hemostatic material with a concentration of 0.5-2 mg / mL to form a thermosensitive gel.

7. The application of the cationized alginic acid hemostatic material according to claim 6 in the preparation of a thermosensitive hemostatic gel product, characterized in that, the thermosensitive polymer is poloxamer, a mixture of poloxamer and hydroxypropyl methylcellulose, a mixture of poloxamer and hydroxypropyl cellulose, or a mixture of poloxamer and hydroxypropyl methylcellulose and hydroxypropyl cellulose.

8. The application of the cationized alginic acid hemostatic material according to claim 6 in the preparation of a thermosensitive hemostatic gel product, characterized in that, the solvent of the thermosensitive polymer solution is water, normal saline, phosphate buffer solution or glucose solution, and the solvent of the solution of the cationized alginic acid hemostatic material is the same as that of the thermosensitive polymer solution.

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