CN108853564B

CN108853564B - Cross-linked dextran microparticles for hemostasis and preparation method thereof

Info

Publication number: CN108853564B
Application number: CN201710317242.7A
Authority: CN
Inventors: 于一帆; 何浩明; 唐小康; 栾立标
Original assignee: Changzhou Institute Of Materia Medica Co ltd
Current assignee: Changzhou Institute Of Materia Medica Co ltd
Priority date: 2017-05-08
Filing date: 2017-05-08
Publication date: 2021-04-06
Anticipated expiration: 2037-05-08
Also published as: CN108853564A

Abstract

The invention discloses a cross-linked dextran particle for hemostasis and a preparation method thereof, wherein epichlorohydrin is used as a cross-linking agent and is prepared by adopting an inverse suspension method, and the prepared product has low residual quantity of the cross-linking agent through detection and good biocompatibility and is suitable for being used as a hemostasis material. The method does not need to introduce other organic solvents for washing in the process of preparing the cross-linked dextran microparticles, and avoids the influence on the product quality caused by the residual organic solvents in the product. The cross-linked dextran microparticles prepared by the invention have irregular edge contour, are not easy to shift after being used, can be fixed at a hemostasis site, have biodegradability, no immunogenicity and no cytotoxicity, and can be used as hemostasis powder for clinical use.

Description

Cross-linked dextran microparticles for hemostasis and preparation method thereof

Technical Field

The present invention relates to a crosslinked dextran microparticle used as a hemostatic powder and a method for producing the crosslinked dextran microparticle.

Background

In various surgical operations, the reduction of bleeding and the shortening of the operation time have important influence on the prognosis of patients. An ideal hemostatic material should have the following characteristics: rapid hemostasis, no toxicity, no antigenicity, no increase of infection probability, no influence on tissue healing, and low price.

In recent years, medical absorbable hemostatic materials have attracted great attention from the medical and industrial fields. The absorbable hemostatic material is a medical material which is applied to a wound bleeding part, achieves the aim of hemostasis by accelerating the blood coagulation process and can be absorbed by a human body within a certain time. Currently, the absorbable hemostatic materials commonly used include fibrin glue, gelatin sponge, oxidized cellulose, microfibrillar collagen, chitosan, calcium alginate fiber and the like.

With respect to hemostatic materials, chinese patent document CN100402096 (application No. 02818207.3) discloses a dry hemostatic composition that can be rapidly rehydrated to form a gelatin hydrogel suitable as a hemostatic sealant, and a method for preparing the same. The preparation method of the composition comprises the following steps: providing an aqueous solution comprising uncrosslinked gelatin in combination with at least one rehydration aid; drying the solution of gelatin and rehydration aid to form a solid; milling the solid to form a powder; crosslinking gelatin to form a hydrogel; removing at least 50% (w/w) rehydration aid from the hydrogel; and drying the cross-linked gelatin to form a powder having a moisture content of less than 20% (w/w); wherein the rehydration aid is selected from the group consisting of glycerol, dextran, polyvinylpyrrolidone and polyethylene glycol.

Chinese patent document CN102178977A (application No. 201110094127.0) discloses a preparation with dual functions of hemostasis and sustained release of granulocyte colony stimulating factor and a preparation method thereof, which consists of glucan particles containing granulocyte colony stimulating factor, degradable sustained and controlled release material and a hemostatic material skeleton, wherein: the glucan particles containing the granulocyte colony stimulating factor and the degradable sustained-release material respectively account for 0.004-400 mg/cm of the weight of the unit area of the hemostatic material framework²And 0.001 mg-4 mg/cm². The preparation method comprises the steps of suspending glucan particles containing the granulocyte colony stimulating factor into a liquid degradable controlled-release material or a degradable controlled-release material dissolved in an organic solvent to prepare a suspension, and finally coating the suspension on the biodegradable fiber or the porous material by using a spraying, brushing or dipping method. The degradable sustained and controlled release material is polylactic acid (PLA), polyglycolic acid (PGA), polylactic-co-glycolic acid (PLGA), Polycaprolactone (PCL), poly (ester), poly (lactic-co-glycolic acid) and derivatives thereof or other biodegradable sustained and controlled release materials and combinations thereof.

Chinese patent document CN103721247B (application No. 201410009613.1) discloses a collagen-based composite hemostatic powder and a preparation method thereof, wherein sanchinin is used for modifying type I collagen, polylysine modified chitosan is used for preparing a solution with the concentration of 1% -2% of the modified type I collagen, medical gelatin is prepared into a solution with the concentration of 1% -3%, the modified chitosan is prepared into a solution with the concentration of 1% -3%, the three solutions are blended according to the mass ratio of 0.5-1: 2-8: 8-2, the mixture is stirred at the temperature of 4-10 ℃ for 8-10 h, and the composite sponge is prepared by freeze drying. And (2) at room temperature, sequentially soaking the composite sponge in the modifier and the blood coagulation factor in an ultrasonic cleaner, fully washing with water, freeze-drying, and crushing by a crusher to obtain the collagen-based composite hemostatic powder.

The hemostatic material has complex composition and higher safety risk of corresponding products. The biological safety of many materials has certain disadvantages, and some products are not even degradable.

Chinese patent document CN 102989031B (application No. 201210439078.4) discloses a high-expansibility medical polysaccharide material and its application, which is a supermolecular powdery or granular solid formed by the interaction of soluble polysaccharide and a crosslinking agent, wherein the soluble polysaccharide is one or two of cellulose derivative, starch and its derivative, dextran and its derivative, chitin and its derivative, chitosan and its derivative, chondroitin sulfate and its derivative, hyaluronic acid and its derivative, alginic acid and its derivative, konjac gum, bletilla gum, and pachyman.

Wherein the dextran is a glucose polymer linked by alpha-1, 6-linkages. The glucan has no toxicity, good bioadhesion, biocompatibility, biodegradability and gel characteristics, and has unique advantages in the aspects of controlled release of drugs and embolotherapy. Dextran (also known as dextran) is a commonly used plasma substitute in hospitals. The dextran is used as a good microsphere preparation raw material, the safety and the effectiveness of the dextran are incomparable with any hemostatic material, and the dextran microparticles have wide application prospects in the field of biomedicine.

Although chinese patent document CN 102989031B mentions that the supramolecular powder or granular solid formed by the interaction of dextran and its derivatives with a cross-linking agent can be used for hemostasis, the whole document does not disclose a method for preparing cross-linked dextran for hemostasis.

Chinese patent document CN 101182380 (application No. 200610107398.4) discloses a method for synthesizing reverse-phase cross-linked dextran, which comprises weighing 100g of dextran, dissolving 10g of sodium hydroxide in 75ml of distilled water to prepare dextran alkali solution, weighing 25-60g of polyvinyl acetate, dissolving in 500-900ml of epichlorohydrin under stirring to prepare polyvinyl acetate alicyclic epoxy chloropropane solution, pouring the dextran alkali solution into the polyvinyl acetate and epichlorohydrin solution under stirring speed of 500rpm, and carrying out cross-linking reaction at 50 ℃ for 5 hours; the reaction product is washed by 3 times of ethanol and distilled water in turn for 3 times, and then dried for 2 hours at 50 ℃ to obtain the product. The cross-linked dextran prepared by the method is a composite cross-linked dextran, the polyvinyl acetate used in the preparation process is a high molecular organic material which is difficult to biodegrade, and the biological safety of the polyvinyl acetate and the cross-linked or dispersed product of the polyvinyl acetate is not reported, so the cross-linked dextran prepared by the method is not suitable for hemostasis.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide the degradable cross-linked dextran microparticles for hemostasis, which have good blood absorption effect and high biological safety; the second technical problem to be solved is to provide a preparation method of the crosslinked dextran microparticles for hemostasis.

The technical scheme for realizing the first purpose of the invention is that the cross-linked dextran particle for hemostasis is prepared by the following steps: uniformly dispersing glucan dry powder in acetone at room temperature; secondly, dropwise adding a sodium hydroxide solution into the materials obtained in the first step, stirring while dropwise adding to obtain uniformly dispersed floccules, performing gradient temperature rise on the materials in the process of dropwise adding the sodium hydroxide solution, raising the temperature to 30-40 ℃, keeping the temperature and stirring for 15-30 min; thirdly, epoxy chloropropane is dripped into the floccule which is uniformly dispersed in the step two, the mass ratio of the dextran to the epoxy chloropropane is 5: 3-5, and the epoxy chloropropane is continuously stirred and reacts for 4-15 hours after the addition of the epoxy chloropropane is finished; dripping hydrochloric acid into the reacted materials in the step (III), and adjusting the pH value of the reacted materials to 4.5-5.5; pouring out the materials in the bottle and filtering, and treating the cross-linked dextran gel particles obtained above the filter paper; fifthly, washing the cross-linked dextran gel particles obtained in the step (iv) by acetone; sixthly, the crosslinked glucan particles after acetone washing in the step five are dried by air blowing; seventhly, screening the dried particles to obtain the cross-linked dextran particles for hemostasis.

The particles have irregular edge profiles and the particle size is 135-350 μm.

The technical scheme for realizing the second aim of the invention is a preparation method of the cross-linked dextran microparticles for hemostasis, which comprises the following steps:

uniformly dispersing glucan dry powder in acetone at room temperature.

And secondly, dropwise adding a sodium hydroxide solution into the materials obtained in the step I, stirring while dropwise adding to obtain uniformly dispersed floccules, performing gradient temperature rise on the materials in the process of dropwise adding the sodium hydroxide solution, raising the temperature to 30-40 ℃, keeping the temperature and stirring for 15-30 min.

And thirdly, dropwise adding epoxy chloropropane into the uniformly dispersed floccule obtained in the step II, wherein the mass ratio of the dextran to the epoxy chloropropane is 5: 3-5, and continuously stirring and reacting for 4-15 hours after the addition of the epoxy chloropropane is finished.

Dripping hydrochloric acid into the reacted materials in the step (III), and adjusting the pH value of the reacted materials to 4.5-5.5; the contents were poured out and filtered, and the Sephadex particles obtained above the filter paper were ready for treatment.

Fifthly, washing the cross-linked dextran gel particles obtained in the step (iv) with acetone.

Sixthly, the crosslinked glucan particles after acetone washing in the step five are dried by air blowing.

Seventhly, screening the dried particles to obtain the cross-linked dextran particles for hemostasis.

And secondly, when the temperature is increased in a gradient manner, the temperature is increased by 4-6 ℃ every 10 min.

When the air drying is carried out, the temperature is controlled to be lower than 40 ℃.

And seventhly, when the dried particles are sieved, the particles to be sieved are sieved by a 60-mesh sieve, the particles passing through the sieve are sieved by a 170-mesh sieve, and the particles above the sieve are taken as the cross-linked glucan particles for hemostasis.

The invention has the positive effects that: (1) the invention uses the inverse suspension method to prepare the cross-linked dextran particles, the preparation method is simple and easy to operate, the solid preparation of the particles can be realized, and the prepared product has low residual quantity of the cross-linking agent through detection and good biocompatibility and is suitable for being used as a hemostatic material.

(2) According to the invention, other organic solvents are not required to be introduced for washing in the process of preparing the cross-linked dextran microparticles, so that the influence on the product quality caused by the residue of the organic solvents in the product is avoided, the production cost is reduced, and the price of the hemostatic powder is further reduced.

(3) The cross-linked dextran microparticles prepared by the invention are not spherical with smooth surfaces, but have irregular edge profiles, are not easy to shift after being used, can be fixed at a hemostasis site, have the particle size of 135-350 mu m, can be loaded in an injection tube, and are pushed to the bleeding site when being used, so that the cross-linked dextran microparticles can rapidly absorb blood and swell to play a role in hemostasis.

(4) The cross-linked dextran microparticles prepared by the invention have biodegradability, no immunogenicity and no cytotoxicity, and can be used as hemostatic powder in clinical application.

Drawings

FIG. 1 is a photomicrograph (64X magnification) of the Sephadex microparticles prepared in example 1;

FIG. 2 is a graph showing the particle size distribution of Sephadex microparticles prepared in example 1;

FIG. 3 is a gas chromatogram for measuring the residual acetone content of the Sephadex microparticles prepared in example 1;

FIG. 4 is a gas chromatogram of cross-linked dextran microparticles obtained in example 1 for detecting the residual amount of cross-linking agent;

FIG. 5 is a photomicrograph (64X magnification) of the Sephadex microparticles prepared in example 2;

FIG. 6 is a graph showing the particle size distribution of Sephadex microparticles prepared in example 2;

FIG. 7 is a gas chromatogram for measuring the residual acetone content of the Sephadex microparticles prepared in example 2;

FIG. 8 is a gas chromatogram of cross-linked dextran microparticles obtained in example 2 for detecting the residual amount of cross-linking agent;

FIG. 9 is a photomicrograph (64X magnification) of the Sephadex microparticles prepared in example 3;

FIG. 10 is a graph showing the particle size distribution of the Sephadex microparticles obtained in example 3.

FIG. 11 is a gas chromatogram for measuring the residual acetone content of the Sephadex microparticles prepared in example 3;

FIG. 12 is a gas chromatogram for measuring the residual amount of the crosslinking agent of the crosslinked dextran microparticles prepared in example 3.

Detailed Description

(example 1)

The method for preparing the sephadex microparticles of the present embodiment comprises the steps of:

adding 300mL of acetone into a 500mL three-neck flask, adding 20g of dextran (also called dextran, which is synthesized by fermenting sucrose through Leuconostoc mesenteroides and has a molecular weight of 4 ten thousand) dry powder at room temperature (15-30 ℃), and stirring to uniformly disperse the dry powder in the acetone.

Secondly, filling 0.2mol/L sodium hydroxide aqueous solution into a dropping funnel, dropwise adding 120mL sodium hydroxide solution into the three-neck flask of the first step for 30 min; the floccules in the three-necked flask were uniformly dispersed by stirring while dropping.

And (3) in the process of dropwise adding the sodium hydroxide solution, carrying out gradient temperature rise on the three-neck flask, raising the temperature by 4-6 ℃ every 10min (5 ℃ in the embodiment), raising the temperature to 40 ℃, keeping the temperature and stirring for 20 min.

And thirdly, epoxy chloropropane is dripped into the three-neck flask in which the floccules are uniformly dispersed in the step II, and the mass ratio of the dextran to the epoxy chloropropane is 5: 3. The epichlorohydrin is continuously stirred and reacted for 14 hours at the temperature of 40 ℃ after the addition of the epichlorohydrin is finished.

Dripping 2mol/L hydrochloric acid into the three-neck flask after the reaction in the step (c) until the pH value of the liquid in the flask is 4.5-5.5 (5.0 in the embodiment); the contents were poured out and filtered, and the Sephadex particles obtained above the filter paper were ready for treatment.

And fifthly, washing the cross-linked dextran gel particles obtained in the step (iv) with acetone for 2-3 times, wherein the volume of acetone used in each washing is 4 times of that of the cross-linked dextran gel particles, and the washing time is 30 min.

Sixthly, drying the crosslinked dextran particles after acetone washing for 1 hour at the temperature of below 40 ℃ by air blast to obtain the crosslinked dextran particles with the particle size distribution diagram shown in figure 2, wherein the average particle size of the prepared particles is 212.471 mu m. The particles obtained above were subjected to particle size measurement using a Mastersizer 2000 type particle size meter from Malvern, uk, and this particle size meter was also used for particle size measurement in the following examples.

Further, the residue of solvent acetone and crosslinking agent epichlorohydrin in the obtained dried microspheres was detected by gas chromatography, fig. 3 is a gas chromatogram of the crosslinked dextran microparticles prepared in this example for detecting the residual amount of acetone, and the residual amount of acetone was 46 μ g/g; FIG. 4 is a gas chromatogram of the Sephadex microparticles prepared in this example, showing that epichlorohydrin-remaining amount was not detected.

Seventhly, performing two-step screening on the dried particles, wherein the structure of a device for the two-step screening is shown in the application number of 2017200921496, the patent name of the device is Chinese patent document of a vibrating screen for preparing microspheres, and a screen on the vibrating screen is selected according to the screening condition. In this embodiment, the mesh sizes of the two screens are 60 meshes and 170 meshes, the particles to be screened are firstly screened by the 60-mesh screen, the particles passing through the screen are then screened by the 170-mesh screen, and the particles above the screen are taken to obtain the target product, namely the cross-linked dextran particles for hemostasis.

A micrograph of the resulting Sephadex microparticles was screened and shown in FIG. 1. It can be seen from the figure that the prepared sephadex particles are not smooth-surfaced spheres but have irregular edge profiles, and the contact area between the particles with the shapes is large, so that the friction force is large and the particles are not easy to displace.

(example 2)

The method of preparing Sephadex microparticles of this example is otherwise the same as in example 1, except that:

step two, the temperature is increased to 45 ℃ in the bottle in a gradient manner.

And step three, after the epichlorohydrin is added, the mass ratio of the dextran to the epichlorohydrin is 5: 4. And continuously stirring and reacting for 8 hours at the temperature of 45 ℃ after the addition of the epichlorohydrin is finished.

A photomicrograph of the Sephadex microparticles (sieved) prepared in this example is shown in FIG. 5.

The particle size distribution of the Sephadex particles obtained in this example, before sieving, is shown in FIG. 6, and the average particle size of the obtained particles is 134.922 μm.

Detecting residues of solvent acetone and crosslinking agent epichlorohydrin in the dried microspheres obtained in the step (c) by using gas chromatography, wherein fig. 7 is a gas chromatogram for detecting the residual amount of acetone by using the crosslinked dextran microparticles prepared in the embodiment, and the residual amount of acetone is 46 ug/g; FIG. 8 is a gas chromatogram of the fine crosslinked dextran particles obtained in this example showing the residual amount of epichlorohydrin, indicating that epichlorohydrin was not detected.

(example 3)

step two, the temperature is increased to 35 ℃ of the material in the bottle in a gradient manner.

And step three, after the epichlorohydrin is added, the mass ratio of the dextran to the epichlorohydrin is 5: 5. And continuously stirring and reacting for 15 hours at the temperature of 35 ℃ after the addition of the epichlorohydrin is finished.

A photomicrograph of the Sephadex microparticles (after sieving) prepared in this example is shown in FIG. 9.

The particle size distribution of the Sephadex particles obtained in this example, before sieving, is shown in FIG. 10, and the average particle size of the obtained particles is 348.129 μm.

Detecting residues of solvent acetone and crosslinking agent epichlorohydrin in the dried microspheres obtained in the step (c) by using gas chromatography, wherein fig. 11 is a gas chromatogram for detecting the residual amount of acetone by using the crosslinked dextran microparticles prepared in the embodiment, and the residual amount of acetone is 52 ug/g; FIG. 12 is a gas chromatogram obtained by measuring the residual amount of epichlorohydrin in the Sephadex fine particles obtained in the present example, and this chromatogram shows that epichlorohydrin was not detected.

(test examples)

The water absorption property, crosslinking degree and hemostatic function of the crosslinked dextran microparticles prepared in the above examples 1 to 3 were examined, and the examination method and results are as follows.

(first) Water absorption detection

Taking 0.5g of dry powder-shaped sephadex particles, putting 0.5g of the dry powder-shaped sephadex particles into a test tube with known weight, slowly adding water into the test tube until the sephadex particles fully absorb water until the excessive water is analyzed, stopping adding the water, inclining the test tube, slowly pouring out the unabsorbed water, respectively weighing the test tube and the contents thereof, and subtracting the weight of the original test tube to obtain the following data of each test object:

the crosslinked dextran microparticles of example 1 absorbed 12.4g of water per g, the crosslinked dextran microparticles of example 2 absorbed 10.3g of water per g, and the crosslinked dextran microparticles of example 3 absorbed 8.2g of water per g, showing a tendency that the larger the amount of the crosslinking agent added, the worse the water absorption, which is likely to be due to the higher the degree of crosslinking and hence the lower the water absorption performance.

(II) detection of the degree of crosslinking

The detection method developed by the applicant is adopted for detecting the crosslinking degree, wherein the crosslinking degree is the mass percentage of the modified part of the crosslinking agent in the microspheres in the whole microspheres, and the mass of the modified part comprises the sum of the mass of crosslinking modified glucan, the mass of monosubstituted modified glucan and the mass of a crosslinking agent fragment; the detection method comprises the following steps:

0.20000g of the tested sephadex microspheres are precisely weighed by an electronic balance, transferred into a 50mL volumetric flask, 50.00mL of 50mM sodium periodate solution is measured by a pipette and transferred into the 50mL volumetric flask, evenly shaken, wrapped by tinfoil in the periphery of the volumetric flask in the dark, subjected to redox reaction at 4 ℃, and fully shaken once every 24h in the reaction process.

The redox reaction equation is as follows:

in the reaction process, the solution in a 0.1mL volumetric flask is sucked into a 100mL volumetric flask every 24 hours, diluted to the scale with water, shaken up and the absorbance of the solution is measured at 223 nm.

The reaction is carried out until the light absorption value reaches a stable valueAt the moment, 20.00mL of supernatant is sucked from the measuring flask into the conical flask, 2mL of ethylene glycol is added into the conical flask, the mixture is shaken up, the conical flask is kept stand for 20min at room temperature in the dark, 2-3 drops of phenolphthalein reagent are added into the conical flask, the mixture is shaken up, then 0.01M sodium hydroxide solution is used for titration, and the consumed volume V is recorded₁。

The same volume of 20mL of distilled water plus 2mL of ethylene glycol solution was used as a blank, the same procedure was followed, titration was performed, and the volume V consumed for the blank was recorded₀。

Substituting the cross-linking degree calculation formula:

in (1).

In the above formula, V₁The volume of sodium hydroxide titration solution is consumed for the sample solution in ml.

V₀The volume of sodium hydroxide titrant in ml was consumed for the blank control.

And c is the concentration of sodium hydroxide titration solution in mol/L.

162g/mol is the molecular molar mass of the glucose residues in the glucan chain.

m is the mass of the dextran microspheres in g.

The microparticle of example 1 had a degree of crosslinking of 62.66% according to the procedure described above; example 2 degree of crosslinking of microparticles 64.28%; example 3 the microparticle crosslinking degree was 65.15%. Confirm the guess for test example 1: the larger the amount of the crosslinking agent added, the higher the degree of crosslinking, and hence the water absorption property is lowered.

(III) animal experiments of hemostatic function

The experiment is a hemostasis experiment of the crosslinked dextran microparticle hemostatic powder on a mouse.

The mice 36 were randomly averaged into 3 groups: control group, positive control group, and sephadex microparticle group.

The mice were anesthetized, femoral artery was exposed and incised, the mice of control group were allowed to stop bleeding naturally, the mice of positive control group were pushed with a syringe at bleeding point with commercially available plant polysaccharide hemostatic powder 0.5g, the mice of sephadex particle group were pushed with a syringe at bleeding point with sephadex particle 0.5g prepared in example 1, femoral artery hemostasis time was recorded as follows:

group of	Femoral artery hemostatic time (min)
		Control group	12.10±4.23
Positive control group	8.41±3.64
		Sephadex fraction	2.80±1.58

The experiments prove that the cross-linked glucan hemostatic powder can obviously reduce the wound hemostatic time and has good hemostatic effect.

Claims

1. A cross-linked dextran microparticle for hemostasis, characterized in that the microparticle is a cross-linked product of dextran and epichlorohydrin, and is prepared by the following steps: uniformly dispersing glucan dry powder in acetone at room temperature; secondly, dropwise adding a sodium hydroxide solution into the materials obtained in the first step, stirring while dropwise adding to obtain uniformly dispersed floccules, performing gradient temperature rise on the materials in the process of dropwise adding the sodium hydroxide solution, raising the temperature to 30-40 ℃, keeping the temperature and stirring for 15-30 min; thirdly, epoxy chloropropane is dripped into the floccule which is uniformly dispersed in the step two, the mass ratio of the dextran to the epoxy chloropropane is 5: 3-5, and the epoxy chloropropane is continuously stirred and reacts for 4-15 hours after the addition of the epoxy chloropropane is finished; dripping hydrochloric acid into the reacted materials in the step (III), and adjusting the pH value of the reacted materials to 4.5-5.5; pouring out the materials in the bottle and filtering, and treating the cross-linked dextran gel particles obtained above the filter paper; fifthly, washing the cross-linked dextran gel particles obtained in the step (iv) by acetone; sixthly, the crosslinked glucan particles after acetone washing in the step five are dried by air blowing; seventhly, screening the dried particles to obtain the cross-linked dextran particles for hemostasis.

2. The crosslinked dextran microparticles for hemostasis according to claim 1, characterized in that: the particles have irregular edge profiles and the particle size is 135-350 μm.

3. A method for preparing crosslinked dextran microparticles for hemostasis, characterized by comprising the steps of:

uniformly dispersing glucan dry powder in acetone at room temperature;

secondly, dropwise adding a sodium hydroxide solution into the materials obtained in the first step, stirring while dropwise adding to obtain uniformly dispersed floccules, performing gradient temperature rise on the materials in the process of dropwise adding the sodium hydroxide solution, raising the temperature to 30-40 ℃, keeping the temperature and stirring for 15-30 min;

thirdly, epoxy chloropropane is dripped into the floccule which is uniformly dispersed in the step two, the mass ratio of the dextran to the epoxy chloropropane is 5: 3-5, and the epoxy chloropropane is continuously stirred and reacts for 4-15 hours after the addition of the epoxy chloropropane is finished;

dripping hydrochloric acid into the reacted materials in the step (III), and adjusting the pH value of the reacted materials to 4.5-5.5; pouring out the materials in the bottle and filtering, and treating the cross-linked dextran gel particles obtained above the filter paper;

fifthly, washing the cross-linked dextran gel particles obtained in the step (iv) by acetone;

sixthly, the crosslinked glucan particles after acetone washing in the step five are dried by air blowing;

4. The method for producing crosslinked dextran microparticles for hemostasis as claimed in claim 3, characterized in that: and step two, when the temperature is increased in a gradient manner, the temperature is increased by 4-6 ℃ every 10 min.

5. The method for producing crosslinked dextran microparticles for hemostasis as claimed in claim 3, characterized in that: and step sixthly, controlling the temperature to be lower than 40 ℃ during forced air drying.

6. The method for producing crosslinked dextran microparticles for hemostasis as claimed in claim 3, characterized in that: and seventhly, when the dried particles are sieved, the particles to be sieved are sieved by a 60-mesh sieve, the particles passing through the sieve are sieved by a 170-mesh sieve, and the particles above the sieve are taken as the cross-linked glucan particles for hemostasis.