CN112812330B

CN112812330B - Compound polysaccharide sodium hyaluronate gel and preparation method thereof

Info

Publication number: CN112812330B
Application number: CN202110021466.XA
Authority: CN
Inventors: 邹圣灿; 姜晓文; 王宝群; 林莎莎; 杨雪
Original assignee: Qingdao Chenland Marine Biotechnology Co ltd
Current assignee: Qingdao Chenland Marine Biotechnology Co ltd
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2022-07-22
Anticipated expiration: 2041-01-08
Also published as: CN112812330A

Abstract

The invention discloses a compound polysaccharide sodium hyaluronate gel and a preparation method thereof, belonging to the technical field of preparation of high polymer materials. The method adopts a multi-level crosslinking mode to simultaneously crosslink sodium alginate polysaccharide and sodium hyaluronate to form composite gel, thereby obtaining the composite gel with stable structure, and the method specifically comprises the steps of dissolving, crosslinking, swelling, homogenizing and the like. The composite polysaccharide sodium hyaluronate gel prepared by the technical scheme of the invention has the advantages of good biocompatibility, good elasticity, high support performance and strong enzymolysis resistance, and can well reduce adverse reactions such as infection, red swelling and the like.

Description

Compound polysaccharide sodium hyaluronate gel and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of high polymer materials, and particularly relates to a compound polysaccharide sodium hyaluronate gel and a preparation method thereof.

Background

The natural hyaluronic acid has good moisture keeping, lubricating, repairing and nourishing effects. The natural hyaluronic acid is easy to decompose in vivo and has poor stability, and the hyaluronic acid can have a more stable structure by an advanced crosslinking technology so as to obtain better mechanical strength and enzymolysis resistance. The cross-linked hyaluronic acid gel is the most widely used subcutaneous injection material in medical cosmetology, and various products are on the market at home and abroad, are used for anti-wrinkle and filling and shaping of skin, and are accepted by more and more beauty lovers due to good biocompatibility and excellent filling effect.

The existing sodium hyaluronate (HHA) gel for injection on the market can be metabolized in vivo, has short degradation time, can mostly keep the filling effect of 6-12 months, needs to be injected, and in order to maintain the filling effect and improve the enzymolysis resistance of the gel, the dosage of a cross-linking agent is increased by many products, the cross-linking agent has certain toxicity, the incidence rate of adverse reactions is also increased by increasing the dosage of the cross-linking agent, and the adverse reactions in clinical application are swelling, infection, pain and the like generally. The traditional gel treatment mode is sieving, drying and granulating, so that the edge of the formed gel particles is not smooth enough, and adverse reactions such as red swelling and the like are easily caused after injection. Therefore, an injection gel with good biocompatibility, enzymatic resistance, excellent filling effect and low content of cross-linking agent is needed.

The multi-level crosslinking adopts a mode of combining high-temperature crosslinking with low-temperature crosslinking, the temperature in the crosslinking reaction plays an important role in gel forming, and the gel prepared under the high-temperature crosslinking (30-60 ℃) is hard and has poor elasticity. The gel prepared by low-temperature crosslinking (4-10 ℃) is compact, good in elasticity and low in hardness. This is probably due to the fact that at lower temperatures, the gelling time is long and the distribution of the substances among the polymeric systems is uniform, which leads to a complete topological structure of the gel and thus to better elasticity. High temperature and high gelling speed, resulting in uneven structure distribution and poor elasticity. After the temperature is raised, the degree of crosslinking is made high, and a gel having high hardness is obtained. Therefore, by combining the advantages of two temperatures, a multi-layer crosslinking mode can be provided, and the composite gel with good mechanical strength and viscoelasticity can be obtained.

Patent CN108774329A provides a preparation method of a conventional sodium hyaluronate gel, the prepared gel is made into gel particles with uniform particle size through a sintering net, a mobile phase is added and mixed to form a two-phase gel, the edges of the prepared gel particles are not smooth, and inflammation, infection and the like are easy to occur at an injection part. Patent CN107522881A discloses a single-phase sodium hyaluronate gel with uniform and smooth particles, and the gel prepared by using sodium hyaluronate as a raw material has the problem of inevitably short degradation period. Patent CN111249172A provides a method for preparing a cosmetic injection gel, which is prepared by dissolving alginate in water, and mixing the alginate with other substances as one component, and is used for improving wrinkles, skin filling and the like. In this method, sodium alginate is not used as a main component but is only one of the components, and the prepared gel is a multi-component and is injected after being mixed by a relatively complicated step before use, so that the method is easy to mix unevenly or cannot ensure the optimal effect and the sterile state of the product to the maximum extent due to the product pollution. Patent CN102911380A provides a hyaluronic acid and biodegradable polymer modified material and a preparation method thereof. In the method, a polymer material and hyaluronic acid are grafted to form a polymer, so that a cross-linked structure is firmer, but the preparation method is complicated, and residual reagents in gel are difficult to clean, so that inflammation, infection and the like after injection can be caused.

Therefore, in summary, the following problems mainly exist in the prior art: most sodium hyaluronate gels prepared from a single raw material are available in the market, and the degradation time is short, so that the effect is maintained by multiple injections, excessive crosslinking agents are added for prolonging the degradation time, and multiple body adverse reactions are caused by excessive crosslinking agents; the existing gel prepared by the crosslinking reaction usually fixes a crosslinking temperature, has poor viscoelasticity and weak supporting force. The processing mode of preparing uniform granules is usually sieving and granulating, and the surfaces of the gel granules prepared by the method are not smooth enough and easily cause clinical symptoms such as inflammation, infection and the like.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a preparation method of a compound polysaccharide sodium hyaluronate gel, which is characterized in that a multi-level crosslinking mode is used to simultaneously crosslink sodium alginate polysaccharide and sodium hyaluronate to form the compound gel, so that the compound gel with a stable structure is obtained.

The technical scheme of the invention is as follows:

a preparation method of compound polysaccharide sodium hyaluronate gel comprises the following steps:

(1) dissolution

Dissolving sodium alginate in a NaOH solution with the mass fraction of 1-3% to ensure that the mass fraction of the sodium alginate in the NaOH solution is 1-10%, uniformly stirring, adding sodium hyaluronate powder, and uniformly stirring to form a mixed solution, wherein the concentration of the sodium hyaluronate in the mixed solution is 10-30 wt%;

(2) cross-linking

Adding a cross-linking agent into the mixed solution obtained in the step (1), fully and uniformly stirring until the mixed solution is transparent, standing in an environment at 20-50 ℃ for carrying out a heat cross-linking reaction for 1-12h, and after the reaction is finished, placing in an environment at 4-10 ℃ for carrying out cold cross-linking for 2-48h to obtain a cross-linked composite gel;

(3) swelling of the composition

Dividing the prepared cross-linked composite gel into small blocks, putting the small blocks into PBS buffer solution for swelling, and replacing the PBS buffer solution every 2-5 hours until the pH value of the gel is 6.8-7.5 and the osmotic pressure is 280-350mOsmol/L, so as to obtain the gel with the swelling multiple of 5-20 times;

(4) homogenizing

Taking out the gel block after swelling, removing excessive water on the surface, and homogenizing; adding 0.5-5% by mass of uncrosslinked sodium hyaluronate solution into the homogenized gel, continuously homogenizing, and uniformly mixing to obtain the product.

On the basis of the technical scheme, in the dissolving step, the molecular weight of the sodium hyaluronate is 100-260 ten thousand daltons.

On the basis of the technical scheme, the stirring process is carried out in a high-speed stirrer, and the stirring speed is controlled at 500-2000 rpm.

On the basis of the technical scheme, the crosslinking agent is one or more of divinyl sulfone (DVS), 1, 4-butanediol diglycidyl ether (BDDE), trimethylolpropane tri (3-aziridinyl propionate), polyepoxy compound and genipin.

On the basis of the technical scheme, the dosage of the cross-linking agent is 5-30% of the content of the sodium hyaluronate.

On the basis of the technical scheme, the PBS buffer solution formula comprises the following components: 10g of sodium chloride, 1.6g of disodium hydrogen phosphate and 0.6g of sodium dihydrogen phosphate are added with water to reach a constant volume of 1000mL, and the PBS buffer solution with the pH value of about 7.0 is obtained.

Based on the technical scheme, the volume ratio of the gel to the PBS buffer solution during swelling is 1: 30-500.

The purpose of changing the PBS buffer solution is to swell the gel by absorbing water and to adjust the pH and osmotic pressure of the gel.

On the basis of the technical scheme, a homogenizer is used for homogenizing, the homogenizing speed is 3000-15000rpm, and the linear speed is 10-50 s/m.

On the basis of the technical scheme, the molecular weight of the used sodium hyaluronate is 50-200 ten thousand daltons in the homogenization process.

A compound polysaccharide sodium hyaluronate gel is prepared by the above method.

The application of the compound polysaccharide sodium hyaluronate gel in preparing medical filling materials.

An injection of compound polysaccharide-sodium hyaluronate gel is prepared by filling the above compound polysaccharide-sodium hyaluronate gel into a prefilled syringe, and performing wet heat sterilization.

The invention has the beneficial effects that:

1. the composite gel is prepared by using sodium alginate and sodium hyaluronate as main components, and the sodium alginate forms a compact structural skeleton in a gel structure, so that biomolecules such as enzyme can be effectively prevented from entering the gel structure, the gel support performance is enhanced, and the degradation time is delayed.

2. The sodium alginate has excellent water solubility and biocompatibility, and can be used for preparing composite gel to improve the biocompatibility of the gel.

3. By adjusting the type of the cross-linking agent, the dosage of the cross-linking agent, the pH value of the system and the like, the gelation speed can be adjusted, so that the sodium alginate forms a structural framework in the gelation process and is inserted into the gel, the gel structure is tighter, the biological macromolecules and the small molecules are not easy to enter, and the prepared gel has better viscoelasticity and stronger enzymolysis resistance.

4. By using a multi-level crosslinking mode combining heat crosslinking and cold crosslinking, the gel crosslinking degree and the structural stability are improved, and the viscoelasticity and the supporting force after injection are increased.

5. The gel is prepared into uniform particles in a homogenizing mode, and the particles can be refined by homogenization, so that the gel is mixed with each other more uniformly, and the system is more uniform; meanwhile, the viscoelasticity of the gel is increased in the homogenization process, the defect that the edges of particles are not smooth enough after artificial sieving is avoided, and adverse reactions such as infection, red swelling and the like in clinical application are reduced.

6. The uncrosslinked sodium hyaluronate solution is added as a mobile phase in the homogenization process, so that the biocompatibility of the gel is improved, and the gel can be smoother in the injection process.

Drawings

FIG. 1 is a schematic representation of the skin irritation test and sensitization test of the gel obtained in example 1.

Detailed Description

Terms used in the present invention have generally meanings as commonly understood by one of ordinary skill in the art, unless otherwise specified.

The present invention is described in further detail below with reference to specific examples and data. The following examples are intended to illustrate the invention, but not to limit the scope of the invention in any way.

The influence of different NaOH dosage, selection of cross-linking agent and dosage on the enzymolysis resistance of the compound polysaccharide sodium hyaluronate gel

Preparing 30mL of 0.5-2% sodium hydroxide solution, adding 1.5g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly to obtain a transparent solution. Adding 300-1000 mu L BDDE/DVS into the solution, uniformly stirring for 30min, taking out, standing in a water bath at 30 ℃ for 5h, transferring to an environment at 4 ℃ after the thermal crosslinking is finished, and continuously crosslinking for 20h to obtain the fast gel. Dividing the fast gel into uniform small blocks, adding 800mL of prepared PBS buffer solution for swelling, and changing the buffer solution every two hours until the pH value of the gel is about 7.0, the osmotic pressure is about 300mOsmol/L, the weight of the gel is 250g, and the swelling end point is reached. Sieving the swollen gel into gel particles by using a 200-mesh metal screen, sieving the gel particles by using a 400-mesh screen to obtain final gel, adding 25mL of 2% uncrosslinked sodium hyaluronate solution (the solvent is PBS buffer) into the gel, uniformly stirring, and collecting a final product. Filling the product into a pre-filled syringe, and performing damp-heat sterilization at 121 ℃.

The test results are shown in table 1:

TABLE 1

As can be seen from table 1, DVS is more toxic than BDDE, so BDDE was chosen as the crosslinker. Gel degradation is accelerated by either too high or too low sodium hydroxide. The cross-linking agent has certain toxicity, so that the selection of a proper amount of the cross-linking agent cannot be too high.

Example 1

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 0.3g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly until the mixed solution is transparent. Adding 500 μ L BDDE into the solution, uniformly stirring for 30min, standing in 30 deg.C water bath for 5h, transferring to 4 deg.C environment after thermal crosslinking, and continuously crosslinking for 20h to obtain block gel. The block gel was divided into small uniform blocks, 800mL of the prepared PBS buffer was added to swell the gel, the buffer was changed every two hours until the pH of the gel was about 7.0, the osmotic pressure was about 300mOsmol/L, the weight of the gel was 250g, and the end point of swelling was reached. Homogenizing the swollen gel with homogenizer for 30min at 7000rpm and 10m/s to obtain composite gel with uniform particles and certain viscoelasticity. 25mL of a 2% strength uncrosslinked sodium hyaluronate solution (PBS buffer as a solvent) was added to the homogenized gel, and the final product was collected after further homogenization for 20 min. Filling the final product into a pre-filled syringe, and performing moist heat sterilization at 121 ℃.

Example 2

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 1.5g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly until the mixed solution is transparent. Adding 500 μ L BDDE into the solution, uniformly stirring for 30min, standing in 30 deg.C water bath for 5h, transferring to 4 deg.C environment after thermal crosslinking, and continuously crosslinking for 20h to obtain block gel. Dividing the fast gel into uniform small blocks, adding 800mL of prepared PBS buffer solution for swelling, changing the buffer solution every two hours until the pH value of the gel is about 7.0, the osmotic pressure is about 300mOsmol/L, the weight of the gel is 250g, and the end point of swelling is reached. Homogenizing the swollen gel with homogenizer for 30min at 7000rpm and 10m/s to obtain composite gel with uniform particles and certain viscoelasticity. 25mL of a 2% strength uncrosslinked sodium hyaluronate solution (PBS buffer as a solvent) was added to the homogenized gel, and the final product was collected after further homogenization for 20 min. Filling the final product into a pre-filled syringe, and performing moist heat sterilization at 121 ℃.

Example 3

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 1.5g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly until the mixed solution is transparent. Adding 500 μ L BDDE into the solution, stirring for 30min, standing in 30 deg.C water bath for 5 hr, transferring to 4 deg.C environment, and crosslinking for 10 hr to obtain block gel. The block gel was divided into small uniform blocks, 800mL of the prepared PBS buffer was added to swell the gel, the buffer was changed every two hours until the pH of the gel was about 7.0, the osmotic pressure was about 300mOsmol/L, the weight of the gel was 250g, and the end point of swelling was reached. Homogenizing the swollen gel with homogenizer for 30min at 7000rpm and 10m/s to obtain composite gel with uniform particles and certain viscoelasticity. 25mL of a 2% strength uncrosslinked sodium hyaluronate solution (PBS buffer as a solvent) was added to the homogenized gel, and the final product was collected after homogenization for 20 min. Filling the final product into a pre-filled syringe, and performing damp-heat sterilization at 121 ℃.

Example 4

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 1.5g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly until the mixed solution is transparent. Adding 500 mu L BDDE into the solution, uniformly stirring for 30min, taking out, standing in a water bath at 30 ℃ for 10h, transferring to an environment at 4 ℃ after the thermal cross-linking is finished, and continuously cross-linking for 20h to obtain blocky gel. The block gel was divided into small uniform blocks, 800mL of the prepared PBS buffer was added to swell the gel, the buffer was changed every two hours until the pH of the gel was about 7.0, the osmotic pressure was about 300mOsmol/L, the weight of the gel was 250g, and the end point of swelling was reached. Homogenizing the swollen gel with homogenizer for 30min at 7000rpm and 10m/s to obtain composite gel with uniform particles and certain viscoelasticity. 25mL of a 2% strength uncrosslinked sodium hyaluronate solution (PBS buffer as a solvent) was added to the homogenized gel, and the final product was collected after further homogenization for 20 min. Filling the final product into a pre-filled syringe, and performing damp-heat sterilization at 121 ℃.

Example 5

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 1.5g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly until the mixed solution is transparent. And adding 500 mu L of BDDE into the solution, uniformly stirring for 30min, taking out, standing in a water bath at 30 ℃ for 5h, transferring to an environment at 4 ℃ after the thermal crosslinking is finished, and continuously crosslinking for 30h to obtain the fast gel. Dividing the fast gel into uniform small blocks, adding 800mL of prepared PBS buffer solution for swelling, and changing the buffer solution every two hours until the pH value of the gel is about 7.0, the osmotic pressure is about 300mOsmol/L, the weight of the gel is 250g, and the swelling end point is reached. Sieving the swollen gel into gel particles by using a 200-mesh metal screen, sieving the gel particles by using a 400-mesh screen to obtain final gel, adding 25mL of 2% uncrosslinked sodium hyaluronate solution (the solvent is PBS buffer) into the gel, uniformly stirring, and collecting a final product. Filling the product into a pre-filled syringe, and carrying out damp-heat sterilization at 121 ℃.

Comparative example 1

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 5.4g of sodium hyaluronate powder into the solution, and uniformly stirring until the solution is transparent. Adding 500 mu L BDDE into the solution, uniformly stirring for 30min, taking out, standing in a water bath at 30 ℃ for 5h, transferring to an environment at 4 ℃ after the thermal cross-linking is finished, and continuously cross-linking for 20h to obtain blocky gel after the cross-linking is finished. The fast gel was divided into small uniform pieces and 800mL of the prepared PBS buffer was added to swell. And homogenizing the swollen gel by a homogenizer to form composite gel with uniform particles and certain viscoelasticity. Adding 25mL of 2% uncrosslinked sodium hyaluronate solution (the solvent is PBS buffer) into the homogenized gel, and collecting the final product after continuous homogenization. Filling the final product into a pre-filled syringe, and performing moist heat sterilization at 121 ℃.

Comparative example 2

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 1.5g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly until the mixed solution is transparent. Adding 500 mu L BDDE into the solution, uniformly stirring for 30min, taking out, standing in a water bath at 25 ℃ for crosslinking for 30h, and obtaining the block gel after crosslinking. The block gel was divided into small uniform blocks, and 800mL of the prepared PBS buffer was added to swell. The swollen gel was homogenized using a homogenizer. 25mL of a 2% uncrosslinked sodium hyaluronate solution (the solvent is PBS buffer) is added into the homogenized gel, and the final product is collected after homogenization. Filling the final product into a pre-filled syringe, and performing moist heat sterilization at 121 ℃.

Comparative example 3

Preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 1.5g of sodium alginate, stirring uniformly, adding 5.4g of sodium hyaluronate powder into the mixed solution, and stirring uniformly until the mixed solution is transparent. Adding 500 mu L BDDE into the solution, uniformly stirring for 30min, taking out, standing in a water bath with the temperature of 25 ℃ for 5h, transferring to the environment with the temperature of 4 ℃ after the thermal crosslinking is finished, continuing to crosslink for 20h to obtain blocky gel after the crosslinking is finished, and obtaining the blocky gel after the crosslinking is finished. The block gel was divided into small uniform blocks, and 800mL of the prepared PBS buffer was added to swell. The swollen gel was homogenized using a homogenizer. Homogenizing, collecting the final product, filling into a pre-filled syringe, and performing moist heat sterilization at 121 deg.C.

Test of

(1) Performance testing of composite polysaccharide sodium hyaluronate gel

The method for detecting the content of the sodium hyaluronate comes from the standard YY/T0962-2014 cross-linked sodium hyaluronate for plastic surgery.

The elastic modulus and viscous modulus were measured as follows: the elastic modulus and the viscous modulus of the gel were measured using a rheometer with a measuring temperature of 25 ℃ and a set frequency of 0.25 Hz.

The enzyme degradation performance test method comprises the following steps: hyaluronidase is selected for degradation experiments. Taking 5g of compound polysaccharide sodium hyaluronate gel, adding 30mL of 200U/mL hyaluronidase solution, adding 20mL of PBS buffer solution with pH of 7.0, performing enzymolysis at 37 ℃, wherein the enzymolysis time is 0-12h, taking out after the enzymolysis is finished, centrifuging, taking supernatant, adding 30mL of PBS buffer solution, determining glucuronic acid content by adopting a carbazole method, calculating the content of degraded hyaluronic acid by utilizing a formula, and taking the ratio of the content of degraded hyaluronic acid to the content of undegraded hyaluronic acid as the degradation rate.

The specific detection method of the swelling capacity is from cross-linked sodium hyaluronate for plastic surgery of the competent standard YY/T0962-2014. Approximately 0.2g of cross-linked sodium hyaluronate gel was placed on two petri dishes, respectively. The two dishes were placed in a drying oven and weighed after a constant weight at 80 ℃ as m 1. Water was added dropwise until the mixture swelled, and after removing excess water, the weight was measured and designated as m 2. The swelling degree was calculated according to the following swelling degree formula:

the test results are shown in table 2:

TABLE 2

As can be seen from Table 2, the viscoelasticity of the gel is improved after the sodium alginate is added, the degree of crosslinking is good, and the degree of swelling is low. Meanwhile, the gel degradation time can be prolonged.

(2) Skin irritation test and sensitization test of composite polysaccharide sodium hyaluronate gel

The complex polysaccharide hyaluronic acid gel obtained in example 2 is prepared according to GB/T14233.2-2005, GB/T16886.10-2005, part 10 of medical device biological evaluation: irritation and delayed hypersensitivity tests.

The method specifically comprises the following steps: leaching with leaching medium (leaching medium: physiological saline and vegetable oil) at a ratio of 0.1g/mL, preparing experimental solution at 37 + -1 deg.C for (72 + -2) h, and performing the test method specified in experimental solution GB/T16886.10-2005. The experimental liquid samples were contacted directly with the skin of the back of the male rat for 24h in a single time, and gauze pieces were contacted with the same method as a control. After contact (1 + -0.1 h), (24 + -2) h, (48 + -2) h, and (72 + -2) h, scores were made for erythema, edema, and formic acid Primary Irritation Index (PII) at the contact site. The test is shown in FIG. 1. The results show that the primary stimulation index (PII) of the male mice of the compound polysaccharide hyaluronic acid gel sample is 0.0, which indicates that the compound polysaccharide hyaluronic acid gel test solution prepared in example 2 has no skin sensitization reaction.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of compound polysaccharide sodium hyaluronate gel is characterized by comprising the following steps:

preparing 30mL of sodium hydroxide solution with the mass fraction of 1%, adding 1.5g of sodium alginate, uniformly stirring, adding 5.4g of sodium hyaluronate powder into the mixed solution, and uniformly stirring until the mixed solution is transparent; adding 500 mu L BDDE into the solution, uniformly stirring for 30min, taking out, standing in a water bath at 30 ℃ for 5h, transferring to the environment at 4 ℃ after thermal crosslinking is finished, and continuously crosslinking for 20h to obtain massive gel after the crosslinking is finished; dividing the block gel into uniform small blocks, adding 800mL of prepared PBS buffer solution for swelling, changing the buffer solution every two hours until the pH value of the gel is 7.0, the osmotic pressure is 300mOsmol/L, the weight of the gel is 250g, and the end point of swelling is at the moment; homogenizing the swollen gel into composite gel with uniform particles and certain viscoelasticity by using a homogenizer, wherein the homogenizing time is 30min, the speed of the homogenizer is 7000rpm, and the linear speed is 10 m/s; adding 25mL of uncrosslinked sodium hyaluronate solution with the concentration of 2% into the homogenized gel, continuing homogenizing for 20min, and collecting a final product; filling the final product into a pre-filled syringe, and carrying out damp-heat sterilization at 121 ℃; the solvent of the uncrosslinked sodium hyaluronate solution is PBS buffer.