CN107349464B - A kind of preparation method of novel medical hemostatic gel dressing - Google Patents

Abstract

The invention relates to a preparation method of a medical hemostatic gel dressing. Human-like collagen (LHC) is dissolved in ultrapure water to prepare a protein solution, and an inorganic salt and a compound cross-linking agent β-diimide zinc complex are added. 1,2,7,8-diepoxyoctane, adjust the pH value of the solution to 2-5.5, stir evenly, put the mixed solution in a 40-80℃ water bath for 0.5-5h, and then undergo two high-temperature steam treatments in turn After washing with water, drying treatment and Co-60 irradiation sterilization, a new type of sterile medical hemostatic gel dressing can be obtained. The medical hemostatic gel dressing prepared by the invention has good air permeability and antibacterial properties, does not cause wound infection, can significantly shorten the hemostasis time, and the hemostatic material does not adhere to the wound after the hemostasis is completed, which obviously reduces the pain of the patient.

Description

A kind of preparation method of novel medical hemostatic gel dressing

technical field

The invention relates to a preparation method of a medical hemostatic gel dressing, belonging to the field of medical materials.

Background technique

Bleeding due to various epidermal or tissue trauma caused by factors such as war, traffic accident, exercise or disease. In recent years, many studies have shown that a large proportion of patients die from excessive blood loss in clinical practice. Therefore, the preparation of a hemostatic material that can quickly stop bleeding without adhesion to tissues is an urgent need to gain time for later rescue and treatment. solved problem.

The main characteristics of ideal dressings currently used for wounds are generally: non-toxic, non-sensitive, non-allergic; close to the wound, and has good hygroscopic properties, which can keep the environment of the joint between the wound and the dressing moist; does not require frequent Replacement; impermeable to microorganisms; cost-effective; provides good mechanical protection and is not easy to adhere to wounds, etc. Hydrogel is a water-rich polymer with a three-dimensional network structure, which is widely used in tissue engineering and drug release. Compared with other materials, hydrogel as a hemostatic material has the advantages of good fit and anti-infection. However, traditional hydrogels have disadvantages such as poor hemostasis and poor air permeability due to the lack of pore structure.

Human-like collagen (LHC) is a human-derived collagen produced by fermentation. It has the characteristics of good cell adhesion, promotion of new cell formation, good processing performance, no hidden virus, good water solubility (avoiding cytotoxicity caused by acid-base solvent residues), and low rejection reaction. Biomaterials for implantable medical devices.

SUMMARY OF THE INVENTION

Aiming at the defects of poor air permeability and easy adhesion to wounds of hemostatic materials on the market, the present invention prepares a new type of medical hemostatic gel dressing that can quickly stop bleeding and does not adhere to tissues. The method has simple process and the prepared material is biocompatible. It has good properties and is expected to be widely used in wartime first aid kits, hemostasis in clinical operations, etc.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A preparation method of a new type of medical hemostatic gel dressing: dissolve the water-soluble macromolecular protein human collagen (LHC) in water, and then add a composite cross-linking agent β-dihydrin in a mass ratio of 1:3-3:1 The amine-zinc complex, the aqueous solution of 1,2,7,8-diepoxyoctane and the inorganic salt aqueous solution are mixed evenly, and the pH value of the solution is adjusted to 2-5.5, and the cross-linking reaction is carried out in a water bath environment to obtain salt-containing condensation. gel; perform high-pressure steam treatment and distilled water immersion washing on the cross-linked hydrogel to remove inorganic salts and residual monomer cross-linking agent, and then perform drying and Co-60 sterilization treatment to obtain a new type of medical hemostasis. Gel dressing.

The concentration of the above human-like collagen solution is 50-400 mg/mL.

The inorganic salt is selected from sodium chloride, sodium phosphate, sodium hydrogen phosphate, ammonium sulfate, ammonium nitrate, potassium nitrate, potassium sulfate, potassium chloride, the concentration of the inorganic salt solution is 10-350 mg/mL, and the inorganic salt solution is added. The volume to protein solution volume ratio is 1:2-1:20.

The mass percentage concentration of the crosslinking agent β-diimide zinc complex solution and the 1,2,7,8-diepoxyoctane solution are both 0.1-5.0%, preferably 0.5-2.0%, and the volume is protein 1-20% of the solution volume, preferably 5-10%.

The pH value of the above reaction solution is regulated by hydrochloric acid and sodium hydroxide solution to 2-5.5; the temperature of the cross-linking reaction can be 40-80°C, and the holding time is 0.5-5h, preferably 1-3h.

In the above two high-pressure steam treatment and distilled water soaking and washing, the first time the sample is kept at 110-121 ° C for 5-30min, preferably 10-20min, and then soaked in ultrapure water for 2-5 days; the second time Keep the sample at 110-121 °C for 1-3 h, preferably for 1.5-2.5 h, and then soak and wash in ultrapure water for 1-3 days to control the total residual crosslinking agent to be less than 2 μg/g.

The drying method of the novel medical hemostatic gel dressing may be a vacuum freeze drying method or a supercritical carbon dioxide drying method.

The above cross-linking agent β-diimide zinc complex is based on literature (Catalytic Reactions Involving C ₁ Feedstocks: New High-Activity Zn(II)-Based Catalysts for the Alternating Copolymerization of Carbon Dioxide and Epoxides, J. Am. Chem. Soc. 1998, 120, 11018-11019.), and its molecular formula is shown in Figure 1.

The formation mechanism of the medical hemostatic porous gel dressing of the present invention: protein molecules contain abundant carboxyl groups and amino groups, which provide two good functional groups for intermolecular cross-linking. The empty orbital of chelated zinc in β-diimide zinc complex can form coordination bond with amino group in protein molecule to realize intermolecular cross-linking of protein molecule. β-Diimine zinc complex has asymmetric ring-opening catalytic function for alkylene oxide, which can accelerate the ring-opening of alkylene oxide at both ends of 1,2,7,8-diepoxyoctane and interact with protein molecules. The carboxyl groups in the protein form covalent bonds to achieve intermolecular cross-linking of protein molecules. Therefore, through the ring-opening catalysis of 1,2,7,8-diepoxyoctane by the β-diimide zinc complex, and the double crosslinking effect of the two crosslinking agents on the different groups of the protein molecules, It effectively realizes and strengthens the cross-linking between water-soluble protein molecules. The addition of inorganic salts effectively destroys the extra-molecular hydration film of water-soluble proteins and promotes the cross-linking reaction between the cross-linking agent and protein molecules. Pore-forming effect of hydrogels.

The invention uses human-like collagen as the main raw material to prepare a novel ultra-porous hydrogel through the synergistic co-cross-linking action of double cross-linking agents. The hydrogel material has an ultra-porous structure, high porosity, good permeability and reasonable pore size, and can quickly absorb water in blood without inhaling cells, thereby promoting blood cell agglutination to achieve rapid hemostasis. The hydrogel material has good biocompatibility and good pore penetration, which ensures the permeability of the wound and helps to promote wound healing. Compared with the traditional gauze or hemostatic sponge, the surface of the hydrogel material has less roughness and is not easy to stick; the good penetration of the pores makes the drug administration very convenient; and the smaller pore size of the material can also prevent wound infection. The novel medical hemostatic gel dressing prepared by the invention can be expected to be used in the fields of first aid kits in wartime, hemostasis in clinical operations and the like.

The present invention also has the following advantages: (1) the hemostatic material prepared by the present invention can significantly shorten the hemostasis time, which is crucial for wound or postoperative recovery; (2) the material prepared by the present invention has good air permeability and antibacterial properties, and does not It will cause wound infection; (3) In addition, the hemostatic material prepared by the present invention will not adhere to the wound after hemostasis is completed, which obviously reduces the pain of the patient; (4) The material prepared by the present invention has a porous structure, which makes the drug administration easier Tonic is very convenient.

Description of drawings

Figure 1 is the molecular structure diagram of the synthesized β-diimide zinc complex;

Fig. 2 is the appearance diagram of the medical hemostatic porous gel dressing sample prepared in Example 1;

Fig. 3 is the SEM image of the medical hemostatic porous gel dressing sample prepared in Example 1;

Fig. 4 is a graph showing the air permeability of the medical hemostatic porous gel dressing prepared in Example 1;

Fig. 5 is a graph showing the hemostatic effect of the medical hemostatic porous gel dressing prepared in Example 1 on the rabbit ear artery and liver;

6 is a graph showing the hemostatic effect of two commercial brands of hemostatic sponges used in Example 1 on rabbit liver.

Detailed ways

The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials, reagents, etc. used can be obtained from commercial sources unless otherwise specified.

Example 1 Preparation of medical hemostatic porous gel dressing

Step 1: Dissolve the water-soluble human-like collagen HLC in 10 mL of distilled water to obtain a solution with a concentration of 100 mg/mL, and add the cross-linking agent β-diimide zinc complex and 1,2,7 with a concentration of 1%. , 1 mL each of 8-diepoxyoctane, then add 2 mL of 10 mg/mL KCl, mix well, and adjust the pH of the solution to 4.5 with dilute hydrochloric acid and sodium hydroxide;

Step 2: Dispense the mixed solution in Step 1 into a mold, keep it at 50 °C for 2 hours, transfer it to a high-pressure steam sterilizer, and keep it at 121 °C for 20 minutes to obtain the first gel product;

Step 3: The primary gel in step 2 is soaked and washed in distilled water for 5 days, and the washing water is changed every 6 hours to remove salt and residual cross-linking agent; the washed primary gel is transferred to a high-pressure steam sterilizer to continue The samples were kept at 121 °C for 2 h, and then soaked and washed with distilled water for 2 days to control the total residual amount of cross-linking agent to be less than 2 μg/g to obtain porous wet gel samples.

Step 4: Pre-freezing the wet gel in step 3 at -80° C. for 3 hours, vacuum freeze-drying, and sterilizing by Co-60 irradiation to obtain a finished sterile medical hemostatic porous gel dressing.

The physicochemical properties of the medical hemostatic porous gel dressing prepared in this example are characterized. Figure 2 is the appearance photo of the freeze-dried sample of the hemostatic gel dressing prepared in Example 1. It can be seen that its appearance is opaque and milky white, and the surface texture is relatively smooth. , showing a porous structure; Figure 3 is a scanning electron microscope (SEM) image of the prepared porous hydrogel hemostatic dressing. The SEM image shows that the inside of the hemostatic dressing has a porous structure, and the pore walls are formed by the adhesion of spherical particles. The pore size generally ranges from tens of nanometers to several micrometers. The pore structure is relatively uniform and dense.

The prepared medical hemostatic porous gel dressing block was placed in the filter device fixed on the syringe, and 5 mL of air was filled into the syringe, and then the syringe was squeezed for air filtration. It was found that there was almost no resistance during this process, and the push rod of the syringe Can be easily pushed to the bottom. The syringe squeeze air filtration experiment demonstrated the air permeability of the hemostatic dressing, as shown in Figure 4, indicating that the pore structure inside the hemostatic material is interconnected. The material has good air permeability and anti-adhesion properties. If the antibacterial drugs can be directly added through the material and slowly released to the wound, the wound will not be infected due to air permeability during the process of hemostasis, and the wound will also not be infected. Festering due to prolonged soaking.

The medical hemostatic porous gel dressing prepared in this example has good elasticity, strong compression resistance (the maximum compressive strain and compressive stress are about 68.9% and 5.6 MPa, respectively), high swelling rate (the swelling equilibrium is basically reached in 8 s), and the porosity is about is 85.4%; the cytotoxicity test results show that the medical hemostatic porous gel dressing prepared in this example has good biocompatibility and no cytotoxicity.

Example 2 Preparation of medical hemostatic porous gel dressing

Step 1: Dissolve the water-soluble human-like collagen HLC in 10 mL of distilled water to obtain a solution with a concentration of 100 mg/mL, and add the cross-linking agent β-diimide zinc complex and 1,2,7 with a concentration of 2%. , 1 mL each of 8-diepoxyoctane, then add 2 mL of 10 mg/mL Na ₂ SO ₄ solution, mix well, and adjust the pH of the solution to 4 with dilute hydrochloric acid and sodium hydroxide;

Step 2: Dispense the mixed solution in step 1 into a mold, keep it in a 60°C water bath for 2 hours, then transfer it to a high-pressure steam sterilizer and keep it at 110°C for 20 minutes to obtain the first gel product;

Step 3: The primary gel in step 2 is soaked and washed in distilled water for 5 days, and the washing water is changed every 6 hours to remove salt and residual cross-linking agent; the washed primary gel is transferred to a high-pressure steam sterilizer to continue Keep at 110 °C for 2 h, then soak and wash with distilled water for 2 days again to remove residual cross-linking agent, control the total residual cross-linking agent to be less than 2 μg/g, and obtain porous wet gel samples.

Step 4: Pre-freezing the wet gel in step 3 at -80° C. for 3 hours, vacuum freeze-drying, and sterilizing by Co-60 irradiation to obtain a finished sterile medical hemostatic porous gel dressing.

The sterile medical hemostatic porous gel dressing obtained in this example is similar to the medical hemostatic gel dressing obtained in Example 1 in physicochemical properties and biological properties.

Example 3 Preparation of medical hemostatic porous gel dressing

Step 1: Dissolve the water-soluble human-like collagen HLC in 20 mL of distilled water to obtain a solution with a concentration of 200 mg/mL, and add the cross-linking agent β-diimide zinc complex and 1,2,7 with a concentration of 1%. , 4 mL each of 8-diepoxyoctane, then add 2 mL of 10 mg/mL NaH ₂ PO ₄ solution, mix well, and adjust the pH of the solution to 5.5 with dilute hydrochloric acid and sodium hydroxide;

Step 2: Dispense the mixed solution in step 1 into a mold, keep it at 70°C for 2 hours, then transfer it to a high-pressure steam sterilizer and keep it at 121°C for 20 minutes to obtain the first gel product;

Step 3: The primary gel in step 2 is soaked and washed in distilled water for 4 days, and the washing water is changed every 6 hours to remove salt and residual cross-linking agent; the washed primary gel is transferred to a high-pressure steam sterilizer to continue Keep at 121 °C for 3 h, then soak and wash with distilled water for 1 day to remove residual cross-linking agent, control the total residual amount of cross-linking agent to be less than 2 μg/g, and obtain porous wet gel samples;

Step 4: Dry the wet gel in Step 3 by supercritical carbon dioxide drying method to prepare an ultra-porous xerogel sample, and sterilize the dry sample by Co-60 irradiation to obtain a finished sterile medical hemostatic porous gel dressing .

The sterile medical hemostatic porous gel dressing obtained in this example is similar to the medical hemostatic gel dressing obtained in Example 1 in physicochemical properties and biological properties.

Example 4 Hemostatic experiment of medical hemostatic porous gel dressing

New Zealand white rabbits were selected as experimental animals to establish rabbit ear trauma hemorrhage and liver trauma hemorrhage models, and the hemostatic gel dressing obtained in Example 1 of the present invention and the hemostatic sponges of two brands of A and B on the market were selected to carry out hemostasis comparison test.

Figure 5 shows the effect of the sterile medical hemostatic porous gel dressing prepared in Example 1 of the present invention on rabbit ear hemostasis (a-c) and liver hemostasis (d-f). And no adhesion to the tissue occurred. The results of liver hemostasis comparison experiment using mainstream A and B hemostatic sponges are shown in Figure 6. It can be seen that the selected two brands of hemostatic materials have basically been completely penetrated by bleeding and require longer hemostasis time. During the experiment, show that the sterile medical hemostasis porous gel dressing prepared in example 1 is respectively 20-30 s and 30-40 s to the hemostasis time of rabbit ear and liver, and two kinds of brand hemostatic sponges of A and B are selected. The hemostasis time for rabbit liver is about 80-90s.

The above results show that the hemostatic gel prepared by the present invention has excellent hemostatic function, which is mainly due to the high porosity of the material, the uniform pore size and the good permeability, which can quickly absorb the water in the blood and make the blood cells in the blood coagulate on the material. It can block ruptured blood vessels, achieve rapid hemostasis, and promote wound healing. It is especially suitable for osmotic bleeding during surgery and massive bleeding caused by arterial rupture. In addition, due to the small pore size of the material itself, it also has antibacterial and antibacterial properties and prevents wound infection.

The content of the present invention is not limited to the examples listed above. Any equivalent transformation to the technical solution of the present invention by those of ordinary skill in the art by reading the description of the present invention, and adjustments that do not change the basic principle are covered by the claims of the present invention. .

Claims (7)

1. a preparation method of a medical hemostatic gel dressing is characterized in that: water-soluble macromolecular protein class human collagen is dissolved in water, and then adding mass ratio is the composite crosslinking agent β- of 3:1-1:3 The zinc diimide complex, the aqueous solution of 1,2,7,8-diepoxyoctane and the aqueous solution of inorganic salt are mixed evenly, and the pH value of the solution is adjusted to 2-5.5. Hydrogel; perform high-pressure steam treatment and distilled water immersion washing on the cross-linked hydrogel to remove inorganic salts and residual monomer cross-linking agent, and then perform drying and Co-60 sterilization treatment to obtain a medical hemostatic gel dressing, The structural formula of the crosslinking agent β-diimide zinc complex is shown in (I):

(I). 2 . The preparation method of the medical hemostatic gel dressing according to claim 1 , wherein the concentration of the humanoid collagen solution is 50-400 mg/mL. 3 . 3. the preparation method of medical hemostatic gel dressing according to claim 1 is characterized in that: described inorganic salt is selected from sodium chloride, sodium phosphate, sodium hydrogen phosphate, ammonium sulfate, ammonium nitrate, potassium nitrate, potassium sulfate , potassium chloride, the concentration of the inorganic salt solution is 10-350 mg/mL, and the ratio of the added volume of the inorganic salt solution to the volume of the protein solution is 1:2-1:20. 4. the preparation method of medical hemostatic gel dressing according to claim 1 is characterized in that: the quality of cross-linking agent β-diimide zinc complex solution and 1,2,7,8-diepoxyoctane solution The percentage concentration is 0.1-5.0%, and the volume is 1-20% of the volume of the protein solution. 5. the preparation method of medical hemostatic gel dressing according to claim 1 is characterized in that: the pH value of reaction solution is regulated by hydrochloric acid and sodium hydroxide solution and its pH value is 2-5.5; the temperature of cross-linking reaction is 40-80 ℃ , the holding time is 0.5-5h. 6. The preparation method of the medical hemostatic gel dressing according to claim 1, wherein the cross-linked hydrogel is subjected to high-pressure steam treatment and distilled water soaking and washing, and the sample is heated at 110-121° C. for the first time. Hold time for 5-30min, then soak and wash in ultrapure water for 2-5 days; keep the sample at 110-121℃ for 1-3 h for the second time, then soak and wash in ultrapure water for 1-3 days to control the residue of crosslinking agent The total amount is less than 2 μg/g. 7. The preparation method of the medical hemostatic gel dressing according to claim 1, wherein the drying method of the medical hemostatic gel dressing is a vacuum freeze drying method or a supercritical carbon dioxide drying method.

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