CN114259324B - Preparation method of multilayer artificial dura mater - Google Patents
Preparation method of multilayer artificial dura mater Download PDFInfo
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- CN114259324B CN114259324B CN202111602983.2A CN202111602983A CN114259324B CN 114259324 B CN114259324 B CN 114259324B CN 202111602983 A CN202111602983 A CN 202111602983A CN 114259324 B CN114259324 B CN 114259324B
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Abstract
The invention relates to a preparation method of a multilayer artificial dura mater, which comprises the following steps: preparing slurry containing sodium chondroitin sulfate and collagen, and sequentially carrying out pre-freezing, freeze-drying, high-temperature vacuum crosslinking and sterilization on the slurry. The method adopts a special gradient pre-freezing process, after pre-freezing, the multi-layer artificial dura mater with different densities can be obtained only by one-time freeze drying, and simultaneously, the process parameters of high-temperature vacuum crosslinking are optimized. The finally prepared multilayer artificial dura mater is excellent in leakage resistance, degradation resistance and sewing performance.
Description
Technical Field
The invention belongs to the technical field of dura mater, and particularly relates to a preparation method of a multilayer artificial dura mater.
Background
The dura mater is a membranous tissue between the skull and the brain tissue and is an important protective membrane of the brain tissue. Trauma, inflammation, tumor erosion, surgical procedures, etc., can cause dural damage and destroy the integrity of the dural. Therefore, the dura mater repair is an important step in the cranial operation, and can better maintain the integrity of the dura mater and prevent the leakage of cerebrospinal fluid.
Among the dura mater products used clinically at present, the acellular matrix products are generally prepared by processing raw materials such as porcine peritoneum, ovine peritoneum, bovine pericardium and the like through an acellular technology. These materials, similar to the dura mater structure, help restore normal physiological anatomy. However, these materials have the disadvantages of cell residues, immunological rejection, viral infection, complicated storage and use steps, and the like.
The collagen sponge product is prepared by taking I type collagen extracted from animal tissues as a raw material and performing a freeze drying process, is an artificial dura mater product which is successfully applied clinically for decades, and has excellent capacity of inducing tissue regeneration. The main problems of the products in use are poor sewing performance, degradation resistance and leakage resistance.
Disclosure of Invention
The invention aims to provide a method for preparing a special biological membrane for a transnasal sphenoidal approach skull base reconstruction operation, which is simple in preparation process and can be used industrially, so as to solve the problems of the leakage resistance and the resilience of the existing dura mater product.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a multilayer artificial dura mater comprises the following steps:
(1) preparing acetic acid solution of sodium chondroitin sulfate and collagen, stirring to dissolve or swell uniformly, and defoaming in vacuum to obtain slurry for later use;
(2) pouring the serous fluid into the freeze-drying tray a and the freeze-drying tray b in sequence, pre-freezing the serous fluid in the freeze-drying tray a for 8-16h at-20 ℃, cooling the serous fluid in the freeze-drying tray b to 4-10 ℃, and then pouring the serous fluid in the freeze-drying tray b into the freeze-drying tray a for 4-8h at-80 ℃ to obtain pre-frozen serous fluid;
(3) freeze-drying the pre-frozen serous fluid for 26-34h at-45-30 ℃ and a vacuum degree of 0.2bar to obtain a semi-finished product of the multilayer artificial dura mater;
(4) vacuum crosslinking the multilayer artificial dura mater semi-finished product at 95-105 deg.C and 0.08-0.1bar for 24-72 hr;
(5) sterilizing to obtain the multilayer artificial dura mater.
Preferably, in the step (1), the mass volume concentration of the sodium chondroitin sulfate in the slurry is 0.03-0.1%, the mass volume concentration of the collagen is 0.3-1.0%, and the acetic acid solution is 0.05M acetic acid solution.
Preferably, in the step (1), the stirring is performed for 1-2h by using a homogenizer at a speed of 15000-.
Preferably, in the step (2), slurry with the depth of 3-5 mm is poured into the freeze-drying tray a, and slurry with the depth of 1-2 mm is poured into the freeze-drying tray b.
Preferably, in step (3), the freeze-drying comprises the following steps:
freezing stage, temperature: -45 to-35 ℃, time: 15 min;
first drying stage, temperature: -10 to-8 ℃, time: 740-920 min, vacuum degree: 0.2 bar;
second drying stage, temperature: -13 to-10 ℃, time: 380-460 min, vacuum degree: 0.2 bar;
third drying stage, temperature: -5 to 0 ℃, time: 400-520 min, vacuum degree: 0.2 bar;
fourth drying stage, temperature: 20-30 ℃, time: 60-100 min, vacuum degree: 0.2 bar.
Preferably, in the step (4), the temperature of the high-temperature vacuum crosslinking is 105 ℃, the vacuum degree is 0.09bar, and the time is 60 hours.
Preferably, in the step (5), the sterilization is performed by at least one of ethylene oxide, Co-60 gamma ray irradiation and ultraviolet irradiation. The ethylene oxide sterilization comprises the following steps: the proportion of ethylene oxide in the mixed gas of ethylene oxide and carbon dioxide is 40-60%, the temperature is 50-60 ℃, the humidity is 20-50% RH, the time is 2-5 h, and the ventilation frequency is 4-7.
The invention has the beneficial effects that:
1. the preparation method of the multilayer artificial dura mater comprises the steps of pre-freezing for 8-16h at-20 ℃ for the first time, wherein the temperature is slightly high, the time is long, the slurry is slowly frozen at the stage, and the ice crystals grow slowly to form a loose structure; the secondary pre-freezing is performed for 4 to 8 hours at the temperature of minus 80 ℃, the temperature is low, the time is short, so that ice crystals can be rapidly generated to form a compact structure. After pre-freezing, only one-time freeze-drying is needed, and the multilayer artificial dura mater with different densities can be obtained. The invention provides a novel method for obtaining the laminated artificial dura mater by a special gradient pre-freezing process and one-time freeze-drying, and the finally prepared laminated artificial dura mater is excellent in leakage resistance, degradation resistance and suture performance. In addition, the electron microscope shows that compared with the existing multilayer artificial dura mater obtained by mechanical pressing and two freeze-drying processes, the multilayer artificial dura mater compact layer prepared by the method has longer hole structure short axis and more approximately circular pores, and is more favorable for cell migration and tissue growth.
2. The preparation method of the multilayer artificial dura mater optimizes the technological parameters of high-temperature vacuum crosslinking, and further improves the resilience of the finally prepared dura mater.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.
In the following examples, the collagen was high purity collagen extracted from bovine achilles tendon, in which type I collagen was not less than 99% of the total protein content and hydroxyproline was not less than 10%.
Example 1
The embodiment provides a preparation method of a multilayer artificial dura mater, which comprises the following steps:
(1) preparing 0.05M acetic acid solution with the mass volume concentration of 0.03% of sodium chondroitin sulfate and 0.3% of collagen, stirring for 2 hours by adopting a homogenizer of 18000r/min, and defoaming in vacuum to obtain slurry for later use;
(2) pouring 3mm thick slurry into a freeze-drying tray a, pouring 1mm thick slurry into a freeze-drying tray b, pre-freezing the slurry in the freeze-drying tray a for 8 hours at-20 ℃, cooling the slurry in the freeze-drying tray b to 4 ℃, then pouring the slurry in the freeze-drying tray b into the freeze-drying tray a, and pre-freezing for 4 hours at-80 ℃ to obtain pre-frozen slurry;
(3) freeze-drying the pre-frozen slurry in a freeze-drying machine to obtain a semi-finished product of the multilayer artificial dura mater; the cold drying comprises the following steps:
freezing stage, temperature: -35 ℃, time: 15 min;
first drying stage, temperature: -8 ℃, time: 920min, vacuum degree: 0.2 bar;
second drying stage, temperature: -10 ℃, time: 460min, vacuum degree: 0.2 bar;
third drying stage, temperature: -5 ℃, time: 520min, vacuum degree: 0.2 bar;
fourth drying stage, temperature: 20 ℃, time: 100min, vacuum degree: 0.2 bar;
(4) putting the multilayer artificial dura mater semi-finished product into a vacuum drying oven, and performing high-temperature vacuum crosslinking for 72 hours at the temperature of 95 ℃ and the vacuum degree of 0.1 bar;
(5) sterilizing with ethylene oxide, wherein the ethylene oxide accounts for 40% of the mixed gas of ethylene oxide and carbon dioxide, the temperature is 50 ℃, the humidity is 20% RH, the time is 5h, and the ventilation frequency is 4 times, thus obtaining the multilayer artificial dura mater.
Example 2
The embodiment provides a preparation method of a multilayer artificial dura mater, which comprises the following steps:
(1) preparing 0.05M acetic acid solution with the mass volume concentration of chondroitin sulfate sodium being 0.1% and the mass volume concentration of collagen being 1.0%, stirring for 2h by adopting a homogenizer at 15000r/min, and defoaming in vacuum to obtain slurry for later use;
(2) pouring 5mm of thick slurry into the freeze-drying plate a, pouring 2mm of thick slurry into the freeze-drying plate b, pre-freezing the slurry in the freeze-drying plate a for 16 hours at the temperature of minus 20 ℃, cooling the slurry in the freeze-drying plate b to 10 ℃, then pouring the slurry in the freeze-drying plate b into the freeze-drying plate a, and pre-freezing for 8 hours at the temperature of minus 80 ℃ to obtain pre-frozen slurry;
(3) freeze-drying the pre-frozen slurry in a freeze-drying machine to obtain a semi-finished product of the multilayer artificial dura mater; the cold drying comprises the following steps:
freezing stage, temperature: -45 ℃, time: 15 min;
first drying stage, temperature: -10 ℃, time: 740min, degree of vacuum: 0.2 bar;
second drying stage, temperature: -13 ℃, time: 380min, vacuum degree: 0.2 bar;
third drying stage, temperature: 0 ℃, time: 400min, vacuum degree: 0.2 bar;
fourth drying stage, temperature: 30 ℃, time: 60min, vacuum degree: 0.2 bar;
(4) putting the multilayer artificial dura mater semi-finished product into a vacuum drying oven, and performing high-temperature vacuum crosslinking for 24 hours at the temperature of 100 ℃ and the vacuum degree of 0.08 bar;
(5) sterilizing with ethylene oxide, wherein the ethylene oxide accounts for 60% of the mixed gas of ethylene oxide and carbon dioxide, the temperature is 60 ℃, the humidity is 50% RH, the time is 2h, and the ventilation frequency is 7 times, thus obtaining the multilayer artificial dura mater.
Example 3
The embodiment provides a preparation method of a multilayer artificial dura mater, which comprises the following steps:
(1) preparing 0.05M acetic acid solution with the mass volume concentration of 0.05 percent of sodium chondroitin sulfate and 0.5 percent of collagen, stirring for 1h by adopting a homogenizer at 20000r/min, and defoaming in vacuum to obtain slurry for later use;
(2) pouring the slurry with the depth of 4mm into the freeze-drying tray a, pouring the slurry with the depth of 2mm into the freeze-drying tray b, pre-freezing the slurry in the freeze-drying tray a for 10 hours at the temperature of minus 20 ℃, cooling the slurry in the freeze-drying tray b to 5 ℃, then pouring the slurry in the freeze-drying tray b into the freeze-drying tray a, and pre-freezing for 6 hours at the temperature of minus 80 ℃ to obtain pre-frozen slurry;
(3) freeze-drying the pre-frozen slurry in a freeze-drying machine to obtain a semi-finished product of the multilayer artificial dura mater; the cold drying comprises the following steps:
freezing stage, temperature: -40 ℃, time: 15 min;
first drying stage, temperature: -10 ℃, time: 800min, vacuum degree: 0.2 bar;
second drying stage, temperature: -13 ℃, time: 410min, vacuum degree: 0.2 bar;
third drying stage, temperature: 0 ℃, time: 420min, vacuum degree: 0.2 bar;
fourth drying stage, temperature: 30 ℃, time: 70min, vacuum degree: 0.2 bar;
(4) putting the multilayer artificial dura mater semi-finished product into a vacuum drying oven, and performing high-temperature vacuum crosslinking for 60 hours at the temperature of 105 ℃ and the vacuum degree of 0.09 bar;
(5) sterilizing with ethylene oxide, wherein the ethylene oxide accounts for 50% of the mixed gas of ethylene oxide and carbon dioxide, the temperature is 60 ℃, the humidity is 30% RH, the time is 3h, and the ventilation frequency is 5 times, thus obtaining the multilayer artificial dura mater.
Firstly, testing the anti-leakage performance: in order to verify the anti-leakage effect of the biological membrane prepared by the method, a certain amount of physiological saline is slowly injected on a biological membrane sample of 100mm multiplied by 100mm, the water dripping time is recorded, and the water dripping time can indirectly reflect the anti-leakage performance of the product, and is shown in table 1. It can be seen that when the water injection amount of the biofilm sample prepared by the method of each embodiment of the invention is 25mL, the dripping time is more than 5min, which shows that the biofilm sample has better anti-seepage performance.
TABLE 1
| Sample(s) | Amount of water injected (mL) | Dripping time (min) |
| Example 1 | 25 | 6.3 |
| Example 2 | 25 | 7.1 |
| Example 3 | 25 | 6.5 |
Secondly, the degradation resistance performance: the digestibility test was carried out according to 6.8 in YY/T1511-2017, see Table 2.
TABLE 2
| Sample (I) | Complete digestion time (min) |
| Example 1 | 61.4±2.1 |
| Example 2 | 66.3±1.7 |
| Example 3 | 63.8±1.3 |
Thirdly, testing the stitching strength: the sample was cut into a 15mm x 15mm square, threaded through the center of the material using a medical suture, secured at one end to the suture and at the other end to 1/3 on the material, and subjected to a static axial pull of 1N for 1min using a tensile machine.
TABLE 3
| Sample(s) | Pulling force (N) |
| Example 1 | 2.1±0.3 |
| Example 2 | 2.3±0.2 |
| Example 3 | 2.2±0.3 |
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (8)
1. A preparation method of a multilayer artificial dura mater is characterized by comprising the following steps:
(1) preparing acetic acid solution of sodium chondroitin sulfate and collagen, stirring to dissolve or swell uniformly, and defoaming in vacuum to obtain slurry for later use;
(2) pouring the serous fluid into the freeze-drying tray a and the freeze-drying tray b in sequence, pre-freezing the serous fluid in the freeze-drying tray a for 8-16h at-20 ℃, cooling the serous fluid in the freeze-drying tray b to 4-10 ℃, and then pouring the serous fluid in the freeze-drying tray b into the freeze-drying tray a for 4-8h at-80 ℃ to obtain pre-frozen serous fluid;
(3) freeze-drying the pre-frozen serous fluid for 26-34h at-45-30 ℃ and a vacuum degree of 0.2bar to obtain a semi-finished product of the multilayer artificial dura mater;
(4) carrying out high-temperature vacuum crosslinking on the multilayer artificial dura mater semi-finished product for 24-72h at the temperature of 95-105 ℃ and the vacuum degree of 0.08-0.1 bar;
(5) sterilizing to obtain the multilayer artificial dura mater.
2. The method for preparing the laminated artificial dura mater according to claim 1, wherein in the step (1), the concentration by volume of the chondroitin sulfate sodium is 0.03-0.1%, the concentration by volume of the collagen is 0.3-1.0%, and the acetic acid solution is 0.05M acetic acid solution.
3. The method for preparing the laminated artificial dura mater according to claim 1, wherein in the step (1), the stirring is performed at a speed of 15000-.
4. The method for preparing the laminated artificial dura mater according to claim 1, wherein in the step (2), the slurry with a depth of 3 to 5mm is poured into the freeze-drying tray a, and the slurry with a depth of 1 to 2mm is poured into the freeze-drying tray b.
5. The method for preparing the laminated artificial dura mater according to claim 1, wherein the step (3) of freeze-drying comprises the steps of:
freezing stage, temperature: -45 to-35 ℃, time: 15 min;
first drying stage, temperature: -10 to-8 ℃, time: 740-920 min, vacuum degree: 0.2 bar;
second drying stage, temperature: -13 to-10 ℃, time: 380-460 min, vacuum degree: 0.2 bar;
third drying stage, temperature: -5-0 ℃, time: 400-520 min, vacuum degree: 0.2 bar;
fourth drying stage, temperature: 20-30 ℃, time: 60-100 min, vacuum degree: 0.2 bar.
6. The method for preparing the laminated artificial dura mater according to claim 1, wherein in the step (4), the temperature of the high-temperature vacuum crosslinking is 105 ℃, the vacuum degree is 0.09bar, and the time is 60 hours.
7. The method for preparing the laminated artificial dura mater according to claim 1, wherein in the step (5), the sterilization is performed by using any one of ethylene oxide, Co-60 γ -ray irradiation, and ultraviolet irradiation.
8. The method for preparing the multilayer artificial dura mater according to claim 7, wherein the ethylene oxide sterilization comprises: the proportion of ethylene oxide in the mixed gas of ethylene oxide and carbon dioxide is 40-60%, the temperature is 50-60 ℃, the humidity is 20-50% RH, the time is 2-5 h, and the ventilation frequency is 4-7.
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