CN116198138A - Manufacturing method of silica gel blood vessel model containing hydrophobic texture inner surface - Google Patents

Abstract

The invention belongs to the technical field of surgical medical simulation equipment, and provides a manufacturing method of a silica gel blood vessel model with a hydrophobic texture inner surface. The method is suitable for customizing different bionic microstructures or texture surfaces in a personalized way, can improve the blood compatibility of the artificial blood vessel, can better realize the uniformity and controllability of the thickness of the blood vessel, has high transparency, and can be used for simulating and observing the thrombosis condition.

Description

A method for making a silicone blood vessel model with a hydrophobic textured inner surface

technical field

The invention belongs to the technical field of surgical medical simulation equipment, and relates to a method for manufacturing a silicone blood vessel with hydrophobic texture on the inner surface.

Background technique

Since the introduction of vascular anastomosis in the early 20th century, the repair and replacement of blood vessels has been the key to the treatment of acute vascular injury and chronic atherosclerotic disease. Until now, vascular replacement and repair is a very common surgical procedure in clinical practice, and there is a huge clinical demand for engineered arterial substitutes. However, in many of these procedures, without systemic anticoagulation, when fibrin and platelets in the flowing blood adhere to the surface of these artificial materials, thrombi can form, and these artificial vessels can rapidly die from thrombus formation. occlusion. Therefore, the combined use of soluble anticoagulant drugs, such as heparin, is required, which greatly reduces the safety of artificial blood vessels and hinders their effectiveness. Heparin causes morbidity and mortality through postoperative bleeding, thrombocytopenia, hypertriglyceridemia, hyperkalemia, and hypersensitivity, heparin is contraindicated in some patient populations, and most adverse clinical events result in drug-related death All due to systemic anticoagulation. Therefore, especially for small-bore or low-flow arterial bypass applications, a suitable non-thrombogenic luminal surface is required, which should prevent contact activation of blood clotting, platelet adhesion and activation, and thrombosis in the arterial system, while facing immune The equally formidable challenges of acceptance, necessary tissue mechanics, low thrombus formation, and immediate availability make widespread clinical application of engineered arteries very difficult.

The hemocompatibility of biomaterials refers to the inhibition of thrombus formation on the surface of biomaterials and the influence of biomaterials on blood physiological functions such as hemolysis, platelet function reduction, white blood cell temporary reduction, function decline, and complement activation. Implantable artificial blood vessels have saved countless lives. These artificial blood vessels will be occluded by the formation of thrombus due to the adhesion of fibrin and platelets in the flowing blood to the surface of these artificial materials. Improving the hemocompatibility of the surface of materials is a crucial link in the field of biomaterials research, and surface modification of biomaterials is the key to this link. The contact between the material and the organism is through the contact between the surface of the material and the organism, so it is very important to modify the surface of the material in order to obtain a material with good blood compatibility. The surface structure and composition of materials, surface morphology, surface energy, hydrophilicity and hydrophobicity, chargeability, etc. can all affect the interaction between materials and organisms. By changing the surface characteristics of materials through surface modification, the interaction between materials and blood will also be affected. will be changed. The hydrophobicity and free energy of the surface are closely related to the adsorption and denaturation of blood components. Through surface chemical treatment, surface physical modification and biological modification of traditional materials, the surface hydrophobicity of the material can be improved, and the surface free energy can be reduced to close to The surface free energy value of the vascular intima, so as to improve the blood compatibility of the material, research and prepare biomedical materials that can meet people's needs.

The way to improve the biocompatibility of materials, especially hemocompatibility, is mainly achieved by changing the surface properties of materials, and changing the wettability of the material surface is one of the effective ways. Generally, materials with strong hydrophobic and strong hydrophilic surfaces have better blood compatibility. When the hydrophobicity of the surface of the material is enhanced, it has better blood compatibility due to the decrease of the adsorption capacity of blood components. In addition, the hydrophobicity and free energy of the material surface are closely related to the adsorption and denaturation of blood components. Improving the hydrophobicity of the surface of the material can reduce the surface free energy, so that the surface free energy can be reduced to a value close to that of the vascular intima, and good antithrombotic performance can be obtained. The wettability of a material surface is determined by both the chemical composition and the microscopic geometry of the surface. The superhydrophobic surface is generally obtained by reducing the surface free energy and constructing a suitable rough structure on the surface of the hydrophobic material. The chemical composition of a material surface determines its surface free energy and thus has an important influence on the wettability of the material. However, for a solid smooth surface, even with the lowest surface free energy surface, its contact angle with water can only reach about 110 degrees. To realize a superhydrophobic surface with a high contact angle, it is necessary to consider building a suitable rough structure on the surface of the hydrophobic material. .

At present, it is difficult to prepare texture or microstructure inside the artificial blood vessel, and there are problems of low efficiency and poor effect. Therefore, here we introduce a method for fabricating silicone blood vessels with a hydrophobic textured inner surface. This manufacturing method is relatively simple, and it is suitable for making small-diameter blood vessels and silicone blood vessel models with different wall thicknesses. It can customize the bionic microstructure inside the blood vessels, and improve blood compatibility by replicating silicone blood vessels with a hydrophobic textured inner surface. It can be used in experiments to simulate and observe the thrombosis of artificial blood vessels, and provide a theoretical basis for clinical blood vessel replacement surgery.

Patent application: Three-layer bionic artificial blood vessel for antithrombotic and tissue regeneration promotion and its preparation method, application number CN202210888742.7. The main problem is that the inner layer of the three-layer bionic artificial blood vessel uses an anticoagulant, which may cause side effects such as anticoagulant shedding or abnormal coagulation function.

Patent application: Preparation method of electrospun artificial blood vessel with micro-nano bionic inner membrane structure, application number CN201210287469.9. The artificial blood vessel prepared by this method has a microstructure imitating the alignment of the intima of the blood vessel, so that the blood compatibility of the artificial blood vessel meets the requirements of clinical anticoagulant performance. The structural surface is difficult.

Patent application: A preparation device and method for artificial blood vessels with microstructures on the inner surface, application number CN202210738869.0. The main problem is that the requirements for the size of the blood vessels to be produced are relatively high, and it is difficult to manufacture small-diameter blood vessels. The specific operation of making microstructured pillars is unknown, and it is difficult to make personalized microstructures.

Contents of the invention

The technical problem to be solved by the present invention is to propose a method for making silicone blood vessel with texture or microstructure on the inner surface. This method can produce a silicone blood vessel model with hydrophobic texture on the inner wall, which has certain advantages for personalized texture or microstructure blood vessel model. versatility. The problem that the existing method requires special processing equipment or complex technological process is solved. The overall manufacturing process of this patent is simple, without any special processing equipment, which improves the applicability of the method.

Technical scheme of the present invention:

A method for making a silicone blood vessel model with a hydrophobic texture inner surface, because most of the animal feathers and the surface of plant leaves in nature have texture characteristics with different wettability. The published experimental data shows that the feathers of birds such as magpie feathers and swan feathers, plant leaves such as ginkgo leaves and lotus leaves, and the surface of marine organisms such as shark skin and textures of shellfish all have high hydrophobicity. This patent mainly uses Take the magpie feather texture as an example. Use the engraving method to engrave the hydrophobic feather texture onto the silicone surface. The engraving method for other textured surfaces is the same. Use a 3D printer to print the replica mold based on soluble materials, and configure the silica gel with a certain proportion of curing agent. Fill the mold with silica gel, stick the feathers flat on the plate and cover them on the mold. After the silica gel completely soaks the feathers, heat the mold to solidify the silica gel, and then dissolve it in a water bath. After removing the feathers, you can get a feather texture. Silicone diaphragm.

Use a 3D printer to print casting molds based on soluble materials, and smooth the surface of the printed model to remove the ladder-shaped problem caused by layer-by-layer printing. Wrap the textured side of the silicone film around the shaft column and insert it into the pouring container. Slowly pour the silica gel from the entrance so that the silica gel flows down along the joints on both sides of the silica film. When the silica gel no longer sinks, heat the mold to make it The silica gel is solidified, and then dissolved in a water bath to obtain a silica gel blood vessel model with inner surface texture.

For the production of vascular models with personalized microstructures, it is necessary to obtain personalized microstructure models first, and then use the method provided by this patent to engrave the microstructures on the inner wall of silicone blood vessels. Among them, the microstructure model can be made by mechanical micromachining, soft lithography, photoetching and other processes, and the existing technical methods are relatively mature.

Specific steps are as follows:

Step 1: Cut the washed magpie feathers into regular shapes, and fix the back of the feathers on the acrylic board;

Step 2: Using a 3D printer, use soluble printing consumables to print out square containers, shaft columns and pouring containers;

Step 3: Wipe the surface of the printed device evenly with water or printing material solvent solution to remove the rough texture on the surface of the printed device, and dry it after multiple times of wiping to obtain a printed device with a smooth surface;

Step 4: Prepare the two-component silica gel AB mixed solution, mix the two-component silica gel AB mixed solution and the curing agent according to a certain ratio to obtain a silica gel solution; use a vacuum pump to remove the bubbles mixed in due to stirring, and obtain a clear and transparent silica gel mixed solution.

Step 5: Fill the square container with the silicone mixture until it overflows, put the feathered acrylic plate upside down on the square container, and cover it with a heavy object;

Step 6: Dry the overall model obtained in step 5. After the silica gel is cured, remove the acrylic plate and feathers, and immerse the overall model in water. After the square container is completely dissolved, a silicone film with feather texture is obtained;

Step 7: Wrap the textured side of the silicone membrane around the shaft and embed it in the pouring container, and slowly inject the silicone mixture from the entrance of the pouring container until the silicone mixture at the entrance no longer sinks;

Step 8: Dry the silicone blood vessel model obtained in step 5 as a whole. After the silica gel is cured, immerse the whole silicone blood vessel model in water. After the pouring container and shaft column are completely dissolved, a silicone blood vessel model with inner surface texture is obtained.

In said step 1, the magpie feathers can be replaced with feathers of other birds, plant blades or surfaces of marine organisms.

In the step 2, the soluble printing consumables are: PVA (polyvinyl alcohol), water-soluble gypsum, HIPS (impact-resistant polystyrene) or ABS (acrylonitrile butadiene styrene), wherein PVA is soluble in water, and HIPS is soluble in Limonene, ABS is soluble in organic solvents such as acetone.

In the step 3, the mass ratio of PVA to water in the printing material dissolving agent solution is 1:10˜1:5.

In the step 4, use the two-component silica gel model 7055, configure the two-component silica gel AB mixed solution according to the mass ratio of A:B=1:1, and add 1% of the total mass of the two-component silica gel AB mixed solution vulcanizing agent to obtain a silica gel solution; stir it evenly and put it into a vacuum machine to vacuum for 0.5-1 hour to obtain a clear and transparent silica gel mixture.

In the step 6, the curing condition is: curing in a constant temperature oven at 60° C. to 90° C. for more than 2 hours.

In the step 6, the dissolving process is as follows: put the cured overall model into the water tank until the square container is completely dissolved. In order to accelerate the dissolution of the square container, inject hot water at 60-100°C into the water tank, replace the hot water every 1-3 hours, use a constant temperature oven to control the water temperature at 60-100°C, and change the water 2-10 times until it is square The container is completely dissolved.

In the step 8, the curing condition is: curing in a constant temperature oven at 60° C. to 90° C. for more than 6 hours.

In step 8, the dissolving process is as follows: put the cured silicone blood vessel model into the water tank, inject 60-100°C hot water into the water tank, replace the hot water every 1-3 hours, and use a constant temperature oven to control the water temperature to 60°C. -100℃, carry out the dissolving operation, after 10-25 times of water change operation, until the pouring container and the inner shaft column are completely dissolved.

Beneficial results of the present invention:

(1) The cost of making silicone blood vessels by this method is low, the process is simple and repeatable;

(2) This method does not use an anticoagulant, but only improves the hemocompatibility of the silicone blood vessel through the hydrophobicity of the surface microstructure;

(3) This method is suitable for customizing different bionic microstructures or textured surfaces, and can make blood vessel models with different diameters and wall thicknesses;

(4) The silicone blood vessel model with textured inner wall produced by this method can be used in experiments to simulate and observe the thrombus formation of artificial blood vessels, and provide a theoretical basis for clinical blood vessel replacement surgery.

Description of drawings

Figure 1 is an acrylic sheet glued with feathers.

Figure 2 is a square container printed by a 3D printer using soluble material PVA.

Figure 3 is a silicone membrane with a feather texture.

Figure 4 shows the pouring container and shaft column printed by the 3D printer using the soluble material PVA.

Figure 5 is a mold with a textured silicone membrane surrounding the shaft.

Figure 6 is a silicone vessel model with a feather texture on the inner surface.

Figure 7 is a schematic diagram of a mold with a textured silicone membrane wrapped around a shaft post.

In the figure, 1 is the pouring container A; 2 is the pouring container B; 3 is the shaft column; 4 is the silicone membrane with a replica texture embedded in the mold; 5 is the pouring entrance.

Detailed ways

Below in conjunction with accompanying drawing, further illustrate the present invention through the embodiment, but not as limitation to the present invention. Specific materials and their sources used in embodiments of the invention are provided below. However, it should be understood that these are merely exemplary and not intended to limit the present invention, and materials with the same or similar type, model, quality, property or function as the following reagents and instruments can be used to implement the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

Taking superhydrophobic magpie feathers as an example, firstly, the magpie feathers are cleaned with clean water, and after drying at room temperature, the feathers are cut into a more regular shape with a width of 15 mm and a length of 50 mm. Use double-sided tape to stick the back of the feather to a square acrylic board with a length of 80mm, as shown in Figure 1.

Use a 3D printer to print the model, and 3D print out a PVA container with a depth of 1.5mm, a width of 20mm, and a length of 50mm, as shown in Figure 2. Wipe evenly with water on the surface of the printed device to remove the rough texture on the surface of the printed device. After 4 times of wiping, it is dried to obtain a printed device with a smooth surface. Model making uses two-component silica gel model 7055, configure silica gel according to the mass ratio of A:B=1:1 and add 1% vulcanizing agent of the total mass of the AB mixture, stir it evenly and put it into a vacuum machine for pumping Vacuum for half an hour to obtain a silica gel mixture.

Fill the square container with the silica gel mixture until it overflows, cover the acrylic plate with feathers on the square PVA container filled with silica gel, press the cap with a heavy object, and place it in a constant temperature oven at 60°C for 2 hours to cure. After the silica gel is completely cured, remove the acrylic plate and feathers, put the silica gel film with feather microstructure on the surface into the water tank, fill the water tank with hot water, change the hot water every three hours, and use a constant temperature oven to control the water temperature to 60 °C. Dissolving operation, after 6 hours and 2 water changes, the soluble PVA container is completely dissolved, and a silicone film with a thickness of 1.5 mm and a feather texture can be obtained, as shown in Figure 3.

Using a 3D printer, print out a PVA material shaft column with a length of 70mm and a diameter of 5mm and a pouring container with an inner diameter of 8mm, as shown in Figure 4. The PVA solution is prepared by PVA material and water with a mass ratio of 1:10, and the PVA solution is evenly coated on the surface of the model. After four times of coating and drying, the overall model surface is smoother. Wrap the surface of the textured side of the silicone membrane around the shaft column and embed it in the pouring container, as shown in Figure 5, slowly inject silicone from the entrance until the silicone at the entrance no longer sinks, then place the entire mold in a constant temperature oven at 60°C Cured in dry box for 6h.

Put the PVA pouring container model cured by silica gel into the water tank, inject hot water into the water tank, change the hot water every three hours, use a constant temperature oven to control the water temperature at 60°C, and carry out the dissolution operation. After 48 hours, 16 water changes , the soluble container and the inner shaft column are completely dissolved, and a silicone blood vessel model with a feather texture can be obtained, as shown in Figure 6.

Compared with the existing artificial silicone blood vessels, the preparation process of the present invention is very simple, and the laziness of processing equipment is not high, which can realize the personalized customization of the inner surface microstructure and the production of blood vessel models with controllable thickness.

The descriptions presented above of the exemplary embodiments are for illustration only and are not intended to be exhaustive or to limit the invention to the precise forms described. Obviously, many modifications and variations from the above examples are possible to those skilled in the art. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application, thereby enabling others skilled in the art to understand, implement and utilize the various exemplary embodiments of the invention and various alternatives thereof and modified form. It is intended that the scope of the invention be defined by the appended claims and their equivalents.

Claims (9)

1. A method for manufacturing a silica gel blood vessel model containing a hydrophobic texture inner surface is characterized by comprising the following specific steps:

step 1: cutting the cleaned magpie feathers into a regular shape, and fixing the back surfaces of the feathers on an acrylic plate;

step 2: printing a square container, a shaft column and a pouring container by using a 3D printer and using soluble printing consumables;

step 3: uniformly coating water or printing material dissolvent solution on the surface of the printing device for removing rough textures on the surface of the printing device, and drying after a plurality of times of coating to obtain the printing device with smooth surface;

step 4: preparing a double-component silica gel AB mixed solution, and mixing the double-component silica gel AB mixed solution with a curing agent according to a certain proportion to obtain a silica gel solution; removing bubbles mixed by stirring by using a vacuum pump to obtain clear and transparent silica gel mixed liquid;

step 5: pouring the silica gel mixed solution into a square container until overflow, pouring an acrylic plate adhered with feathers on the square container, and capping with a weight;

step 6: drying the integral model obtained in the step 5, after the silica gel is solidified, taking down the acrylic plate and the feathers, immersing the integral model in water, and obtaining a silica gel film containing the feathers after the square container is completely dissolved;

step 7: embedding the textured surface of the silica gel film into a pouring container after wrapping the shaft column, and slowly injecting the silica gel mixed solution from the inlet of the pouring container until the silica gel mixed solution at the inlet is not sinking;

step 8: and 5, integrally drying the silica gel blood vessel model obtained in the step 5, immersing the whole silica gel blood vessel model in water after the silica gel is solidified, and obtaining the silica gel blood vessel model containing the inner surface texture after the pouring container and the shaft column are completely dissolved.

2. The method according to claim 1, wherein in step 1, the magpie feathers are replaced by feathers of other birds, plant leaves or marine organisms.

3. The method for manufacturing a silicone vascular model with a hydrophobic texture inner surface according to claim 1, wherein in the step 2, the dissolvable printing consumables are: PVA, water soluble gypsum, HIPS, or ABS.

4. The method for manufacturing a silica gel vascular model with a hydrophobic texture inner surface according to claim 1, wherein in the step 3, the mass ratio of PVA to water in the printing material dissolver solution is 1:10-1:5.

5. The method of claim 1, wherein in step 4, a two-component silica gel of type 7055 is used according to a: b=1: preparing a double-component silica gel AB mixed solution according to the mass ratio of 1, and adding a vulcanizing agent accounting for 1% of the total mass of the double-component silica gel AB mixed solution to obtain a silica gel solution; and (3) uniformly stirring, and then placing the mixture into a vacuum machine for vacuumizing for 0.5-1 hour to obtain clear and transparent silica gel mixed solution.

6. The method for preparing a silica gel vascular model with a hydrophobic texture inner surface according to claim 1, wherein in the step 6, the curing conditions are as follows: curing in a constant temperature oven at 60-90 deg.c for over 2 hr.

7. The method for preparing a silica gel vascular model with a hydrophobic texture inner surface according to claim 1, wherein in the step 6, the dissolution process is as follows: placing the solidified integral model into a water tank until the square container is completely dissolved; in order to accelerate dissolution of the square container, hot water at 60-100 ℃ can be injected into the water tank, the hot water is replaced every 1-3 hours, the water temperature is controlled to be 60-100 ℃ by using a constant-temperature oven, and water replacement operation is carried out for 2-10 times until the square container is completely dissolved.

8. The method for preparing a silica gel vascular model with a hydrophobic texture inner surface according to claim 1, wherein in the step 8, the curing conditions are as follows: curing in a constant temperature oven at 60-90 deg.c for over 6 hr.

9. The method for preparing a silica gel vascular model with a hydrophobic texture inner surface according to claim 1, wherein in the step 8, the dissolution process is as follows: the solidified silica gel vascular model is put into a water tank, hot water at 60-100 ℃ is injected into the water tank, the hot water is replaced every 1-3 hours, a constant temperature oven is used for controlling the water temperature to be 60-100 ℃, dissolving operation is carried out, and 10-25 times of water replacing operation is carried out until the pouring container and the inner shaft column are completely dissolved.

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