A hollow vascular anastomosis stent based on 3D-printed self-expandable hydrogel

Abstract

The present invention discloses a hollow vascular anastomosis stent based on 3D-printed self-expandable hydrogel, which is characterized in that the hollow vascular anastomosis stent comprises an anastomosis branch sleeve (1) and a plurality of irregular hollow holes (2) distributed on the anastomosis branch sleeve (1). In the present invention, by providing a vascular anastomosis stent composed of hollow holes and an anastomosis branch sleeve based on 3D printing, the blood in the blood vessel can well nourish the tube wall of the vascular anastomosis stent through the hollow holes. At the same time, during suturing, the peripheral silk thread can well fix the blood vessel on the vascular anastomosis stent through the hollow holes, making the fixation of the peripheral silk thread more convenient. Therefore, the present invention well solves the problems of the existing vascular anastomosis stent that the tube wall cannot be nourished by blood and the fixation of the peripheral silk thread is inconvenient.

Description

Technical Field

[0001] The present invention relates to the technical field of vascular anastomosis stents, and specifically refers to a hollow vascular anastomosis stent based on 3D printed self-expandable hydrogel. Background Art

[0002] At present, liver transplantation surgery is considered an effective means for treating end-stage liver diseases and is widely carried out worldwide. However, the implementation of liver transplantation still faces various problems. Therefore, establishing a stable liver transplantation animal model for relevant research has extremely important clinical significance. In the relevant research of liver transplantation animal models, since the postoperative liver function recovery of the arterialized mouse liver transplantation model is better and closer to human physiological indicators, the mouse liver transplantation model is used as the main liver transplantation animal model for relevant research. However, the blood vessels of mice are extremely thin and can only be anastomosed under a microscope. During the anastomosis process, the time of the anhepatic phase needs to be controlled, and the anastomosis of the inferior vena cava and the portal vein can only be completed within 15 - 20 minutes. Therefore, when dealing with the infrahepatic inferior vena cava, a vascular anastomosis stent or a venous catheter anastomosis method needs to be used. Among them, using a vascular anastomosis stent is the main anastomosis method currently adopted.

[0003] However, the existing vascular anastomosis stents are mainly made of polyethylene (PE) material catheters. Although the diameter of the polyethylene (PE) material catheters can reach 16G (1.6 mm), because their tube walls are airtight and smooth, the blood in the tube cannot enter the tube wall, and it is not convenient for fixing the peripheral silk thread. In addition, the catheter usually needs to be smaller than the diameter of the vena cava to enter, but the polyethylene (PE) material catheter cannot achieve self-expansion, resulting in some gaps between the polyethylene (PE) material catheter and the blood vessel after suture, causing blood coagulation in the blood vessel and seriously affecting the effect of liver transplantation surgery. Therefore, we have developed a vascular anastomosis stent that not only can be nourished by blood on the tube wall, is convenient for fixing the peripheral silk thread, but also can achieve self-expansion function and reduce the risk of thrombosis. Summary of the Invention

[0004] The purpose of the present invention is to solve the above problems and provide a hollow vascular anastomosis stent based on 3D printed self-expandable hydrogel, which can not only be nourished by blood on the tube wall, is convenient for fixing the peripheral silk thread, but also can achieve self-expansion to prevent blood coagulation in the blood vessel.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A hollow vascular anastomosis stent based on 3D printed self-expandable hydrogel, the hollow vascular anastomosis stent includes an anastomosis branch sleeve, and a number of irregular hollow holes distributed on the anastomosis branch sleeve; the hollow holes are distributed in a spiral shape on the anastomosis branch sleeve, making the branch sleeve wall of the anastomosis branch sleeve present a spiral surface.

[0007] Furthermore, the hollow vascular anastomosis stent made of 3D-printed self-expandable hydrogel is composed of the following substances in parts by weight: 0.5 - 2 parts of acrylic acid, 0.5 - 2 parts of acrylamide, 6 - 8 parts of absolute ethanol, 0.06 - 1 part of PEGDA, 0.01 - 0.04 part of light absorbent, and 0.01 - 1 part of initiator.

[0008] As a preferred embodiment of the present invention, the mass ratio of acrylic acid to acrylamide is 1:1 or 1:3 or 3:1; wherein, the viscosity of acrylic acid (mPa·s, 25°C): 1.2 - (mPa·s, 25°C): 1.3, relative density (25°C, 4°C): 1.012 - (25°C, 4°C): 1.2.

[0009] As a preferred embodiment of the present invention, the PEGDA is polyethylene glycol diacrylate - 200; the density of PEGDA is 1.12 g / mL at 25°C - 1.2 g / mL at 25°C, and the molecular weight is 200.

[0010] As a preferred embodiment of the present invention, the density of acrylamide is 1.255 g / cm 3 ~1.35 g / cm 3 , and the melting point is 90°C.

[0011] Furthermore, the light absorbent is one or a mixture of several of curcumin, fast green, lemon yellow, and sudan.

[0012] As a preferred embodiment of the present invention, the initiator is organic blue light phenyl(2,4,6 - trimethylbenzoyl) lithium phosphate, and the molecular weight of this initiator is 294.2, with a purity ≥ 98.5%.

[0013] In addition, the preparation steps of the hollow vascular anastomosis stent made of 3D-printed self-expandable hydrogel are as follows:

[0014] S1. Add 0.5 - 2 parts by weight of acrylic acid, 0.5 - 2 parts by weight of acrylamide, and 6 - 8 parts by weight of absolute ethanol into a container, stir clockwise for 3 - 6 min, then let it stand for 2 min, and then stir counterclockwise for 3 - 6 min to obtain a clear solution.

[0015] S2. Add 0.06 - 1 part by weight of PEGDA to the obtained clear solution, stir for 5 - 10 min, then let it stand until there are no bubbles, add 0.01 - 1 part by weight of initiator and 0.01 - 0.04 part by weight of light absorbent, and stir again for 5 - 15 min to obtain 3D-printed hydrogel ink.

[0016] S3. Add the obtained 3D printing hydrogel ink into the photocuring 3D printing curing pool for printing to obtain a prefabricated hollow vascular anastomosis stent with a certain shape, and immerse the obtained prefabricated hollow vascular anastomosis stent in a sodium hydroxide ethanol solution at room temperature for 6 hours.

[0017] S4. Take out the soaked primary hollow vascular anastomosis stent, repeatedly wash off the excessive sodium hydroxide with absolute ethanol, and obtain the final hollow vascular anastomosis stent after natural air drying.

[0018] Furthermore, the sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide. The sodium ions in this sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] (1) In the present invention, a vascular anastomosis stent based on 3D printing and composed of hollow holes and anastomosis sleeves is provided. The blood in the blood vessel can well nourish the tube wall of the vascular anastomosis stent through the hollow holes. At the same time, when suturing, the peripheral silk thread can well fix the blood vessel on the vascular anastomosis stent through the hollow holes, making the fixation of the peripheral silk thread more convenient. Therefore, the present invention well solves the problems that the tube wall of the existing vascular anastomosis stent cannot be nourished by blood and the fixation of the peripheral silk thread is inconvenient.

[0021] (2) In the present invention, a 3D printing self-expanding hydrogel composed of acrylic acid, acrylamide, absolute ethanol, PEGDA and an initiator is adopted. The cooperation of acrylic acid and acrylamide in the 3D printing self-expanding hydrogel can achieve high-precision printing, and by introducing sodium ions to coordinate with the carboxyl groups in the acrylic acid part of the polymer network to form sodium salts, the osmotic pressure and water absorption of the stent are increased, which can promote the self-expansion of the vascular anastomosis stent after absorbing moisture. Therefore, the present invention well solves the problem that the existing vascular anastomosis stent cannot achieve self-expansion, resulting in partial gaps between the polyethylene PE catheter and the blood vessel after suturing, causing blood coagulation in the blood vessel.

[0022] (3) The 3D printed vascular anastomosis stent of the present invention is soaked in an ethanol solution containing 10% sodium hydroxide and having monovalent sodium ions, which improves the self-expansion effect and speed of the vascular anastomosis stent after absorbing moisture.

[0023] (4) By adjusting the mass ratio of acrylic acid to acrylamide, the viscosity and relative density of acrylic acid, the present invention effectively ensures the printing accuracy and density of the vascular anastomosis stent, effectively improves the mechanical properties of the vascular anastomosis stent, and also well improves the nourishing effect of blood on the tube wall of the vascular anastomosis stent. Description of the Drawings

[0024] Figure 1This is the overall structural schematic diagram of the present invention.

[0025] The reference numeral names in the accompanying drawings are: 1 - anastomosis branch sleeve, 2 - hollow hole. Specific embodiments

[0026] The present invention will be further described in detail below in conjunction with embodiments, but the embodiments of the present invention are not limited thereto.

[0027] Embodiment 1

[0028] The hollow vascular anastomosis stent based on 3D-printed self-expanding hydrogel in this embodiment is as Figure 1 shown. The hollow vascular anastomosis stent includes an anastomosis branch sleeve 1 and a hollow hole 2. Specifically, the anastomosis branch sleeve 1 is a hollow body in this embodiment, and both ends of the anastomosis branch sleeve 1 are open. The anastomosis branch sleeve 1 is formed by photocuring 3D printing. The hollow hole 2 is an irregular hole, and the number of the hollow holes 2 is several. The several hollow holes 2 are distributed on the anastomosis branch sleeve 1, and the hollow hole 2 penetrates through the sleeve arm of the anastomosis branch sleeve 1, making the sleeve wall of the anastomosis branch sleeve 1 present a threaded surface, so as to facilitate the fixation of blood vessels, prevent the blood vessels from slipping off the anastomosis branch sleeve 1, and ensure the reliability of the hollow vascular anastomosis stent. When in use, the blood in the blood vessel soaks the whole anastomosis branch sleeve 1 through the hollow hole 2, and the blood soaks into the sleeve arm of the anastomosis branch sleeve 1 through the hollow hole 2, nourishing the tube wall of the anastomosis branch sleeve 1 well. The irregular setting of the hollow hole 2 can improve the nourishing effect of the anastomosis branch sleeve 1. In actual production and use, the hollow hole 2 can also be designed into holes of different shapes according to needs, such as: circular, square, triangular, etc. At the same time, when suturing, the peripheral silk thread can fix the blood vessel on the anastomosis branch sleeve 1 well through the hollow hole 2, making the fixation of the peripheral silk thread more firm and more convenient.

[0029] Furthermore, the hollow vascular anastomosis stent made of 3D printed self-expanding hydrogel is composed of the following substances in parts by weight: 0.5 - 2 parts of acrylic acid, 0.5 - 2 parts of acrylamide, 6 - 8 parts of absolute ethanol, 0.06 - 1 part of PEGDA, 0.01 - 0.04 part of light absorbent, and 0.01 - 1 part of initiator. The mass ratio of acrylic acid to acrylamide is 1:1 or 1:3 or 3:1; among them, the viscosity of acrylic acid (mPa·s, 25°C): 1.2 - (mPa·s, 25°C): 1.3, relative density (25°C, 4°C): 1.012 - (25°C, 4°C): 1.2. During production and use, the mass ratio of acrylic acid to acrylamide can be selected according to actual needs, and at the same time, according to the selected mass ratio of acrylic acid to acrylamide, the viscosity and relative density of acrylic acid can be set to ensure the printing accuracy, effectively improving the mechanical properties of the vascular anastomosis stent and making the self-expansion of the vascular anastomosis stent faster and more accurate. PEGDA is polyethylene glycol diacrylate-200. The density of PEGDA is 1.12 g / mL at 25°C - 1.2 g / mL at 25°C, and the molecular weight is 200. The density of acrylamide is 1.255 g / cm 3 ~1.35 g / cm 3 , and the melting point is 90°C. The initiator is organic blue light phenyl(2,4,6-trimethylbenzoyl) lithium phosphate, and the molecular weight of this initiator is 294.2, with a purity ≥ 98.5%. The light absorbent is one or a mixture of several of curcumin, fast green, lemon yellow, and sudan.

[0030] The hollow vascular anastomosis stent made of 3D printed self-expanding hydrogel in this example is composed of the following substances in parts by weight: 2 parts of acrylic acid, 2 parts of acrylamide, 6 parts of absolute ethanol, 0.06 part of PEGDA, 0.02 part of light absorbent, and 0.01 part of initiator. Among them, the mass ratio of acrylic acid to acrylamide is 1:1. The viscosity of acrylic acid (mPa·s, 25°C): 1.2, relative density (25°C, 4°C): 1.012. PEGDA is polyethylene glycol diacrylate-200, and the density of PEGDA is 1.12 g / mL at 25°C. The density of acrylamide is 1.255 g / cm 3 , and the melting point is 90°C. The initiator is organic blue light phenyl(2,4,6-trimethylbenzoyl) lithium phosphate, and the molecular weight of this initiator is 294.2, with a purity ≥98.5%. The light absorbent is a mixture of curcumin, fast green, and lemon yellow.

[0031] When in use, it is a 3D printed self-expanding hydrogel composed of acrylic acid, acrylamide, absolute ethanol, PEGDA and an initiator. The cooperation of acrylic acid and acrylamide in the 3D printed self-expanding hydrogel can achieve high-precision printing. By introducing sodium ions to coordinate with the carboxyl groups in the acrylic acid part of the polymer network to form sodium salts, the osmotic pressure and water absorption of the stent can be increased, which can promote the self-expansion of the vascular anastomosis stent after absorbing moisture. After anastomosis and opening of blood flow, the hollow vascular anastomosis stent can slowly expand to achieve fixation and support of the inferior vena cava. Due to the smooth blood flow at the support site, the risk of thrombosis can be significantly reduced.

[0032] In addition, the preparation steps of the hollow vascular anastomosis stent based on the 3D printed self-expanding hydrogel are as follows:

[0033] S1. Add 2 parts by weight of acrylic acid, 2 parts by weight of acrylamide and 6 parts by weight of absolute ethanol into a container, stir clockwise for 6 min, let stand for 2 min, and then stir counterclockwise for 6 min to obtain a clear solution.

[0034] S2. Add 0.06 part by weight of PEGDA to the obtained clear solution, stir for 5 min, let stand until there are no bubbles, then add 0.01 part by weight of the initiator and 0.02 part by weight of the light absorbent, and stir again for 5 min to obtain the 3D printed hydrogel ink.

[0035] S3. Add the obtained 3D printed hydrogel ink into the photocuring 3D printing curing pool for printing to obtain a prefabricated hollow vascular anastomosis stent with a certain shape, and soak the obtained prefabricated hollow vascular anastomosis stent in a sodium hydroxide ethanol solution at room temperature for 6 h.

[0036] S4. Take out the soaked primary hollow vascular anastomosis stent, repeatedly wash the excess sodium hydroxide with absolute ethanol, and naturally air-dry to obtain the final hollow vascular anastomosis stent. The sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide. The sodium ions in the sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12. Through the soaking of the 3D printed vascular anastomosis stent in the ethanol solution containing 10% sodium hydroxide and having monovalent sodium ions, the sodium ions in the sodium hydroxide ethanol solution coordinate with the carboxyl groups in the acrylic acid part of the polymer network to form sodium salts, increasing the osmotic pressure and water absorption of the stent, and improving the self-expansion effect and speed of the vascular anastomosis stent after absorbing moisture.

[0037] Example 2

[0038] This example is basically the same as Example 1, and the difference is:

[0039] The hollow vascular anastomosis stent made of 3D-printed self-expandable hydrogel in this embodiment is composed of the following substances in parts by weight: 0.5 part of acrylic acid, 1.5 parts of acrylamide, 8 parts of absolute ethanol, 0.06 part of PEGDA, 0.02 part of light absorbent, and 0.01 part of initiator.

[0040] Among them, the mass ratio of acrylic acid to acrylamide is 1:3. Viscosity of acrylic acid (mPa·s, 25°C): 1.3, relative density (25°C, 4°C): 1.2. PEGDA is polyethylene glycol diacrylate-200. The density of PEGDA is 1.2 g / mL at 25°C, and the molecular weight is 200. The density of acrylamide is 1.35 g / cm 3 , and the melting point is 90°C. The light absorbent is curcumin.

[0041] In addition, the preparation steps of the hollow vascular anastomosis stent based on 3D-printed self-expandable hydrogel are as follows:

[0042] S1. Add 0.5 part by weight of acrylic acid, 1.5 parts by weight of acrylamide, and 8 parts by weight of absolute ethanol into a container, stir clockwise for 6 min, let stand for 2 min, and then stir counterclockwise for 6 min to obtain a clear solution.

[0043] S2. Add 0.06 part by weight of PEGDA to the obtained clear solution, stir for 5 min, let stand until there are no bubbles, then add 0.01 part by weight of initiator and 0.02 part by weight of light absorbent, and stir again for 5 min to obtain 3D-printed hydrogel ink.

[0044] S3. Add the obtained 3D-printed hydrogel ink into a photocuring 3D printing curing pool for printing to obtain a prefabricated hollow vascular anastomosis stent with a certain shape, and soak the obtained prefabricated hollow vascular anastomosis stent in a sodium hydroxide ethanol solution at room temperature for 6 h.

[0045] S4. Take out the soaked primary hollow vascular anastomosis stent, repeatedly wash off the excess sodium hydroxide with absolute ethanol, and naturally dry it to obtain the final hollow vascular anastomosis stent. The sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide. The sodium ions in this sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12. Through the soaking of the 3D-printed vascular anastomosis stent in an ethanol solution containing 10% sodium hydroxide and having monovalent sodium ions, the sodium ions in the sodium hydroxide ethanol solution coordinate with the carboxyl groups in the acrylic acid part of the polymer network to form sodium salts, increasing the osmotic pressure and water absorption of the stent, and improving the self-expansion effect and speed of the vascular anastomosis stent after absorbing moisture.

[0046] Example 3

[0047] This embodiment is basically the same as Embodiment 1, and the differences are as follows:

[0048] The hollow vascular anastomosis stent made of 3D printed self - expanding hydrogel in this embodiment is composed of the following substances in parts by weight: 1 part of acrylic acid, 1 part of acrylamide, 8 parts of absolute ethanol, 1 part of PEGDA, 0.03 part of light absorbent, and 0.05 part of initiator.

[0049] Among them, the mass ratio of acrylic acid to acrylamide is 1:1; the viscosity of acrylic acid (mPa·s, 25℃): 1.3, relative density (25℃, 4℃): 1.2. PEGDA is polyethylene glycol diacrylate - 200. The density of PEGDA is 1.2 g / mL at 25℃, and the molecular weight is 200. The density of acrylamide is 1.3 g / cm 3 , and the melting point is 90℃. The light absorbent is a mixture of curcumin and sudan.

[0050] In addition, the preparation steps of the hollow vascular anastomosis stent based on 3D printed self - expanding hydrogel are as follows:

[0051] S1. Add 1 part by weight of acrylic acid, 1 part by weight of acrylamide, and 8 parts by weight of absolute ethanol into a container, stir clockwise for 3 min, let it stand for 2 min, and then stir counterclockwise for 3 min to obtain a clear solution.

[0052] S2. Add 1 part by weight of PEGDA to the obtained clear solution, stir for 10 min, let it stand until there are no bubbles, then add 0.05 part by weight of initiator and 0.03 part by weight of light absorbent, and stir again for 10 min to obtain 3D printing hydrogel ink.

[0053] S3. Add the obtained 3D printing hydrogel ink into a photo - curing 3D printing curing pool for printing to obtain a pre - formed hollow vascular anastomosis stent with a certain shape, and immerse the obtained pre - formed hollow vascular anastomosis stent in a sodium hydroxide ethanol solution at room temperature for 6 h.

[0054] S4. Take out the soaked primary hollow vascular anastomosis stent, wash it repeatedly with absolute ethanol to remove the excess sodium hydroxide, and air - dry it naturally to obtain the final hollow vascular anastomosis stent. The sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide. The sodium ions in this sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12. Through the immersion of the 3D - printed vascular anastomosis stent in an ethanol solution containing 10% sodium hydroxide and having monovalent sodium ions, the sodium ions in the sodium hydroxide ethanol solution coordinate with the carboxyl groups in the acrylic acid part of the polymer network to form sodium salts, increasing the osmotic pressure and water absorption of the stent, and improving the self - expanding effect and speed of the vascular anastomosis stent after absorbing moisture.

[0055] Embodiment 4

[0056] This embodiment is basically the same as Embodiment 1, and the difference lies in that:

[0057] The hollow vascular anastomosis stent made of 3D printed self-expanding hydrogel in this embodiment is composed of the following substances in parts by weight: 1.5 parts of acrylic acid, 0.5 part of acrylamide, 8 parts of absolute ethanol, 0.06 part of PEGDA, 0.01 part of light absorbent, and 1 part of initiator.

[0058] Among them, the mass ratio of acrylic acid to acrylamide is 3:1; the viscosity of acrylic acid (mPa·s, 25°C): 1.3, relative density (25°C, 4°C): 1.012. PEGDA is polyethylene glycol diacrylate-200. The density of PEGDA is 1.2 g / mL at 25°C, and the molecular weight is 200. The density of acrylamide is 1.255 g / cm 3 , and the melting point is 90°C. The light absorbent is a mixture of tartrazine and Sudan.

[0059] In addition, the preparation steps of the hollow vascular anastomosis stent made of 3D printed self-expanding hydrogel are as follows:

[0060] S1. Add 1.5 parts by weight of acrylic acid, 0.5 part by weight of acrylamide, and 8 parts by weight of absolute ethanol into a container, stir clockwise for 3 min, let it stand for 2 min, and then stir counterclockwise for 3 min to obtain a clear solution.

[0061] S2. Add 0.06 part by weight of PEGDA to the obtained clear solution, stir for 10 min, let it stand until there are no bubbles, then add 1 part by weight of initiator and 0.01 part by weight of light absorbent, and stir again for 10 min to obtain 3D printed hydrogel ink.

[0062] S3. Add the obtained 3D printed hydrogel ink into a photocuring 3D printing curing pool for printing to obtain a prefabricated hollow vascular anastomosis stent with a certain shape, and immerse the obtained prefabricated hollow vascular anastomosis stent in a sodium hydroxide ethanol solution at room temperature for 6 h.

[0063] S4. Remove the soaked primary hollow vascular anastomosis stent, repeatedly wash off excess sodium hydroxide with anhydrous ethanol, and air-dry to obtain the final hollow vascular anastomosis stent. The sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide, the sodium ions in the sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12. The 3D-printed vascular anastomosis stent is soaked in the ethanol solution containing 10% sodium hydroxide and monovalent sodium ions. The sodium ions in the sodium hydroxide ethanol solution coordinate with the carboxyl groups of the acrylic acid portion in the polymer network to form sodium salts, increasing the osmotic pressure and water absorption of the stent, and improving the self-expansion effect and speed of the vascular anastomosis stent after moisture absorption.

[0064] Example 5

[0065] This embodiment is basically the same as the first embodiment, except that:

[0066] The 3D-printed self-expanding hydrogel hollow vascular anastomosis stent in this embodiment is composed of the following materials in parts by weight: 2 parts acrylic acid, 8 parts anhydrous ethanol, 0.06 parts PEGDA, 0.04 parts light absorber, and 0.01 parts initiator. The viscosity of acrylic acid (mPa·s, 25°C) is 1.2, and the relative density (25°C, 4°C) is 1.012. PEGDA is polyethylene glycol diacrylate-200. PEGDA has a density of 1.2 g / mL at 25°C and a molecular weight of 200. The density of acrylamide is 1.35 g / cm 3 , with a melting point of 90° C. The light absorber is lemon yellow.

[0067] In addition, the preparation steps of the hollow vascular anastomosis stent based on 3D printing self-expanding hydrogel are as follows:

[0068] S1. Add 2 parts by weight of acrylic acid and 8 parts by weight of anhydrous ethanol into a container and stir clockwise for 3 minutes, let it stand for 2 minutes, and then stir counterclockwise for 3 minutes to obtain a clear solution.

[0069] S2. Add 0.06 parts by weight of PEGDA to the obtained clear solution, stir for 10 minutes, let it stand until there are no bubbles, add 0.01 parts by weight of initiator and 0.04 parts by weight of light absorber, and stir again for 10 minutes to obtain 3D printing hydrogel ink.

[0070] S3. Add the obtained 3D printing hydrogel ink into a light-curing 3D printing curing tank for printing to obtain a prefabricated hollow vascular anastomosis stent of a certain shape, and soak the obtained prefabricated hollow vascular anastomosis stent in a sodium hydroxide ethanol solution at room temperature for reaction for 6 hours.

[0071] S4. Take out the soaked primary hollow vascular anastomosis stent, repeatedly wash off the excessive sodium hydroxide with absolute ethanol, and obtain the final hollow vascular anastomosis stent after natural air drying. The sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide. The sodium ions in the sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12. The 3D printed vascular anastomosis stent is soaked in an ethanol solution containing 10% sodium hydroxide and having monovalent sodium ions. The sodium ions in the sodium hydroxide ethanol solution coordinate with the carboxyl groups of the acrylic acid part in the polymer network to form sodium salts, increasing the osmotic pressure and water absorption of the stent, and improving the self-expansion effect and speed of the vascular anastomosis stent after absorbing moisture.

[0072] Example 6

[0073] This example is basically the same as Example 1, and the difference is as follows:

[0074] The 3D printed self-expanding hydrogel hollow vascular anastomosis stent in this example is composed of the following substances in parts by weight: 2 parts of acrylamide, 8 parts of absolute ethanol, 0.5 part of PEGDA, 0.02 part of light absorbent, and 0.01 part of initiator. PEGDA is polyethylene glycol diacrylate - 200. The density of PEGDA is 1.12 g / mL at 25 °C, and the molecular weight is 200. The density of acrylamide is 1.255 g / cm 3 , and the melting point is 90 °C.

[0075] In addition, the preparation steps of the 3D printed self-expanding hydrogel hollow vascular anastomosis stent are as follows:

[0076] S1. Add 2 parts by weight of acrylamide and 8 parts by weight of absolute ethanol to a container, stir clockwise for 3 min, let stand for 2 min, and then stir counterclockwise for 3 min to obtain a clear solution. The light absorbent is a mixture of fast green and lemon yellow.

[0077] S2. Add 0.5 part by weight of PEGDA to the obtained clear solution, stir for 10 min, let stand until there are no bubbles, add 0.01 part by weight of initiator and 0.02 part by weight of light absorbent, and stir again for 10 min to obtain 3D printed hydrogel ink.

[0078] S3. Add the obtained 3D printed hydrogel ink to a photocuring 3D printing curing pool for printing to obtain a prefabricated hollow vascular anastomosis stent with a certain shape, and soak the obtained prefabricated hollow vascular anastomosis stent in a sodium hydroxide ethanol solution at room temperature for 6 h.

[0079] S4. Take out the soaked primary hollow vascular anastomosis stent, repeatedly wash off the excessive sodium hydroxide with absolute ethanol, and obtain the final hollow vascular anastomosis stent after natural air drying. The sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide. The sodium ions in the sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12. The 3D printed vascular anastomosis stent is soaked in an ethanol solution containing 10% sodium hydroxide and having monovalent sodium ions. The sodium ions in the sodium hydroxide ethanol solution coordinate with the carboxyl groups of the acrylic acid part in the polymer network to form sodium salts, increasing the osmotic pressure and water absorption of the stent, and improving the self-expansion effect and speed of the vascular anastomosis stent after absorbing moisture.

[0080] Example 7

[0081] This example is basically the same as Example 1, and the difference lies in:

[0082] The 3D printed self-expanding hydrogel hollow vascular anastomosis stent in this example is composed of the following substances in parts by weight: 2 parts of acrylamide, 8 parts of absolute ethanol, 0.5 part of PEGDA, 0.02 part of light absorbent, and 0.01 part of initiator. PEGDA is polyethylene glycol diacrylate-200. The density of PEGDA is 1.12 g / mL at 25 °C, and the molecular weight is 200. The density of acrylamide is 1.255 g / cm 3 , and the melting point is 90 °C. In this example, the stent was not reacted with the sodium hydroxide ethanol solution.

[0083] In addition, the preparation steps of the 3D printed self-expanding hydrogel hollow vascular anastomosis stent are as follows:

[0084] S1. Add 2 parts by weight of acrylamide and 8 parts by weight of absolute ethanol to a container, stir clockwise for 3 min, let stand for 2 min, and then stir counterclockwise for 3 min to obtain a clear solution. The light absorbent is a mixture of fast green and lemon yellow.

[0085] S2. Add 0.5 part by weight of PEGDA to the obtained clear solution, stir for 10 min, let stand until there are no bubbles, add 0.01 part by weight of initiator and 0.02 part by weight of light absorbent, and stir again for 10 min to obtain 3D printed hydrogel ink.

[0086] S3. Add the obtained 3D printed hydrogel ink to a photocuring 3D printing curing pool for printing to obtain a prefabricated hollow vascular anastomosis stent with a certain shape. Wash the prefabricated hollow vascular anastomosis stent repeatedly with absolute ethanol to wash off the excessive sodium hydroxide, and obtain it after natural air drying

[0087] S4. Wash the prefabricated hollow vascular anastomosis stent repeatedly with absolute ethanol to remove the excessive sodium hydroxide, and then air-dry it naturally to obtain the final hollow vascular anastomosis stent.

[0088] To illustrate the differences in mechanical properties and swelling ratios between the 3D-printed self-expandable hydrogel hollow vascular anastomosis stents prepared in Examples 1-6 of the present invention and the existing vascular anastomosis stents, the mechanical properties and swelling ratios of the 3D-printed self-expandable hydrogel hollow vascular anastomosis stents prepared in Examples 1-6 were respectively tested. During the test, the lengths, diameters, and wall thicknesses of the selected vascular anastomosis stents were the same, and the test data are shown in Table 1 below:

[0089]

[0090]

[0091] Table 1

[0092] From Table 1 above, it can be well concluded that the mechanical properties and swelling ratios of the 3D-printed self-expandable hydrogel hollow vascular anastomosis stents in each embodiment of the present application are superior to those of the existing vascular anastomosis stents. Among them, it is also concluded that the mechanical properties and swelling ratios of the 3D-printed self-expandable hydrogel hollow vascular anastomosis stent prepared in Example 1 of the present invention are superior to those of the 3D-printed self-expandable hydrogel hollow vascular anastomosis stents prepared in other embodiments and the existing vascular anastomosis stents, which also fully shows that the components and weight parts of the 3D-printed self-expandable hydrogel hollow vascular anastomosis stent in Example 1 of the present invention are the best.

[0093] Therefore, it shows that in the present invention, by setting a vascular anastomosis stent based on 3D printing and composed of hollow holes and anastomosis sleeves, the blood in the blood vessel can well nourish the wall of the vascular anastomosis stent through the hollow holes. At the same time, when suturing, the peripheral silk thread can well fix the blood vessel on the vascular anastomosis stent through the hollow holes, making the fixation of the peripheral silk thread more convenient. At the same time, by using a 3D-printed self-expandable hydrogel composed of acrylic acid, acrylamide, absolute ethanol, PEGDA, and an initiator, the cooperation of acrylic acid and acrylamide in the 3D-printed self-expandable hydrogel can achieve high-precision printing, and by introducing ionic bonds, it can promote the self-expansion of the vascular anastomosis stent after absorbing moisture. Thus, the present invention well solves the problem that the existing vascular anastomosis stent cannot achieve self-expansion, resulting in partial gaps between the polyethylene PE catheter and the blood vessel after suturing, causing blood coagulation in the blood vessel.

[0094] As described above, the present invention can be well realized.

Claims

1. A hollow vascular anastomosis stent based on 3D-printed self-expandable hydrogel, characterized in that, The hollow blood vessel anastomosis stent includes an anastomosis branch sleeve (1) and a number of irregular hollow holes (2) distributed on the anastomosis branch sleeve (1); the hollow holes (2) are distributed in a spiral shape on the anastomosis branch sleeve (1), making the sleeve wall of the anastomosis branch sleeve (1) present a spiral surface. The 3D printed self-expandable hydrogel hollow blood vessel anastomosis stent is composed of the following substances in parts by weight: 0.5 - 2 parts of acrylic acid, 0.5 - 2 parts of acrylamide, 6 - 8 parts of absolute ethanol, 0.06 - 1 part of PEGDA, 0.01 - 0.04 part of light absorbent, and 0.01 - 1 part of initiator. The mass ratio of the acrylic acid to the acrylamide is 1:1 or 1:3 or 3:1; among them, the viscosity of acrylic acid (mPa·s, 25°C): 1.2~(mPa·s, 25°C): 1.3, relative density (25°C, 4°C): 1.012~(25°C, 4°C): 1.

2. The PEGDA is polyethylene glycol diacrylate - 200; the density of PEGDA is 1.12 g / mL at 25 °C~1.2 g / mL at 25 °C, and the molecular weight is 200.

2. The hollow vascular anastomosis stent based on 3D printed self-expanding hydrogel according to claim 1, wherein The density of the acrylamide is 1.255 g / cm 3 ~1.35 g / cm 3 , and the melting point is 90 °C.

3. The hollow vascular anastomosis stent based on 3D printed self-expanding hydrogel according to claim 2, wherein The initiator is organic blue light phenyl(2,4,6 - trimethylbenzoyl) lithium phosphate, and the molecular weight of this initiator is 294.2, with a purity ≥98.5%.

4. The self-expandable hollow vascular anastomosis stent based on 3D-printed hydrogel according to claim 3, wherein The light absorbent is one or a mixture of several of curcumin, fast green, lemon yellow, and sudan.

5. The hollow vascular anastomosis stent based on 3D printed self-expandable hydrogel according to any one of claims 1 to 4, characterized in that, The preparation steps of the hollow blood vessel anastomosis stent based on 3D printed self-expandable hydrogel are as follows: S1. Add 0.5 - 2 parts by weight of acrylic acid, 0.5 - 2 parts by weight of acrylamide, and 6 - 8 parts by weight of absolute ethanol into a container, stir clockwise for 3 - 6 min, then let it stand for 2 min, and then stir counterclockwise for 3 - 6 min to obtain a clear solution. S2. Add 0.06 - 1 part by weight of PEGDA to the obtained clear solution, stir for 5 - 10 min, then let it stand until there are no bubbles, add 0.01 - 1 part by weight of initiator and 0.01 - 0.04 part by weight of light absorbent, and stir again for 5 - 15 min to obtain 3D printed hydrogel ink. S3. Add the obtained 3D printed hydrogel ink into a photo-curing 3D printing curing pool for printing to obtain a prefabricated hollow blood vessel anastomosis stent with a certain shape, and immerse the obtained prefabricated hollow blood vessel anastomosis stent in a sodium hydroxide ethanol solution at room temperature for 6 h. S4. Take out the soaked primary hollow blood vessel anastomosis stent, repeatedly wash off the excessive sodium hydroxide with absolute ethanol, and naturally air-dry to obtain the final hollow blood vessel anastomosis stent.

6. The hollow vascular anastomosis stent based on 3D printed self-expanding hydrogel according to claim 5, characterized in that, The sodium hydroxide ethanol solution is an ethanol solution containing 10% sodium hydroxide, the sodium ions in this sodium hydroxide ethanol solution are monovalent sodium ions, and the pH value is 12.

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