Preparation method of an easily sutured woven artificial blood vessel

Abstract

The present invention belongs to the technical field of biomedical material manufacturing, and particularly relates to a preparation method of an easily sutureable braided artificial blood vessel. In the present invention, untwisted polyester filaments are used as the core yarn, and water-soluble vinylon is used as the covering yarn to make a polyester covered yarn; then, the water-soluble vinylon filaments are dissolved by water washing, and then coating, densification treatment, and re-coating are carried out to obtain an easily sutureable braided artificial blood vessel. The easily sutureable braided artificial blood vessel prepared by the above method is soft and fluffy, reduces the difficulty of surgical suture, and is beneficial to the attachment and growth of endothelial cells. The two coatings and densification treatment increase the coating fastness and uniformity, and effectively reduce the permeability of the easily sutureable braided artificial blood vessel.

Description

Technical Field

[0001] This invention patent relates to the technical field of biomedical material manufacturing, and specifically relates to a preparation method of an easily suturable braided artificial blood vessel. Background Art

[0002] The coating impermeability and suturability of artificial blood vessels are key evaluation indicators for the success of surgery. Currently, in order to increase the density of the tube blank and improve the impermeability performance, warp yarns with a fineness of 30 - 150D yarns are selected, and high-density weaving technology is adopted. In order to enable the weaving to proceed smoothly, sizing is applied to the warp yarns. However, the ultra-high density makes it difficult to completely remove the sizing agent, which affects the biocompatibility of the blood vessel products. To solve this problem, currently, the domestic research and development of braided blood vessels basically uses twisted yarns for weaving, and then through a series of treatments, an artificial blood vessel is finally obtained. However, the problem is that it has a relatively hard hand feeling, and it is relatively difficult for the suture needle to enter and exit, which affects the surgical operation. Secondly, the highly cohesive twisted yarns also affect the coating effect of the pre-coagulation coating, making it difficult for the coating to penetrate between fibers, and it is very easy to have the "sweating" phenomenon during surgery, reducing the success rate of the surgery. Summary of the Invention

[0003] To solve the problems existing in the above-mentioned prior art, the present invention provides a preparation method of an easily suturable braided artificial blood vessel. The method uses a covered yarn of untwisted polyester filament coated with water-soluble vinylon filament to weave an easily suturable braided artificial blood vessel tube blank. After washing with water to remove the vinylon, then coating, densification treatment, texturing, and re-coating, the obtained easily suturable braided artificial blood vessel is soft and fluffy, reducing the difficulty of surgical suture and being beneficial to the attachment and growth of endothelial cells. The two coatings and densification treatment increase the coating fastness and uniformity, effectively reducing the permeability of the easily suturable braided artificial blood vessel.

[0004] To achieve the above technical objectives, the technical solution adopted by the present invention for a preparation method of an easily suturable braided artificial blood vessel is as follows:

[0005] (1) Using 50 - 120D FDY untwisted polyester filament as the core yarn and high-temperature water-soluble vinylon filament as the covered yarn, the vinylon filament is evenly coated on the surface of the polyester filament through a covering device to obtain a polyester covered yarn. The high-temperature water-soluble vinylon filament is a filament that can dissolve in water at 90°C, and the fineness of the vinylon filament is 50 - 100D. During weaving, the vinylon plays a protective role for the untwisted polyester, preventing fiber fuzzing and yarn breakage, enabling the weaving to proceed smoothly;

[0006] (2) Weaving the polyester covered yarn obtained in step (1) through an artificial blood vessel weaving device to obtain a tube blank.

[0007] (3) Use pure water washing to dissolve the vinylon filaments on the green tube obtained in step (2). The bath ratio is 1:30. Under the temperature condition of 95 - 100 °C, wash with hot water twice, each time for 10 - 30 min. Then wash with warm water at 60 - 70 °C for 1 - 2 times, and then wash with normal temperature water for 1 - 2 times. Repeat the whole washing process 2 - 3 times and then dry at 60 °C.

[0008] (4) Use a polycarbonate-based polyurethane solution with a weight fraction of 0.5 - 3% as coating solution I, and use the dip coating method to coat the green tube obtained in step (3). After coating, dry at a temperature of 40 - 80 °C for 60 - 90 min. The fibers between the green tubes from which the vinylon filaments are removed are relatively loose, which is conducive to the coating solution I infiltrating each fiber.

[0009] (5) Put the green tube obtained in step (4) on a hollow tube with a corresponding size, and treat it with dry hot air at 180 - 220 °C for 120 - 500 s to make the polyester filaments shrink at high temperature for densification treatment. After densification treatment, the fiber bundles and fibers tightly hold each other, increasing the density of the green tube, reducing the porosity, and wrapping the coating in it, which is beneficial to improving the coating fastness and coating uniformity.

[0010] (6) Put the coated green tube obtained in step (5) on a corresponding size texturing die for texturing to obtain a textured green tube.

[0011] (7) Coat the textured green tube obtained in step (6) with coating solution II. The coating method is one of perfusion and dip coating. After coating, dry at a temperature of 37 - 60 °C for 2 - 3 h to prepare an easily sutureable braided artificial blood vessel.

[0012] The effective component of the coating solution II is one of gelatin and collagen, with a weight fraction of 0.5 - 10%. The gelatin is bovine bone gelatin with a bloom value of 200 - 300 Bloomg, and the collagen is type I collagen.

[0013] The coating solution II also contains a toughening agent and a crosslinking agent. The toughening agent is one of glycerol and polyethylene glycol. The purity of glycerol is 99%, the molecular weight of polyethylene glycol is 700 - 2000, and the weight fraction is 1 - 10%. The crosslinking agent is one of formaldehyde, glutaraldehyde, and genipin, and the weight fraction is 0.04 - 0.5%.

[0014] Beneficial effects

[0015] The preparation method of the easily sutureable braided artificial blood vessel described in the present invention uses vinylon-coated polyester filament as the warp yarn, which can greatly reduce the phenomena of fluffing and filament breakage of untwisted polyester filament during the weaving process. After being washed with water, an untwisted artificial blood vessel blank tube is obtained. The blank tube woven in this way is soft and fluffy. The softness can reduce the difficulty of surgical suture, and the fluffiness is conducive to the attachment and growth of endothelial cells. The active ingredient of Coating Solution I is polyurethane. The polyurethane material has a macroscopically smooth and microscopically phase-separated structure. Coating with it endows the wall of the artificial blood vessel with excellent anticoagulant performance. After densification treatment, the fiber shrinks to tightly wrap Coating Solution I between the fibers, which can increase the coating fastness and uniformity. Further coating the patterned blank tube can improve the biocompatibility of the artificial blood vessel and further effectively reduce the permeability of the artificial blood vessel. Detailed implementation mode

[0016] To further understand the present invention, the present invention will be described below in conjunction with embodiments. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0017] The easily sutureable braided artificial blood vessels prepared in the examples and comparative examples were tested for overall water permeability and puncture strength for comparison. The overall water permeability was detected according to the method of 8.7.2.1.2 Overall water permeability / leakage in YY / T 0500-2021 Cardiovascular implants - Vascular prostheses - Tubular vascular grafts and vascular patches. The puncture strength was detected according to the test method in GB / T 23318—2009 Determination of puncture strength of textiles. The test was carried out using punch A. For the artificial blood vessels obtained under the same warp and weft density and the same coating method, a small acupuncture result represents good softness of the artificial blood vessel, smooth needle insertion, good sutureability, and reduced suture difficulty during clinical surgical use.

[0018] Example 1

[0019] A preparation method of an easily sutureable braided artificial blood vessel includes the following steps:

[0020] (1) Select 120D FDY untwisted polyester filament as the core yarn, and select 100D water-soluble vinylon filament as the coating yarn. The vinylon filament is evenly coated on the surface of the polyester filament through a long fiber doubling twister to obtain a polyester-coated yarn, and the selected water-soluble vinylon filament is soluble at 90°C.

[0021] (2) Use the polyester-coated yarn obtained in step (1) as the warp yarn, and weave it through an artificial blood vessel weaving device to obtain a blank tube.

[0022] (3) The green tube obtained in step (2) is washed twice with pure water at a bath ratio of 1:30 at a temperature of 95 - 100 °C for 30 minutes each time, then washed twice with warm water at 60 - 70 °C and twice with normal temperature water. The entire water washing process is repeated 3 times to completely dissolve the vinylon on the braided green tube. Finally, it is dried at 60 °C to obtain a twistless polyester braided green tube.

[0023] (4) Using biocompatible DMF as a solvent, a polycarbonate-based polyurethane solution with a weight fraction of 3% is stirred and dissolved at 90 °C as coating solution I for 3 hours to ensure complete dissolution of the polycarbonate-based polyurethane. The coating is carried out by the dip coating method and dried at 80 °C for 90 minutes to obtain a preliminarily coated braided green tube.

[0024] (5) The preliminarily coated braided green tube obtained in step (4) is sleeved onto a hollow tube, and treated with 180 °C dry hot air for 500 s to cause the polyester filaments to shrink at high temperature, perform densification treatment, increase the density of the green tube, and reduce the porosity to obtain a coated braided green tube.

[0025] (6) The coated braided green tube obtained in step (5) is sleeved onto a texturing die for texturing to obtain a textured green tube.

[0026] (7) Prepare a 0.5% type I collagen coating solution II, add 1% glycerol with a purity of 99% and 0.5% formaldehyde to the coating solution, and coat the textured green tube obtained in step (6) by the perfusion coating method. After coating, it is dried at 37 °C for 2 hours to prepare an easily sutureable braided artificial blood vessel.

[0027] Comparative Example 1

[0028] A method for preparing a braided artificial blood vessel, comprising the following steps:

[0029] (1) Select 120D FDY twistless polyester filaments as the core yarn, and twist the polyester filaments at 400 turns / m through a long fiber doubling twister.

[0030] (2) Use the twisted polyester filaments obtained in step (1) as the warp yarns, and weave through an artificial blood vessel weaving device to obtain a green tube.

[0031] (3) According to steps (4), (5), (6), and (7) of the preparation method of an easily sutureable braided artificial blood vessel in Example 1, a braided artificial blood vessel is prepared.

[0032] Example 2

[0033] A method for preparing an easily sutureable braided artificial blood vessel, comprising the following steps:

[0034] (1) Select 80D FDY untwisted polyester filament as the core yarn, and select 80D water-soluble vinylon filament as the covering yarn. Uniformly cover the vinylon filament on the surface of the polyester filament through a long fiber double twister to obtain a polyester covered yarn. The selected water-soluble vinylon filament is soluble at 90°C.

[0035] (2) Use the polyester covered yarn obtained in step (1) as the warp yarn, and weave it through a vascular knitting device to obtain a blank tube.

[0036] (3) For the blank tube obtained in step (2), use pure water, with a bath ratio of 1:30, wash it twice with hot water at a temperature of 95 - 100°C for 20 minutes each time, then wash it once with warm water at 60 - 70°C, and then wash it once with normal temperature water. Repeat the entire water washing process 3 times to completely dissolve the vinylon on the knitted blank tube. Finally, dry it at 60°C to obtain an untwisted polyester knitted blank tube.

[0037] (4) Use biocompatible DMF as the solvent, stir and dissolve a 0.5% by weight polycarbonate-based polyurethane solution at 90°C as coating solution I for 2 hours to ensure complete dissolution of the polycarbonate-based polyurethane. Apply the coating by the dip coating method, and dry it at 40°C for 60 minutes to obtain a preliminarily coated knitted blank tube.

[0038] (5) Put the preliminarily coated knitted blank tube obtained in step (4) onto a hollow tube, and treat it with dry hot air at 200°C for 300 s to make the polyester filament shrink at high temperature for densification treatment, increase the density of the blank tube, and reduce the porosity to obtain a coated knitted blank tube.

[0039] (6) Put the coated knitted blank tube obtained in step (5) onto a texturing die for texturing to obtain a textured blank tube.

[0040] (7) Prepare a 10% dynamic value 250 Bloomg bovine bone gelatin coating solution II, and add 10% polyethylene glycol with a molecular weight of 2000 and 0.04% glutaraldehyde to the coating solution. Coat the textured blank tube obtained in step (6) by the perfusion coating method, and dry it at 60°C for 3 hours to obtain an easily suture knitted artificial blood vessel.

[0041] Comparative Example 2

[0042] A method for preparing a knitted artificial blood vessel, comprising the following steps:

[0043] (1) Select 100D FDY untwisted polyester filament as the core yarn, and twist the polyester filament at 400 turns / m through a long fiber double twister.

[0044] (2) Use the twisted polyester filament obtained in step (1) as the warp yarn, and weave a green tube through an artificial blood vessel weaving device.

[0045] (3) According to steps (4), (5), (6), and (7) of the preparation method of an easily sutureable woven artificial blood vessel in Example 2, an woven artificial blood vessel is prepared.

[0046] Example 3

[0047] A preparation method of an easily sutureable woven artificial blood vessel, comprising the following steps:

[0048] (1) Select 50D FDY untwisted polyester filament as the core yarn, and select 50D water-soluble vinylon filament as the covering yarn. Uniformly cover the vinylon filament on the surface of the polyester filament through a long fiber doubling twister to obtain a polyester covered yarn, and the selected water-soluble vinylon filament is soluble at 90 °C.

[0049] (2) Use the polyester covered yarn obtained in step (1) as the warp yarn, and weave a green tube through an artificial blood vessel weaving device.

[0050] (3) For the green tube obtained in step (2), use pure water, with a bath ratio of 1:30, wash twice with hot water at a temperature of 95-100 °C for 10 minutes each time, then wash once with warm water at 60-70 °C and once with normal temperature water, repeat the entire water washing process 2 times to completely dissolve the vinylon on the woven green tube, and finally dry at 60 °C to obtain an untwisted polyester woven green tube.

[0051] (4) Use biocompatible DMF as the solvent, stir and dissolve a polycarbonate-based polyurethane solution with a weight fraction of 1.5% at 90 °C as coating solution I for 3 hours to ensure complete dissolution of the polycarbonate-based polyurethane. Coating is carried out by the dip coating method, and after coating, it is dried at 60 °C for 60 minutes to obtain a preliminarily coated woven green tube.

[0052] (5) Put the preliminarily coated woven green tube obtained in step (4) onto a hollow tube, and treat it with dry hot air at 220 °C for 120 s to make the polyester filament shrink at high temperature for densification treatment, increase the density of the green tube, and reduce the porosity to obtain a coated woven green tube.

[0053] ((6) Put the coated woven green tube obtained in step (5) onto a texturing mold for texturing to obtain a textured green tube.

[0054] (7) Prepare a 5% type I collagen coating solution II, add 5% glycerol with a purity of 99% and 0.3% genipin to the coating solution, and coat the patterned blank tube obtained in step (6) by perfusion coating. After coating, dry it at a temperature of 50°C for 3 hours to obtain an easily sutureable braided artificial blood vessel.

[0055] Comparative Example 3

[0056] A method for preparing a braided artificial blood vessel, comprising the following steps:

[0057] (1) Select 100D FDY untwisted polyester filament as the core yarn, and twist the polyester filament at 400 turns / m through a long fiber doubling and twisting machine.

[0058] (2) Use the twisted polyester filament obtained in step (1) as the warp yarn, and weave it through an artificial blood vessel weaving device to obtain a blank tube.

[0059] (3) According to steps (4), (5), (6), and (7) of the preparation method of an easily sutureable braided artificial blood vessel in Example 3, prepare a braided artificial blood vessel.

[0060] Overall water permeability test results at 120 mmHg: Before coating, the easily sutureable braided artificial blood vessels in Examples 1-3 and Comparative Examples 1-3 leaked severely, and the leakage volume was as high as 271.58 ml / cm 2 ·min. After coating, the leakage volume of the easily sutureable braided artificial blood vessels in Examples 1-3 and Comparative Examples 1-3 was 0.

[0061] Puncture strength test results: The puncture strengths of Examples 1-3 were all less than those of Comparative Examples 1-3 under the same warp and weft density and the same coating method, indicating that the examples improved the softness of the artificial blood vessel and reduced the suture difficulty during clinical surgery.

[0062] Table 1 Comparison of puncture strengths between the examples and comparative examples of the present invention

[0063] Example 1 Comparative Example 1 Example 2 Comparative Example 2 Example 3 Comparative Example 3 Puncture strength (N) 18.2 21.5 22.1 24.7 22.4 24.9

Claims

1. A preparation method of a suture - friendly woven artificial blood vessel, characterized in that, It includes the following steps: (1) Using untwisted polyester filament as the core yarn and water-soluble vinylon filament as the covering yarn, and evenly covering the vinylon filament on the surface of the polyester filament through a covering device to produce a polyester covered yarn; the water-soluble vinylon filament is a high-temperature water-soluble vinylon, which dissolves in water at 90 °C; (2) Weaving the polyester covered yarn obtained in step (1) into a green tube through an artificial blood vessel weaving device; (3) For the green tube obtained in step (2), use pure water, with a bath ratio of 1:30, at a temperature of 95 - 100 °C, wash it twice with hot water, each time for 10 - 30 min, then wash it 1 - 2 times with warm water at 60 - 70 °C, and then wash it 1 - 2 times with normal temperature water; repeat the whole water washing process 2 - 3 times to dissolve the water-soluble vinylon filament, and then dry it at 60 °C; (4) Coating the green tube obtained in step (3) with coating solution I, the coating method is dip coating, and dry it at a temperature of 40 - 80 °C for 60 - 90 min after coating; the effective component of the coating solution I is polycarbonate-based polyurethane, with a weight fraction of 0.5 - 3%; (5) Put the green tube obtained in step (4) on a hollow tube with a corresponding size, and treat it with dry hot air at 180 - 220 °C for 120 - 500 s to make the polyester filament shrink at high temperature, carry out densification treatment, increase the density of the green tube, and reduce the porosity; (6) Put the green tube obtained in step (5) on a texturing die with a corresponding size for texturing to obtain a textured green tube; (7) Infuse or dip coat the textured green tube obtained in step (6) with coating solution II, and dry it at a temperature of 37 - 60 °C for 2 - 3 h after coating.

2. The preparation method of the easily sutureable woven artificial blood vessel according to claim 1, characterized in that, The untwisted polyester filament described in step (1) is FDY yarn, with a fineness of 50 - 120 D, and the fineness of the water-soluble vinylon filament is 50 - 100 D.

3. The preparation method of the easily sutured woven artificial blood vessel according to claim 1, wherein, The effective component of the coating solution II described in step (7) is one of gelatin and collagen, with a weight fraction of 0.5 - 10%.

4. The preparation method of the easily sutureable woven artificial blood vessel according to claim 3, characterized in that, The gelatin is bovine bone gelatin with a bloom value of 200 - 300 Bloomg, and the collagen is type I collagen.

5. The preparation method of the easily sutureable woven artificial blood vessel according to claim 3, wherein, In the coating solution II described in step (7), a toughening agent and a cross-linking agent are also added. The toughening agent is one of glycerol and polyethylene glycol, with a weight fraction of 1 - 10%; the cross-linking agent is one of formaldehyde, glutaraldehyde, and genipin, with a weight fraction of 0.04 - 0.5%.

6. The preparation method of the easily sutured woven artificial blood vessel according to claim 5, wherein, The purity of the glycerol is 99%, and the molecular weight of the polyethylene glycol is 700 - 2000.