Tissue engineering tubular dressing as well as preparation method and application thereof

Abstract

The invention discloses a tissue engineering tubular dressing and a preparation method and application thereof.The preparation method of the tissue engineering tubular dressing comprises the steps that a degradable material is adopted to form a tubular supporting layer, pretreated animal tissue is arranged on the tubular supporting layer, and a biodegradable tubular material is obtained; the animal tissue pretreatment comprises decellularization through a chemical reagent, the decellularization temperature is 25-37 DEG C, the concentration of decellularization liquid is 0.1-800 mmol / L, the decellularization treatment time is 1-48 h, and the decellularization liquid is replaced once every 2-12 h; the obtained biodegradable tubular material is treated with solutions containing growth factors and a hemostatic material, the concentration of the growth factors is 0.1-10 ng / m < l >, the treatment time of the growth factors is 0.5-12 h, the treatment temperature is 25-37 DEG C, the concentration of the hemostatic material is 0.1-10 mg / m < l >, the treatment time of the hemostatic material is 0.5-12 h, and the treatment temperature of the hemostatic material is 25-37 DEG C; and drying and sterilizing the treated biodegradable tubular material to obtain the tissue engineering tubular dressing.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a tissue engineering tubular dressing and a preparation method and application thereof. Background Art

[0002] Diabetes is a common chronic metabolic disease in clinical practice, with many complications and a rapid growth trend in incidence. According to the data from the International Diabetes Federation, the global prevalence of diabetes (20-79 years old) in 2021 is estimated to be 10.5% (536.6 million people), and 1 in 10 adults has diabetes, and this number will continue to grow at a faster rate in the future. Diabetic foot ulcer is a stubborn multifactorial disease and one of the most serious complications of diabetes. It is a foot infection, ulcer or tissue destruction accompanied by diabetic peripheral neuropathy and peripheral vascular disease. Studies have found that the probability of diabetic foot in diabetic patients during their lifetime is about 19-34%, and diabetic foot is a chronic wound. These wounds are usually difficult to heal, which will further lead to amputation and even death. The recurrence rate of ulcers after diabetic foot wound healing is as high as 40%, and the mortality rate after amputation is more than 70% within 5 years. The treatment cycle is very long. Patients not only suffer great pain physically, but also face great psychological and social pressure. Therefore, there is an urgent need for a dressing that promotes diabetic foot wound healing, reduces wound infection, and promotes tissue regeneration in the affected area to relieve the pain of diabetic patients.

[0003] There are many classification systems for diabetic foot ulcers, and the most commonly used ones are the Wagner classification and the Texas classification. The Wagner classification divides the wound surface into grades 0-5 according to the area and depth of the ulcer. Because it is simple and practical, it is widely used in clinical work. The Texas classification is divided into grades 0-3 according to the degree of foot ulcers. Grade 0: history of foot ulcers; Grade 1: superficial ulcers; Grade 2: ulcers involving tendons; Grade 3: ulcers involving bones and joints. At the same time, it is divided into stages A, B, C, and D according to whether there is infection and (or) ischemia in the wound surface: Stage A: no ischemia and infection; Stage B: combined infection; Stage C: combined ischemia; Stage D: coexistence of infection and ischemia. Compared with the traditional staging and grading method, the guidelines released by IWGDF in 2023 proposed that the wound size, ischemia and infection degree (WFI) scoring system based on the three main factors of wound, ischemia, and foot infection can be considered to stratify and grade diabetic foot patients. At the same time, IWGDF recommends that scholars and medical staff use the SINBAD system to grade and score by distinguishing the foot location, degree of ischemia, neuropathy, bacterial infection, ulcer area and depth, so as to facilitate the comparison of the treatment and prognosis of DFU patients in medical institutions around the world in the future. The classification of diabetic foot ulcers can better guide the impact of dressings, thereby more effectively promoting the healing of ulcers.

[0004] As a temporary skin substitute on the surface of the ulcer, dressings play an important role in controlling infection, the growth and healing of nearby ulcers, etc. Regarding the treatment of diabetic foot ulcers, dressings are conducive to the formation of a closed state of the ulcer, which is beneficial to maintaining the skin's barrier function, normal body temperature regulation, water balance and sensory function.

[0005] The ideal new dressing should meet the multiple needs of diabetic foot ulcers: First, keep the ulcer base moist: a moist environment is conducive to the formation of granulation tissue, ulcer autolysis and angiogenesis, while promoting faster migration of epidermal cells at the base of the skin and promoting ulcer healing. Second, absorb exudate: prevent the skin around the ulcer from continuous contact with exudate

[0006] Or infiltrated by exudate, it protects the skin around the ulcer. Third, promote cell and angiogenesis: the dressing can keep the ulcer relatively closed and moist, form low oxygen tension on the surface of the ulcer, stimulate the release of growth factors, promote cell proliferation, accelerate the formation of new blood vessels, and also relieve the pain of the ulcer. Fourth, reduce secondary damage: the dressing does not adhere to the ulcer, and can avoid damaging the new granulation tissue when torn off, protect the peripheral nerves, and relieve pain. Fifth, antibacterial effect: the new dressing can isolate microorganisms in the external environment, reduce the probability of re-infection of the ulcer, and even improve the bactericidal ability of the wound. Sixth, it can play a certain hemostatic role on the surface of bleeding wounds.

[0007] Currently, new dressings that are on the market or under development include hydrogel dressings, hydrocolloid dressings, foam dressings, film dressings, silver ion dressings, alginate dressings, and water-based fibrous dressings. Although the aforementioned dressings can relieve patients' pain and have certain effects in promoting healing and anti-inflammatory, there is currently no dressing that can meet all the characteristics of an ideal dressing. Summary of the invention

[0008] The main purpose of the present invention is to provide a tissue engineering tubular dressing and a preparation method and application thereof, aiming to solve the above problems.

[0009] To achieve the above object, the present invention provides a method for preparing a tissue engineering tubular dressing, the method comprising:

[0010] A tubular support layer is formed by using a degradable material, and a pretreated animal tissue is arranged on the tubular support layer to obtain a biodegradable tubular material, wherein the animal tissue pretreatment includes decellularization by chemical reagents, the decellularization temperature is 25-37°C, the concentration of the decellularization liquid is 0.1-800 mmol / L, the decellularization treatment time is 1-48 hours, and the decellularization liquid is replaced every 2-12 hours;

[0011] The obtained biodegradable tubular material is treated with a solution containing a growth factor and a hemostatic material, wherein the concentration of the growth factor is 0.1-10 ng / ml, the growth factor treatment time is 0.5-12 h, the treatment temperature is 25-37° C., the concentration of the hemostatic material is 0.1-10 mg / ml, the hemostatic material treatment time is 0.5-12 h, and the hemostatic material treatment temperature is 25-37° C.;

[0012] The treated biodegradable tubular material is dried and sterilized to obtain a tissue engineering tubular dressing.

[0013] Preferably, in the preparation method of the tissue engineering tubular dressing, the tubular support layer is formed by using a degradable material, and the tubular support layer is provided with a pretreated animal tissue. In the step of obtaining the biodegradable tubular material, the tubular support layer is prepared by using an electrospinning material, and the filament diameter of the electrospinning material is 50nm-500nm.

[0014] Preferably, in the method for preparing the tissue engineering tubular dressing, the tubular support layer is formed by using a degradable material, and the tubular support layer is provided with pretreated animal tissue. In the step of obtaining the biodegradable tubular material, the pretreatment chemical reagents include 0.01 to 500 mmol / L of ionic detergents and non-ionic detergents.

[0015] Preferably, in the method for preparing the tissue engineering tubular dressing, the chemical reagent is a mixture of a nonionic detergent and a zwitterionic detergent;

[0016] Wherein, the nonionic detergent includes one or more of polyoxyethylene fatty amine, polyoxyethylene amide, alkylphenol polyoxyethylene ether, monoglyceride of fatty acid, pentaerythritol fatty acid ester, sorbitan fatty acid ester, fatty acid diethanolamide, amine oxide and alkyl polyglycoside;

[0017] The zwitterionic detergent is one or more of decyl sulfobetaine, lauryl sulfobetaine, myristoyl sulfobetaine, palmityl sulfobetaine, and octyl sulfobetaine.

[0018] Preferably, in the preparation method of the tissue engineering tubular dressing, the obtained biodegradable tubular material is treated with a solution containing growth factors and hemostatic materials, respectively, and the growth factor is one or more of EGF, TGFα, TGFβ, αFGF, βFGF, IGF-I, I FG-II, and NGF;

[0019] The hemostatic material is one or more of gelatin, oxidized cellulose, collagen, thrombin, fibrinogen, coagulation factor, and microporous polysaccharide.

[0020] Preferably, in the preparation method of the tissue engineering tubular dressing, in the step of drying and sterilizing the treated biodegradable tubular material to obtain the tissue engineering tubular dressing, the drying method is drying or cooling, and the water content after drying is less than 50%;

[0021] Among them, the drying temperature is 20-35°C and the drying time is 4-72h;

[0022] Freeze drying temperature 0℃--80℃, time 4-72h.

[0023] Preferably, in the method for preparing the tissue engineering tubular dressing, the biodegradable material is used to form a tubular support layer, and the pretreated animal tissue is provided on the tubular support layer to obtain a biodegradable tubular material.

[0024] The animal tissue is one or more of small intestinal submucosa, mesenteric artery, rectal artery, trachea, ureter, esophagus, epidermis, connective tissue, and adipose tissue;

[0025] The animal tissue is from cattle, sheep, dog, rabbit, horse, or pig;

[0026] The biodegradable material is one or more of polylactic acid, poly(lactide-glycolide) copolymer, polyvinyl alcohol, polycaprolactone, polyurethane, polyglycerol sebacate, polyanhydride, polyorthoester, polyphosphazene, collagen, gelatin, chitin, hyaluronic acid, and cellulose.

[0027] Preferably, in the preparation method of the tissue engineering tubular dressing, the obtained biodegradable tubular material is treated with solutions containing growth factors and hemostatic materials, wherein the growth factor preparation solution is one or more combinations of physiological saline, PBS, bovine serum, and cell culture medium.

[0028] In order to achieve the above object, the present invention further provides a tissue engineering tubular dressing, which is prepared by the above-mentioned method for preparing the tissue engineering tubular dressing.

[0029] In order to achieve the above objectives, the present invention also provides an application of the above tissue engineering tubular dressing, wherein the tissue engineering tubular dressing is used for deep wounds, diabetic ulcer wounds, bedsores, venous ulcers, chronic vascular ulcers, diabetic ulcers, traumatic wounds, and surgical wounds.

[0030] The present invention has at least the following beneficial effects:

[0031] The preparation method of the tissue engineering tubular dressing provided by the present invention comprises the following steps: using a degradable material to form a tubular support layer, on which a pretreated animal tissue is arranged, to obtain a biodegradable tubular material, wherein the animal tissue pretreatment comprises decellularization by chemical reagents, the decellularization temperature is 25-37°C, and the concentration of the decellularization liquid is 0.1-800 mmol / l. l / L, the decellularization treatment time is 1-48h, and the decellularization liquid is replaced every 2-12h; the obtained biodegradable tubular material is treated with solutions containing growth factors and hemostatic materials respectively, wherein the concentration of the growth factor is 0.1-10ng / ml, the growth factor treatment time is 0.5-12h, the treatment temperature is 25-37°C, the concentration of the hemostatic material is 0.1-10mg / ml, the hemostatic material treatment time is 0.5-12h, and the hemostatic material treatment temperature is 25-37°C; the treated biodegradable tubular material is dried and sterilized to obtain a tissue engineering tubular dressing, wherein the biodegradable tubular material obtained in this way has a liquid absorption capacity greater than 200mg / g, an in vitro degradable performance test shows that the weight loss rate in one month is greater than 50%, and the tensile strength is greater than 0.6N.

[0032] Furthermore, the degradable tubular dressing completely degrades in vivo within 1-18 months.

[0033] Furthermore, the tissue engineering tubular dressing provided by the present invention adopts biodegradable materials that are treated with growth factors and coagulation materials. When used on the affected area, it can not only maintain a moist environment at the ulcer, but also absorb exudate. The dressing promotes the regeneration of cells and blood vessels at the affected area due to its biodegradable and porous structure, while preventing adhesion of the ulcer and having a hemostatic effect. It is an ideal dressing for patients with diabetic foot.

[0034] Furthermore, the tissue engineering tubular dressing obtained by the preparation method of the tissue engineering tubular dressing provided by the present invention can maintain a moist environment at the ulcer base; can absorb exudate; promote cell and angiogenesis; can reduce secondary damage; has antibacterial effect; and can play a certain hemostatic role on the surface of bleeding wounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of a process of one embodiment of a method for preparing a tissue engineering tubular dressing provided by the present invention;

[0037] Figure 2 This is a physical picture of the degradable tubular dressing of Example 1 of the present invention;

[0038] Figure 3 This is a physical picture of the polymer stent according to Example 2 of the present invention;

[0039] Figure 4a , Figure 4b The inner surface of the polymer stent in Example 2 of the present invention is magnified 1000 times and 10000 times by SEM;

[0040] Figure 5a , Figure 5b The SEM images of the outer surface and inner surface of the polymer stent in Example 2 of the present invention are magnified 1000 times and 10000 times;

[0041] Figure 6 This is a SEM cross-section of the polymer stent in Example 2 of the present invention magnified 200 times.

[0042] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0044] Figure 1 The schematic diagram of the preparation method of the tissue engineering tubular dressing of the present invention is shown. Figure 1In step S100, the animal tissue is pretreated. The animal tissue is selected from the group consisting of small intestinal submucosa, mesenteric artery, rectal artery, trachea, ureter, esophagus, epidermis, connective tissue, and adipose tissue. The animal tissue may be one or more of small intestinal submucosa, mesenteric artery, rectal artery, trachea, ureter, esophagus, epidermis, connective tissue, and adipose tissue. The animal tissue is from one or more of cattle, sheep, dogs, rabbits, horses, and pigs.

[0045] The pretreatment chemical reagent includes 0.01 to 500 mmol / L of ionic detergent and non-ionic detergent. The chemical reagent is a mixture of non-ionic detergent and zwitterionic detergent. The concentration of ionic detergent and non-ionic detergent can also be 1 mmol / L, 50 mmol / L, 100 mmol / L, 200 mmol / L, or 300 mmol / L.

[0046] Wherein, the nonionic detergent includes one or more of polyoxyethylene fatty amine, polyoxyethylene amide, alkylphenol polyoxyethylene ether, monoglyceride of fatty acid, pentaerythritol fatty acid ester, sorbitan fatty acid ester, fatty acid diethanolamide, amine oxide and alkyl polyglycoside;

[0047] The zwitterionic detergent is one or more of decyl sulfobetaine, lauryl sulfobetaine, myristoyl sulfobetaine, palmityl sulfobetaine, and octyl sulfobetaine.

[0048] Specifically, the animal tissue is decellularized using chemical reagents, the decellularization temperature is 25-37°C, the concentration of the decellularization liquid is 0.1-800mmo l / L, the decellularization treatment time is 1-48h, and the decellularization liquid is replaced every 2-12h. The decellularization temperature can also be 26°C, 30°C, 32°C, or 35°C. The concentration of the decellularization liquid can also be 1mmo l / L, 100mmo l / L, 200mmo l / L, or 400mmo l / L. The interval time for replacing the decellularization liquid can also be 3h, 5h, 8h, or 10h.

[0049] In step S200, a tubular support layer is formed using a degradable material, and a pre-treated animal tissue is provided on the tubular support layer to obtain a biodegradable tubular material. The biodegradable material is one or more of polylactic acid, poly(lactide-glycolide) copolymer, polyvinyl alcohol, polycaprolactone, polyurethane, polyglycerol sebacate, polyanhydride, polyorthoester, polyphosphazene, collagen, gelatin, chitin, hyaluronic acid, and cellulose.

[0050] Wherein, the tubular support layer is prepared by electrospinning material, and the wire diameter of the electrospinning material is 50nm-500nm. In other embodiments, the wire diameter of the electrospinning material can also be 100nm, 200nm, or 400nm.

[0051] In other embodiments, the tubular support layer can also be prepared by solution casting or perfusion. When solution casting is used, the concentration of the solution is 0.3-1.5 mg / ml (w / v). When the perfusion method is used to prepare the tubular support layer, the density of the tubular material is 0.2-5 mg / cm 2 In other embodiments, the density of the tubular material may also be 0.5 mg / cm 2 , 0.8mg / cm 2 , 1.5mg / cm 2 , 2mg / cm 2 , or 3mg / cm 2 .

[0052] The outer contour of the dressing is circular, oval, square, or irregular, that is, the tubular support layer can be circular, oval, square, or irregular.

[0053] At step S300, the obtained biodegradable tubular material is treated with solutions containing growth factors and hemostatic materials, wherein the concentration of the growth factors is 0.1-10 ng / ml, the growth factor treatment time is 0.5-12 hours, and the treatment temperature is 25-37° C. The concentration of the hemostatic material is 0.1-10 mg / ml, the hemostatic material treatment time is 0.5-12 hours, and the hemostatic material treatment temperature is 25-37° C. The concentration of the growth factors can also be 1 ng / ml, 3 ng / ml, 6 ng / ml, or 8 ng / ml. The treatment time of the growth factors and hemostatic materials can also be 2° C., 5° C., or 10° C.

[0054] The growth factor is one or more of EGF, TGFα, TGFβ, αFGF, βFGF, IGF-I, I FG-II, and NGF. The growth factor preparation solution is one or more of physiological saline, PBS, bovine serum, and cell culture medium.

[0055] The hemostatic material is one or more of gelatin, oxidized cellulose, collagen, thrombin, fibrinogen, coagulation factor, and microporous polysaccharide.

[0056] In step S400, the treated biodegradable tubular material is dried and sterilized to obtain a tissue engineering tubular dressing.

[0057] The drying method is drying or cooling drying, and the moisture content after drying is less than 50%;

[0058] The drying temperature is 20-35° C., and the drying time is 4-72 hours. The drying temperature can also be 25° C. or 30° C., and the drying time can also be 10 hours, 20 hours, 50 hours, or 60 hours.

[0059] The freeze drying temperature is 0°C--80°C, and the time is 4-72 hours. The freeze drying temperature can also be -20°C, -30°C, or -60°C. The freeze drying time can also be 10 hours, 20 hours, 30 hours, 50 hours, or 60 hours.

[0060] The present invention provides a tissue engineering tubular dressing, which is prepared by the above-mentioned method for preparing the tissue engineering tubular dressing. The embodiment of the tissue engineering tubular dressing includes the embodiment of the above-mentioned method for preparing the tissue engineering tubular dressing; the beneficial effects of the method for preparing the tissue engineering tubular dressing can be applied to the tissue engineering tubular dressing.

[0061] The present invention provides an application of the tissue engineering tubular dressing, which is used for deep wounds, diabetic ulcer wounds, pressure sores, venous ulcers, chronic vascular ulcers, diabetic ulcers, traumatic wounds, and surgical wounds. The application of the tissue engineering tubular dressing includes the embodiments of the tissue engineering tubular dressing, and the beneficial effects of the tissue engineering tubular dressing can be applied to the application of the tissue engineering tubular dressing.

[0062] Example 1

[0063] S1, take the liver of a pig weighing 500 kg from a slaughterhouse, healthy and passed quarantine. Use medical scissors to carefully remove the dried surrounding fat and connective tissue. Treat the liver with 300mmol / L monoglyceride and 100mmol / L octyl sulfobetaine at 25℃ for 36h, and change the liquid every 6h;

[0064] S2, forming a tubular support layer using a degradable material, wherein the pretreated liver tissue is arranged on the tubular support layer to obtain a biodegradable tubular material.

[0065] S3, treating the obtained biodegradable tubular material with 0.2ng / ml αFGF growth factor for 5h at a temperature of 25°C; coating the surface of the biodegradable tubular material with 300nm of 0.1mg / ml gelatin solution, treating the hemostatic material for 5h at a temperature of 25°C.

[0066] S4, the treated biodegradable tubular material is freeze-dried at -60°C for 48 hours until the moisture content is 4.2%, and then double-packed and sterilized with ethylene oxide for use in venous ulcers and deep wounds.

[0067] Example 2

[0068] S1, take the liver of a pig weighing 500 kg from a slaughterhouse, healthy and passed quarantine. Use medical scissors to carefully remove the dried surrounding fat and connective tissue. Treat the liver with 300mmol / L monoglyceride and 100mmol / L octyl sulfobetaine at 25℃ for 36h, and change the liquid every 6h;

[0069] S2, using 0.5 mg / ml PLGA solution to electrospin to prepare a tubular scaffold with a wall thickness of 500 nm to form a tubular support layer, on which the pretreated liver tissue is provided, to obtain a biodegradable tubular material.

[0070] S3, treating the obtained biodegradable tubular material with 5 ng / ml βFGF growth factor at 37°C for 5 hours; coating the surface of the biodegradable tubular material with 200 nm of coagulation factor, treating the hemostatic material for 5 hours at a temperature of 25°C.

[0071] S4, drying the treated biodegradable tubular material at 25°C for 24 hours at normal pressure until the moisture content is less than 5%, sterilizing it with ethylene oxide after double-packaging, and using it for deep wounds.

[0072] Example 3

[0073] S1, take the liver of a pig weighing 500 kg from a slaughterhouse, healthy and passed quarantine. Use medical scissors to carefully remove the dried surrounding fat and connective tissue. Treat the liver with 300mmol / L monoglyceride and 100mmol / L octyl sulfobetaine at 25℃ for 36h, and change the liquid every 6h;

[0074] S2, preparing a 1.5 mg / ml gelatin solution at 60° C., and filling the tube with the solution by casting to form a tubular support layer, on which the pretreated liver tissue is arranged, to obtain a biodegradable tubular material.

[0075] S3, treating the obtained biodegradable tubular material with 0.5 ng / ml I GF-I growth factor at 37°C for 6 hours; coating the surface of the biodegradable tubular material with 100 nm of oxidized cellulose, treating the hemostatic material for 5 hours, and treating the hemostatic material at a temperature of 25°C.

[0076] S4, drying the treated biodegradable tubular material under reduced pressure at 25°C for 12 hours to obtain a moisture content of 8%, double-packing the material, and irradiating and sterilizing the material for use on surgical wounds and pressure sores.

[0077] Comparative Example 1

[0078] S1, the inferior vena cava of sheep weighing 200 kg, healthy and passed quarantine was obtained from the slaughterhouse. The fat and connective tissue around the blood vessel were carefully removed using medical scissors without damaging the adventitia of the blood vessel.

[0079] S2, decellularization: the pretreated inferior vena cava was treated with 100 mmol / L pentaerythritol fatty acid ester at 37°C for 24 h, and the liquid was changed every 12 h;

[0080] S3, the treated inferior vena cava was treated with 2 ng / ml EGF at 37°C for 5 h, and then 0.3 ng / ml fibrinogen was sprayed on the surface of the inferior vena cava with a thickness of 100 nm;

[0081] S4, the treated inferior vena cava is freeze-dried at -60℃ for 48h until the moisture content is less than 10%, and then double-wrapped and irradiated for sterilization for use in the repair of diabetic foot and deep wounds.

[0082] The following experiments were conducted on Examples 1 to 3 and Comparative Example 1 respectively.

[0083] (1) Axial tensile strength

[0084] The test was carried out according to the method in standard YY / T 1511-2017, with the clamp spacing set to 3 cm and the stretching rate set to 5 mm / min. A 1 cm wide dressing withstood a tensile force of 0.6 N without breaking.

[0085] (2) Water absorption performance

[0086] Prepare a container with 500 ml of saline solution;

[0087] After accurately weighing the product, place it in a container filled with physiological saline. Start timing when the liquid level completely covers the product. Soak at room temperature for 10 minutes.

[0088] Take the test sample out of the container, wipe the surface moisture of the sample with a clean towel, weigh it immediately on a balance, and record the wet weight;

[0089] Water absorption rate = (wet weight - initial weight) / initial weight * 100%

[0090] (3) Degradability

[0091] Degradability is based on YY / T 1806.1-2021 Evaluation method for in vitro degradation performance of biomedical materials.

[0092] After the product is accurately weighed, place the product in a sealable container with a volume greater than 2L, with the volume of phosphate buffer (pH = 7.4 ± 0.3) and the sample mass at a ratio of 40:1. After the liquid surface completely covers the product, seal the container and place it in a 37 ± 1°C stability box. Test 3 parallel samples for each sample.

[0093] After 4 weeks, take out the samples, separate the degraded samples and fragments from the experimental solution, rinse the filtrate three times with a small amount of secondary water for analysis that complies with GB / T6682, dry the filter and the filtrate together to constant weight under vacuum at room temperature, and calculate the mass loss of the sample before and after degradation.

[0094] Table 1 Comparison of experimental results of embodiments and comparative examples

[0095] Axial tensile strength Water absorption Degradability - weight loss after 1 month Example 1 1.5N 343mg / g 65％ Example 2 2.7N 278mg / g 78％ Example 3 1.8N 215mg / g 81％ Comparative Example 1 0.45N 95mg / mg 45％

[0096] in, Figures 2 to 6 The schematic diagram of the embodiment is shown. The product obtained in Example 1 has a DNA content of 32ng / mg, an axial tensile strength of 1.5N, a water absorption of 343mg / g, and a weight loss rate of 65% after PBS immersion for one month. The product obtained in Example 2 has an axial tensile strength of 2.7N, a water absorption of 278mg / g, and a weight loss rate of 81% after PBS immersion for one month. The product obtained in Example 3 has an axial tensile strength of 1.8N, a water absorption of 215mg / g, and a weight loss rate of 81% after PBS immersion for one month. The product obtained in Comparative Example 1 has an axial tensile strength of 0.45N, a water absorption of 95mg / g, and a weight loss rate of 45% after PBS immersion for one month.

[0097] It can be seen from Table 1 that the biodegradable tubular material prepared by the preparation method provided by the present invention has a liquid absorption capacity greater than 200 mg / g, an in vitro degradable performance test shows a one-month weight loss rate greater than 50%, and a tensile strength greater than 0.6N.

[0098] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A method for preparing a tissue engineering tubular dressing, characterized in that: include: A tubular support layer is formed by using a degradable material, and a pretreated animal tissue is arranged on the tubular support layer to obtain a biodegradable tubular material, wherein the animal tissue pretreatment includes decellularization by chemical reagents, the decellularization temperature is 25-37°C, the concentration of the decellularization liquid is 0.1-800mmol / L, the decellularization treatment time is 1-48h, and the decellularization liquid is replaced every 2-12h; The obtained biodegradable tubular material is treated with a solution containing a growth factor and a hemostatic material, wherein the concentration of the growth factor is 0.1-10 ng / ml, the growth factor treatment time is 0.5-12 h, the treatment temperature is 25-37° C., the concentration of the hemostatic material is 0.1-10 mg / ml, the hemostatic material treatment time is 0.5-12 h, and the hemostatic material treatment temperature is 25-37° C.; The treated biodegradable tubular material is dried and sterilized to obtain a tissue engineering tubular dressing.

2. The method for preparing the tissue engineering tubular dressing according to claim 1, characterized in that: The tubular support layer is formed by using a degradable material, and the tubular support layer is provided with pretreated animal tissue. In the step of obtaining the biodegradable tubular material, the tubular support layer is prepared by using an electrospinning material, and the filament diameter of the electrospinning material is 50nm-500nm.

3. The method for preparing the tissue engineering tubular dressing according to claim 1, characterized in that: The tubular support layer is formed by using a degradable material, and the tubular support layer is provided with pretreated animal tissue. In the step of obtaining the biodegradable tubular material, the pretreated chemical reagents include 0.01-500mmol / L of ionic detergents and non-ionic detergents.

4. The method for preparing the tissue engineering tubular dressing according to claim 3, characterized in that: The chemical reagent is a mixture of a nonionic detergent and a zwitterionic detergent; Wherein, the nonionic detergent includes one or more of polyoxyethylene fatty amine, polyoxyethylene amide, alkylphenol polyoxyethylene ether, monoglyceride of fatty acid, pentaerythritol fatty acid ester, sorbitan fatty acid ester, fatty acid diethanolamide, amine oxide and alkyl polyglycoside; The zwitterionic detergent is one or more of decyl sulfobetaine, lauryl sulfobetaine, myristoyl sulfobetaine, palmityl sulfobetaine, and octyl sulfobetaine.

5. The method for preparing the tissue engineering tubular dressing according to claim 1, characterized in that: The obtained biodegradable tubular material is treated with a solution containing growth factors and hemostatic materials, wherein the growth factor is one or more of EGF, TGFα, TGFβ, αFGF, βFGF, IGF-I, IFG-II, and NGF; The hemostatic material is one or more of gelatin, oxidized cellulose, collagen, thrombin, fibrinogen, coagulation factor, and microporous polysaccharide.

6. The method for preparing the tissue engineering tubular dressing according to claim 1, characterized in that: In the step of drying and sterilizing the treated biodegradable tubular material to obtain the tissue engineering tubular dressing, the drying method is drying or cooling drying, and the water content after drying is less than 50%; Among them, the drying temperature is 20-35°C and the drying time is 4-72h; Freeze drying temperature 0℃--80℃, time 4-72h.

7. The method for preparing the tissue engineering tubular dressing according to claim 1, characterized in that: The biodegradable material is used to form a tubular support layer, and the tubular support layer is provided with pre-treated animal tissue to obtain a biodegradable tubular material. The animal tissue is one or more of small intestinal submucosa, mesenteric artery, rectal artery, trachea, ureter, esophagus, epidermis, connective tissue, and adipose tissue; The animal tissue is from cattle, sheep, dog, rabbit, horse, or pig; The biodegradable material is one or more of polylactic acid, poly(lactide-glycolide) copolymer, polyvinyl alcohol, polycaprolactone, polyurethane, polyglycerol sebacate, polyanhydride, polyorthoester, polyphosphazene, collagen, gelatin, chitin, hyaluronic acid, and cellulose.

8. The method for preparing the tissue engineering tubular dressing according to claim 1, characterized in that: The obtained biodegradable tubular material is treated with a solution containing growth factors and hemostatic materials, wherein the growth factor preparation solution is one or more combinations of physiological saline, PBS, bovine serum, and cell culture medium.

9. A tissue engineering tubular dressing, characterized in that: The tissue engineering tubular dressing is prepared by the method for preparing a tissue engineering tubular dressing according to any one of claims 1 to 8.

10. Use of the tissue engineering tubular dressing according to claim 9, characterized in that: The tissue engineering tubular dressing is used for deep wounds, diabetic ulcer wounds, bedsores, venous ulcers, chronic vascular ulcers, diabetic ulcers, traumatic wounds, and surgical wounds.

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