Nano-silver antibacterial collagen suture and preparation method thereof

Abstract

The invention relates to the technical field of medical treatment, and particularly discloses a nano-silver antibacterial collagen suture and a preparation method thereof. A preparation method of a nano-silver antibacterial collagen suture comprises the following steps: at the temperature of 2-8 DEG C, stirring and fully mixing a nano-silver solution and a collagen solution according to the weight ratio of (1-2): (8-9) for 1-2 hours to obtain a mixed solution; at the temperature of 2-8 DEG C, extruding the mixed solution into a filamentous substance by adopting a microfluid technology, and curing, dehydrating and shaping the filamentous substance in ethanol with the concentration of 75-95% to obtain a nano-silver antibacterial collagen suture 1; and dehydrating and air-drying the nano-silver antibacterial collagen suture 1 at the temperature of 2-8 DEG C and the relative humidity of 45-65%, polishing, matching with a needle, and sterilizing to obtain the nano-silver antibacterial collagen suture. The suture prepared by the method has the advantages of good antibacterial property, lasting antibacterial effect and high breaking strength.

Description

Technical Field

[0001] The present application relates to the field of medical technology, and more specifically, to a nano-silver antibacterial collagen suture and a preparation method thereof. Background Art

[0002] In the medical field, surgical suture is a vital part of the wound healing process. Medical surgical suture not only requires effective wound closure, but also needs to consider reducing complications, promoting healing and aesthetic effects. With the advancement of medical technology, suture materials have undergone significant development, from the initial non-absorbable sutures, to the later catgut, chemical synthetic sutures, and then to absorbable collagen sutures. Each step marks an important progress in medical material science.

[0003] However, despite the continuous improvement of suture technology and materials, postoperative infection, especially complications caused by bacterial wound inflammation, remains a problem that needs to be solved. Traditional antibacterial sutures mainly achieve antibacterial effects by adhering broad-spectrum antibacterial agents (such as triclosan) on the suture surface, but this antibacterial method has limitations such as insufficient antibacterial performance and easy shedding, which makes it difficult to meet the clinical demand for long-term effective antibacterial.

[0004] In order to overcome this technical difficulty, it is particularly important to develop a suture with stronger antibacterial properties and stable and reliable properties. Summary of the invention

[0005] In order to improve the antibacterial properties of sutures, the present application provides a nano-silver antibacterial collagen suture and a preparation method thereof.

[0006] In the first aspect, the present application provides a method for preparing a nano-silver antibacterial collagen suture, which adopts the following technical scheme: A method for preparing nano silver antibacterial collagen suture comprises the following steps: (1) at a temperature of 2-8° C., stirring and mixing the nanosilver solution and the collagen solution in a ratio of (1-2): (8-9) for 1-2 h to obtain a mixed solution; (2) After the mixed solution is extruded into a filamentous substance by using microfluidics technology at a temperature of 2-8° C., the substance is solidified, dehydrated and shaped in 75%-95% ethanol to obtain a nano-silver antibacterial collagen suture 1; (3) The nano-silver antibacterial collagen suture 1 is dehydrated and air-dried at a temperature of 2-8° C. and a relative humidity of 45-65%, and then polished, needled, and sterilized to obtain the nano-silver antibacterial collagen suture.

[0007] The diameter of the filamentous material extruded from the mixed liquid 2 is 0.100-0.500 mm.

[0008] By adopting the above technical solution, the nanosilver solution and the collagen solution are mixed in a precise proportion, and the nanosilver particles are stably combined in the collagen matrix to form a composite structure with the characteristics of continuous and slow release of silver ions. These released silver ions have excellent bactericidal and antibacterial properties, can effectively penetrate and destroy the cell membrane of bacteria, and show strong inhibitory and killing effects on a variety of pathogenic microorganisms including Escherichia coli and Chlamydia trachomatis. More importantly, this process not only kills bacteria, but also blocks their reproductive ability and avoids the generation of drug-resistant strains, thereby ensuring the durability and non-drug resistance of the antibacterial effect, and significantly improving the antibacterial efficacy of the prepared sutures and their long-term antibacterial stability.

[0009] Ensure that the nanosilver particles are evenly dispersed in the collagen matrix to form a mixed liquid. Under the same temperature conditions, use microfluidic technology to extrude the mixed liquid into a filamentous substance, accurately control the diameter of the filamentous substance, improve production efficiency and product consistency, and make the prepared nanosilver antibacterial collagen suture have a finer structure and better flexibility, making it easier to operate in surgery.

[0010] Solidification, dehydration and shaping in 75%-95% ethanol not only helps to further remove moisture and improve the stability of the suture, but also promotes the nanosilver particles to approach and stably bind to collagen through the penetration of ethanol, ensuring the durability of the antibacterial effect. The stable combination of nanosilver and collagen can prevent the nanosilver particles from being quickly washed away in body fluids, thereby prolonging their residence time at the site of action and ensuring the durability of the antibacterial effect.

[0011] Dehydration and air drying under specific temperature and relative humidity conditions ensure that the suture will not undergo drastic physical and chemical changes due to environmental changes during the dehydration process, retaining its optimal physical properties and biocompatibility. Polishing improves the surface finish of the suture and reduces friction with the tissue. Further sterilization steps ensure the sterility of the product, further improving the safety and reliability of the product.

[0012] Therefore, the nanosilver collagen suture made by uniformly dispersing nanosilver particles in the collagen matrix not only has excellent antibacterial properties, but also can maintain the antibacterial effect for a long time.

[0013] Optionally, the collagen solution is prepared by the following method: Step 1: Soak the animal tendon in a mixed solution of NaClO and NaOH with a pH of 12-14 for 1-2 hours at a temperature of 2-8°C, and filter out to obtain the animal tendon 1; Step 2: At a temperature of 2-8°C, soak the animal tendon 1 in a mixture A for 2-3 hours, rinse it in purified water, and obtain the animal tendon 2; then, transfer the animal tendon 2 to a mixture B and soak it for 36-48 hours, and after salting out and dialysis, obtain an animal tendon collagen extract to obtain the collagen solution; the mixture A is composed of a trypsin solution with a concentration of 0.2-1.0wt% and a Na+ solution with a concentration of 0.15-0.65 mol / L. 2 CO 3 The solution composition is that the mixed solution B is composed of a pepsin solution with a concentration of 0.3-2.5wt% and an acetic acid solution with a concentration of 0.1-0.6 mol / L.

[0014] By adopting the above technical solution, the collagen solution prepared using animal tendons has the advantages of better absorbability and biocompatibility, can reduce inflammatory response, and does not require stitches to be removed after surgery.

[0015] Preparing collagen solution at a low temperature of 2-8°C helps slow down the chemical reaction rate, avoid excessive degradation of collagen, and inhibit the growth of bacteria and other microorganisms. Using a mixed solution of NaClO and NaOH as a disinfectant, its strong oxidizing and alkaline environment can effectively kill viruses and microorganisms in the tendon, ensuring the safety of the extract. At the same time, high pH can also destroy the structural stability of non-collagenous proteins (such as fat, blood, cell residues, etc.), laying the foundation for the subsequent removal of these impurities.

[0016] The animal tendon that has been preliminarily treated with NaClO and NaOH is placed in a mixed solution of trypsin and sodium carbonate. Sodium carbonate is used to adjust the pH value of the solution to the optimal activity range of trypsin. Trypsin further decomposes the non-collagen residues in the animal tendon and preliminarily destroys the higher-order structure of collagen, making it easier to be further enzymatically hydrolyzed by pepsin in the subsequent steps. After rinsing with purified water to remove the remaining non-collagen residues and trypsin and sodium carbonate, acetic acid is added to adjust the solution to an acidic environment to activate pepsin and make it work under the optimal activity conditions. Pepsin can degrade collagen and convert it into soluble small molecule peptides or collagen fragments. Pure collagen solution is extracted through salting out, dialysis and other methods.

[0017] Optionally, the animal tendons are tendons of nutria limbs and tail.

[0018] By adopting the above technical solution, nutria tendon is rich in high-quality collagen and has good biocompatibility, which can reduce postoperative rejection reactions. At the same time, its fiber structure is tight, so that the prepared suture has excellent mechanical properties and suture stability.

[0019] Optionally, the weight ratio of the tendon to trypsin and sodium carbonate is (7-9): (0.5-1.5): (0.5-1.5); the weight ratio of the tendon to pepsin and acetic acid is (7-9): (0.5-1.5): (0.5-1.5).

[0020] By adopting the above technical solution, the appropriate ratio of trypsin and sodium carbonate ensures the high efficiency of the enzymatic hydrolysis process, which can remove non-collagen components in the tendon to the maximum extent while retaining the integrity of collagen. After effectively removing impurities, the obtained collagen solution has a higher purity and the breaking strength of the prepared suture is also higher. The addition of an appropriate amount of acetic acid adjusts the solution environment so that pepsin is in a highly active state, further degrading macromolecular collagen, controlling the raw material ratio to ensure that pepsin works within the optimal concentration range, optimizing the enzymatic hydrolysis process, and improving the extraction purity of collagen. Appropriate enzymatic hydrolysis conditions can maintain the intact structure and biological activity of collagen, avoid structural damage and loss of function caused by excessive degradation, and ensure the mechanical properties and biocompatibility of the prepared suture.

[0021] Optionally, the concentration of NaClO is 0.01-10wt%, and the concentration of NaOH is 0.05-0.15 mol / L.

[0022] By adopting the above technical scheme, a mixed solution with a NaClO concentration of 0.01-10wt% and a NaOH concentration of 0.05-0.15 mol / L has a strong disinfection ability in the collagen extraction process, which not only effectively kills the viruses, bacteria and microorganisms that may exist in the tendon, ensuring the safety of the subsequent extraction process, but more importantly, the strong oxidizing property of NaClO can destroy the cell membrane of microorganisms and inhibit their reproduction ability, thereby improving the antibacterial properties of the final prepared sutures at the source.

[0023] Optionally, the concentration of the nanosilver solution in step (1) is 0.005-0.03 wt %, wherein the particle size of the nanosilver is 10-25 nm.

[0024] By adopting the above technical solution, the smaller the particle size of nanosilver is, the better its bactericidal performance is. However, the smaller the particle size of silver particles is, the more difficult its processing technology is, and the higher the manufacturing cost is. Considering the cost problem, the particle size of nanosilver in the nanosilver solution in this application is set to 10-25nm. The nanosilver particles within this particle size range not only have good antibacterial properties, but also can better combine with collagen molecules to form a stable composite structure, maintain the stability of nanosilver particles in sutures, and prevent them from falling off or losing during use, thereby extending the duration of the antibacterial effect. At the same time, in the preparation process of sutures, by accurately controlling the particle size and concentration of nanosilver, it can be ensured that the sutures have strong antibacterial properties while not being toxic or irritating to the human body.

[0025] Optionally, the steps also include performing a performance enhancement treatment on the mixed liquid, placing a 254nm ultraviolet lamp into the mixed liquid for irradiation at 2-8°C for 7-8 hours, and at the same time, filling the mixed liquid with 10-30g / h of ozone for 4-5 hours. The whole process is fully stirred and mixed to obtain a performance-enhanced mixed liquid.

[0026] By adopting the above technical scheme, through further treatment with ultraviolet rays and ozone, the cross-linking and rearrangement of collagen molecules are promoted to form a denser and more stable network structure, thereby enhancing the strength of the suture. At the same time, the surface activity of the nanosilver particles can be increased, making it easier for them to interact with the functional groups in the collagen matrix, thereby enhancing the binding force between the nanosilver particles and the collagen matrix, thereby improving the sterilization durability of the suture.

[0027] Optionally, the sterilization operation in step (3) uses 18-25 kGy Co60-γ ray radiation sterilization.

[0028] By adopting the above technical solution, Co60-γ rays have strong penetrating power, can achieve uniform and thorough sterilization, effectively kill bacteria, viruses and other microorganisms, ensure the sterility of sutures, and at the same time, the use of 18-25kGy Co60-γ ray radiation sterilization will not introduce heat during the sterilization process, will not destroy the original properties of the sutures, and maintain their good biocompatibility.

[0029] In a second aspect, the present application provides a nano-silver antibacterial collagen suture prepared by the above method.

[0030] By adopting the above technical solution, the suture prepared in the present application has good biocompatibility, safety and good breaking strength, and it has an effective and lasting bactericidal effect.

[0031] In summary, this application has the following beneficial effects: 1. The antibacterial properties of the collagen solution were significantly improved by using a mixed solution of NaClO and NaOH as the initial disinfection step, combined with the addition of nanosilver particles, and subsequent ultraviolet and ozone performance enhancement treatment. The strong oxidizing property of NaClO destroys the cell membrane of microorganisms and inhibits their reproduction ability; the nanosilver particles enhance the antibacterial effect of the sutures with their tiny particle size and efficient bactericidal ability; ultraviolet and ozone treatment further enhances the binding force between nanosilver and the collagen matrix, ensuring the durability of the antibacterial effect. The combined effect of these measures makes the final sutures have excellent antibacterial properties, effectively reducing the risk of postoperative infection and inflammation.

[0032] 2. This application uses nutria tendon as raw material, which is rich in high-quality collagen and has good biocompatibility, and can significantly reduce postoperative rejection reactions. During the preparation process, by precisely controlling the conditions and proportions of enzymatic hydrolysis, the non-collagen components are effectively removed, and the complete structure and biological activity of collagen are retained, so that the prepared collagen solution has a higher purity, thereby improving the biocompatibility and mechanical properties of the suture. At the same time, the performance enhancement treatment of ultraviolet rays and ozone promotes the cross-linking and rearrangement of collagen molecules, forming a denser and more stable network structure, further enhancing the strength and stability of the suture.

[0033] 3. During the entire preparation process, a variety of sterilization measures were adopted, including preliminary disinfection with NaClO and NaOH, rinsing with purified water, and final Co60-y ray radiation sterilization. These measures together ensure the sterility of the sutures and effectively avoid microbial contamination. In particular, Co60-y ray radiation sterilization, with its strong penetration and no thermal effect, achieves uniform and thorough sterilization, which not only ensures the sterility of the sutures, but also avoids the negative effects that may be caused by high-temperature treatment. In addition, the entire preparation process is carried out at low temperatures, which helps to slow down the chemical reaction rate, avoid excessive degradation of collagen, preserve the structural integrity of collagen in the tendon, and improve the stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a diagram of the nano silver antibacterial collagen suture provided by the present application; Figure 2 These are cytotoxicity detection images after using the sutures prepared by the present application. 1 is a cell image of the nanosilver antibacterial collagen suture prepared by Example 1, 2 is a cell image of the nanosilver antibacterial collagen suture prepared by Example 2, 3 is a cell image of the nanosilver antibacterial collagen suture prepared by Example 3, and 4 is a normal cell control image; Figure 3 This is a group of animal experimental tissue inflammatory response images after using the sutures prepared by the present application. 1 is a rat heart pathological section after using the nano-silver antibacterial collagen suture prepared in Example 1; 2 is a rat heart pathological section after using the nano-silver antibacterial collagen suture prepared in Example 2; 3 is a rat heart pathological section after using the nano-silver antibacterial collagen suture prepared in Example 3; 4 is a rat heart pathological section after using the nano-silver antibacterial collagen suture prepared in Comparative Example 1. DETAILED DESCRIPTION

[0035] The present application is further described in detail below with reference to the embodiments.

[0036] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0037] Bovine collagen was purchased from Beijing Yaanda Biotechnology Co., Ltd., product number 5010D. Preparation examples of raw materials and / or intermediates

[0038] Preparation Example 1 A collagen solution, the preparation comprising the following steps: Step 1: At a temperature of 2°C, 8 kg of nutria tendon was soaked in a mixed solution of 1 wt% NaClO and 0.05 mol / L NaOH at a pH of 12 for 1.5 h, and then nutria tendon 1 was obtained by filtering; Step 2: At a temperature of 2°C, nutria tendon 1 is placed in mixed solution A and soaked for 2.5 hours, and then rinsed in purified water to obtain animal tendon 2; then, animal tendon 2 is transferred to mixed solution B and soaked for 36 hours, and after salting out and dialysis, an animal tendon collagen extract is obtained to obtain the collagen solution; the nutria tendon is the nutria limb and tail tendon; the mixed solution A is composed of a trypsin solution with a concentration of 0.2wt% and a Na+ solution with a concentration of 0.15mol / L. 2 CO 3 Solution composition, wherein the trypsin solution contains 1kg of trypsin, Na 2 CO 3 The solution contains Na 2 CO 3 1kg; mixed solution B consists of a pepsin solution with a concentration of 0.3wt% and an acetic acid solution with a concentration of 0.3mol / L, wherein the pepsin solution contains 1kg of pepsin and the acetic acid solution contains 1kg of acetic acid.

[0039] Preparation Example 2 A collagen solution, the preparation comprising the following steps: Step 1: At a temperature of 5°C, 8 kg of nutria tendon was soaked in a mixed solution of 5 wt% NaClO and 0.1 mol / L NaOH at a pH of 14 for 1 h, and nutria tendon 1 was obtained by filtering; Step 2: At a temperature of 5°C, nutria tendon 1 is placed in mixed solution A and soaked for 3 hours, and then rinsed in purified water to obtain animal tendon 2; then, the animal tendon 2 is transferred to mixed solution B and soaked for 48 hours, and after salting out and dialysis, an animal tendon collagen extract is obtained to obtain the collagen solution; the nutria tendon is the limb and tail tendons of nutria; the mixed solution A is composed of a trypsin solution with a concentration of 0.6wt% and a Na+ solution with a concentration of 0.65mol / L. 2 CO 3 The solution composition includes 1.5 kg trypsin, Na 2 CO 3 The solution contains Na 2 CO 3 0.5kg; mixed solution B consists of a pepsin solution with a concentration of 2.5wt% and an acetic acid solution with a concentration of 0.1mol / L, wherein the pepsin solution contains 0.5kg of pepsin and the acetic acid solution contains 1.5kg of acetic acid.

[0040] Preparation Example 3 A collagen solution, the preparation comprising the following steps: Step 1: At a temperature of 8°C, 8 kg of nutria tendon was soaked in a mixed solution of 10 wt% NaClO and 0.15 mol / L NaOH at a pH of 13 for 2 h, and nutria tendon 1 was obtained by filtering; Step 2: at a temperature of 8°C, immerse the nutria tendon 1 in a mixture A for 2 hours, rinse it in purified water, and obtain the animal tendon 2; then, transfer the animal tendon 2 to a mixture B and immerse it for 42 hours, and after salting out and dialysis, obtain an animal tendon collagen extract to obtain the collagen solution; the nutria tendon is the nutria limb and tail tendon; the mixture A is composed of a trypsin solution with a concentration of 1wt% and a Na 2 CO 3 The solution composition includes 0.5 kg of trypsin, Na 2 CO 3 The solution contains Na 2 CO 3 1.5kg; mixed solution B consists of a pepsin solution with a concentration of 1.4wt% and an acetic acid solution with a concentration of 0.6mol / L, wherein the pepsin solution contains 1.5kg of pepsin and the acetic acid solution contains 0.5kg of acetic acid. Example

[0041] Example 1 A nano silver antibacterial collagen suture, the preparation of which comprises the following steps: (1) At a temperature of 2°C, a 0.02wt% nanosilver solution (nanosilver particle size of 25nm) and a collagen solution were stirred and mixed in a ratio of 1:9 for 1.5h. After obtaining a mixed solution, a 254nm ultraviolet lamp was placed in the mixed solution for 7.5h at 2°C, and 20g / h of ozone was added for 4.5h. The whole process was stirred and mixed to obtain a performance-enhanced mixed solution; (2) At a temperature of 2°C, the performance-enhanced mixed solution was extruded into a filamentous substance using microfluidic technology, and the diameter of the extrusion port was 0.225 mm. The substance was solidified, dehydrated and shaped in 85% ethanol to obtain a nano-silver antibacterial collagen suture 1; (3) The nano-silver antibacterial collagen suture 1 was dehydrated and air-dried at a temperature of 2°C and a relative humidity of 50%, and its surface was polished in a special polishing device to make it smoother. After the polished suture was equipped with a suture needle, it was irradiated and sterilized under 20 kGy Co60-γ rays to obtain the nano-silver antibacterial collagen suture; the collagen solution was the collagen solution prepared in Preparation Example 1. The schematic diagram of the prepared collagen suture is shown in the attached Figure 1 .

[0042] Example 2 A nano silver antibacterial collagen suture, the preparation of which comprises the following steps: (1) At a temperature of 5°C, a 0.005wt% nanosilver solution (nanosilver particle size of 10nm) and a collagen solution were stirred and mixed in a ratio of 2:8 for 2h. After obtaining a mixed solution, a 254nm ultraviolet lamp was placed in the mixed solution for 7h at 5°C, and 30g / h of ozone was added for 5h. The whole process was stirred and mixed to obtain a performance-enhanced mixed solution; (2) At a temperature of 5°C, the performance-enhanced mixed solution was extruded into a filamentous substance using microfluidic technology, and the diameter of the extrusion port was 0.225 mm. The substance was solidified, dehydrated and shaped in 75% ethanol to obtain a nano-silver antibacterial collagen suture 1; (3) The nano-silver antibacterial collagen suture 1 was dehydrated and air-dried at a temperature of 5°C and a relative humidity of 45%, and its surface was polished in a special polishing device to make it smoother. The polished suture was equipped with a suture needle and then irradiated and sterilized under 18 kGy Co60-γ rays to obtain the nano-silver antibacterial collagen suture; the collagen solution was the collagen solution prepared in Preparation Example 1.

[0043] Example 3 A nano silver antibacterial collagen suture, the preparation of which comprises the following steps: (1) At a temperature of 8°C, a 0.03wt% nanosilver solution (nanosilver particle size of 18nm) and a collagen solution were stirred and mixed in a ratio of 1.5:8.5 for 1h. After obtaining a mixed solution, a 254nm ultraviolet lamp was placed in the mixed solution for 8h at 8°C, and 10g / h of ozone was added for 4h. The whole process was stirred and mixed to obtain a performance-enhanced mixed solution; (2) at a temperature of 8°C, the performance-enhanced mixed solution was extruded into a filamentous substance by using microfluidic technology, the diameter of the extrusion port was 0.225 mm, and the substance was solidified, dehydrated and shaped in 95% ethanol to obtain nanosilver antibacterial collagen suture 1; (3) The nano-silver antibacterial collagen suture 1 was dehydrated and air-dried at a temperature of 8°C and a relative humidity of 65%, and its surface was polished in a special polishing device to make it smoother. After the polished suture was equipped with a suture needle, it was irradiated and sterilized under 25 kGy Co60-γ rays to obtain the nano-silver antibacterial collagen suture; the collagen solution was the collagen solution prepared in Preparation Example 1.

[0044] Embodiment 4-5 A nano silver antibacterial collagen suture, which is different from Example 1 in that the collagen solutions are respectively selected from those prepared in Preparation Examples 2 and 3.

[0045] Example 6 A nano-silver antibacterial collagen suture, which is different from Example 1 in that the particle size of the nano-silver added during its preparation is 28 nm.

[0046] Example 7 A nano-silver antibacterial collagen suture, which is different from Example 1 in that the concentration of the nano-silver solution added during its preparation is 0.04 wt %.

[0047] Example 8 A nano-silver antibacterial collagen suture, which is different from Example 1 in that the concentration of the nano-silver solution added during its preparation is 0.004 t%.

[0048] Example 9 A nano silver antibacterial collagen suture, which is different from Example 1 in that the preparation process thereof does not include a performance enhancement treatment step, and the preparation includes the following steps: (1) At a temperature of 2°C, a 0.02wt% nanosilver solution (nanosilver particle size of 25nm) and a collagen solution were stirred and mixed in a ratio of 1:9 for 1.5h to obtain a mixed solution; (2) At a temperature of 2° C., the mixed solution was extruded into a filamentous substance by using microfluidics technology, and the diameter of the extrusion port was 0.225 mm. The substance was solidified, dehydrated and shaped in ethanol with a concentration of 85% to obtain a nano-silver antibacterial collagen suture 1; The remaining steps are the same as in Example 1.

[0049] Example 10 A nano silver antibacterial collagen suture, which is different from Example 1 in that the collagen solution used in this example is a bovine collagen solution.

[0050] Comparative Example Comparative Example 1 A nano-silver antibacterial collagen suture is different from Example 1 in that in this comparative example, a triclosan solution of the same concentration is used to replace the nano-silver solution and mix with the collagen solution.

[0051] Comparative Example 2 A nano silver antibacterial collagen suture, the preparation of which comprises the following steps: (1) Take the collagen solution prepared in Preparation Example 1, place a 254 nm ultraviolet lamp into the mixed solution for 7.5 hours at 2°C, and simultaneously inject 20 g / h of ozone for 4.5 hours. The mixture is fully stirred and mixed during the whole process to obtain a mixed solution with enhanced performance; (2) At a temperature of 2° C., the performance-enhanced mixed solution was extruded into a filamentous substance using microfluidic technology, and the diameter of the extrusion port was 0.225 mm. The substance was soaked in a 0.02wt% nanosilver solution for 1.5 h, then taken out, solidified, dehydrated and shaped in 85% ethanol to obtain a nanosilver antibacterial collagen suture 1. The remaining steps were the same as those in Example 1.

[0052] Comparative Example 3 A nano-silver antibacterial collagen suture, which is different from Example 1 in that the weight ratio of the nano-silver solution to the collagen solution is 3:9.

[0053] Comparative Example 4 A nano-silver antibacterial collagen suture, which is different from Example 1 in that the weight ratio of the nano-silver solution to the collagen solution is 1:10.

[0054] Comparative Example 5 A nano silver antibacterial collagen suture, which is different from Example 1 in that the entire preparation process is carried out at 10°C.

[0055] Performance testing Detection method / test method

[0056] Cytotoxicity test: Cytotoxicity test was performed on the sutures prepared in Examples 1-3 and normal cells according to the method in GB / T 16886.11 Biological evaluation of medical devices Part 11: Systemic toxicity test. The results are shown in the attached figure. Figure 2 As shown, Figures 1-3 are the cytotoxicity test results of Examples 1-3, and Figure 4 is the toxicity test result of normal cells. By comparing with normal cells, it can be seen that the suture prepared in the present application has no toxic side effects on cells and has good cell proliferation.

[0057] Inflammatory cell infiltration detection: The sutures prepared in Examples 1-3 and Comparative Example 1 were used to suture the incisions of rabbits, and then the incision samples of the sutures on the 10th day in the animal body were taken for HE staining and sectioning, and the inflammatory reaction of the sutures was observed under a ×10 microscope, see the attached Figure 3 ,It can be seen from the figure that no inflammatory cell infiltration was observed in 1, 2, and 3, no obvious swelling and rupture of myocardial fibers, and no inflammatory cell infiltration was observed in the interstitium, while inflammatory cell infiltration was obvious in 4, and there was an obvious inflammatory reaction.

[0058] Breaking strength test: A suture tension tester was used to test the breaking strength of the sutures prepared in the embodiment and the preparation example. The test results are shown in Table 1.

[0059] Antibacterial performance test: According to the oscillation bottle method shown in ASTM E2149-10, Escherichia coli was selected and 5 cm of suture was taken for testing, and its antibacterial activity was calculated. The test results are shown in Table 1.

[0060] Long-term antibacterial activity: The suture to be tested was placed on the agar medium coated with bacteria prepared in the above antibacterial performance test method, and cultured in a constant temperature box. After the culture time reached 24 hours, it was taken out and replaced with a new culture medium. That is, the suture was moved to a new agar medium coated with the same concentration of bacteria, and then cultured in a constant temperature box. The antibacterial activity was detected after 3 days and 6 days. The test results are shown in Table 1.

[0061] Table 1 Test results

[0062] Combining Examples 1-3 and Comparative Examples 1-2 and Table 1, it can be seen that the experimental data of Examples 1-3 are better than those of Comparative Example 1, indicating that in the process of preparing collagen sutures, the nanosilver solution is introduced and mixed with the collagen solution to form a thread, and the nanosilver with a bactericidal effect is evenly dispersed in the collagen matrix to form a stable complex, giving the suture good antibacterial properties, and effectively improving the antibacterial durability of the material.

[0063] Combining Example 1 with Comparative Examples 3-4 and Table 1, it can be seen that the weight ratio of nanosilver to collagen solution in the process of preparing sutures in Comparative Examples 3-4 exceeds the scope of the present application. When there is too much nanosilver solution, it is easy to form larger agglomerates, affecting the structural uniformity of the suture, and the breaking strength of the prepared suture is reduced; too little nanosilver solution cannot achieve the optimal antibacterial effect, indicating that the suture prepared by mixing the nanosilver solution and the collagen solution in a specific proportion not only has good antibacterial properties, but also meets the breaking strength requirements of the corresponding models in the industry standard YY1116-2020, and has better breaking strength.

[0064] Combining Example 1 with Comparative Example 5 and Table 1, it can be seen that the collagen solution has good stability at 2-8°C. Controlling the temperature within this range can maintain the stability of the raw materials and ensure the best performance during the preparation process. At the same time, preparation under low temperature conditions helps to inhibit the growth and reproduction of bacteria, thereby improving the breaking strength and antibacterial properties of the prepared suture.

[0065] Combining Example 1 with Examples 4-5 and Example 10 and Table 1, it can be seen that the collagen solution prepared using the method of the present application has good biocompatibility, and the prepared suture has good antibacterial performance, good antibacterial durability and breaking strength.

[0066] Combining Examples 1-3 with Example 6 and Table 1, it can be seen that the particle size of nanosilver affects its stability in the suture. Nanosilver with a particle size range of 10-25 μm can better combine with collagen molecules to form a stable composite structure, prevent it from falling off or losing during use, and prolong the antibacterial effect of the suture.

[0067] Combining Example 1 with Examples 7-8 and Table 1, it can be seen that the concentration of the nanosilver solution affects the performance of the prepared suture. The nanosilver solution in the appropriate concentration range can ensure that the suture has strong antibacterial properties, and better combination with the collagen solution enables the prepared suture to have better breaking strength.

[0068] Combining Example 1 with Example 9 and Table 1, it can be seen that further performance enhancement through ultraviolet rays and ozone can promote the cross-linking and rearrangement of collagen molecules and the formation of a denser and more stable network structure with nanosilver particles, while activating the surface activity of the nanosilver particles, further improving the breaking strength and antibacterial durability of the suture.

[0069] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing nano silver antibacterial collagen suture, characterized in that: The steps include: (1) at a temperature of 2-8° C., stirring and mixing the nanosilver solution and the collagen solution in a weight ratio of (1-2): (8-9) for 1-2 h to obtain a mixed solution; (2) After the mixed solution is extruded into a filamentous substance by using microfluidics technology at a temperature of 2-8° C., the substance is solidified, dehydrated and shaped in 75%-95% ethanol to obtain a nano-silver antibacterial collagen suture 1; (3) The nano-silver antibacterial collagen suture 1 is dehydrated and air-dried at a temperature of 2-8° C. and a relative humidity of 45-65%, and then polished, needled, and sterilized to obtain the nano-silver antibacterial collagen suture.

2. The method for preparing a nano silver antibacterial collagen suture according to claim 1, characterized in that: The collagen solution is prepared by the following method: Step 1: Soak the animal tendon in a mixed solution of NaClO and NaOH with a pH of 12-14 for 1-2 hours at a temperature of 2-8°C, and filter out to obtain the animal tendon 1; Step 2: At a temperature of 2-8°C, soak the animal tendon 1 in mixed solution A for 2-3 hours, rinse it in purified water, and obtain the animal tendon 2; then, transfer the animal tendon 2 to mixed solution B and soak it for 36-48 hours, and after salting out and dialysis, obtain the animal tendon collagen solution; the mixed solution A is composed of a trypsin solution with a concentration of 0.2-1.0wt% and a Na2CO3 solution with a concentration of 0.15-0.65 mol / L, and the mixed solution B is composed of a pepsin solution with a concentration of 0.3-2.5wt% and an acetic acid solution with a concentration of 0.1-0.6 mol / L.

3. The method for preparing a nano silver antibacterial collagen suture according to claim 2, characterized in that: The animal tendons are the tendons of nutria limbs and tail.

4. The method for preparing a nano silver antibacterial collagen suture according to claim 2, characterized in that: The weight ratio of the tendon to trypsin and sodium carbonate is (7-9): (0.5-1.5): (0.5-1.5); the weight ratio of the tendon to pepsin and acetic acid is (7-9): (0.5-1.5): (0.5-1.5).

5. The method for preparing a nano silver antibacterial collagen suture according to claim 2, characterized in that: The concentration of NaClO is 0.01-10wt%, and the concentration of NaOH is 0.05-0.15 mol / L.

6. The method for preparing a nano silver antibacterial collagen suture according to claim 1, characterized in that: The concentration of the nanosilver solution in step (1) is 0.005-0.03 wt %, wherein the particle size of the nanosilver is 10-25 nm.

7. The method for preparing a nano silver antibacterial collagen suture according to claim 1, characterized in that: The steps also include performing a performance enhancement treatment on the mixed liquid, placing a 254nm ultraviolet lamp in the mixed liquid at 2-8°C for 7-8 hours, and at the same time, filling the mixed liquid with 10-30g / h of ozone for 4-5 hours. The whole process is fully stirred and mixed to obtain a performance-enhanced mixed liquid.

8. The method for preparing a nano silver antibacterial collagen suture according to claim 1, characterized in that: In the sterilization operation of step (3), 18-25 kGy Co60-γ ray radiation sterilization is used.

9. A nano-silver antibacterial collagen suture prepared by the method described in any one of claims 1 to 8.

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