Absorbable serrated material and method of making

Abstract

The present application relates to the technical field of biological materials, in particular to an absorbable serrated material and a preparation method thereof.The present application comprises the following steps: S1: taking pretreated mulberry silk braiding thread, immersing it in a double-bonded polycaprolactone melt, performing encapsulation treatment, and then cutting serrations on the surface of the thread by using a serration cutter to obtain serrated suture thread; S2: adding curcumin ethanol solution into a mercapto silk fibroin solution, mixing uniformly to obtain a mixed solution, freezing, thawing at room temperature, obtaining a nanoparticle emulsion, and then centrifuging and freeze-drying to obtain composite microspheres; S3: uniformly mixing the composite microspheres, mercapto collagen, a photoinitiator LAP and a phosphate buffer solution to obtain a coating solution; S4: immersing the serrated suture thread in the coating solution, performing ultraviolet light irradiation, washing and drying to obtain the absorbable serrated material, which has excellent mechanical properties and antibacterial effect.

Description

Technical Field

[0001] This invention relates to the field of biomaterials technology, specifically to an absorbable serrated material and its preparation method. Background Technology

[0002] With the continuous improvement of people's living standards and the rapid development of the medical field, serrated sutures, as a new minimally invasive cosmetic technique, have been widely used to improve facial aging. The main causes of facial aging are the sagging of the SMAS fascia system, the drooping of the cheek fat pads, the deepening of nasolabial folds, and the formation of cheek wrinkles, leading to overall sagging of facial skin tissue. Therefore, plastic surgeons generally believe that lifting and repositioning sagging tissues will be the core issue of modern facelift surgery.

[0003] The principle behind facial thread lifting is to implant serrated sutures into the corresponding layers of soft tissue. Because the serrated suture material is relatively tough, it is processed to create numerous barbs on its surface. These barbs have a certain strength and are aligned in the same direction; each serration adheres tightly to and is fixed to the soft tissue. When the serrated suture is pulled, the serrations fully open and come into close contact with the SMAS fascia layer at that location. Continued traction causes the tissue to be lifted and repositioned by a force in the same direction as the serrated suture. Simultaneously, as the serrated suture is absorbed, it stimulates fibroblast proliferation and collagen production, thereby promoting skin tightening and improving skin elasticity.

[0004] Absorbable serrated sutures often use synthetic absorbable materials such as poly(p-dioxanone) (PPDO), polyglycolic acid (PGA), polycaprolactone (PCL), polylactic acid (PLLA), and other copolymers. However, current sutures have poor biocompatibility, causing foreign body reactions in some patients, leading to redness, swelling, induration, and even granulomas. Some materials (such as PLGA) produce acidic metabolites (lactic acid, glycolic acid) after degradation, which may cause a decrease in local pH and irritate the tissue. Furthermore, the degradation rate of the suture is uncontrollable; if degradation is too rapid (e.g., PDO, typically 6-8 months), the lifting effect is short-lived, requiring frequent repeat treatments. Some absorbable serrated sutures experience a rapid decline in mechanical properties within 3-6 months after implantation, failing to maintain a long-term lifting effect; the mismatch between suture stiffness and soft tissue mechanical properties may lead to cutting or breakage.

[0005] Therefore, an absorbable serrated suture is needed that can avoid biological rejection reactions and has sufficient mechanical properties to maintain a long-term lifting effect. Summary of the Invention

[0006] The purpose of this invention is to provide an absorbable serrated material and its preparation method to solve the problems raised in the prior art.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] A method for preparing an absorbable serrated material includes the following steps:

[0009] Step S1: Take the pretreated mulberry silk braided thread, immerse it in double-bonded polycaprolactone melt, perform coating treatment, and then cut serrations on the surface of the thread body using a tooth cutting machine to obtain serrated sutures;

[0010] Step S2: Add the ethanol solution containing curcumin to the mercapto-modified silk fibroin solution, mix well to obtain a mixture, freeze, and then thaw at room temperature to obtain a nanoparticle emulsion. After centrifugation and freeze-drying, composite microspheres are obtained.

[0011] Step S3: Mix the composite microspheres, thiolized collagen, photoinitiator LAP and phosphate buffer evenly to obtain the coating solution;

[0012] Step S4: Immerse the serrated stitches in the coating solution, expose them to ultraviolet light, and after washing and drying, obtain an absorbable serrated material.

[0013] Furthermore, the preparation method of the pretreated mulberry silk braided thread is as follows: immerse the mulberry silk braided thread in water at 98±2℃ for 25-35 minutes, wash it with water 3-6 times, and dry it to obtain the pretreated mulberry silk braided thread.

[0014] Furthermore, the parameters of the tooth cutting machine are as follows: tooth length 0.30mm±0.10mm, tooth spacing 1.0mm±0.2mm, tooth angle α 40-45°, outward expansion angle θ 30-35°, and tooth depth a is 1 / 3 of the diameter of the toothed suture.

[0015] Furthermore, the preparation method of the double-bonded polycaprolactone is as follows:

[0016] Step A: Under argon protection, ε-caprolactone, polyethylene glycol and stannous octoate are mixed evenly and reacted at 120-130℃ for 22-24h. The reaction is terminated with cold water. The product is dissolved in chloroform, precipitated with petroleum ether, filtered, and dried to obtain PEG-PCL block copolymer.

[0017] Step B: Vacuum-dried PEG-PCL block copolymer, methacrylamide chitosan and isophorone diisocyanate are mixed evenly, stannous octoate is added, and the mixture is reacted at 70-80℃ for 8-10 h. The mixture is then filtered under reduced pressure to obtain double-bonded polycaprolactone.

[0018] Further, in step A, the mass ratio of ε-caprolactone, polyethylene glycol, and stannous octoate is 1:(10-11):(0.005-0.007).

[0019] Further, in step B, the molar ratio of hydroxyl groups in the PEG-PCL block copolymer, hydroxyl groups in the methacrylamide chitosan, and isophorone diisocyanate is 1:1:(1.0-1.2), and the mass of stannous octoate is 0.3-0.5% of the total mass of the PEG-PCL block copolymer and the methacrylamide chitosan.

[0020] In the above technical solution, stannous octoate is used as a catalyst to initiate the ring-opening polymerization of ε-caprolactone (CL) with star-shaped polyethylene glycol (PEG) to prepare a star-shaped PEG-PCL block copolymer. Further, using the PEG-PCL block copolymer and methacrylamide chitosan as raw materials, and isophorone diisocyanate (IPDI) as a coupling agent, unsaturated carbon-carbon double bonds are introduced into the star-shaped polycaprolactone to obtain double-bonded polycaprolactone.

[0021] Furthermore, the concentration of the ethanol solution containing curcumin is 1-3 mg / mL, and the mass fraction of the thiolated silk fibroin solution is 2-4%.

[0022] Furthermore, the volume ratio of the ethanol solution containing curcumin to the mercapto silk fibroin solution is 1:(2-4).

[0023] Further, in step S3, the mass ratio of the composite microspheres, thiolized collagen, photoinitiator LAP, and phosphate buffer is 1:(0.3-0.5):(0.1-0.3):(50-100).

[0024] Furthermore, the process conditions for ultraviolet irradiation are: irradiation wavelength 360-400nm, irradiation time 30-120s, and irradiation intensity 20-35mW / cm². 2 .

[0025] Furthermore, the method for preparing the thiolized collagen is as follows:

[0026] Collagen was added to an acetic acid solution and stirred to dissolve, thus obtaining a collagen solution. The collagen solution was transferred to a dialysis bag and dialyzed at 4-6°C with an alkaline phosphate buffer solution. Dialysis was performed until the pH reached 9-10. DL-N-acetylhomocysteine ​​and ethylenediaminetetraacetic acid were added, and the reaction was carried out under nitrogen protection for 22-24 hours. Dithiothreitol was then added, and stirring was continued for 10-12 hours. The mixture was then dialyzed and freeze-dried to obtain thiolized collagen.

[0027] Furthermore, the concentration of the acetic acid solution is 0.4-0.6M.

[0028] Further, the mass ratio of collagen, acetic acid solution, DL-N-acetylhomocysteine ​​thiolactone, ethylenediaminetetraacetic acid, and dithiothreitol is 1:(250-500):(0.8-1.5):(0.05-0.10):(0.25-0.75).

[0029] Furthermore, the thickness of the adhesive layer in the overmolding process is 5-20 μm.

[0030] Furthermore, the thickness of the coating is 10-30 μm.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. This invention uses mulberry silk braided thread as the core. Through hot-melt coating technology, molten double-bonded polycaprolactone is uniformly coated onto the surface of mulberry silk as the thread shell. After cooling, a smooth thread with controllable diameter is obtained. Then, the smooth thread is serrated. By controlling the serration process parameters, a serrated suture with good lifting force is obtained, which significantly improves the suturing effect and durability. Polycaprolactone (PCL) in the polymer has a low melting point and good processability. PCL can be completely degraded in vivo, and its metabolites are water and carbon dioxide, leaving no residue or side effects in vivo. At the same time, PCL is a powerful collagen regenerator. After being implanted into the skin, it can promote the reorganization and regeneration of collagen and elastic fibers, achieving the purpose of continuously delaying skin aging. Methacrylated chitosan is a natural polysaccharide derivative with broad-spectrum antibacterial and non-toxic properties. By introducing methacrylated chitosan into the star-shaped PEG-PCL block copolymer, not only are the mechanical properties of the material improved, but its antibacterial properties are also enhanced.

[0033] 2. Silk fibroin is a biomaterial composed of 18 amino acids. It has a wide range of raw material sources, is easy to obtain and process, and possesses advantages such as low immunogenicity, excellent mechanical properties, good biocompatibility with the human body, and the ability to promote tissue regeneration. This invention uses thiolated silk fibroin as a carrier to prepare composite microspheres loaded with the natural antibacterial agent curcumin. These microspheres exhibit good antibacterial properties and cell compatibility, and are expected to inhibit surgical site infections. Under the action of the photoinitiator LAP, tyrosine in the silk fibroin undergoes photocrosslinking to form a double tyrosine structure, generating a photocrosslinking network. Simultaneously, the composite microspheres, thiolated collagen, and double-bonded polycaprolactone in the coating solution undergo a "thiol-ene" click chemical reaction, forming a strong double crosslinking network. This ensures the tight bond between the coating and the fibroin. The synergistic effect between curcumin and methacryloxychitosan achieves long-term and effective inhibition of bacterial growth, significantly extending the antibacterial efficacy. Attached Figure Description

[0034] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0035] Figure 1 This is a schematic diagram of the absorbable serrated suture structure in this invention;

[0036] Figure 2 This is a schematic diagram of the serrations in the absorbable serrated suture of the present invention;

[0037] In the diagram: α is the sawtooth angle, θ is the outward expansion angle, and a is the sawtooth depth. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include: mulberry silk braiding thread: No. 4-0 thread, diameter 0.45mm, length 150mm; methacrylamide chitosan: model Q-0291683, purchased from Xi'an Qiyue Biotechnology Co., Ltd.; thiolated silk fibroin: purchased from Shenzhen Meiluo Technology Co., Ltd.; collagen: collagen type I, model C8061, purchased from Beijing Solarbio Technology Co., Ltd.

[0040] Example 1: An absorbable serrated material and its preparation method, comprising the following steps:

[0041] Step S1: Immerse the mulberry silk braided thread in 96℃ water for 25 minutes, wash it three times with water, and dry it to obtain pretreated mulberry silk braided thread; take the pretreated mulberry silk braided thread, immerse it in double-bonded polycaprolactone melt for coating treatment, and then cut serrations on the surface of the thread body using a tooth cutting machine. The serration length is 0.30mm, the serration spacing is 1.0mm, the serration angle α is 40°, the outward expansion angle θ is 30°, and the serration depth a is 1 / 3 of the diameter of the serrated suture to obtain the serrated suture;

[0042] Step S2: Add 500 mL of ethanol solution containing 1 mg / mL curcumin to 1000 mL of 2 wt% mercapto-modified silk fibroin solution, mix well, freeze the resulting mixture at -20℃ for 12 h, and then thaw at room temperature to obtain nanoparticle emulsion. After centrifugation and freeze-drying, composite microspheres are obtained.

[0043] Step S3: Mix 10g of composite microspheres, 3g of thiolized collagen, 1 part of photoinitiator LAP and 500g of phosphate buffer evenly to obtain a coating solution;

[0044] Step S4: Immerse the serrated suture in the coating solution for 5 minutes, then irradiate with ultraviolet light at a wavelength of 360 nm for 30 seconds and an intensity of 35 mW / cm². 2 After washing and drying, an absorbable serrated material is obtained.

[0045] The preparation method of double-bonded polycaprolactone is as follows:

[0046] Step A: Under argon protection, ε-caprolactone, polyethylene glycol and stannous octoate were mixed evenly in a mass ratio of 1:10:0.005 and reacted at 120°C for 22 h. The reaction was terminated with cold water. The product was dissolved in chloroform, precipitated with petroleum ether, filtered, and dried to obtain PEG-PCL block copolymer.

[0047] Step B: The vacuum-dried PEG-PCL block copolymer, methacrylamide chitosan, and isophorone diisocyanate were mixed evenly, and stannous octoate was added. The mixture was reacted at 70°C for 8 hours, and then filtered under reduced pressure to obtain double-bonded polycaprolactone. The molar ratio of hydroxyl groups in the PEG-PCL block copolymer, the hydroxyl groups in the methacrylamide chitosan, and isophorone diisocyanate was 1:1:1, and the mass of stannous octoate was 0.3% of the total mass of the PEG-PCL block copolymer and the methacrylamide chitosan.

[0048] The preparation method of thiolized collagen is as follows:

[0049] 3g of collagen was added to 750g of 0.4M acetic acid solution and stirred to dissolve, thus obtaining a collagen solution. The collagen solution was transferred to a dialysis bag and dialyzed at 4°C with alkaline phosphate buffer solution. Dialysis was performed until the pH reached 9. 2.4g of DL-N-acetylhomocysteine ​​thiolactone and 0.15g of ethylenediaminetetraacetic acid were added, and the reaction was carried out under nitrogen protection for 22h. Then, 0.75g of dithiothreitol was added, and stirring was continued for 10h. Dialysis and freeze-drying were performed to obtain thiolized collagen.

[0050] Example 2: An absorbable serrated material and its preparation method, comprising the following steps:

[0051] Step S1: Immerse the mulberry silk braided thread in 98℃ water for 30 minutes, wash it with water 4 times, and dry it to obtain pretreated mulberry silk braided thread; take the pretreated mulberry silk braided thread, immerse it in double-bonded polycaprolactone melt for coating treatment, and then cut serrations on the surface of the thread body using a tooth cutting machine. The tooth length is 0.30mm, the tooth spacing is 1.0mm, the tooth angle α is 40°, the outward expansion angle θ is 30°, and the tooth depth a is 1 / 3 of the diameter of the serrated suture to obtain the serrated suture;

[0052] Step S2: Add 500 mL of ethanol solution containing 2 mg / mL curcumin to 1500 mL of 3 wt% mercapto-modified silk fibroin solution, mix well, freeze the resulting mixture at -20℃ for 18 h, and then thaw at room temperature to obtain nanoparticle emulsion. After centrifugation and freeze-drying, composite microspheres are obtained.

[0053] Step S3: Mix 10g of composite microspheres, 4g of thiolized collagen, 2g of photoinitiator LAP and 800g of phosphate buffer evenly to obtain a coating solution;

[0054] Step S4: Immerse the serrated suture in the coating solution for 8 minutes, then irradiate with ultraviolet light at a wavelength of 380 nm for 60 seconds at an intensity of 30 mW / cm². 2 After washing and drying, an absorbable serrated material is obtained.

[0055] The preparation method of double-bonded polycaprolactone is as follows:

[0056] Step A: Under argon protection, ε-caprolactone, polyethylene glycol and stannous octoate were mixed evenly in a mass ratio of 1:10.5:0.006 and reacted at 125°C for 23 h. The reaction was terminated with cold water. The product was dissolved in chloroform, precipitated with petroleum ether, filtered, and dried to obtain PEG-PCL block copolymer.

[0057] Step B: The vacuum-dried PEG-PCL block copolymer, methacrylamide chitosan, and isophorone diisocyanate were mixed evenly, stannous octoate was added, and the mixture was reacted at 75°C for 9 hours. After vacuum filtration, double-bonded polycaprolactone was obtained. The molar ratio of hydroxyl groups in the PEG-PCL block copolymer, hydroxyl groups in the methacrylamide chitosan, and isophorone diisocyanate was 1:1:1.1, and the mass of stannous octoate was 0.4% of the total mass of the PEG-PCL block copolymer and methacrylamide chitosan.

[0058] The preparation method of thiolized collagen is as follows:

[0059] 4g of collagen was added to 1500g of 0.5M acetic acid solution and stirred to dissolve, thus obtaining a collagen solution. The collagen solution was transferred to a dialysis bag and dialyzed at 5°C with alkaline phosphate buffer solution. Dialysis was performed until the pH reached 9.5. 4g of DL-N-acetylhomocysteine ​​thiolactone and 0.32g of ethylenediaminetetraacetic acid were added, and the reaction was carried out under nitrogen protection for 23h. Then, 2g of dithiothreitol was added, and stirring was continued for 11h. Dialysis and freeze-drying were performed to obtain thiolized collagen.

[0060] Example 3: An absorbable serrated material and its preparation method, comprising the following steps:

[0061] Step S1: Immerse the mulberry silk braided thread in 100℃ water for 35 minutes, wash it with water 6 times, and dry it to obtain pretreated mulberry silk braided thread; take the pretreated mulberry silk braided thread, immerse it in double-bonded polycaprolactone melt for coating treatment, and then cut serrations on the surface of the thread body using a tooth cutting machine. The tooth length is 0.30mm, the tooth spacing is 1.0mm, the tooth angle α is 40°, the outward expansion angle θ is 30°, and the tooth depth a is 1 / 3 of the diameter of the serrated suture to obtain the serrated suture;

[0062] Step S2: Add 500 mL of ethanol solution containing 2 mg / mL curcumin to 2000 mL of 4 wt% mercapto-modified silk fibroin solution, mix well, freeze the resulting mixture at -20℃ for 24 h, and then thaw at room temperature to obtain nanoparticle emulsion. After centrifugation and freeze-drying, composite microspheres are obtained.

[0063] Step S3: Mix 10g of composite microspheres, 5g of thiolized collagen, 3g of photoinitiator LAP and 1000g of phosphate buffer evenly to obtain a coating solution;

[0064] Step S4: Immerse the serrated suture in the coating solution for 10 minutes, then irradiate with ultraviolet light at a wavelength of 400 nm for 120 seconds at an intensity of 20 mW / cm². 2 After washing and drying, an absorbable serrated material is obtained.

[0065] The preparation method of double-bonded polycaprolactone is as follows:

[0066] Step A: Under argon protection, ε-caprolactone, polyethylene glycol and stannous octoate were mixed evenly in a mass ratio of 1:11:0.007 and reacted at 130°C for 24 h. The reaction was terminated with cold water. The product was dissolved in chloroform, precipitated with petroleum ether, filtered, and dried to obtain PEG-PCL block copolymer.

[0067] Step B: The vacuum-dried PEG-PCL block copolymer, methacrylamide chitosan, and isophorone diisocyanate were mixed evenly, and stannous octoate was added. The mixture was reacted at 80°C for 10 h, and then filtered under reduced pressure to obtain double-bonded polycaprolactone. The molar ratio of hydroxyl groups in the PEG-PCL block copolymer, the hydroxyl groups in the methacrylamide chitosan, and isophorone diisocyanate was 1:1:1.2, and the mass of stannous octoate was 0.5% of the total mass of the PEG-PCL block copolymer and the methacrylamide chitosan.

[0068] The preparation method of thiolized collagen is as follows:

[0069] 5g of collagen was added to 2500g of 0.6M acetic acid solution and stirred to dissolve, thus obtaining a collagen solution. The collagen solution was transferred to a dialysis bag and dialyzed at 6°C with an alkaline phosphate buffer solution. Dialysis was continued until the pH reached 10. 7.5g of DL-N-acetylhomocysteine ​​thiolactone and 0.5g of ethylenediaminetetraacetic acid were added, and the reaction was carried out under nitrogen protection for 24h. Then, 3.75g of dithiothreitol was added, and stirring was continued for 12h. Dialysis and freeze-drying were performed to obtain thiolized collagen.

[0070] Comparative Example 1: An absorbable serrated material and its preparation method, comprising the following steps:

[0071] The mulberry silk braided thread was immersed in 98℃ water for 30 minutes, washed with water 4 times, and dried to obtain pretreated mulberry silk braided thread. The pretreated mulberry silk braided thread was then immersed in polycaprolactone melt for coating treatment. Then, a sawtooth was cut on the surface of the thread using a sawtooth cutting machine. The sawtooth length was 0.30 mm, the sawtooth spacing was 1.0 mm, the sawtooth angle α was 40°, the outward expansion angle θ was 30°, and the sawtooth depth a was 1 / 3 of the diameter of the sawtooth suture to obtain a sawtooth suture, which can absorb sawtooth materials.

[0072] Based on Example 2, Comparative Example 1 replaced the double-bonded polycaprolactone with the same mass of polycaprolactone.

[0073] Comparative Example 2: An absorbable serrated material and its preparation method, comprising the following steps:

[0074] Step S1: Immerse the mulberry silk braided thread in 98℃ water for 30 minutes, wash it with water 4 times, and dry it to obtain pretreated mulberry silk braided thread; take the pretreated mulberry silk braided thread, immerse it in double-bonded polycaprolactone melt for coating treatment, and then cut serrations on the surface of the thread body using a tooth cutting machine. The tooth length is 0.30mm, the tooth spacing is 1.0mm, the tooth angle α is 40°, the outward expansion angle θ is 30°, and the tooth depth a is 1 / 3 of the diameter of the serrated suture to obtain the serrated suture;

[0075] Step S2: Mix 10g of thiolated silk fibroin, 4g of thiolated collagen, 2g of photoinitiator LAP and 800g of phosphate buffer evenly to obtain a coating solution;

[0076] Step S3: Immerse the serrated suture in the coating solution for 8 minutes, then irradiate with ultraviolet light at a wavelength of 380 nm for 60 seconds at an intensity of 30 mW / cm². 2 After washing and drying, an absorbable serrated material is obtained.

[0077] Based on Example 2, Comparative Example 2 replaced the composite microspheres with the same mass of thiolated silk fibroin, while the remaining process steps and reaction parameters were the same as in Example 2.

[0078] Comparative Example 3: Based on Example 2, Comparative Example 3 does not introduce thiolized collagen, and the remaining process steps and reaction parameters are the same as in Example 2.

[0079] experiment:

[0080] Tensile strength test: The absorbable serrated materials obtained in Examples 1-3 and Comparative Examples 1-3 were tested according to GB / T14344-2022 standard, with a tensile speed of 50 mm / min.

[0081] Degradation stability test: The absorbable serrated materials obtained in Examples 1-3 and Comparative Examples 1-3 were tested according to GB / T16886.13-2017 standard. Experimental procedure: PBS solution (pH=7.4) containing 1 U / mL collagenase was used as the soaking solution. The mass ratio of absorbable serrated material to soaking solution volume was 0.1g:40mL. The samples were placed in a constant temperature shaking incubator at 37±1℃ and 60 rpm for 60 days. The soaking solution was changed every 3 days. During the degradation process, the change in mechanical strength of the samples was recorded, and the retention rate of mechanical strength of the embedded wire after degradation was calculated.

[0082] Antibacterial test: Staphylococcus aureus was cultured to the logarithmic growth phase, and the original bacterial solution was diluted to 10⁻⁶. 6 CFU / mL. Take 15ml of bacterial suspension and add the absorbable serrated material obtained in Examples 1-3 and Comparative Examples 1-3 respectively. Incubate in a 37°C incubator, dilute with PBS, and spread 100 uL of the diluted bacterial suspension evenly on an agar plate. Invert the plate and incubate statically in a 37°C incubator for 24h. Observe the morphology of Staphylococcus aureus and count the bacteria to calculate the inhibition rate.

[0083] The test results are shown in Table 1.

[0084] Table 1. Performance test results of absorbable serrated materials

[0085]

[0086] Based on the data in the table above, the following conclusions can be clearly drawn: the medical surgical sutures prepared in the embodiments of the present invention have superior mechanical properties, biocompatibility, bactericidal and antibacterial properties, extend the service life of the material, and have good absorbability.

[0087] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0088] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for preparing an absorbable serrated material, characterized in that: Includes the following steps: Step S1: Take the pretreated mulberry silk braided thread, immerse it in double-bonded polycaprolactone melt, perform coating treatment, and then cut serrations on the surface of the thread body using a tooth cutting machine to obtain serrated sutures; Step S2: Add the ethanol solution containing curcumin to the mercapto-modified silk fibroin solution, mix well to obtain a mixture, freeze, and then thaw at room temperature to obtain a nanoparticle emulsion. After centrifugation and freeze-drying, composite microspheres are obtained. Step S3: Mix the composite microspheres, thiolized collagen, photoinitiator LAP and phosphate buffer evenly to obtain the coating solution; Step S4: Immerse the serrated stitches in the coating solution, expose them to ultraviolet light, and after washing and drying, obtain an absorbable serrated material. The preparation method of the double-bonded polycaprolactone is as follows: Step A: Under argon protection, ε-caprolactone, polyethylene glycol and stannous octoate are mixed evenly and reacted at 120-130℃ for 22-24h. The reaction is terminated with cold water. The product is dissolved in chloroform, precipitated with petroleum ether, filtered, and dried to obtain PEG-PCL block copolymer. Step B: Vacuum-dried PEG-PCL block copolymer, methacrylamide chitosan and isophorone diisocyanate are mixed evenly, stannous octoate is added, and the mixture is reacted at 70-80℃ for 8-10 h. The mixture is then filtered under reduced pressure to obtain double-bonded polycaprolactone.

2. The method for preparing an absorbable serrated material according to claim 1, characterized in that: The preparation method of the pretreated mulberry silk braided thread is as follows: Immerse the mulberry silk braided thread in water at 98±2℃ for 25-35 minutes, wash it with water 3-6 times, and dry it to obtain the pretreated mulberry silk braided thread.

3. The method for preparing an absorbable serrated material according to claim 1, characterized in that: The parameters of the tooth cutting machine are as follows: tooth length 0.30mm±0.10mm, tooth spacing 1.0mm±0.2mm, tooth angle α 40-45°, outward expansion angle θ 30-35°, and tooth depth a is 1 / 3 of the diameter of the toothed suture.

4. The method for preparing an absorbable serrated material according to claim 1, characterized in that: In step A, the mass ratio of ε-caprolactone, polyethylene glycol, and stannous octoate is 1:(10-11):(0.005-0.007).

5. The method for preparing an absorbable serrated material according to claim 1, characterized in that: The concentration of the ethanol solution containing curcumin is 1-3 mg / mL, and the mass fraction of the thiolated silk fibroin solution is 2-4%.

6. The method for preparing an absorbable serrated material according to claim 1, characterized in that: In step S3, the mass ratio of the composite microspheres, thiolized collagen, photoinitiator LAP, and phosphate buffer is 1:(0.3-0.5):(0.1-0.3):(50-100).

7. The method for preparing an absorbable serrated material according to claim 6, characterized in that: The method for preparing the thiolized collagen is as follows: Collagen is added to an acetic acid solution and stirred to dissolve, thus obtaining a collagen solution. The collagen solution was transferred to a dialysis bag and dialyzed at 4-6°C with an alkaline phosphate buffer solution. The dialysate was dialyzed until the pH reached 9-10. DL-N-acetylhomocysteine ​​thiolactone and ethylenediaminetetraacetic acid were added, and the reaction was carried out under nitrogen protection for 22-24 hours. Then, dithiothreitol was added, and the mixture was stirred for another 10-12 hours. The mixture was then dialyzed and freeze-dried to obtain thiolized collagen.

8. The method for preparing an absorbable serrated material according to claim 7, characterized in that: The mass ratio of collagen, acetic acid solution, DL-N-acetylhomocysteine ​​thiolactone, ethylenediaminetetraacetic acid, and dithiothreitol is 1:(250-500):(0.8-1.5):(0.05-0.10):(0.25-0.75).

9. An absorbable serrated material prepared by the preparation method according to any one of claims 1-8.

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