A sutureable membrane with adhesion ability and preparation method thereof

Abstract

The present invention discloses a sutureable membrane with adhesive ability and a preparation method thereof, specifically comprising the following steps: placing a silk fabric in an alkaline degumming solution for degumming, and washing and drying to obtain a substrate; mixing a polymer solute with water to obtain a polymer aqueous solution with a mass ratio of 2 to 5%; mixing the polymer aqueous solution with a plasticizer, and vacuum degassing to obtain a mixture; taking the mixture and the substrate to form a membrane, freezing and drying to obtain a base membrane; spraying a silk fibroin aqueous solution and a gelatin aqueous solution on one side of the base membrane, drying, and then cross-linking to obtain a sutureable membrane with adhesive ability. The present invention provides a sutureable membrane with adhesive ability, which uses degummed silk as a base material for processing and supplemented with a polymer solution for filling to ensure that the sutured needle holes can be blocked and prevent cerebrospinal fluid from penetrating.

Description

Technical Field

[0001] The present invention relates to the technical field of sewable films, and in particular to a sewable film with adhesion ability and a preparation method thereof. Background Art

[0002] Dural defects are common in spinal surgery and neurosurgery. Cerebrospinal fluid leakage following dural rupture can lead to a range of complications. To prevent CSF leakage, suturing the defect with a patch may be necessary in clinical practice to reduce the risk of leakage.

[0003] Currently, sutureable membranes used in repair materials are mostly polyester and polymer biomaterials. Polyester materials offer excellent strength and biocompatibility, but are susceptible to degradation and acidic properties, leading to tissue damage. Polymer biomaterials offer good biocompatibility and biodegradability, but their application is limited by cost, strength, and toughness. Therefore, developing a suture membrane with high strength, toughness, reasonable cost, and excellent bioperformance is a current research hotspot for treating dural defects. Summary of the Invention

[0004] The object of the present invention is to provide a sutureable membrane with adhesion ability and a preparation method thereof, so as to overcome the deficiencies in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The present application discloses a method for preparing a sutureable membrane with adhesion ability, which specifically comprises the following steps:

[0007] S1, placing the silk fabric in an alkaline degumming solution for degumming, and washing and drying the silk fabric to obtain a substrate;

[0008] S2. Mixing the polymer solute with water and stirring to obtain a polymer aqueous solution with a mass ratio of 2 to 5%;

[0009] S3, mixing the polymer aqueous solution in step S2 with the plasticizer, stirring, and vacuum degassing to obtain a mixture;

[0010] S4, taking the mixture of step S3 and the substrate of step S1 to form a membrane, and then freezing and drying to obtain a base membrane;

[0011] S5. Spraying a silk fibroin aqueous solution and a gelatin aqueous solution on one side of the base membrane in step S4, and then cross-linking after drying to obtain a sutureable membrane with adhesion ability.

[0012] Preferably, the silk fabric in step S1 is a knitted warp knitted fabric or a knitted weft knitted fabric; and the drying temperature is 25-85°C.

[0013] Preferably, the high molecular weight solute in step S2 includes a combination of one or more of carboxymethyl chitosan, gelatin, collagen, and sodium alginate.

[0014] Preferably, in step S3, the plasticizer is one or more of triethyl citrate, triethyl glycerol, and isopropyl palmitate; the mass ratio of the polymer aqueous solution to the plasticizer is 95:5 to 98:2; the vacuum degassing time is 2 to 5 minutes, and the stirring time is 5 to 10 minutes.

[0015] Preferably, the specific operations of step S4 are as follows:

[0016] S41, taking the mixture and the substrate according to a mass ratio of the polymer solute in the mixture to the substrate of 10:1 to 25:1;

[0017] S42, spreading the mixture on the mold according to the proportion, placing a negative base, and then spreading the mixture on the base to complete the film laying;

[0018] S43, after pre-freezing, freezing, and drying, a base membrane is obtained;

[0019] Preferably, in step S43, the pre-freezing time is 3 to 6 hours, and the freezing time is 24 to 48 hours.

[0020] Preferably, the ratio of the mixture to the mold in step S42 is 1g:1cm 2 .

[0021] Preferably, in step S5 , the concentrations of the silk fibroin aqueous solution and the gelatin aqueous solution are both 2%, wherein the mass ratio of the silk fibroin aqueous solution to the gelatin aqueous solution is 6:4 to 4:6, and the drying temperature is 25 to 85° C.

[0022] Preferably, the aperture of the spray in step S5 is 0.1-1 μm and the spraying time is 5-10 min.

[0023] The present invention also discloses a sutureable membrane with adhesion ability, which is prepared by the preparation method of a sutureable membrane with adhesion ability as described above; the product structure has four layers, which are, from top to bottom, an adhesive layer, a sealing layer, a base layer and a sealing layer; it can be applied and sutured.

[0024] Beneficial effects of the present invention:

[0025] 1. The present invention provides a sutureable membrane with adhesion ability. The method uses degummed silk as a base material for processing and is supplemented with a polymer solution for filling to ensure that the needle holes after suture can be blocked and cerebrospinal fluid penetration can be prevented.

[0026] 2. Using degummed silk as the base material is non-immunogenic and has the ability to enhance cell repair and regeneration, blocking the formation of melanin from the source, promoting collagen synthesis, and increasing the skin's metabolism rate. It is also widely available and low-cost.

[0027] 3. The sprayed nanoparticles make the product sticky.

[0028] 4. The product has excellent mechanical properties.

[0029] The features and advantages of the present invention will be described in detail through embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 1 is a structural diagram of a test device for anti-permeability performance according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. However, it should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the present invention.

[0032] Example 1:

[0033] S1. Degumming a knitted warp knitted fabric by placing it in a 0.1 wt% sodium carbonate solution for 2 degumming times of 10 min / time, followed by washing with water; finally, drying the fabric in a stainless steel tray at 25° C. to obtain a substrate;

[0034] S2, mixing gelatin and aqueous solution at 45°C to obtain a 2% gelatin aqueous solution;

[0035] S3, taking 2% gelatin aqueous solution and triethyl citrate in a ratio of 95g:5g, mixing and stirring for 5 minutes, and vacuum degassing for 2 minutes to obtain a mixture;

[0036] S4, spread 50g of the mixture on an area of ​​100cm 2 A mold was prepared, and a 0.2 g substrate was placed on it; 50 g of the mixture was continued to be spread on the substrate; the mixture was placed in a refrigerator for 3 hours and freeze-dried for 24 hours to obtain a base membrane;

[0037] S5. A 2% silk fibroin aqueous solution and a 2% gelatin aqueous solution were mixed in a mass ratio of 6:4 by spraying technology, and then sprayed on one side of the base membrane of S4 for 5 minutes and dried at 25°C; the dried product was fumigated with glutaraldehyde and cross-linked to obtain the product; the aperture of the sprayer was 0.1 μm.

[0038] Product experimental test:

[0039] The thickness, tensile strength, seam strength and adhesive strength of the membrane were tested.

[0040] I. Tensile Strength / Elongation at Break Test: After rehydrating the silk protein membrane prepared in Example 1 for 1 minute, the sample was cut into 50 mm × 10 mm strips. The strip thickness D (in mm) was measured. The strips were then secured at both ends to the clamps of a universal testing machine, with the clamps spaced 20 mm apart. The strips were then stretched at a constant rate of 50 mm / min until they broke. The maximum force F (in Newtons) during this process was recorded. The tensile strength T was calculated as follows:

[0041]

[0042] Where: W is the width of the specimen, 10 mm.

[0043] The elongation at break is the percentage of length change before and after stretching.

[0044] Suture Strength: After rehydrating the silk protein membrane prepared in Example 1 for 1 minute, the sample was cut into 20 mm × 20 mm specimens. A 2-0 medical nylon suture was inserted through the specimen 2 mm from one end, forming a semi-circular suture. The specimen and suture were secured to the fixture of a universal testing machine. The suture was stretched at a rate of 50 mm / min. The maximum force required to pull the suture from the specimen or damage the specimen was recorded, representing the suture strength (S (N).

[0045] 3. Adhesion strength:

[0046] Take any sample and cut it into a circle with a diameter of 3.0 cm ± 0.1 cm.

[0047] Take the Tyvek ring and moisten it with a small amount of saline using a spray bottle;

[0048] Take the test sample and place it on the Tyvek ring with the text facing up. The center of the test sample and the ring should coincide.

[0049] Gently press the test sample until it is completely adhered to the surface of the ring. There should be no visible bubbles or gaps.

[0050] Place the sample face down in saline for rehydration for 30 seconds, remove and flip; place the ring face down in saline for another 30 seconds; remove and use filter paper to remove water droplets on the surface of the sample and the ring;

[0051] Take a PVC tape disc and stick it on the upper surface of the test sample. The center of the test sample and the disc should coincide.

[0052] Use a roller to roll back and forth five times in both directions of a cross just above the tape disc; place the ring face up on the test module of the tensile testing machine, fix it, and apply pressure to the sample at a speed of 50 mm / min through the ring hole. Record the maximum pressure value during the process of the sample falling off the ring.

[0053] 4. Anti-penetration performance:

[0054] Sampling: Cut the sample to a size of 3.2~3.4cm in diameter;

[0055] Place the sample between two PVC pipes and use aluminum foil tape to glue the pipes and the sample together (as shown in the figure). Figure 1 Inject a standard water column into the upper part of the pipe and hold for 1 minute to observe whether it penetrates.

[0056] Example 2:

[0057] S1. Take a knitted warp knitted fabric and place it in a sodium carbonate solution with a concentration of 0.1wt% for degumming. The degumming process is 2 times and the time is 10min / time. Then, the fabric is washed with water. Finally, the fabric is dried in a stainless steel tray at 85°C to obtain a substrate.

[0058] S2, mixing carboxymethyl chitosan and the aqueous solution at 45° C. and stirring to obtain a carboxymethyl chitosan aqueous solution with a solute content of 5%;

[0059] S3, 5% carboxymethyl chitosan aqueous solution and triethyl glycerol were mixed in a ratio of 98 g:2 g, stirred for 10 min, and vacuum degassed for 5 min to obtain a mixture;

[0060] S4, spread 50g of the mixture on an area of ​​100cm 2 A mold was prepared, and 0.2 g of substrate was placed on it; 50 g of the mixture was continued to be spread on the substrate; the mixture was placed in a refrigerator for 6 hours and freeze-dried for 48 hours to obtain a base membrane;

[0061] S5. Mixing a 2% silk fibroin aqueous solution and a 2% gelatin aqueous solution in a mass ratio of 4:6 by spraying technology, and then spraying the mixture on one side of the base membrane for 10 minutes, drying the mixture at 85° C., and fumigating the mixture with glutaraldehyde for cross-linking to obtain a product.

[0062] Among them, the aperture of the sprayer is 1um.

[0063] Example 3:

[0064] S1, taking a knitted weft-knitted fabric, placing it in a sodium carbonate solution with a concentration of 0.1 wt% for degumming, degumming twice for 10 min each time, and then washing with water; finally, placing it in a stainless steel tray and drying it at 60°C to obtain a substrate;

[0065] S2, dissolving 1.44 g of collagen and 1.44 g of carboxymethyl chitosan in 93.12 g of water to obtain a 3% aqueous solution of high molecular weight solutes;

[0066] S3, 3% aqueous solution of polymer solute B and isopropyl palmitate were mixed in a ratio of 96 g:4 g, stirred for 7 min, and vacuum degassed for 3 min to obtain a mixture;

[0067] S4, spread 50g of the mixture on an area of ​​100cm 2 A mold was prepared, and 0.2 g of substrate was placed on it; 50 g of the mixture was continued to be spread on the substrate; the mixture was placed in a refrigerator for 4 hours and freeze-dried for 36 hours to obtain a base membrane;

[0068] S5. Mixing a 2% silk fibroin aqueous solution and a 2% gelatin aqueous solution in a mass ratio of 5:5 by spraying technology, and then spraying the mixture on one side of the base membrane for 7.5 minutes. Drying the mixture at 60° C. and fumigating the mixture with glutaraldehyde to crosslink the mixture after drying, thereby obtaining a product.

[0069] Among them, the aperture of the sprayer is 0.5um.

[0070] Example 4:

[0071] S1, taking a knitted weft fabric, placing it in a sodium carbonate solution with a concentration of 0.1wt% for degumming, degumming twice for 10 minutes each time, and then washing with water; finally, drying it in a stainless steel tray at 37°C to obtain a substrate;

[0072] S2, dissolving 2.88 g of sodium alginate in 93.12 g of water to obtain a 3% sodium alginate aqueous solution;

[0073] S3. Mix 96 g of 3% sodium alginate aqueous solution with 2 g of isopropyl palmitate and 2 g of triethyl palmitate, stirring for 7 min, and vacuum degassing for 3 min to obtain a mixture;

[0074] S4, spread 50g of the mixture on an area of ​​100cm 2 A mold was prepared, and 0.2 g of substrate was placed on it; 50 g of the mixture was continued to be spread on the substrate; the mixture was placed in a refrigerator for 4 hours and freeze-dried for 36 hours to obtain a base membrane;

[0075] S5. A 2% silk fibroin aqueous solution and a 2% gelatin aqueous solution were mixed in a mass ratio of 5:5 by spraying technology, and then sprayed on one side of the base membrane for 5 minutes. The mixture was dried at 37°C and then fumigated with glutaraldehyde for cross-linking to obtain the product.

[0076] Among them, the aperture of the sprayer is 0.5um.

[0077] Comparative Example 1:

[0078] The only difference between this comparative example and Example 1 is that the drying temperature in steps S1 and S5 is 105°C.

[0079] Comparative Example 2:

[0080] The only difference between this comparative example and Example 1 is that the drying temperature in steps S1 and S5 is 10°C;

[0081] Comparative Example 3:

[0082] The only difference between this comparative example and Example 1 is that: in step S2, gelatin and an aqueous solution are mixed and stirred at 45° C. to obtain a gelatin aqueous solution with a solute content of 1%;

[0083] Comparative Example 4:

[0084] The difference between this comparative example and Example 1 is that: in step S2, gelatin and the aqueous solution are mixed and stirred at 45° C. to obtain a gelatin aqueous solution with a solute content of 7%, and the rest is the same as in Example 1;

[0085] Comparative Example 5:

[0086] The only difference between this comparative example and Example 1 is that in step S3, 2% gelatin aqueous solution and triethyl citrate are mixed and stirred at a ratio of 99 g:1 g for 5 min, and vacuum degassing is performed for 2 min;

[0087] Comparative Example 6:

[0088] The only difference between this comparative example and Example 1 is that in step S3, 2% gelatin aqueous solution B and triethyl citrate are mixed and stirred at a ratio of 93 g:7 g for 5 min, and vacuum degassing is performed for 2 min;

[0089] Comparative Example 7:

[0090] The only difference between this comparative example and Example 1 is that in step S3, the degassing time in step S3 is 1 min.

[0091] Comparative Example 8:

[0092] The only difference between this comparative example and Example 1 is that in step S3, the stirring time in step S3 is 3 minutes.

[0093] Comparative Example 9:

[0094] The difference between this comparative example and Example 1 is that in step S4, 50 g of the mixture is spread on an area of ​​100 cm 2 A mold was prepared, and a 0.4 g substrate was placed on it; 50 g of the mixture was continued to be spread on the substrate; the mixture was placed in a refrigerator for 3 hours and freeze-dried for 24 hours;

[0095] Comparative Example 10:

[0096] The difference between this comparative example and Example 1 is that in step S4, 50 g of the mixture is spread on an area of ​​100 cm 2 A mold was prepared, with a negative pressure of 0.067 g of substrate placed on it; 50 g of the mixture was continued to be spread on the substrate; the mixture was placed in a refrigerator for 3 h and then freeze-dried for 24 h;

[0097] Comparative Example 11:

[0098] The difference between this comparative example and Example 1 is that in step S4, 50 g of the mixture is spread on an area of ​​100 cm 2 A mold was prepared, and a 0.2 g substrate was placed on it; 50 g of the mixture was continued to be spread on the substrate; the mixture was placed in a refrigerator for 1 hour and freeze-dried for 20 hours;

[0099] Comparative Example 12:

[0100] The only difference between this comparative example and Example 1 is that in step S5, a 2% silk fibroin aqueous solution and a 2% gelatin aqueous solution are mixed in a mass ratio of 7:3 by spraying technology, and then sprayed on one side of the base membrane and dried at 25°C; the aperture of the sprayer is 0.1um.

[0101] Comparative Example 13:

[0102] The only difference between this comparative example and Example 1 is that in step S5, a 2% silk fibroin aqueous solution and a 2% gelatin aqueous solution are mixed in a mass ratio of 3:7 by spraying technology, and then sprayed on one side of the base membrane and dried at 25°C. The aperture of the sprayer is 0.1um.

[0103] Comparative Example 14:

[0104] The only difference between this comparative example and Example 1 is that in step S5, a 2% silk fibroin aqueous solution and a 2% gelatin aqueous solution are mixed in a mass ratio of 6:4 by spraying technology, and then sprayed on one side of the base membrane and dried at 25°C. The aperture of the sprayer is 0.2 μm.

[0105] Comparative Example 15:

[0106] The only difference between this comparative example and Example 1 is that in step S5, the spraying time is 1 min.

[0107] Comparative Example 16:

[0108] The only difference between this comparative example and Example 1 is that in step S5, the spraying time is 15 minutes.

[0109] Table 1 Strength test comparison

[0110]

[0111] From Example 1 and Comparative Example 1, it can be seen that when the temperature is too high, the obtained film is relatively brittle; when the temperature is too low in Comparative Example 2, the drying speed is too slow and the efficiency is too low, so this parameter is not selected;

[0112] In the preparation process of Comparative Example 3, the polymer tends to be relatively dilute, the silk fabric cannot float on it, and the product cannot be obtained;

[0113] The membrane sealing layer prepared in Comparative Example 4 was too thick, and it swelled too much after absorbing water, resulting in liquid leakage;

[0114] Comparative Example 5 used less plasticizer, and the resulting film was extremely brittle and could not be tested or used;

[0115] From Example 1 and Comparative Example 6, it can be seen that adding too much plasticizer will soften the film but reduce its strength;

[0116] During the preparation of Comparative Examples 7 and 8, it was found that the test time was insufficient to obtain a uniform film;

[0117] It can be seen from Example 1 and Comparative Example 9 that under the same film laying area, the higher the quality of the substrate A, the thicker the product. During the test process, the outer sealing layer of the final product cracked first.

[0118] It can be seen from Example 1 and Comparative Example 10 that the substrate is too thin and the product strength is too low;

[0119] In Comparative Example 11, it was found during the test that the film was not completely dried;

[0120] By comparing Example 1 with Comparative Examples 13 and 12, it can be seen that the parameters outside the scope of the claims have poor viscosity. Gelatin and silk fibroin have electrostatic interactions to form a viscous gel, with large ratio deviations and weak electrostatic interactions;

[0121] Comparative Example 14 has a large spray aperture, a small area in contact with tissue, and low viscosity;

[0122] Comparative Example 15 had a short spraying time and less product was sprayed out;

[0123] In Comparative Example 16, increasing the spray time did not result in better viscosity, so this parameter was not selected.

[0124] This product also has excellent adhesion. After being sutured with the tissue, it can be tightly fixed to the defect position to prevent the problem of cerebrospinal fluid leaking through the suture needle.

[0125] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A method for preparing a sutureable membrane having adhesion ability, characterized in that: The specific steps include: S1, placing the silk fabric in an alkaline degumming solution for degumming, and washing and drying the silk fabric to obtain a substrate; S2. Mixing the polymer solute with water and stirring to obtain a polymer aqueous solution with a mass ratio of 2 to 5%; S3, mixing the polymer aqueous solution in step S2 with the plasticizer, stirring, and vacuum degassing to obtain a mixture; S4, taking the mixture of step S3 and the substrate of step S1 to form a membrane, and then freezing and drying to obtain a base membrane; S5, spraying a silk fibroin aqueous solution and a gelatin aqueous solution on one side of the base membrane in step S4, drying and then cross-linking to obtain a sutureable membrane with adhesion ability; The polymer solute in step S2 includes a combination of one or more of carboxymethyl chitosan, gelatin, collagen, and sodium alginate; In step S3, the plasticizer is one or more of triethyl citrate, triethyl glycerol, and isopropyl palmitate; the mass ratio of the polymer aqueous solution to the plasticizer is 95:5 to 98:2; and the vacuum degassing time is 2 to 5 minutes; The specific operations of step S4 are as follows: S41, taking the mixture and the substrate according to a mass ratio of the polymer solute in the mixture to the substrate of 10:1 to 25:1; S42, spreading the mixture on the mold according to the proportion, placing a negative base, and then spreading the mixture on the base to complete the film laying; S43, after pre-freezing, freezing, and drying, a base membrane is obtained; In step S5 , the concentrations of the silk fibroin aqueous solution and the gelatin aqueous solution are both 2%, wherein the mass ratio of the silk fibroin aqueous solution to the gelatin aqueous solution is 6:4 to 4:6, and the drying temperature is 25 to 85° C.

2. The method for preparing a sutureable film having adhesion according to claim 1, wherein: The silk fabric in step S1 is a knitted warp knitted fabric or a knitted weft knitted fabric; and the drying temperature is 25-85°C.

3. The method for preparing a sutureable film having adhesion according to claim 1, wherein: In step S43, the pre-freezing time is 3 to 6 hours, and the freezing time is 24 to 48 hours.

4. The method for preparing a sutureable film having adhesion according to claim 1, wherein: The ratio of the mixture to the mold in step S42 is 1g:1cm 2 .

5. The method for preparing a sutureable film having adhesion according to claim 1, wherein: The aperture of the spray in step S5 is 0.1~1 and the time is 5~10min.

6. A sewable membrane having adhesive properties, characterized in that: The method for preparing a sutureable film with adhesion ability as described in any one of claims 1 to 5 is used for preparing the film.

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