Tissue sealing membrane as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a tissue sealing membrane and a preparation method and application thereof. The prepared tissue sealing film is of a multi-layer composite structure and is composed of an anti-sticking layer and a bonding layer, and the anti-sticking layer comprises an anti-sticking layer bottom layer and an anti-sticking layer transition layer; the multi-layer composite structure specifically comprises an anti-sticking layer bottom layer, a first anti-sticking layer transition layer, a second anti-sticking layer transition layer, a first bonding layer, a second bonding layer and a third bonding layer which are sequentially arranged from bottom to top. By adjusting the composition and proportion of the mixed solvent, designing the transition layer and the interlayer structure (pit / bulge structure), adjusting the component proportion of the bonding layer and other conditions, the bonding layer and the anti-bonding layer are compounded and molded through physical action and chemical action, so that the mechanical matching property and the compounding effect of the two polymers are improved; the mechanical property and the adhesion property of the tissue sealing membrane are improved, and the tissue sealing membrane has a wide application prospect.

Description

Technical Field

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

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] In surgical operations, sutures are often used to close damaged visceral tissues, but the pinholes at the sutures are prone to liquid / gas leakage, and sutures cannot solve low-pressure leakage or slow bleeding in organs. Therefore, many synthetic and semi-synthetic tissue sealants are used to close visceral wounds, such as porcine fibrin adhesives and polyethylene glycol-based polymer synthetic sealants. These products require the preparation of solutions in advance and use with spray tools, which increases the complexity of use and the duration of surgery.

[0004] In recent years, there are literature reports that a tissue sealing film is prepared by compounding a suitable sheet or substrate with an adhesive for visceral wound closure. The compounding of the substrate and the adhesive is an important step in the preparation process of the sealing film, which affects its performance and use effect. For example, patent CN109821057A discloses a visceral hemostatic film and its preparation method and use. The sample is prepared by a layer-by-layer stacking method, and its flexibility is difficult to meet the needs of interventional surgery; patent CN112716702A discloses a degradable medical film and its preparation method. The film includes an AB-type composite structure with alternating coating settings. The force between the AB components and the adhesion to the tissue are enhanced by changing the coating direction. The film obtained by this method has weak interlayer bonding force, and the coating direction needs to be changed manually, which is difficult to industrialize; patent CN115671406A discloses a tissue sealing film, which uses polyacrylic acid as an adhesive and is directly coated on the basement membrane. Polyacrylic acid has swelling properties and is easy to detach from the basement membrane after swelling in the body, causing sealing failure.

[0005] In addition, postoperative tissue adhesion is a common and thorny problem in surgical operations. Currently, commonly used anti-adhesion materials include polylactic acid (PLA) anti-adhesion membranes, hyaluronic acid gels, etc. These products have no tissue adhesion properties and are prone to cause barrier detachment or fragmentation during tissue and organ peristalsis, thereby reducing the anti-adhesion effect. At the same time, with the growing development of endoscopic surgery, anti-adhesion membranes need to be folded or rolled into a tight structure before being introduced into the body, which places higher requirements on the flexibility of the product.

[0006] Therefore, there is an urgent need for a tissue sealing membrane having a strong composite effect between the base and the adhesive, good flexibility and wet adhesion strength, an anti-adhesion function, a simple process and suitable for magnification, and a preparation method thereof. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a tissue sealing film and a preparation method and application thereof. The material prepared by the present invention solves the problems of the existing tissue sealing film, such as the mismatch between the mechanical properties of the substrate and the adhesive, the weak composite force of the two layers, the insufficient flexibility of the sealing film and the low wet bonding strength, and the easy curling and rupture of the sealing film during the preparation process.

[0008] In order to achieve the above object, the present invention adopts the following technical solution: According to a first aspect of the present invention, a tissue sealing film is provided. The tissue sealing film is a multi-layer composite structure, which is composed of an anti-adhesive layer and an adhesive layer. The anti-adhesive layer includes an anti-adhesive layer bottom layer and an anti-adhesive layer transition layer. The multi-layer composite structure specifically includes an anti-adhesive layer bottom layer, a first anti-adhesive layer transition layer, a second anti-adhesive layer transition layer, a first adhesive layer, a second adhesive layer and a third adhesive layer, which are arranged in sequence from bottom to top.

[0009] Preferably, the thickness of the bottom layer of the anti-sticking layer is 5-50 μm; the thickness of the transition layer of the anti-sticking layer is 2-20 μm; and the thickness of the adhesive layer is 10-100 μm.

[0010] Preferably, the thickness of the first anti-sticking layer transition layer and the second anti-sticking layer transition layer is 1-10 μm, preferably 4-8 μm; the thickness of the first adhesive layer, the second adhesive layer and the third adhesive layer are all 4-40 μm, preferably 8-20 μm.

[0011] Preferably, the surface of the anti-sticking layer transition layer is made into pits, protrusions or grid structures by a customized mold to increase the composite effect with the adhesive layer; preferably, it is a pit structure, and the pit structure is composed of a continuous stripe structure or a discontinuous lattice structure.

[0012] Preferably, the anti-adhesive layer bottom layer comprises a film-forming high molecular polymer; the anti-adhesive layer transition layer comprises a film-forming high molecular polymer, a tissue adhesive polymer and an additive; and the adhesive layer comprises a tissue adhesive polymer, a film-forming high molecular polymer and an additive.

[0013] Further preferably, the film-forming high molecular polymer is selected from one or more of poly(lactide-co-glycolide) (PLGA), polylactic acid (PLA), polycaprolactone (PCL), and polylactide-caprolactone copolymer (PLCL); and the tissue adhesive polymer is selected from one or more of acrylic resin adhesives with benzaldehyde or active ester.

[0014] Further preferably, the film-forming high molecular polymer is poly(lactide-co-glycolide) (PLGA); the tissue adhesive polymer is selected from one of poly(acrylic acid-co-hydroxybenzaldehyde acrylic acid) (abbreviated as PAA-PAA (BA)) and poly(acrylic acid-co-acrylic acid N-hydroxysuccinimide ester) (abbreviated as PAA-PAA (NHS)).

[0015] Preferably, the additives include plasticizers, cross-linking agents, and one or more of active drugs, preservatives, and defoaming agents.

[0016] Further preferably, the plasticizer is selected from one or more of glycerol, triethyl citrate, palm triisopropyl ester, triethyl citrate, low molecular weight polyethylene glycol (PEG), and silk fibroin; the cross-linking agent is selected from one or more of sucrose, hydroxypropyl cellulose, polylysine, aminopolyethylene glycol, low molecular weight chitosan, tannic acid, and trilysine; the active drug is selected from one or more of antibacterial agents, antibiotics, growth factors, and analgesics; the preservative is selected from one or more of benzoic acid, sodium benzoate, sorbic acid, and potassium sorbate.

[0017] A second aspect of the present invention provides a method for preparing the above-mentioned tissue sealing film, comprising the following steps: S1, dissolving a film-forming high molecular polymer in an organic solvent to obtain a release layer solution, and coating the solution on the surface of a substrate to obtain a release layer bottom layer; S2, dissolving a tissue adhesive polymer, a plasticizer and a cross-linking agent in a mixed solvent to obtain an adhesive layer solution, mixing the anti-adhesive layer solution and the adhesive layer solution in different volume ratios to obtain a first anti-adhesive layer transition layer solution and a second anti-adhesive layer transition layer solution, and coating them on the surface of the anti-adhesive layer bottom layer in sequence to obtain an anti-adhesive layer transition layer; S3, mixing the anti-adhesive layer solution and the adhesive layer solution in different volume ratios, coating them on the surface of the second anti-adhesive layer transition layer in sequence to obtain an adhesive layer, and then preparing a tissue sealing film through post-processing.

[0018] Preferably, in step S1, the mass concentration of the film-forming high molecular polymer is 5% to 25%, the viscosity of the anti-sticking layer solution is 100 to 2000 mPa·s; and the organic solvent is selected from one or more of dichloromethane, chloroform, hexafluoroisopropanol, acetone, and ethyl acetate.

[0019] Preferably, in step S1, the substrate is selected from one or more of a glass plate, a stainless steel plate, a tetrafluoroethylene plate, a release paper, and a release film; the coating blade height is 20-200 μm, and the coating speed is 100-2000 mm / min.

[0020] Preferably, in step S2, the mass ratio of the tissue adhesive polymer, the plasticizer and the cross-linking agent is 60-94:5-30:1-10, and the viscosity of the adhesive layer solution is 100-1000 mPa·s.

[0021] Preferably, in step S2, the mixed solvent includes a first solvent and a second solvent; the first solvent is selected from one or more of dichloromethane, chloroform, hexafluoroisopropanol, acetone, and ethyl acetate; the second solvent is selected from one or more of methanol, ethanol, and isopropanol; further preferably, the mixed solvent is dichloromethane and methanol; further preferably, the volume ratio of the first solvent to the second solvent is 1~6:1.

[0022] Preferably, in step S2, the coating blade height is 10-80 μm, and the coating speed is 100-2000 mm / min.

[0023] Preferably, in step S2, the first anti-sticking layer transition layer solution is obtained by mixing an anti-sticking layer solution and an adhesive layer solution in a volume ratio of 7~9:1~3, and the second anti-sticking layer transition layer solution is obtained by mixing an anti-sticking layer solution and an adhesive layer solution in a volume ratio of 1~3:7~9, and the solutions are sequentially coated on the surface of the anti-sticking layer bottom layer to obtain an anti-sticking layer transition layer.

[0024] Further preferably, the anti-sticking layer solution and the adhesive layer solution are mixed in a volume ratio of 8:2, and coated on the surface of the anti-sticking layer bottom layer to obtain a first anti-sticking layer transition layer; the anti-sticking layer solution and the adhesive layer solution are mixed in a volume ratio of 2:8, and coated on the surface of the anti-sticking layer bottom layer to obtain a second anti-sticking layer transition layer.

[0025] Preferably, in step S3, the coating is performed with a scraper having a height of 40-400 μm and a coating speed of 100-2000 mm / min.

[0026] Preferably, in step S3, the adhesive layer includes a first adhesive layer, a second adhesive layer and a third adhesive layer, and the three layers are mixed with the anti-adhesive layer solution in a trend of increasing volume proportion of the adhesive layer solution. The specific coating method is: first, a layer of the mixed solution is coated on the surface of the second anti-adhesive layer transition layer at a volume ratio of 5~7:3~5 to obtain the first adhesive layer; then, a layer of the mixed solution is coated on the first adhesive layer at a volume ratio of 7~9:1~3 to obtain the second adhesive layer; and then, a layer of the mixed solution is coated on the second adhesive layer at a volume ratio of 8~9:1~2 to obtain the third adhesive layer.

[0027] Further preferably, the specific coating method of the anti-sticking layer transition layer is: first, a layer of the mixed solution is coated on the surface of the second anti-sticking layer transition layer at a volume ratio of 6:4 to obtain a first adhesive layer; then, a layer of the mixed solution is coated on the first adhesive layer at a volume ratio of 8:2 to obtain a second adhesive layer; and then, a layer of the mixed solution is coated on the second adhesive layer at a volume ratio of 9:1 to obtain a third adhesive layer.

[0028] Preferably, in step S3, the post-processing includes drying, cutting, packaging, and sterilizing the coated sample to obtain a tissue sealing film sample.

[0029] A third aspect of the present invention provides use of the tissue sealing film described in the first aspect and / or the tissue sealing film prepared by the preparation method described in the second aspect in the field of medical devices.

[0030] The beneficial effects achieved by one or more technical solutions of the present invention are as follows: (1) The present invention adjusts the composition and proportion of the mixed solvent, designs the transition layer, the interlayer structure (pit / convex structure), adjusts the proportion of the adhesive layer components, and other conditions, so that the adhesive layer and the anti-adhesive layer are composited through physical and chemical effects, thereby increasing the mechanical matching and composite effect of the two polymers and improving the mechanical properties and adhesion properties of the tissue sealing film. At the same time, different additives, such as active drugs, can be mixed into the adhesive layer and the anti-adhesive layer to slowly release the drug at the site of use, thereby achieving the dual effects of tissue sealing and local drug release and reducing the systemic toxicity of the drug.

[0031] (2) The tissue sealing film prepared by the present invention can be used as a hemostatic material or wound dressing when internal organs are ruptured, damaged or bleeding; it can be used as a tissue repair material for blood vessel sealing and dura mater repair sealing in neurosurgery; it can be used as an anti-adhesion material for abdominal wall hernia, postoperative abdominal cavity, chest cavity and other parts; it can be used as a treatment and delivery device that seals the tissue surface and releases one or more drugs to the target site. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 Schematic diagram of the appearance and structure of the tissue sealing film sample prepared in Example 1 of the present invention, wherein A is the appearance of the tissue sealing film sample; B is the schematic diagram of the structure of the tissue sealing film sample, wherein 1-anti-adhesive bottom layer; 2-anti-adhesive transition layer; 3-anti-adhesive layer; 4-adhesive layer; Figure 2The appearance pictures of the tissue sealing films prepared in Comparative Examples 1, 6, 9 and 10 of the present invention, wherein (a) is the appearance picture of the tissue sealing film of Comparative Example 1, (b) is the appearance picture of the tissue sealing film of Comparative Example 6, (c) is the appearance picture of the tissue sealing film of Comparative Example 9, and (d) is the appearance picture of the tissue sealing film of Comparative Example 10; Figure 3 The swelling results of the tissue sealing films prepared in Example 1 and Comparative Example 2 of the present invention, wherein (a) is the swelling result of the tissue sealing film of Example 1, and (b) is the swelling result of the tissue sealing film of Comparative Example 2; Figure 4 The tensile strength and elongation at break test results of the tissue sealing films prepared in Examples 1 to 3 of the present invention and Comparative Examples 2 to 10, wherein (a) is a graph showing the tensile strength test results of the tissue sealing films, and (b) is a graph showing the elongation at break test results of the tissue sealing films; Figure 5 The test results of the contact angle of the anti-adhesive layer of the tissue sealing film prepared in Example 1 and Comparative Example 2 of the present invention are shown in FIG. (a) is a test result of the contact angle of the anti-adhesive layer of the tissue sealing film of Comparative Example 2, and (b) is a test result of the contact angle of the anti-adhesive layer of the tissue sealing film of Example 1; Figure 6 The results of the adhesive strength test of the tissue sealing films prepared in Examples 1 to 3 and Comparative Examples 2 to 10 of the present invention are shown; wherein (a) is a schematic diagram of the adhesive strength test process, and (b) is a diagram of the adhesive strength test results of the tissue sealing films; Figure 7 The in vitro organ tissue adhesion results of the tissue sealing membrane prepared in Example 1 of the present invention, wherein (a) is the heart, (b) is the liver, (c) is the lung, (d) is the kidney, and (e) is the small intestine. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0035] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0036] Embodiment 1: This embodiment provides a tissue sealing film and a preparation method thereof, comprising the following steps: The tissue sealing film provided in this embodiment is a multi-layer composite structure, and its appearance is as follows Figure 1 As shown in A; like Figure 1As shown in B, the tissue sealing film provided in this embodiment comprises an anti-adhesive layer 3 and an adhesive layer 4, wherein the anti-adhesive layer comprises an anti-adhesive layer bottom layer 1 and an anti-adhesive layer transition layer 2; The multi-layer composite structure specifically includes an anti-sticking layer bottom layer 1, a first anti-sticking layer transition layer, a second anti-sticking layer transition layer, a first adhesive layer, a second adhesive layer and a third adhesive layer which are arranged in sequence from bottom to top.

[0037] The thickness of the bottom layer of the anti-sticking layer is 15 μm; the thickness of the first anti-sticking layer transition layer and the second anti-sticking layer transition layer is 5 μm; the thickness of the first adhesive layer, the second adhesive layer and the third adhesive layer are all 15 μm.

[0038] The specific preparation method is as follows: (1) Weigh 1 g of PLGA and add it to 10 mL of dichloromethane to prepare a 0.1 g / mL anti-adhesive layer solution. Use a small coating machine to add the PLGA solution to the surface of the release paper, coat it, and dry it at room temperature for 20 min to obtain the anti-adhesive layer bottom layer.

[0039] (2) Dichloromethane and methanol were mixed at a volume ratio of 2.5:1 to obtain a mixed solvent. 3.0 g of PAA-PAA(BA), 0.3 g of glycerol and 0.1 g of hydroxypropyl cellulose were weighed and added to 10 mL of the mixed solvent to obtain a PAA-PAA(BA) solution. The PAA-PAA(BA) solution and the PLGA solution prepared in step (1) were mixed at a volume ratio of 8:2 and coated on the anti-adhesive layer base to obtain a first anti-adhesive layer transition layer; the PAA-PAA(BA) solution and the PLGA solution were mixed at a volume ratio of 2:8 and continued to coat to obtain a second anti-adhesive layer transition layer. A custom mold with convex patterns was placed on the coating surface, dried at room temperature for 20 min, and the mold was removed to obtain an anti-adhesive layer with concave patterns.

[0040] (3) The PAA-PAA (BA) solution and the PLGA solution were mixed evenly at a volume ratio of 6:4, and coated on the surface of the second anti-adhesive layer transition layer to obtain the first adhesive layer; the PAA-PAA (BA) solution and the PLGA solution were mixed evenly at a volume ratio of 8:2, and coated on the surface of the first adhesive layer to obtain the second adhesive layer; the PAA-PAA (BA) solution and the PLGA solution were mixed evenly at a volume ratio of 9:1, and coated on the surface of the second adhesive layer to obtain the third adhesive layer. The sealing film sample was dried in a fume hood for 30 min, and the sample was transferred to an oven for high-temperature crosslinking and drying. After cutting, packaging, and sterilization, the tissue sealing film sample was obtained.

[0041] Embodiment 2: This embodiment provides a tissue sealing film and a preparation method thereof, comprising the following steps: (1) Weigh 1.0 g of PLGA and add it to 10 mL of dichloromethane to prepare a 0.1 g / mL anti-adhesive layer solution. Use a small coating machine to add the PLGA solution to the surface of the release paper, coat it, and dry it at room temperature for 20 min to obtain the anti-adhesive layer bottom layer.

[0042] (2) Dichloromethane and methanol were mixed at a volume ratio of 2.5:1 to obtain a mixed solvent. 3.0 g of PAA-PAA(NHS), 0.3 g of glycerol and 0.1 g of hydroxypropyl cellulose were weighed and added to 10 mL of the mixed solvent to obtain a PAA-PAA(NHS) solution. The PAA-PAA(NHS) solution and the PLGA solution prepared in step (1) were mixed at a volume ratio of 8:2 and coated on the anti-adhesive layer base to obtain a first anti-adhesive layer transition layer; the PAA-PAA(NHS) solution and the PLGA solution were mixed at a volume ratio of 2:8 and continued to be coated to obtain a second anti-adhesive layer transition layer. A custom mold with convex patterns was placed on the coating surface, dried at room temperature for 20 min, and the mold was removed to obtain an anti-adhesive layer with concave patterns.

[0043] (3) The PAA-PAA (NHS) solution and the PLGA solution were mixed evenly at a volume ratio of 6:4, and coated on the surface of the second anti-adhesive layer transition layer to obtain the first adhesive layer; the PAA-PAA (NHS) solution and the PLGA solution were mixed evenly at a volume ratio of 8:2, and coated on the surface of the first adhesive layer to obtain the second adhesive layer; the PAA-PAA (NHS) solution and the PLGA solution were mixed evenly at a volume ratio of 9:1, and coated on the surface of the second adhesive layer to obtain the third adhesive layer. The sealing film sample was dried in a fume hood for 30 min, and the sample was transferred to an oven for high-temperature crosslinking and drying. After cutting, packaging, and sterilization, the tissue sealing film sample was obtained. Among them, the thickness of the anti-adhesive layer bottom layer was 15 μm; the thickness of the first anti-adhesive layer transition layer and the second anti-adhesive layer transition layer was 5 μm; the thickness of the first adhesive layer, the second adhesive layer, and the third adhesive layer were all 15 μm.

[0044] Embodiment 3: This embodiment provides a tissue sealing film and a preparation method thereof, comprising the following steps: (1) Weigh 1.0 g of PLGA and add it to 10 mL of dichloromethane to prepare a 0.1 g / mL anti-adhesive layer solution. Weigh 1.0 g of PLGA and 0.1 g of rifampicin (RFP) and add them to 10 mL of dichloromethane to obtain a drug-loaded anti-adhesive layer solution with a drug mass fraction of 10%. Use a small coating machine to add the RFP / PLGA solution to the surface of the release paper, coat it, and dry it at room temperature for 20 min to obtain the anti-adhesive layer bottom layer loaded with RFP.

[0045] (2) Dichloromethane and methanol were mixed at a volume ratio of 2.5:1 to obtain a mixed solvent. 3.0 g of PAA-PAA(NHS), 0.3 g of glycerol and 0.1 g of hydroxypropyl cellulose were weighed and added to 10 mL of the mixed solvent to obtain a PAA-PAA(NHS) solution. The PAA-PAA(NHS) solution and the PLGA solution were mixed at a volume ratio of 8:2 and coated on the anti-adhesive layer base to obtain a first anti-adhesive layer transition layer. The PAA-PAA(NHS) solution and the PLGA solution were mixed at a volume ratio of 2:8 and continued to be coated to obtain a second anti-adhesive layer transition layer. A custom mold with convex patterns was placed on the coating surface, dried at room temperature for 20 min, and the mold was removed to obtain an anti-adhesive layer with concave patterns.

[0046] (3) Weigh 0.15 g of doxorubicin hydrochloride (DOX) and add it to 5 mL of PAA-PAA (NHS) solution to obtain a drug-loaded adhesive layer solution with a drug mass fraction of 10% (referred to as DOX / PAA-PAA (NHS) solution). Mix the DOX / PAA-PAA (NHS) solution and PLGA solution at a volume ratio of 6:4 and apply a film on the surface of the second anti-adhesive transition layer to obtain the first adhesive layer; mix the DOX / PAA-PAA (NHS) solution and PLGA solution at a volume ratio of 8:2 and apply a film on the surface of the first adhesive layer to obtain the second adhesive layer; mix the DOX / PAA-PAA (NHS) solution and PLGA solution at a volume ratio of 9:1 and apply a film on the surface of the second adhesive layer to obtain the third adhesive layer. Dry the sealing film sample in a fume hood for 30 min, transfer the sample to an oven, crosslink and dry at high temperature, cut, package and sterilize to obtain the drug-loaded tissue sealing film sample. The thickness of the bottom layer of the anti-sticking layer is 15 μm; the thickness of the first anti-sticking layer transition layer and the second anti-sticking layer transition layer is 5 μm; the thickness of the first adhesive layer, the second adhesive layer and the third adhesive layer are all 15 μm.

[0047] Comparative Example 1: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (2), 3.0 g of PAA-PAA (BA), 0.3 g of glycerol and 0.1 g of hydroxypropyl cellulose are weighed and added to 10 mL of methanol to obtain a PAA-PAA (BA) solution.

[0048] The contents of other components, the preparation method and the thickness of each layer are consistent with those in Example 1.

[0049] Comparative Example 2: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (2), the preparation of the anti-adhesive layer transition layer is not performed, that is, the PAA-PAA (BA) solution and the PLGA solution prepared in step (1) are directly mixed at a volume ratio of 6:4 and then coated on the surface of the anti-adhesive layer bottom layer to obtain the first adhesive layer; the PAA-PAA (BA) solution and the PLGA solution are mixed at a volume ratio of 8:2 and then coated on the surface of the first adhesive layer to obtain the second adhesive layer; the PAA-PAA (BA) solution and the PLGA solution are mixed at a volume ratio of 9:1 and then coated on the surface of the second adhesive layer to obtain the third adhesive layer. The sealing film sample is dried in a fume hood for 30 minutes, and the sample is transferred to an oven for high-temperature crosslinking and drying, and cut, packaged, and sterilized to obtain a tissue sealing film sample.

[0050] The contents of other components and the preparation method are consistent with those in Example 1. The thickness of the anti-adhesive layer bottom layer is 15 μm, and the thicknesses of the first adhesive layer, the second adhesive layer and the third adhesive layer are all 15 μm.

[0051] Comparative Example 3: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (2), only one anti-adhesive transition layer is prepared, that is, the PAA-PAA (BA) solution and the PLGA solution prepared in step (1) are directly mixed in a ratio of 8:2 and coated on the anti-adhesive bottom layer to obtain an anti-adhesive transition layer. A custom mold with convex patterns is placed on the coating surface, dried at room temperature for 20 minutes, and the mold is removed to obtain an anti-adhesive layer with concave patterns.

[0052] The contents of other components and the preparation method are consistent with those in Example 1. The thickness of the anti-adhesive layer bottom layer is 15 μm, the thickness of the anti-adhesive layer transition layer is 5 μm, and the thickness of the first adhesive layer, the second adhesive layer and the third adhesive layer are all 15 μm.

[0053] Comparative Example 4: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (2), the coating slurry of the first anti-adhesive layer transition layer and the second anti-adhesive layer transition layer is the same, that is, the PAA-PAA (BA) solution and the PLGA solution prepared in step (1) are directly mixed in a volume ratio of 8:2, and the mixture is repeatedly coated twice on the anti-adhesive layer bottom layer to obtain an anti-adhesive layer transition layer. A custom mold with convex patterns is placed on the coating surface, dried at room temperature for 20 minutes, and the mold is removed to obtain an anti-adhesive layer with concave patterns.

[0054] The contents of other components, the preparation method and the thickness of each layer are consistent with those in Example 1.

[0055] Comparative Example 5: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (2), the coating slurry of the first anti-sticking layer transition layer and the second anti-sticking layer transition layer is the same and is a single component (PAA-PAA (BA) solution), that is, the PAA-PAA (BA) solution is directly coated twice on the surface of the anti-sticking layer bottom layer, the sealing film sample is dried in a fume hood for 30 min, the sample is transferred to an oven, cross-linked and dried at high temperature, and the tissue sealing film sample is obtained after cutting, packaging and sterilization.

[0056] The contents of other components, the preparation method and the thickness of each layer are consistent with those in Example 1.

[0057] Comparative Example 6: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (3), the adhesive layer is coated in one layer, that is, the PAA-PAA (BA) solution and the PLGA solution are directly mixed in a volume ratio of 9:1, and then coated on the surface of the second anti-adhesive layer transition layer to obtain the adhesive layer. The sealing film sample is dried in a fume hood for 30 minutes, and the sample is transferred to an oven for high-temperature crosslinking and drying, and the tissue sealing film sample is obtained after cutting, packaging, and sterilization.

[0058] The contents of other components and the preparation method are consistent with those in Example 1. The thickness of the anti-adhesive layer bottom layer is 15 μm; the thickness of the first anti-adhesive layer transition layer and the second anti-adhesive layer transition layer is 5 μm; and the thickness of the adhesive layer is 45 μm.

[0059] Comparative Example 7: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (3), the volume ratio of the coating slurry of the three adhesive layers is the same, that is, the PAA-PAA (BA) solution and the PLGA solution are directly mixed in a volume ratio of 9:1, and the mixture is repeatedly coated on the surface of the anti-adhesive layer and the transition layer for 3 times to obtain the adhesive layer, and the sealing film sample is dried in a fume hood for 30 min, and the sample is transferred to an oven for high-temperature crosslinking and drying, and the tissue sealing film sample is obtained after cutting, packaging and sterilization.

[0060] The contents of other components, the preparation method and the thickness of each layer are consistent with those in Example 1.

[0061] Comparative Example 8: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (3), the coating slurry of the three adhesive layers is the same, which is a single-component PAA-PAA (BA) solution, that is, the PAA-PAA (BA) solution is directly and repeatedly coated on the surface of the anti-adhesive layer and transition layer for 3 times to obtain the adhesive layer, and the sealing film sample is dried in a fume hood for 30 min, and the sample is transferred to an oven for high-temperature crosslinking and drying, and then cut, packaged, and sterilized to obtain a tissue sealing film sample.

[0062] The contents of other components, the preparation method and the thickness of each layer are consistent with those in Example 1.

[0063] Comparative Example 9: This comparative example provides a tissue sealing film and a preparation method thereof The difference between this comparative example and Example 1 is that in step (2), the surface of the anti-sticking layer transition layer is not embossed using a relief mold; the contents of other components, the preparation method, and the thickness of each layer are consistent with those in Example 1.

[0064] Comparative Example 10: This comparative example provides a tissue sealing film and a preparation method thereof, comprising the following steps: (1) Weigh 1.0 g of PLGA and add it to dichloromethane to prepare a 0.1 g / mL anti-adhesive layer solution (referred to as PLGA solution). Use a small coating machine to add the PLGA solution to the surface of the release paper, coat it, and dry it at room temperature for 20 min to obtain the first anti-adhesive layer.

[0065] (2) Dichloromethane and methanol were mixed in a volume ratio of 2.5:1 to obtain a mixed solvent, and 3.0 g of PAA-PAA (BA), 0.3 g of glycerol and 0.1 g of hydroxypropyl cellulose were weighed and added to the mixed solvent to obtain a PAA-PAA (BA) solution. The PAA-PAA (BA) solution was coated on the first anti-adhesive layer and dried at room temperature for 20 min to obtain a first adhesive layer.

[0066] (3) Repeat steps (1) and (2) to obtain a four-layer sealing film sample with an anti-adhesive layer and an adhesive layer alternately distributed. Dry the sample in a fume hood for 30 min, transfer the sample to an oven, crosslink and dry at high temperature, cut, package, and sterilize to obtain a tissue sealing film sample. The thickness of the anti-adhesive layer and the adhesive layer are both 15 μm.

[0067] Test Example 1: This test example tests the appearance and swelling of the tissue sealing membranes prepared in the examples and comparative examples. Experimental process: Swelling and stratification test of samples in PBS buffer Take a sealing film sample, use a 1 / 10,000 balance to accurately weigh the sample to 0.05g, place it in a reagent bottle, add 2 mL of phosphate buffer (pH=7.4) preheated to 37℃±1℃, seal the reagent bottle and place it in a constant temperature shaker at 37℃±1℃ and 60rpm. Take out the sample after 24 hours and observe its swelling. The results are shown in Table 1 and Table 2: Table 1

[0068] Table 2

[0069] As can be seen from Tables 1-2, the samples (Examples 1-3) prepared by the present invention have a smooth appearance and swell without stratification in PBS buffer. The results of Example 1 are as follows: Figure 3 As shown in (a); Comparative Example 2 has no anti-adhesive transition layer, swells in PBS buffer and delaminates, detaches from the anti-adhesive layer, and cannot ensure lasting adhesive strength. The results are as follows Figure 3 As shown in (b) in .

[0070] The adhesive layer of the sample prepared by using a single solvent in Comparative Example 1 was separated from the anti-adhesive layer and was incomplete. Figure 2 As shown in (a), the tensile strength and bonding strength tests cannot be performed; in Comparative Example 6, the sample surface obtained by coating with a single layer of bonding layer has a large number of bubbles and large bubbles, and the appearance is as follows Figure 2 As shown in (b) in the figure, the thickness of the sample is uneven and cannot be used; in the preparation process of the samples of Comparative Examples 9 and 10, no embossing mold is used for embossing, resulting in curling of the film, which is not conducive to subsequent packaging and use. The appearance is as shown in Figure 2 As shown in (c) and (d).

[0071] Test Example 2: This test example tests the tensile strength and elongation at break of the tissue sealing films prepared in the examples and comparative examples. Experimental process: The sealing film samples were cut into dumbbell-shaped specimens with a test length of 10.0 mm and a width of 2.0 mm. A universal tensile machine was used to test at a tensile rate of 5 mm / min, the fracture of the specimens was observed, and the tensile strength and elongation at break were calculated.

[0072] like Figure 4As shown in (a), the tensile strength values ​​of the tissue sealing films of Examples 1 to 3 and Comparative Examples 2 to 10 are 17.37±2.14 MPa, 16.15±1.01 MPa, 15.44±0.71 MPa, 6.64±0.19 MPa, 10.33±0.26 MPa, 12.15±1.22 MPa, 4.64±0.19 MPa, 4.91±0.59 MPa, 11.10±0.57 MPa, 5.71±0.26 MPa, 14.88±0.47 MPa, and 10.94±0.66 MPa, respectively.

[0073] like Figure 4 As shown in (b), the elongation at break of the tissue sealing films of Examples 1 to 3 and Comparative Examples 2 to 10 are 79.34±3.43%, 64.34±5.64%, 60.33±3.39%, 40.81±0.84%, 42.67±3.74%, 43.67±3.23%, 21.83±1.16%, 21.73±2.14%, 53.88±3.96%, 27.20±0.65%, 59.21±5.11%, and 39.95±2.31%, respectively.

[0074] From the comparison between the above values, it can be seen that Example 1 has higher tensile strength and elongation at break, while when there is no anti-adhesive transition layer (Comparative Example 2) or there is only one anti-adhesive transition layer (Comparative Example 3), the flexibility of the sample decreases. This is because the addition of the anti-adhesive transition layer increases the hydrophilicity of the anti-adhesive layer, which is beneficial to the coating of the adhesive layer and the interlayer bonding. Among them, the contact angle results of the anti-adhesive layer of Example 1 and Comparative Example 2 are as follows: Figure 5 As shown, it can be seen that the contact angle of Example 1 of the present invention is 56° (as shown in Figure 5 ), while the contact angle of the anti-adhesive layer of Comparative Example 2 is 73° (as shown in FIG. Figure 5 As shown in Figure (a) in the figure), therefore, the anti-adhesive layer of the tissue sealing film in Example 1 is more hydrophilic, which is conducive to the spreading of the adhesive layer.

[0075] The anti-sticking transition layers of Comparative Examples 4 and 5 are both two layers of the same composition. The two transition layers of Comparative Example 4 are mainly PLGA, and the tensile strength of the sealing film is relatively high. The two transition layers of Comparative Example 5 are tissue adhesive polymers, and the sealing film is relatively brittle and has a relatively low tensile strength.

[0076] In Comparative Example 6, the adhesive layer was coated once, and a large number of bubbles were generated on the surface of the film, resulting in structural defects, and the film had lower tensile strength and elongation at break.

[0077] The adhesive layers of Comparative Examples 7 and 8 are both three layers of the same composition. The adhesive layer of Comparative Example 7 is doped with a certain amount of PLGA, and its tensile strength is higher than the tensile strength of the sample of Comparative Example 8.

[0078] Test Example 3: This test example tests the adhesive strength of the tissue sealing films prepared in the examples and comparative examples. Experimental process: Use cyanoacrylate glue to fix 2.5×2.5 cm pigskin on a T-shaped board. Cut the sealing film into 2.5×2.5 cm samples and fix them on another T-shaped board with double-sided tape. Align the pigskin and the sample and apply a force of 1~2 N to bond the two together as the sample to be tested. Place the clamping rod of the T-shaped board of the sample to be tested into the fixture and load the sample at a speed of 2 mm / min until it is destroyed. The schematic diagram of the test process is shown in the figure below. Figure 6 Calculate the bonding strength as shown in Figure (a).

[0079] like Figure 6 As shown in (b), the adhesion strengths of the tissue sealing films of Examples 1 to 3 and Comparative Examples 2 to 10 are 0.71±0.11 MPa, 0.68±0.15 MPa, 0.67±0.11 MPa, 0.35±0.11 MPa, 0.44±0.12 MPa, 0.38±0.17 MPa, 0.61±0.08 MPa, 0.43±0.04 MPa, 0.52±0.19 MPa, 0.39±0.06 MPa, 0.65±0.21 MPa, and 0.32±0.05 MPa, respectively.

[0080] As can be seen from the figure, the bonding strength of Example 1 is higher than that of Comparative Example 7. The gradient introduction of the hydrophobic component PLGA in the bonding layer increases the composite effect of the bonding layer and the anti-adhesive layer, thereby improving the bonding strength. At the same time, the test results of the sample of Example 3 show that the introduction of the drug has little effect on the tensile strength and bonding strength of the sealing film. The bonding layer of Comparative Example 8 uses a single-component PAA-PAA (BA) solution, which results in a strong hydrophilicity on the surface of the bonding layer, making it impossible to discharge a small amount of moisture on the surface of the tissue, thereby reducing the bonding strength. Comparative Example 10 uses alternating coating, and the bonding force between the bonding layer and the anti-adhesive layer is weak, and the cohesive strength of the sealing film is low, resulting in a low bonding strength.

[0081] Test Example 4: This test example tests the adhesion test of the tissue sealing membranes prepared in the examples and comparative examples on the in vitro organ tissues. Experimental process: The adhesion effect of tissue sealing film on different organs was evaluated through in vitro organ tissue adhesion test. The heart, liver, lung, kidney, small intestine and other in vitro organ tissues of New Zealand rabbits were taken for adhesion test. A hole was punched on the surface of the tissue with a 27G needle, and a square sealing film with a side length of 10 mm was attached to the hole. After pressing for 10 seconds, the adhesion to the tissue was observed to check whether there was sample detachment and liquid leakage. The bonded organ tissue was placed in 37℃ physiological saline, and after soaking for 24 hours, the adhesion to the tissue was observed to check whether there was sample detachment and liquid leakage.

[0082] like Figure 7 As shown in Figures (a)-(e), the tissue sealing film has good adhesion and anti-leakage effect on different organs of New Zealand rabbits (heart, liver, lung, kidney, small intestine). After the sample was immersed in saline for 24 hours, the sealing film could still adhere to the tissue surface, and the sample was not seen to be detached from the tissue, indicating that the sealing film has a good adhesion effect in a wet environment.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tissue sealing membrane, characterized in that: The tissue sealing film is a multi-layer composite structure, consisting of an anti-sticking layer and an adhesive layer, wherein the anti-sticking layer includes an anti-sticking layer bottom layer and an anti-sticking layer transition layer; the multi-layer composite structure specifically includes an anti-sticking layer bottom layer, a first anti-sticking layer transition layer, a second anti-sticking layer transition layer, a first adhesive layer, a second adhesive layer and a third adhesive layer, which are arranged in sequence from bottom to top.

2. The tissue sealing film according to claim 1, characterized in that: The thickness of the anti-sticking layer bottom layer is 5~50 μm; the thickness of the anti-sticking layer transition layer is 2~20 μm; the thickness of the adhesive layer is 10~100 μm; wherein the thickness of the first anti-sticking layer transition layer and the second anti-sticking layer transition layer is 1~10 μm; the thickness of the first adhesive layer, the second adhesive layer and the third adhesive layer are all 4~40 μm.

3. The tissue sealing film according to claim 1, characterized in that: The surface of the anti-sticking layer transition layer is formed into pits, convex structures or grid structures through a mold.

4. The tissue sealing film according to claim 1, characterized in that: The anti-adhesive layer bottom layer includes a film-forming high molecular polymer; the anti-adhesive layer transition layer includes a film-forming high molecular polymer, a tissue adhesive polymer and an additive; the adhesive layer includes a tissue adhesive polymer, a film-forming high molecular polymer and an additive; Wherein, the film-forming high molecular polymer is selected from one or more of poly (lactide-co-glycolide), polylactic acid, polycaprolactone, polylactide-caprolactone copolymer; the tissue adhesive polymer is selected from one or more of acrylic resin adhesives with benzaldehyde or active ester.

5. The tissue sealing film according to claim 4, characterized in that: The additives include plasticizers, cross-linking agents, and one or more active drugs, preservatives, and defoaming agents; the plasticizer is selected from one or more of glycerol, triethyl citrate, palm triisopropyl ester, triethyl citrate, low molecular weight polyethylene glycol, and silk fibroin; the cross-linking agent is selected from one or more of sucrose, hydroxypropyl cellulose, polylysine, aminopolyethylene glycol, low molecular weight chitosan, tannic acid, and trilysine; the active drug is selected from one or more of antibacterial agents, antibiotics, growth factors, and analgesics; the preservative is selected from one or more of benzoic acid, sodium benzoate, sorbic acid, and potassium sorbate.

6. A method for preparing a tissue sealing membrane according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, dissolving a film-forming high molecular polymer in an organic solvent to obtain a release layer solution, and coating the solution on the surface of a substrate to obtain a release layer bottom layer; S2, dissolving a tissue adhesive polymer, a plasticizer and a cross-linking agent in a mixed solvent to obtain an adhesive layer solution, mixing the anti-adhesive layer solution and the adhesive layer solution in different volume ratios to obtain a first anti-adhesive layer transition layer solution and a second anti-adhesive layer transition layer solution, and coating them on the surface of the anti-adhesive layer bottom layer in sequence to obtain an anti-adhesive layer transition layer; S3, mixing the anti-adhesive layer solution and the adhesive layer solution in different volume ratios, coating them on the surface of the second anti-adhesive layer transition layer in sequence to obtain an adhesive layer, and then preparing a tissue sealing film through post-processing.

7. The preparation method according to claim 6, characterized in that: In step S1, the mass concentration of the film-forming polymer is 5% to 25%, and the viscosity of the anti-adhesive layer solution is 100 to 2000 mPa·s; The organic solvent is selected from one or more of dichloromethane, chloroform, hexafluoroisopropanol, acetone, and ethyl acetate; the substrate is selected from one or more of a glass plate, a stainless steel plate, a tetrafluoroethylene plate, a release paper, and a release film.

8. The preparation method according to claim 6, characterized in that: In step S2, the mass ratio of the tissue adhesive polymer, the plasticizer and the cross-linking agent is 60-94:5-30:1-10, and the viscosity of the adhesive layer solution is 100-1000 mPa·s; The mixed solvent comprises a first solvent and a second solvent; the first solvent is selected from one or more of dichloromethane, chloroform, hexafluoroisopropanol, acetone, and ethyl acetate; the second solvent is selected from one or more of methanol, ethanol, and isopropanol; the volume ratio of the first solvent to the second solvent is 1-6:1; The anti-sticking layer transition layer includes a first anti-sticking layer transition layer and a second anti-sticking layer transition layer. The first anti-sticking layer transition layer solution is obtained by mixing an anti-sticking layer solution and an adhesive layer solution in a volume ratio of 7-9:1-3. The second anti-sticking layer transition layer solution is obtained by mixing an anti-sticking layer solution and an adhesive layer solution in a volume ratio of 1-3:7-9. The solutions are sequentially coated on the surface of the anti-sticking layer bottom layer to obtain the anti-sticking layer transition layer.

9. The preparation method according to claim 6, characterized in that: In step S3, the adhesive layer includes a first adhesive layer, a second adhesive layer and a third adhesive layer, and the specific coating method is: firstly, a layer of mixed solution is coated on the surface of the second anti-adhesive layer transition layer at a volume ratio of 5-7:3-5 to obtain a first adhesive layer; then, a layer of mixed solution is coated on the first adhesive layer at a volume ratio of 7-9:1-3 to obtain a second adhesive layer; and then, a layer of mixed solution is coated on the second adhesive layer at a volume ratio of 8-9:1-2 to obtain a third adhesive layer; The post-processing includes drying, cutting, packaging and sterilizing the coated sample to obtain the tissue sealing film sample.

10. Use of the tissue sealing film according to any one of claims 1 to 5 and / or the tissue sealing film prepared by the preparation method according to any one of claims 6 to 9 in the field of medical devices.

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