Bionic sucker type double-layer composite fiber membrane patch, preparation and application of patch in preparation of intestinal anastomosis device

Abstract

The invention relates to a bionic sucker type double-layer composite fiber membrane patch, preparation and application of the bionic sucker type double-layer composite fiber membrane patch in preparation of an intestinal anastomosis device, and belongs to the field of biomedical engineering. The patch comprises a double-layer composite fiber membrane, a flexible suction cup, a suction cup structure and a round hole structure. The double-layer composite fiber membrane comprises an outer hydrophobic layer and an inner hydrophilic layer; the inner side hydrophilic layer is bonded and fixed with the flexible sucking disc; the suction cup structures are arranged on the periphery of the flexible suction cup, and the round hole structures are arranged on the flexible suction cup in an array mode. The suction cup structure comprises a hemispherical base and a cylindrical top. The patch designed by the invention can be used in an intestinal anastomosis operation, the physical adsorption effect of the flexible sucker and the chemical adhesion effect of the hydrophilic layer of the composite fiber membrane are in synergistic interaction, and the strong tissue adhesion characteristic is exerted; the hydrophobic layer of the composite fiber membrane has a physical barrier effect, and postoperative adhesion of surrounding tissues is avoided. The biological patch designed by the invention has the characteristics of simple operation, firm adhesion, adhesion prevention and biological safety.

Description

Technical Field

[0001] This invention belongs to the field of biomedical engineering, and more specifically, relates to a biomimetic suction cup type double-layer composite fiber membrane patch, its preparation, and its application in the preparation of intestinal anastomosis devices. Background Technology

[0002] Anastomosis of severed intestinal tissue is a common and fundamental surgical procedure in gastrointestinal surgery. Clinically, this procedure still relies on traditional manual sutures or mechanical suturing, which is not only difficult and time-consuming but also prone to compressing the tissue, inevitably leading to secondary damage and significant tissue tension. Furthermore, the two most common complications after intestinal anastomosis surgery include: 1) Anastomotic leakage: This occurs when the anastomosis is not secure or excessive tissue tension causes it to reopen, resulting in leakage of intestinal contents. Anastomotic leakage can cause severe abdominal infection and septic shock within a short period. 2) Postoperative adhesions: These are caused by the inflammatory response and fibrinolytic inhibition induced by tissue damage, leading to abnormal fibrin deposition due to the activation of fibroblasts. Postoperative adhesions are extremely common and vary in severity. Mild cases may be asymptomatic, while severe intestinal anastomotic adhesions can lead to secondary intestinal obstruction. These challenges pose significant difficulties to the clinical application of intestinal anastomosis surgery and seriously threaten patient safety.

[0003] In recent years, advancements in biomaterials and bioengineering technologies have offered new opportunities to overcome these clinical challenges. Based on chemical adhesion, some bio-adhesives or tissue adhesion patches have been developed. However, chemical adhesives inevitably suffer from off-target effects, and to date, no mature product can replace traditional manual or mechanical suturing. Additionally, some chemical products, such as chitosan and polylactic acid, have been developed for postoperative adhesion prevention. The drawback is that these anti-adhesion chemical products often have limited effects, requiring only supplementary spraying after the anastomosis procedure, and cannot guarantee complete coverage of the anastomosis and effective retention. To address these issues, developing a new generation of bio-patterns with stronger tissue adhesion and effective prevention of postoperative adhesion for use in anastomosis procedures has significant clinical value. Summary of the Invention

[0004] To overcome the shortcomings of existing biomaterials and bioengineering technologies in intestinal anastomosis surgery, this invention provides a biomimetic suction cup-type composite fiber membrane patch for use in intestinal anastomosis surgery. This patch system is prepared using biosafe materials and includes a flexible suction cup and a double-layer composite fiber membrane. The flexible suction cup provides physical adsorption, while the hydrophilic layer of the composite fiber membrane provides chemical adhesion; the two work synergistically to produce strong tissue adhesion properties. Furthermore, the hydrophobic layer of the composite fiber membrane acts as a physical barrier, preventing postoperative adhesion of surrounding tissues. The biopatch of this invention is characterized by simple operation, reliable adhesion, adhesion avoidance, and biosafety.

[0005] According to a first aspect of the present invention, a biomimetic suction cup type double-layer composite fiber membrane patch is provided, comprising a double-layer composite fiber membrane, a flexible suction cup, a suction cup structure, and a circular hole structure; the double-layer composite fiber membrane comprises an outer hydrophobic layer and an inner hydrophilic layer; the inner hydrophilic layer is bonded and fixed to the flexible suction cup; the suction cup structure is arranged around the flexible suction cup, and the circular hole structure is arranged in an array on the flexible suction cup; the suction cup structure comprises a hemispherical base and a cylindrical top.

[0006] Preferably, the fiber diameter of the double-layer composite fiber membrane is 0.2μm-5μm.

[0007] Preferably, the thickness of the double-layer composite fiber membrane is 50μm-500μm.

[0008] Preferably, the diameter of the circular hole structure is 1mm-5mm.

[0009] Preferably, the number of circular holes is 10-100.

[0010] Preferably, the diameter of the hemispherical base of the suction cup structure is 1mm-3mm.

[0011] Preferably, the number of suction cup structures is 10-100.

[0012] According to another aspect of the present invention, a method for preparing the biomimetic suction cup type double-layer composite fiber membrane patch as described in any one of the claims is provided, comprising the following steps:

[0013] (1) Polylactic acid is dissolved to obtain polylactic acid spinning solution; polyvinyl alcohol is dissolved to obtain polyvinyl alcohol spinning solution; the polylactic acid solution is spun using electrospinning technology to obtain the outer hydrophobic layer of the composite fiber membrane, and then polyvinyl alcohol solution is used to continue spinning on the outer hydrophobic layer to obtain the inner hydrophilic layer of the composite fiber membrane, thereby obtaining a double-layer composite fiber membrane; a flexible suction cup is designed, and then a positive mold is obtained by 3D printing. Flexible silicone material is poured on the positive mold, and after drying, the mold is demolded to obtain the flexible suction cup;

[0014] (2) Adhere the inner hydrophilic layer of the double-layer composite fiber membrane obtained in step (1) to the back side of the suction cup structure of the flexible suction cup, so that the double-layer composite fiber membrane covers the circular hole structure of the flexible suction cup, thus obtaining the biomimetic suction cup type double-layer composite fiber membrane patch.

[0015] According to another aspect of the present invention, the application of the aforementioned biomimetic suction cup-type double-layer composite fiber membrane patch in the preparation of an intestinal anastomosis device is provided.

[0016] Preferably, the procedure specifically includes the following steps:

[0017] S1: Suspend and fix the mesenteric edge and the opposite mesenteric edge of the severed intestinal tube respectively, and align the intestinal tissue neatly;

[0018] S2: Cover the intestinal serosa surface with the suction cup structure of the biomimetic suction cup type double-layer composite fiber membrane patch, and press the biomimetic suction cup type double-layer composite fiber membrane patch so that the inner hydrophilic layer of the composite fiber membrane can fully contact the tissue through the round hole structure.

[0019] S3: Squeeze out the air from the suction cup structure of the biomimetic suction cup-type double-layer composite fiber membrane patch and make the suction cup structure fully contact and adsorb with the intestinal tissue to complete the intestinal anastomosis.

[0020] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0021] (1) The patch prepared by this invention has a strong tissue adhesion effect. The patch designed by this invention comprises a flexible suction cup array and a double-layer composite fiber membrane. The flexible suction cup array is inspired by the Virginia creeper: the ends of Virginia creeper tendrils are specialized into flat suction cup structures. When the edge of the suction cup contacts the substrate, the mucus material sealed by the suction cup forms a sealing ring, expelling the internal air and forming a local vacuum, thereby achieving physical adsorption with the help of atmospheric pressure. This invention designs a suction cup array around the patch. When the internal air is squeezed out, it can be firmly adsorbed to the tissue surface with the help of external atmospheric pressure. The hydrophilic side of the double-layer composite fiber membrane is made of polyvinyl alcohol, which contains a large number of hydroxyl groups in its molecular structure. In use, the polyvinyl alcohol fiber membrane faces the anastomosis site. After contacting the tissue, it will dissolve rapidly, and the hydroxyl groups in the molecular structure will generate a large number of hydrogen bonds with the biological tissue, thereby providing tissue adhesion. In addition, the polyvinyl alcohol polymer chains are intertwined to form a dense structure, thereby further enhancing the adhesion.

[0022] (2) The patch prepared by this invention has a definite anti-adhesion effect. The patch designed by this invention uses polylactic acid (PLA) material on the hydrophobic side of the double-layer composite fiber membrane. Its molecular structure contains low-polarity or non-polar groups such as methyl and ester groups, thus exhibiting outstanding hydrophobic properties. In use, the PLA fiber membrane faces outward, isolating the damaged tissue surface through physical barrier action, preventing fibrin cross-linking and fibroblast migration. Its hydrophobic surface can reduce the non-specific adsorption of proteins and platelets, avoiding excessive aggregation of inflammatory cells. In addition, the PLA fiber membrane has controllable degradation characteristics and can be gradually hydrolyzed into lactic acid in vivo without triggering inflammation or immune response, thus exhibiting definite biosafety.

[0023] (3) The patch prepared by this invention has excellent mechanical properties and flexible shape adaptability. The patch designed by this invention uses an electrospinning process to prepare the double-layer composite fiber membrane. On the one hand, polylactic acid and polyvinyl alcohol, as long-chain polymer materials, both have high mechanical strength and strong stretchability; on the other hand, the electrospinning process uses a high-voltage electric field to draw the polymer solution into micron or nano-scale ultrafine fibers, which are then randomly stacked on the collector to form a highly porous three-dimensional network. These microscopic properties endow the material with good flexibility and elasticity. The flexible suction cup is obtained by using Ecoflex material through 3D printing and molding. Ecoflex, as a bio-inert silicone material, has a molecular backbone composed of alternating silicon and oxygen atoms. The silicon-oxygen bond length is relatively long, and the rotational steric hindrance is small, which endows the molecular chain with extremely high flexibility. Therefore, the suction cup array prepared by Ecoflex is easy to stretch and curl. Overall, the biomimetic suction cup-type double-layer composite fiber membrane patch designed in this invention has good mechanical strength and flexible shape adaptability. It can be easily rolled into a cylindrical structure to adapt to the shape of the intestinal tract, which is beneficial for its practical application in intestinal anastomosis.

[0024] (4) The patch prepared by this invention is simple to operate and easy to master. The patch designed by this invention provides tissue adhesion through the physical adsorption of the suction cup and the chemical adhesion of the hydrophilic layer of the composite fiber membrane, without relying on sutures or mechanical assistance. In specific use, simply place the patch on the surface of the intestinal tissue, apply appropriate force to achieve a tight fit and squeeze out the air in the suction cup to complete the operation. The use of this patch system does not require professional or complicated surgical skills, the steps are simple, the surgeon can easily master it, and it will effectively shorten the operation time.

[0025] (5) The patch prepared by this invention has good biocompatibility. The composite fiber membrane contained in the patch is prepared using polylactic acid and polyvinyl alcohol, both of which are biodegradable materials. The flexible suction cup array contained in the patch is prepared using Ecoflex, which is a bio-inert medical silicone that does not cause inflammation or foreign body rejection. The patch as a whole has good biocompatibility and is suitable for clinical surgical scenarios. Attached Figure Description

[0026] Figure 1 : Schematic diagram of the structure of the present invention; wherein: 1-double-layer composite fiber membrane, 2-flexible suction cup, 3-outer hydrophobic layer, 4-inner hydrophilic layer, 5-suction cup structure, 6-circular hole structure.

[0027] Figure 2 A: Preparation and apparent properties of composite fiber membranes; B: Physical images of various shapes; C: Thickness measurement of fiber membranes using vernier calipers; D: SEM images of polylactic acid fiber membranes; E: SEM images of polyvinyl alcohol fiber membranes.

[0028] Figure 3 Performance characterization of composite fiber membranes; A: puncture characteristics; B: tensile characteristics, compared with small intestinal tissue; C: contact angle test; D: fluorescent images of live and dead cells stained after co-culturing with L929; E: cell viability statistics after co-culturing with L929.

[0029] Figure 4 : Fabrication of flexible suction cup array; A: Design of male mold in SolidWorks; B: Schematic diagram of the fabrication process of flexible suction cup array, including 3D printing of male mold, Ecoflex molding, and demolding; C: Implementation examples of flexible suction cup array fabrication.

[0030] Figure 5 A: Interaction between biomimetic suction cup composite fiber membrane patch and biological tissue; B: Contact changes between polyvinyl alcohol fiber membrane and isolated small intestinal tissue; C: Contact between flexible suction cup array and isolated small intestinal tissue.

[0031] Figure 6 : Tissue adhesion of biomimetic suction cup composite fiber membrane patch; A: Before the interaction of polyvinyl alcohol fiber membrane with small intestinal tissue; B: Small intestinal tissue is vertically lifted by the polyvinyl alcohol fiber membrane; C: Before the interaction of flexible suction cup array with small intestinal tissue; D: Small intestinal tissue is vertically lifted by the flexible suction cup array. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0033] This invention provides a biomimetic suction cup-type composite fiber membrane patch, comprising a flexible suction cup array and a double-layer composite fiber membrane. The flexible suction cups include multiple suction cup structures distributed around the perimeter; each suction cup structure includes a hemispherical base and a cylindrical top; the flexible suction cups are fabricated using 3D printing and molding processes. The composite fiber membrane comprises a double-layer structure, with an inner layer composed of a hydrophilic material and an outer layer composed of a hydrophobic material; the double-layer composite fiber membrane is fabricated using an electrospinning process. The flexible suction cups and the double-layer composite fiber membrane are bonded and fixed together using bio-adhesive.

[0034] Preferably, the fiber diameter of the double-layer composite fiber membrane is 0.2μm-5μm.

[0035] Preferably, the thickness of the double-layer composite fiber membrane is 50μm-500μm.

[0036] Preferably, the flexible suction cup has 10-100 suction cups.

[0037] Preferably, the bottom diameter of the suction cup structure is 1mm-3mm.

[0038] Preferably, the height of the suction cup structure is 1mm-3mm.

[0039] Preferably, the number of circular holes is 10-100.

[0040] Preferably, the diameter of the circular hole structure is 1mm-5mm.

[0041] The present invention also provides a method for preparing the patch, comprising the following steps:

[0042] S1: Polylactic acid is dissolved in a mixed solvent of dichloromethane and N,N-dimethylformamide to obtain a polylactic acid spinning solution; polyvinyl alcohol is dissolved in a mixed solvent of deionized water and N,N-dimethylformamide to obtain a polyvinyl alcohol spinning solution; the polylactic acid solution is spun using electrospinning technology to obtain a hydrophobic outer layer of a composite fiber membrane, and the polyvinyl alcohol solution is further spun on it to obtain a hydrophilic inner layer of a composite fiber membrane, thus obtaining a bilayer composite fiber membrane;

[0043] S2: Design a flexible suction cup array using SolidWorks software, 3D print a positive mold, ultrasonically clean the positive mold and dry it; cast Ecoflex on the positive mold, dry it in a forced-air drying oven and demold it to obtain the flexible suction cup array.

[0044] S3: Cut the double-layer composite fiber membrane to an appropriate size, and use bio-adhesive to bond it to the back of the flexible suction cup array with the hydrophilic side facing down, ensuring that the double-layer composite fiber membrane completely covers the circular hole structure of the flexible suction cup array, thus obtaining a biomimetic suction cup type double-layer composite fiber membrane patch.

[0045] Preferably, the polylactic acid spinning solution has a mass fraction of 5%-15%.

[0046] Preferably, the mass fraction of the polyvinyl alcohol spinning solution is 5%-15%.

[0047] Preferably, the Ecoflex drying temperature is 50-70℃ and the drying time is 1-3 hours.

[0048] The present invention also provides the application of the patch in an end-to-end anastomosis device for intestinal tubes.

[0049] Preferably, the procedure specifically includes the following steps:

[0050] S1: Suspend and fix the mesenteric edge and the opposite mesenteric edge of the severed intestinal tube respectively, and align the intestinal tissue neatly;

[0051] S2: Place the patch with the suction cup side down on the serosa of the intestinal tract, and press the center of the patch so that the hydrophilic layer of the composite fiber membrane can fully contact and adhere to the tissue through the round hole structure;

[0052] S3: Press the surrounding area of ​​the patch in sequence to squeeze out the air in the suction cup and make it effectively contact and adhere to the intestinal tissue to complete the anastomosis.

[0053] This invention designs a biomimetic suction cup-type composite fiber membrane patch for use in intestinal anastomosis surgery. Compared to traditional manual anastomosis methods or mechanical staplers, this patch system has significant advantages such as strong adhesion, prevention of adhesion, simple operation, and flexible adaptability. Figure 1 As shown, the patch system includes a double-layer composite fiber membrane 1 and a flexible suction cup 2. The double-layer composite fiber membrane 1 includes an outer hydrophobic layer 3 and an inner hydrophilic layer 4. The double-layer composite fiber membrane 1 is prepared using an electrospinning process. The flexible suction cup 2 includes suction cup structures 5 arranged around the perimeter and circular hole structures 6 arranged in the center. Each suction cup structure 5 consists of a hemispherical base and a cylindrical top. The flexible suction cup 2 is obtained using 3D printing and molding processes. The double-layer composite fiber membrane 1 and the flexible suction cup 2 are bonded and fixed using bio-adhesive.

[0054] The outer hydrophobic layer 3 of this invention is a polylactic acid fiber membrane, which is used to prevent postoperative adhesion.

[0055] The inner hydrophilic layer 4 of this invention is a polyvinyl alcohol fiber membrane, which is used to provide chemical adhesion towards the anastomosis.

[0056] The present invention relates to a method for preparing a biomimetic suction cup-type composite fiber membrane patch for intestinal anastomosis, comprising the following steps:

[0057] (1) Preparation of bilayer composite fiber membrane: Polylactic acid was dissolved in a mixed solvent of dichloromethane and N,N-dimethylformamide to obtain polylactic acid spinning solution; polyvinyl alcohol was dissolved in a mixed solvent of deionized water and N,N-dimethylformamide to obtain polyvinyl alcohol spinning solution; the polylactic acid solution was spun using electrospinning technology to obtain a hydrophobic outer layer of composite fiber membrane, and polyvinyl alcohol solution was spun on it to obtain a hydrophilic inner layer of composite fiber membrane, thus obtaining a bilayer composite fiber membrane;

[0058] In some embodiments, the volume fraction of dichloromethane in the mixed solvent of dichloromethane and N,N-dimethylformamide is 20%-80%;

[0059] In some implementation examples, the polylactic acid spinning solution has a mass fraction of 8%-15%;

[0060] In some embodiments, the volume fraction of N,N-dimethylformamide in the mixed solvent of deionized water and N,N-dimethylformamide is 30%-70%.

[0061] In some implementation examples, the mass fraction of the polyvinyl alcohol spinning solution is 8%-15%;

[0062] In some implementation examples, the voltage of the electrospinning is 12KV-25KV;

[0063] In some implementation examples, the electrospinning flow rate is 0.5 mL / h-2 mL / h;

[0064] In some implementation examples, the diameter of the electrospinning nozzle is 15G-23G;

[0065] In some implementation examples, the distance between the electrospinning nozzle and the collecting roller is 8cm-15cm;

[0066] In some implementation examples, the rotational speed of the electrospinning collecting roller is 100 r / min-300 r / min;

[0067] In some embodiments, the thickness of the polylactic acid fiber membrane is 0.04 mm to 0.08 mm;

[0068] In some embodiments, the thickness of the polyvinyl alcohol fiber film is 0.08 mm to 0.12 mm;

[0069] In some embodiments, the polylactic acid fiber membrane has a fiber diameter of 0.5 μm-2 μm;

[0070] In some embodiments, the fiber diameter of the polyvinyl alcohol fiber membrane is 0.2 μm-2 μm;

[0071] (2) Fabrication of the flexible suction cup array: A male mold for the flexible suction cup array was designed using SolidWorks software. The flexible suction cup array is rectangular and includes multiple suction cup structures distributed around its perimeter. Each suction cup structure includes a cylindrical top and a hemispherical bottom. Subsequently, the male mold was 3D printed, ultrasonically cleaned, and dried. Flexible silicone material Ecoflex was poured onto the male mold, dried in a forced-air drying oven, and then demolded to obtain the flexible suction cup array.

[0072] In some implementation examples, the width of the array is 1cm-4cm;

[0073] In some implementation examples, the length of the array is 2cm-8cm;

[0074] In some implementation examples, the number of suction cups is 10-100;

[0075] In some implementation examples, the diameter of the circular hole structure is 1mm-5mm;

[0076] In some implementation examples, the number of the circular hole structures is 10-100;

[0077] In some implementation examples, the Ecoflex flexible silicone material is dried in a forced-air drying oven at a temperature of 40-50°C for 1-3 hours.

[0078] (3) Assembly of the patch system: Cut the double-layer composite fiber membrane to a suitable size, and use bio-adhesive to bond it to the back side of the flexible suction cup array with the hydrophilic side facing down, so as to ensure that the double-layer composite fiber membrane completely covers the circular hole structure of the flexible suction cup array, thus obtaining a biomimetic suction cup double-layer composite fiber membrane patch.

[0079] In some implementation examples, the width of the double-layer composite fiber membrane is 1cm-4cm;

[0080] In some implementation examples, the length of the double-layer composite fiber membrane is 2cm-8cm;

[0081] (4) Application of patch system in intestinal anastomosis: The mesenteric edge and the opposite mesenteric edge of the severed intestinal segment are suspended and fixed respectively, and the intestinal tissue is aligned neatly; the patch with the suction cup side facing down is placed over the serosal surface of the intestinal segment, and an appropriate force is applied to the center of the patch and maintained for a certain period of time, so that the hydrophilic layer of the composite fiber membrane can fully contact and adhere to the tissue through the round hole structure; an appropriate force is applied to the periphery of the patch in turn and maintained for a certain period of time, squeezing out the air in the suction cup and making it effectively contact and adsorb with the intestinal tissue to complete the anastomosis.

[0082] In some implementation examples, the magnitude of the force applied to the center of the patch is 1-10N;

[0083] In some implementation examples, the duration of the force applied to the center of the patch is 5-10 seconds;

[0084] In some implementation examples, the magnitude of the force applied to the periphery of the patch is 1-10N;

[0085] In some implementation examples, the duration of the force applied around the patch is 5-10 seconds;

[0086] The following are specific embodiments.

[0087] Example 1: Preparation of composite fiber membrane

[0088] Composite fiber membranes were prepared using electrospinning. 1 g of polylactic acid (PLA) was dissolved in a mixed solvent of 9 g dichloromethane and N,N-dimethylformamide (6:4, w / w) to obtain a PLA spinning solution; 1 g of polyvinyl alcohol (PVA) was dissolved in a mixed solvent of 9 g deionized water and N,N-dimethylformamide (7:3, w / w) to obtain a PVA spinning solution. 6 mL of the PLA spinning solution was drawn and electrospinned under an 18 kV high-voltage electric field at a spinning flow rate of 1 mL / h. The nozzle diameter was 18 G, the distance between the nozzle and the collecting roller was 10 cm, and the collecting roller rotation speed was 300 r / min. 6 mL of the PVA spinning solution was drawn and electrospinned under a 24 kV high-voltage electric field at a spinning flow rate of 0.5 mL / h. The nozzle diameter was 23 G, the distance between the nozzle and the collecting roller was 10 cm, and the collecting roller rotation speed was 300 r / min. Figure 2 As shown, the prepared polylactic acid (PLA) or polyvinyl alcohol (PVA) fiber membranes are uniform and flexible, and can be adapted to various shapes. The thickness of the fiber membranes was measured using calipers, revealing that the PLA fiber membrane was approximately 0.6 mm thick and the PVA membrane was approximately 0.9 mm thick. Scanning electron microscopy (SEM) revealed that the fiber membranes consist of uniformly sized, interwoven nanofibers.

[0089] Example 2: Performance Characterization of Composite Fiber Membranes

[0090] like Figure 3 As shown, the properties of the composite fiber membrane were characterized. The puncture performance of the composite fiber membrane was tested using a universal testing machine at a puncture speed of 100 mm / min. The force required to puncture the polylactic acid (PLA) fiber membrane was approximately 0.4 N, and the force required to puncture the polyvinyl alcohol (PVA) fiber membrane was approximately 0.9 N. The tensile properties of the composite fiber membrane were tested using a universal testing machine and compared with small intestinal tissue at a tensile speed of 2 mm / min. The elastic modulus of PLA or PVA was significantly higher than that of small intestinal tissue, demonstrating their superior mechanical properties. The hydrophilicity / hydrophobicity of the fiber membrane was tested using a contact angle meter. The contact angle between the PLA fiber membrane and the liquid surface was obtuse, while the contact angle between the PVA fiber membrane and the liquid surface was acute, indicating that the PLA fiber membrane is hydrophobic and the PVA fiber membrane is hydrophilic. After autoclaving, the polyfiber membrane was co-cultured with L929 cells. Cell morphology was observed under a fluorescence microscope after staining with Calcein-AM and PI. All cells showed normal morphology, and most cells were viable. Quantitative monitoring of cell viability using CCK-8 showed that cell viability could reach over 80%, confirming its good cell compatibility.

[0091] Example 3: Fabrication of a Flexible Suction Cup Array

[0092] like Figure 4 As shown, a male mold for a suction cup array was designed in SolidWorks software. The array has a width of 1 cm, a length of 2 cm, 26 suction cups, a bottom diameter of 1.6 mm, a height of 1 mm, and 28 circular holes, each with a bottom diameter of 1.6 mm. The male mold was then 3D printed, ultrasonically cleaned, and dried. Ecoflex was then cast onto the male mold, which was dried in a forced-air drying oven at 50°C for 2 hours. Demolding was then performed to obtain the flexible suction cup array.

[0093] Example 4: Interaction between biomimetic suction cup-type composite fiber membrane patch and biological tissue

[0094] like Figure 5As shown, isolated porcine small intestine was taken, and a polyvinyl alcohol (PVA) cellulose membrane was placed on the surface of the small intestine. The membrane rapidly dissolved and contracted inwards within a short time. The PVA cellulose membrane completely dissolved within one minute, forming a liquid viscous substance. Simultaneously, the inward contraction during dissolution provided tissue traction. After placing a flexible suction cup on the surface of the small intestine tissue, the air inside the suction cup was squeezed out, allowing it to firmly adhere to the intestinal tissue. A bilayer composite cellulose membrane was adhered to the back side of the flexible suction cup array with its hydrophilic side facing down using bio-adhesive, ensuring that the bilayer composite cellulose membrane completely covered the circular pore structure of the flexible suction cup array. When a biomimetic suction cup-type bilayer composite cellulose membrane patch was placed on the surface of the small intestine tissue, the PVA cellulose membrane contacted, dissolved, and chemically adhered to the tissue through the circular pore structure; the flexible suction cups, on the other hand, adhered and adsorbed to the tissue through physical action.

[0095] Example 5: Tissue adhesion of biomimetic suction cup composite fiber membrane patch

[0096] like Figure 6 As shown, isolated porcine small intestine was taken, and a composite fibrous membrane with the hydrophilic side facing down was attached to the surface of the intestinal tissue. A force of 5N was applied and maintained for 10 seconds. The composite fibrous membrane was able to overcome gravity and vertically lift the small intestine tissue. Flexible suction cups were attached to the surface of the intestinal tissue, and a force of 5N was applied to expel air from the suction cups. This was maintained for 10 seconds. The flexible suction cup array was able to overcome gravity and vertically lift the small intestine tissue, indicating that it has a strong adhesive force with the intestinal tissue.

[0097] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A biomimetic suction cup type double-layer composite fiber membrane patch, characterized in that, It includes a double-layer composite fiber membrane (1), a flexible suction cup (2), a suction cup structure (5), and a circular hole structure (6); the double-layer composite fiber membrane (1) includes an outer hydrophobic layer (3) and an inner hydrophilic layer (4); the inner hydrophilic layer (4) is bonded and fixed to the flexible suction cup (2); the suction cup structure (5) is arranged around the flexible suction cup (2), and the circular hole structure (6) is arranged in an array on the flexible suction cup (2); the suction cup structure (5) includes a hemispherical base and a cylindrical top.

2. The biomimetic suction cup type double-layer composite fiber membrane patch as described in claim 1, characterized in that, The fiber diameter of the double-layer composite fiber membrane (1) is 0.2μm-5μm.

3. The biomimetic suction cup type double-layer composite fiber membrane patch as described in claim 1, characterized in that, The thickness of the double-layer composite fiber membrane (1) is 50μm-500μm.

4. The biomimetic suction cup type double-layer composite fiber membrane patch as described in claim 1, characterized in that, The diameter of the circular hole structure (6) is 1mm-5mm.

5. The biomimetic suction cup type double-layer composite fiber membrane patch as described in claim 1 or 4, characterized in that, The number of circular hole structures (6) is 10-100.

6. The biomimetic suction cup type double-layer composite fiber membrane patch as described in claim 1, characterized in that, The diameter of the hemispherical base of the suction cup structure (5) is 1mm-3mm.

7. The biomimetic suction cup type double-layer composite fiber membrane patch as described in claim 1 or 6, characterized in that, The number of suction cup structures (5) is 10-100.

8. The method for preparing the biomimetic suction cup type double-layer composite fiber membrane patch as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Polylactic acid was dissolved to obtain polylactic acid spinning solution; polyvinyl alcohol was dissolved to obtain polyvinyl alcohol spinning solution; Electrospinning technology was used to spin polylactic acid solution to obtain an outer hydrophobic layer of composite fiber membrane. Then, polyvinyl alcohol solution was used to spin on the outer hydrophobic layer to obtain an inner hydrophilic layer of composite fiber membrane, thus obtaining a double-layer composite fiber membrane. A flexible suction cup was designed and then 3D printed to obtain a male mold. Flexible silicone material was poured on the male mold, dried, and then demolded to obtain the flexible suction cup. (2) Adhere the inner hydrophilic layer of the double-layer composite fiber membrane obtained in step (1) to the back side of the suction cup structure of the flexible suction cup, so that the double-layer composite fiber membrane covers the circular hole structure of the flexible suction cup, thus obtaining the biomimetic suction cup type double-layer composite fiber membrane patch.

9. The application of the biomimetic suction cup type double-layer composite fiber membrane patch as described in any one of claims 1-7 in the preparation of an intestinal anastomosis device.

10. The application as described in claim 9, characterized in that, Specifically, the following steps are included: S1: Suspend and fix the mesenteric edge and the opposite mesenteric edge of the severed intestinal tube respectively, and align the intestinal tissue neatly; S2: Cover the intestinal serosa surface with the suction cup structure of the biomimetic suction cup type double-layer composite fiber membrane patch, and press the biomimetic suction cup type double-layer composite fiber membrane patch so that the inner hydrophilic layer of the composite fiber membrane can fully contact the tissue through the round hole structure. S3: Squeeze out the air from the suction cup structure of the biomimetic suction cup-type double-layer composite fiber membrane patch and make the suction cup structure fully contact and adsorb with the intestinal tissue to complete the intestinal anastomosis.

Images