A surgical patch with both tissue adhesion and anti-adhesion functions and its preparation method

Abstract

The present invention discloses a surgical patch with both tissue adhesion and anti-adhesion functions and a preparation method thereof. The patch comprises a wound adhesion layer and a base layer. The wound adhesion layer contains fibrinogen and a stabilizer. Some lysine residues of the fibrinogen contain hydrophobic groups. The stabilizer is used to maintain the activity of fibrinogen. The base layer is a hydrophilic polymer porous scaffold. The surgical patch prepared by the present invention has excellent mechanical strength and adhesion performance, and its performance is significantly better than that of existing surgical adhesive products and emergency hemostasis products under the same conditions. The patch has good biocompatibility, can effectively prevent tissue adhesion, and is beneficial to promoting cell proliferation and differentiation, accelerating wound healing and the recovery of defective tissues. It has great potential in clinical applications.

Description

Technical Field

[0001] The present invention relates to a surgical patch with both tissue adhesion and anti-adhesion properties and a preparation method thereof, belonging to the field of medical tissue engineering. Background Art

[0002] Uncontrolled bleeding during trauma or surgery is a major cause of global death, resulting in more than 2 million deaths annually. It is necessary and crucial to minimize blood loss, seal tissue and organ structures, reduce surgical complications, and shorten the surgical time in the operating room during surgical procedures. Tissue adhesives can effectively prevent blood and other body fluid leakage.

[0003] Postoperative adhesions are common clinical complications in surgical operations (especially abdominal and intestinal surgeries), such as chronic pain, ischemia, intestinal obstruction, organ dysfunction, etc. These complications usually require reoperation for adhesion lysis. To prevent postoperative tissue adhesions, introducing a physical barrier between damaged tissue and adjacent tissue to hinder the formation of tissue adhesions has been widely accepted and clinically used.

[0004] Fibrin glue, as a commonly used adhesive in surgery, has good procoagulant properties and biocompatibility, and is one of the most widely used adhesives. However, the mechanical strength and adhesion performance of fibrin glue are both poor, it cannot achieve efficient adhesion to wet tissues, and often needs to cooperate with thrombin to play a role. Therefore, although fibrin glue has high procoagulant properties, the hemostatic effect is not very ideal.

[0005] Then, how to regulate the composition and structure of fibrin glue / fibrinogen to enhance its mechanical strength and adhesion performance? At the same time, how to ensure that fibrin glue / fibrinogen has excellent tissue adhesion function while hindering the adhesion between damaged tissue and adjacent tissue? Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a surgical patch with both tissue adhesion and anti-adhesion properties and a preparation method. The present invention unexpectedly obtains a brand-new tissue patch by a simple method. The surgical patch comprises a wound adhesion layer and a base layer. The wound adhesion layer comprises hydrophobized fibrinogen, which has excellent mechanical strength and adhesion performance and can be better applied to hemostasis or tissue adhesion; at the same time, after being rinsed with normal saline, the wound adhesion layer can reduce the adhesion between the wound adhesion layer, damaged tissue and adjacent tissue; the base layer is a hydrophilic polymer porous scaffold, which is used to further reduce the tissue adhesion between damaged tissue and adjacent tissue.

[0007] The present invention adopts the following method:

[0008] A surgical patch with both tissue adhesion and anti-adhesion functions, the patch comprising a wound adhesion layer and a base layer, the wound adhesion layer comprising fibrinogen and a stabilizer, and partial lysine residues of the fibrinogen containing hydrophobic groups; the stabilizer is used to maintain the activity of fibrinogen; the base layer is a hydrophilic polymer porous scaffold.

[0009] The base layer comprises one or more of regenerated oxidized cellulose, chitosan, hyaluronic acid, collagen, and polylactic acid.

[0010] When in use, the wound adhesion layer faces the damaged tissue side and is used for tissue adhesion and preventing adhesion to surrounding tissues; the base layer is used to support the mechanical properties of the wound adhesion layer, further prevent tissue adhesion, and promote cell growth, migration, proliferation, and differentiation.

[0011] In the above technical solution, the stabilizer for maintaining the activity of fibrinogen not only refers to maintaining the spatial structure and biological activity of fibrinogen; it also includes maintaining the stability of fibrinogen in the state of the patch and during the process of making the wound adhesion layer of the patch. The stabilizer can generally be one or more of sodium chloride, calcium chloride, potassium chloride, magnesium chloride, sodium citrate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, arginine hydrochloride, and glycine.

[0012] The hydrophobic group is a hydrocarbon group containing one or more groups such as a carbonyl group, a carbon-carbon double bond, an ester group, an amide bond, and a phenyl group.

[0013] Preferably, the thickness of the wound adhesion layer is 0.1 - 1 mm.

[0014] Preferably, the thickness of the surgical patch is 0.1 - 3 mm.

[0015] Preferably, the base layer further comprises one or more derivatives obtained by chemically modifying regenerated oxidized cellulose, chitosan, hyaluronic acid, collagen, and polylactic acid.

[0016] Preferably, the base layer further comprises one or any combination of hydroxypropyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, cellulose acetate, sodium carboxymethyl cellulose, acetaldehyde dimethyl cellulose acetate, and their derivatives, salts, and copolymers.

[0017] Preferably, the hydrophobic group is -CO-(CH 2 ) n CH 3 , n = 1 - 19; more preferably, the hydrophobic group is -CO-(CH 2 ) n CH 3, n = 2 - 10; Most preferably, the hydrophobic group is -CO-(CH 2 ) n CH 3 , n = 3 - 6.

[0018] Preferably, the hydrophobic group forms an amide bond (-NH-CO-) with the primary amine of the lysine residue of fibrinogen.

[0019] The lysine residues containing hydrophobic groups on the fibrinogen account for 2% - 70% of the total number of lysine residues, by quantity; the total number of lysine residues is the sum of the lysine residues containing hydrophobic groups and the unmodified lysine residues.

[0020] Preferably, the lysine residues containing hydrophobic groups on the fibrinogen account for 5% - 40% of the total number of lysine residues; more preferably, the lysine residues containing hydrophobic groups on the fibrinogen account for 10% - 30% of the total number of lysine residues.

[0021] The proportion of lysine residues containing hydrophobic groups on the fibrinogen needs to be within a specific range to ensure the entanglement of fibrinogen molecules containing hydrophobic groups at the microscopic level, so that the mechanical properties of the wound adhesion layer of the surgical patch can be reflected at the macroscopic level. If the proportion of lysine residues containing hydrophobic groups on the fibrinogen is too low, such as less than 2%, there is no obvious change in the mechanical properties of the wound adhesion layer of the surgical patch compared with the unmodified fibrinogen layer at the macroscopic level. If the proportion of lysine residues containing hydrophobic groups on the fibrinogen is higher than 70%, due to the replacement of a large number of basic amino acids (lysine) on the protein surface, it will lead to protein denaturation and unstable spatial structure of fibrinogen, and ultimately result in poor mechanical properties of the patch, even worse than the original unmodified fibrinogen. Therefore, a specific degree of modification of lysine residues is beneficial to achieving high mechanical properties of the modified fibrinogen.

[0022] The wound adhesion layer contains not less than 2 mg of fibrinogen containing hydrophobic groups per square centimeter. Preferably, the wound adhesion layer contains 4 - 100 mg of fibrinogen containing hydrophobic groups per square centimeter; preferably, the wound adhesion layer contains 10 - 50 mg of fibrinogen containing hydrophobic groups per square centimeter; more preferably, the wound adhesion layer contains 20 - 30 mg of fibrinogen containing hydrophobic groups per square centimeter.

[0023] The wound adhesion layer must have at least a certain amount of fibrinogen containing hydrophobic groups per square centimeter to ensure that the wound adhesion layer has continuous and uniform fibrinogen to achieve a certain strength of mechanical properties.

[0024] The fibrinogen can be derived from any one or more of human, bovine, porcine, and recombinant sources.

[0025] The surgical patch contains a pharmaceutically active ingredient, which is a substance with medical utility or physiological activity and can be used to treat and relieve disease symptoms. The pharmaceutically active ingredient includes drugs for targeted or controlled release. Preferably, the pharmaceutically active ingredient includes a plasmin inhibitor.

[0026] The present invention also provides a method for preparing a surgical patch with both tissue adhesion and anti-adhesion properties, and the specific steps are as follows:

[0027] Step 1: Use fibrinogen containing a hydrophobic group and a stabilizer as raw materials to prepare the wound adhesion layer;

[0028] Step 2: Spray, immerse, or cast a hydrophilic polymer gel on the wound adhesion layer, and obtain the porous scaffold substrate layer after freeze-drying.

[0029] The preparation steps of the wound adhesion layer include:

[0030] ① Ultrasonically treat the mixed solution of fibrinogen and the stabilizer, and the mass fraction of the obtained fibrinogen solution is 5 - 200 mg / mL;

[0031] ② Dropwise add a hydrophobic modification reagent to the fibrinogen solution under stirring conditions, and react at 37 °C for 0.5 - 5 h to obtain a fibrinogen solution containing a hydrophobic group;

[0032] ③ Dialyze the obtained fibrinogen solution containing a hydrophobic group at 4 - 37 °C for 5 - 72 h;

[0033] ④ Concentrate the obtained fibrinogen solution containing a hydrophobic group to 50 - 200 mg / mL, and the concentration temperature is 4 - 37 °C; and perform freeze-drying, and the freeze-drying temperature is -85 - -35 °C to obtain the wound adhesion layer.

[0034] The preparation method of the substrate layer includes spraying, immersing, or casting a gel containing a hydrophilic polymer onto the wound adhesion layer, and crosslinking at room temperature on the contact surface with the wound adhesion layer; after pre-cooling and freeze-drying, obtain the substrate layer of the hydrophilic polymer porous scaffold.

[0035] The substrate layer contains one or more of regenerated oxidized cellulose, chitosan, hyaluronic acid, collagen, and polylactic acid.

[0036] Preferably, the substrate layer further includes one or more of derivatives obtained by chemically modifying regenerated oxidized cellulose, chitosan, hyaluronic acid, collagen, and polylactic acid.

[0037] Preferably, the base layer further comprises one or any combination of hydroxypropyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, cellulose acetate, sodium carboxymethyl cellulose, acetaldehyde dimethyl cellulose acetate, and their derivatives, salts, and copolymers.

[0038] In the above technical solution, the hydrophobic modification reagent contains a hydrophobic group, which is used to modify the lysine residue of fibrinogen; the hydrophobic modification reagent contains a succinimide group, which is used to react with the primary amine of the lysine residue to form a stable amide bond.

[0039] The hydrophobic modification reagent consists of two types of groups. One part of the group is used to modify the lysine residue of fibrinogen, which is the hydrophobic group described in the present invention. The other part of the group is used to react with the primary amine on the lysine residue of fibrinogen. Final removal . For example, the succinimide group described in the present invention reacts with the primary amine on the lysine residue to form a stable amide bond and release N-hydroxysuccinimide (NHS).

[0040] Preferably, the succinimide group contains a sulfonic acid group (-SO 3 - ). The sulfonic acid group can increase the water solubility of the hydrophobic modification reagent, and more importantly, increase the reaction efficiency of the hydrophobic modification reagent with fibrinogen.

[0041] When the hydrophobic modification reagent contains a succinimide group and a hydrophobic group, during the reaction, the reactive group (succinimide group) on the hydrophobic modification reagent can reduce or prevent protein denaturation of fibrinogen induced by the hydrophobic modification reagent. The hydrophobic modification reagent described in the present invention cannot be an acid anhydride with a hydrophobic group. The acid anhydride with a hydrophobic group is very likely to cause denaturation of fibrinogen. The denatured fibrinogen is likely to precipitate from the solution, making it impossible to modify the hydrophobic group onto fibrinogen and even more impossible to form the fibrinogen-based patch described in the present invention.

[0042] The hydrophobic group is a hydrocarbon group containing one or more of a carbonyl group, a carbon-carbon double bond, an ester group, an amide bond, and a phenyl group.

[0043] Preferably, the hydrophobic group is -CO-(CH 2 ) n CH 3 , where n = 1 - 19; more preferably, the hydrophobic group is -CO-(CH 2 ) n CH 3, n = 2 - 10; Most preferably, the hydrophobic group is -CO-(CH 2 ) n CH 3 , n = 3 - 6.

[0044] Preferably, the hydrophobic group forms an amide bond (-NH-CO-) with the primary amine of the fibrinogen lysine residue.

[0045] Compared with the prior art, the present invention has the following advantages:

[0046] 1. The present invention has prepared a brand-new surgical patch for the first time. The surgical patch comprises a wound adhesion layer and a base layer. The wound adhesion layer comprises hydrophobized fibrinogen. The hydrophobized fibrinogen has strong intermolecular interactions compared with wild-type (unmodified) fibrinogen. The hydrophobic group can induce the entanglement of fibrinogen protein molecules with each other, and the formed wound adhesion layer has excellent mechanical properties and adhesion properties. At the same time, the surgical patch also comprises a base layer of a hydrophilic polymer porous scaffold, which can reduce tissue adhesion between damaged tissues and adjacent tissues.

[0047] 2. The wound adhesion layer in the surgical patch provided by the present invention does not rely on externally added thrombin and forms a wound adhesion layer of fibrinogen by itself. Currently, in the application of fibrinogen / glue in tissue adhesion, it is all based on the reaction between fibrinogen and thrombin, and it has not been seen that fibrinogen alone can play a role in tissue sealing. Further, not relying on externally added thrombin can reduce the degree and solve the problem of difficult enzyme storage. The existing technologies mainly rely on dissolving fibrinogen and thrombin to form a solution, or absorbing water to dissolve. Generally, the dissolution process is time-consuming and complex, and it takes time to prepare before use. The surgical patch with a wound adhesion layer provided by the present invention can be taken and used at any time during actual application.

[0048] 3. The surgical patch provided by the present invention has excellent biosafety, can effectively prevent tissue adhesion, and is beneficial to promoting cell proliferation and differentiation, accelerating wound healing and the recovery of defective tissues.

[0049] 4. The preparation method used in the present invention is convenient to operate and the process is simple; the surgical patch is convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Schematic diagram of the surgical patch with both tissue adhesion and anti-adhesion functions provided by the present invention, 1 - wound adhesion layer, 2 - base layer;

[0051] Figure 2 Scanning electron microscope image of the wound adhesion layer of the surgical patch in Example 1;

[0052] Figure 3 Molecular dynamics simulations were performed on the interactions of unmodified fibrinogen molecules and the fibrinogen molecules containing hydrophobic groups according to the present invention. By comparison, it can be seen that the fibrinogen molecules containing hydrophobic groups exhibit strong interactions, inducing entanglement between molecules;

[0053] Figure 4 The time for unmodified fibrinogen and the fibrinogen containing hydrophobic groups in Example 1 of the present invention to be recognized by thrombin to form a fibrin gel;

[0054] Figure 5 The in vitro cytotoxicity of the wound adhesion layer of Example 1 and the Surgicel Fibrillar products of Comparative Example 1 and Comparative Example 4;

[0055] Figure 6 The adhesion performance and anti-adhesion performance of the surgical patch of Example 1 in a rat liver hemostasis test;

[0056] Figure 7 The shear strength of the wound adhesion layer of Example 1 and three surgical adhesive products (Fibrin Glue, Surgicel Fibrillar, Gelatin Sponge) of Comparative Example 1 and Comparative Example 4;

[0057] Figure 8 The adhesion energy of the wound adhesion layer of Example 1 and three surgical adhesive products (Fibrin Glue, Surgicel Fibrillar, Gelatin Sponge) of Comparative Example 1 and Comparative Example 4;

[0058] Figure 9 The hemostasis time and blood loss in the livers of New Zealand white rabbits of the wound adhesion layer of Example 1 and the surgical adhesive products (Surgicel Fibrillar, Gelatin Sponge) of Comparative Example 4; Specific Examples

[0059] The following specifically describes in detail the technical problems to be solved, the technical solutions and the beneficial effects of the present invention in combination with specific examples. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0060] The present invention provides a surgical patch with both tissue adhesion and anti-adhesion properties. The surgical patch comprises a wound adhesion layer and a base layer. The wound adhesion layer comprises hydrophobized fibrinogen and a stabilizer. The hydrophobized fibrinogen has hydrophobic groups on some lysine residues. When the lysine residues on the surface of fibrinogen are modified with hydrophobic groups, in the solution state, due to the participation of water molecules (electrostatic interaction, hydrogen bond, etc.), the van der Waals interaction of most hydrophobic groups is weakened. During the formation of the wound adhesion layer by removing water, the van der Waals interaction between hydrophobic chains is enhanced due to the proximity, resulting in excellent mechanical properties and adhesion properties of the wound adhesion layer of the surgical patch. The stabilizer is one or more of sodium chloride, calcium chloride, sodium citrate, sodium dihydrogen phosphate, disodium hydrogen phosphate, L-arginine hydrochloride, and glycine.

[0061] The stabilizer is to maintain the spatial structure and biological activity of fibrinogen. The stabilizer is to maintain the stability of fibrinogen in the state of the patch and during the preparation of the wound adhesion layer of the surgical patch. The stabilizer is introduced when preparing the fibrinogen solution in the patch.

[0062] Shear strength test: Refer to the American Society for Testing and Materials standard (ASTM F2255-05). Add the surgical patch to the surface of fresh porcine skin. The area of the patch is 10×20 mm. Place another piece of porcine skin on the surface of the patch for adhesion, and keep the two pieces of porcine skin overlapping at the patch site. Use a universal material testing machine to test the shear strength of the sample at a strain rate of 5 mm / min.

[0063] Adhesion energy test: Refer to the American Society for Testing and Materials standard (ASTM F2256-05). Add the surgical patch to the surface of fresh porcine skin. The area of the patch is 15×35 mm. Place another piece of porcine skin aligned on the surface of the patch. Use a universal material testing machine to test the adhesion performance of the sample at a strain rate of 5 mm / min.

[0064] Hepatic hemostasis test on New Zealand white rabbits: Use the liver lobe of New Zealand white rabbits (2.5 - 3 kg). Make an incision with a length of 10 mm and a depth of 5 mm on the liver surface, and record the bleeding volume in the first 10 s of free bleeding. Add the wound adhesion layer of the surgical patch to the surface of the liver incision and press for 15 s. Evaluate the wound closure state, hemostasis time, and blood loss of the traumatic bleeding wound.

[0065] Rat liver hemostasis test: SD rats (250 - 300 g) were used. A 6-cm incision was made along the midline of the abdomen from the xiphoid process. The liver lobe was removed from the abdomen. A sterile dry gauze pad was placed under the liver lobe, and an 8-mm long and 3-mm deep incision was made on the liver surface. The bleeding volume before was recorded during 10 s of free bleeding. The surgical patch was applied to the liver incision and pressed for 15 s; the abdominal wound was closed, and the wound healing of the liver and the adhesion state of the abdominal tissue were observed at 1, 2, 3, and 4 weeks after the operation.

[0066] Example 1

[0067] Step 1: The wound adhesion layer was prepared using fibrinogen containing a hydrophobic group and a stabilizer as raw materials.

[0068] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and disperse it evenly by ultrasonic wave;

[0069] ② Under light-shielded conditions, 200 μL of 0.4 M N-(hexanoyloxy) succinimide was added dropwise to the fibrinogen solution under stirring conditions, and it was dispersed by a triple mixing process of vortexing for 5 min and ultrasonic wave for 5 min. Under the condition of 37 °C, the reaction was carried out for 4 h to obtain a fibrinogen solution containing a hydrophobic group;

[0070] ③ The obtained fibrinogen solution containing a hydrophobic group was dialyzed at 4 °C for 72 h;

[0071] ④ The obtained fibrinogen solution containing a hydrophobic group was frozen, concentrated to 100 mg / mL, and the concentration temperature was 37 °C; then it was freeze-dried to obtain the wound adhesion layer.

[0072] Step 2: Regenerated oxidized cellulose gel was sprayed, impregnated or cast on the wound adhesion layer, and the base layer was obtained after freeze-drying.

[0073] In the fibrinogen solution containing a hydrophobic group, the hydrophobic modification reagent (N-(hexanoyloxy) succinimide) and the fibrinogen solution do not belong to a simple mixture, but react with the primary amine of the lysine residue on the fibrinogen surface to form a stable amide bond and bind to the fibrinogen molecule.

[0074] The surgical patch prepared by the present invention Figure 1 As shown in the schematic diagram, the surgical patch includes a wound adhesion layer and a base layer. The wound adhesion layer faces the damaged tissue side during use and is used for tissue adhesion and preventing tissue adhesion; the base layer is used to support the mechanical properties of the wound adhesion layer, further prevent tissue adhesion, and promote the growth, migration, proliferation and differentiation of cells.

[0075] The microscopic structure of the wound adhesion layer of the surgical patch prepared in this example is asFigure 2 As shown, its surface has a pore-like structure. The hydrophobic group of fibrinogen in the wound adhesion layer is -CO-(CH 2 ) 4 CH 3 , which reacts with the primary amine of lysine residues on the fibrinogen surface to form an amide bond (-NH-CO-). According to molecular dynamics simulation calculations, it can be found that the van der Waals interaction between hydrophobic chains is enhanced due to the proximity of the distance, inducing entanglement between protein molecules ( Figure 3 ), making the wound adhesion layer have strong mechanical properties and adhesion properties. In this example, the stabilizer of the wound adhesion layer is Na 2 HPO 4 , KH 2 PO 4 , NaCl and KCl. In order to facilitate the comparison of the mechanical properties of the wound adhesion layer in different examples with those of the comparative example, the stabilizers in the following preparation process remain the same. At the same time, the stabilizer in the present invention can also be one or more of sodium chloride, calcium chloride, potassium chloride, magnesium chloride, sodium citrate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, L-arginine hydrochloride, and glycine. The wound adhesion layer of the surgical patch prepared in this example contains 20 mg of fibrinogen with hydrophobic groups per square centimeter.

[0076] The adhesion energy of the wound adhesion layer of the surgical patch in Example 1 is 160 J / m 2 , and the shear strength is 8750 Pa. In addition, the time for unmodified fibrinogen and the fibrinogen with hydrophobic groups described in the present invention to be catalyzed by thrombin to form a fibrin gel is similar, indicating that the modified fibrinogen retains the ability to be recognized by thrombin ( Figure 4 ). The wound adhesion layer of the surgical patch has appropriate low cytotoxicity ( Figure 5 ).

[0077] Implant the surgical patch described in this example into the wound area of the rat liver. The surgical patch can quickly seal the liver wound and effectively prevent adhesion with the surrounding abdominal tissues. One week after the operation, open the abdomen for observation. The liver contour is clear and no tissue adhesion is seen; two weeks after the operation, the liver wound heals well. Open the abdomen for observation. The liver contour is clear and no tissue adhesion is seen; four weeks after the operation, the liver wound heals well. Open the abdomen for observation. The liver contour is clear and no tissue adhesion is seen; it is absorbed in the body ( Figure 6 ).

[0078] Example 2

[0079] First step: Prepare the wound adhesion layer using fibrinogen with hydrophobic groups and a stabilizer as raw materials.

[0080] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and ultrasonically disperse it evenly;

[0081] ② Under light - avoiding conditions, add 200 μL of 0.4 M 2,5 - dioxopyrrolidin - 1 - yl dodecanoate dropwise to the fibrinogen solution under stirring conditions, and disperse it under a triple mixing process of vortexing for 5 min and ultrasonically for 5 min. React at 37 °C for 5 h to obtain a fibrinogen solution containing hydrophobic groups;

[0082] ③ Dialyze the obtained fibrinogen solution containing hydrophobic groups at 4 °C for 72 h;

[0083] ④ Freeze the obtained fibrinogen solution containing hydrophobic groups, concentrate it to 100 mg / mL at a concentration temperature of 37 °C; then perform freeze - drying to obtain a wound - adhering layer.

[0084] The second step: Spray, immerse or cast a regenerated oxidized cellulose gel on the wound - adhering layer, and then perform freeze - drying to obtain a base layer.

[0085] In the wound - adhering layer of the surgical patch in this example, the hydrophobic group of fibrinogen is -CO-(CH 2 ) 10 CH 3 , which reacts with the primary amine of lysine residues on the fibrinogen surface to form an amide bond (-NH - CO-). Each square centimeter of the surgical wound - adhering layer prepared in this example contains 20 mg of fibrinogen containing hydrophobic groups. The adhesion energy is 175 J / m 2 , and the shear strength is 10320 Pa.

[0086] Implant the surgical patch described in this example into the wound area of a rat's liver. The surgical patch can quickly seal the liver wound and effectively prevent adhesion to the surrounding abdominal tissues. 28 days after the operation, the liver wound heals well. Open the abdomen for observation, and no tissue adhesion is seen.

[0087] Example 3

[0088] The first step: Use fibrinogen containing hydrophobic groups and a stabilizer as raw materials to prepare the wound - adhering layer.

[0089] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and ultrasonically disperse it evenly;

[0090] ② Under light - avoiding conditions, 200 μL of 0.4 M N - hydroxysuccinimide methacrylate was added dropwise to the fibrinogen solution under stirring conditions, and dispersion was carried out under a triple mixing process of vortexing for 5 min and ultrasonic treatment for 5 min. The reaction was carried out at 37 °C for 3 h to obtain a fibrinogen solution containing hydrophobic groups;

[0091] ③ The obtained fibrinogen solution containing hydrophobic groups was dialyzed at 25 °C for 24 h;

[0092] ④ The obtained fibrinogen solution containing hydrophobic groups was frozen, concentrated to 100 mg / mL at a concentration temperature of 4 °C; then freeze - dried to obtain the wound - adhering layer.

[0093] The second step: Spray, immerse or cast regenerated oxidized cellulose gel on the wound - adhering layer, and then freeze - dry to obtain the base layer.

[0094] In the wound - adhering layer of the surgical patch in this example, the hydrophobic group of fibrinogen is -CO - CH(CH 3 ) = CH 2 , which contains a carbon - carbon double bond and reacts with the primary amine of lysine residues on the fibrinogen surface to form an amide bond (-NH - CO-). The surgical wound - adhering layer prepared in this example contains 20 mg of fibrinogen with hydrophobic groups per square centimeter. The adhesion energy is 146 J / m 2 , and the shear strength is 7320 Pa.

[0095] The surgical patch described in this example was implanted into the wound area of the rat liver. The surgical patch could quickly seal the liver wound and effectively prevent adhesion with the surrounding abdominal tissues. 28 days after the operation, the liver wound healed well. Opening the abdomen for observation, no tissue adhesion was seen.

[0096] Example 4

[0097] The first step: Use fibrinogen containing hydrophobic groups and a stabilizer as raw materials to prepare the wound - adhering layer.

[0098] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, and disperse it evenly by stirring and ultrasonic treatment;

[0099] ② Under light - avoiding conditions, 200 μL of 0.4 M 2,5 - Dioxopyrrolidin - 1 - yl methyl glutarate was added dropwise to the fibrinogen solution under stirring conditions, and dispersion was carried out under a triple mixing process of vortexing for 5 min and ultrasonic treatment for 5 min. The reaction was carried out at 37 °C for 3 h to obtain a fibrinogen solution containing hydrophobic groups;

[0100] ③ Dialyze the obtained fibrinogen solution containing hydrophobic groups at 25 °C for 24 h;

[0101] ④ Freeze the obtained fibrinogen solution containing hydrophobic groups, concentrate it to 100 mg / mL at 37 °C; then perform lyophilization to obtain the wound adhesion layer.

[0102] Step 2: Spray, immerse or cast regenerated oxidized cellulose gel on the wound adhesion layer, and then perform lyophilization to obtain the base layer.

[0103] In the wound adhesion layer of the surgical patch in this example, the hydrophobic group of fibrinogen is -CO-(CH 2 ) 3 -COOCH 3 , which contains an ester group and reacts with the primary amine of lysine residues on the surface of fibrinogen to form an amide bond (-NH-CO-). The surgical wound adhesion layer prepared in this example contains 20 mg of fibrinogen with hydrophobic groups per square centimeter. The adhesion energy is 156 J / m 2 , and the shear strength is 8568 Pa.

[0104] Implant the surgical patch described in this example into the wound area of the rat liver. The surgical patch can quickly seal the liver wound and effectively prevent adhesion with the surrounding abdominal tissues. 28 days after the surgery, the liver wound healed well. Open the abdomen for observation, and no tissue adhesion was found.

[0105] Example 5

[0106] Step 1: Use fibrinogen containing hydrophobic groups and a stabilizer as raw materials to prepare the wound adhesion layer.

[0107] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and disperse it evenly by ultrasonic wave;

[0108] ② Under light-shielded conditions, add 200 μL of 0.4 M 1-(2,5-Dioxopyrrolidin-1-yl)8-methyl octanedioate (1-(2,5-dioxopyrrolidin-1-yl)8-methyl suberate) dropwise to the fibrinogen solution under stirring, and disperse it by vortexing for 5 min and ultrasonic wave for 5 min under triple mixing process. React at 37 °C for 3 h to obtain a fibrinogen solution containing hydrophobic groups;

[0109] ③ Dialyze the obtained fibrinogen solution containing hydrophobic groups at 25 °C for 24 h;

[0110] ④ Freeze the obtained fibrinogen solution containing hydrophobic groups, concentrate it to 100 mg / mL at a temperature of 37 °C; then perform freeze-drying to obtain a fibrinogen patch.

[0111] Step 2: Spray, immerse or cast a regenerated oxidized cellulose gel on the wound adhesion layer, and obtain a base layer after freeze-drying.

[0112] In this example, the hydrophobic group of fibrinogen in the wound adhesion layer of the surgical patch is -CO-(CH 2 ) 5 -COOCH 3 , which contains an ester group and reacts with the primary amine of the lysine residue on the fibrinogen surface to form an amide bond (-NH-CO-). Each square centimeter of the surgical wound adhesion layer prepared in this example contains 20 mg of fibrinogen containing hydrophobic groups. The adhesion energy is 159 J / m 2 , and the shear strength is 8850 Pa.

[0113] Implant the surgical patch described in this example into the wound area of the rat liver. The surgical patch can quickly seal the liver wound and effectively prevent adhesion with the surrounding abdominal tissues. 28 days after the surgery, the liver wound healed well. Open the abdomen for observation, and no tissue adhesion was found.

[0114] Example 6

[0115] Step 1: Use fibrinogen containing hydrophobic groups and a stabilizer as raw materials to prepare the wound adhesion layer.

[0116] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and disperse it evenly by ultrasonic waves;

[0117] ② Under light-shielded conditions, add 200 μL of 0.4 M N-(hexanoyloxy) succinimide dropwise to the fibrinogen solution under stirring conditions, and disperse it by a triple mixing process of vortexing for 5 min and ultrasonic waves for 5 min. React at 37 °C for 4 h to obtain a fibrinogen solution containing hydrophobic groups;

[0118] ③ Dialyze the obtained fibrinogen solution containing hydrophobic groups at 4 °C for 72 h;

[0119] ④ Freeze the obtained fibrinogen solution containing hydrophobic groups, concentrate it to 100 mg / mL at a temperature of 37 °C; then perform freeze-drying to obtain a wound adhesion layer.

[0120] Step 2: Spray a chitosan gel on the wound adhesion layer, and obtain a base layer of a porous scaffold after freeze-drying.

[0121] In the wound adhesion layer of the surgical patch in this embodiment, the hydrophobic group of fibrinogen is -CO-(CH 2 ) 4 CH 3 , which reacts with the primary amine of lysine residues on the surface of fibrinogen to form an amide bond (-NH-CO-). The surgical wound adhesion layer prepared in this embodiment contains 20 mg of fibrinogen with hydrophobic groups per square centimeter. The adhesion energy of the patch wound adhesion layer is 160 J / m 2 , and the shear strength is 8750 Pa.

[0122] When the surgical patch described in this embodiment is implanted into the wound area of the rat liver, the surgical patch can quickly seal the liver wound and effectively prevent adhesion to the surrounding abdominal tissues. 28 days after the surgery, the liver wound healed well. Opening the abdomen for observation, no tissue adhesion was seen.

[0123] Example 7

[0124] First step: Use fibrinogen with hydrophobic groups and a stabilizer as raw materials to prepare the wound adhesion layer.

[0125] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and ultrasonically disperse it evenly;

[0126] ② Under light-shielded conditions, add 200 μL of 0.4 M N-(hexanoyloxy) succinimide dropwise to the fibrinogen solution under stirring conditions, and disperse it under a triple mixing process of vortexing for 5 min and ultrasonically for 5 min. React at 37 °C for 4 h to obtain a fibrinogen solution with hydrophobic groups;

[0127] ③ Dialyze the obtained fibrinogen solution with hydrophobic groups at 4 °C for 72 h;

[0128] ④ Freeze the obtained fibrinogen solution with hydrophobic groups, concentrate it to 100 mg / mL, and the concentration temperature is 37 °C; then perform freeze-drying to obtain the wound adhesion layer.

[0129] Second step: Spray poly(lactic acid) gel on the wound adhesion layer, and freeze-dry it to prepare the base layer of the porous scaffold.

[0130] In the wound adhesion layer of the surgical patch in this embodiment, the hydrophobic group of fibrinogen is -CO-(CH 2 ) 4 CH 3 , which reacts with the primary amine of lysine residues on the surface of fibrinogen to form an amide bond (-NH-CO-). The surgical wound adhesion layer prepared in this embodiment contains 20 mg of fibrinogen with hydrophobic groups per square centimeter. The adhesion energy of the patch wound adhesion layer is 160 J / m2 , the shear strength is 8750 Pa.

[0131] The surgical patch described in this example was implanted into the wound area of the rat liver. The surgical patch could quickly seal the liver wound and effectively prevent adhesion to the surrounding abdominal tissues. 28 days after the surgery, the liver wound healed well. Opening the abdomen for observation, no tissue adhesion was seen.

[0132] Comparative Example 1

[0133] Fibrinogen without hydrophobic modification was used for the preparation of the wound adhesion layer

[0134] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and disperse it evenly by ultrasonic waves;

[0135] ② Under light-shielded conditions, 200 μL of PBS solution was added dropwise to the fibrinogen solution under stirring conditions, and dispersion was carried out under a triple mixing process of vortexing for 5 min and ultrasonic waves for 5 min. Under the condition of 37 °C, the reaction was carried out for 4 h to obtain an unmodified fibrinogen solution;

[0136] ③ The obtained unmodified fibrinogen solution was dialyzed at 4 °C for 72 h.

[0137] ④ The obtained unmodified fibrinogen solution was frozen and concentrated to 100 mg / mL, and the concentration temperature was 37 °C; then freeze-drying was carried out to obtain an unmodified fibrinogen wound adhesion layer (during the freeze-drying process of unmodified fibrinogen, the intermolecular interaction was relatively weak, and the formed patch was not shaped).

[0138] The difference between Comparative Example 1 and Example 1 is that there is no hydrophobic group modification. The wound adhesion layer prepared in this example contains 20 mg of fibrinogen per square centimeter.

[0139] The adhesion energy is 10 J / m 2 , and the shear strength is 1233 Pa. The mechanical properties and adhesion properties of the unmodified fibrinogen patch are much lower than those of the wound adhesion layer of the surgical patch described in the present invention ( Figure 7 and Figure 8 ). This shows that the hydrophobic group modification is the key factor for improving the performance of the wound adhesion layer of the surgical patch described in the present invention.

[0140] Comparative Example 2

[0141] (1) Fibrinogen solution containing hydrophobic groups:

[0142] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and disperse it evenly by ultrasonic waves;

[0143] ② Under light - avoiding conditions, while stirring the fibrinogen solution, 200 μL of 0.4 M N - (hexyloxycarbonyloxy) succinimide was added dropwise, and dispersion was carried out under a triple mixing process of vortexing for 5 min and ultrasonic treatment for 5 min. Under the condition of 37 °C, the reaction was carried out for 4 h to obtain a fibrinogen solution containing hydrophobic groups;

[0144] ③ The obtained fibrinogen solution containing hydrophobic groups was dialyzed at 4 °C for 72 h.

[0145] (2) Unmodified fibrinogen solution:

[0146] ① Take a fibrinogen solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and disperse it evenly by ultrasonic treatment;

[0147] ② Under light - avoiding conditions, while stirring the fibrinogen solution, 200 μL of PBS solution was added dropwise, and dispersion was carried out under a triple mixing process of vortexing for 5 min and ultrasonic treatment for 5 min. Under the condition of 37 °C, the reaction was carried out for 4 h to obtain an unmodified fibrinogen solution;

[0148] ③ The obtained unmodified fibrinogen solution was dialyzed at 4 °C for 72 h.

[0149] The adhesion energy of the fibrinogen solution containing hydrophobic groups is 7.5 J / m 2 , and the shear strength is 800 Pa. The mechanical properties of the wound - adhering layer of the surgical patch in Example 1 of the present invention are far superior to those of the fibrinogen solution containing hydrophobic groups obtained in this example, indicating that the present invention needs to form a freeze - dried patch layer to achieve excellent mechanical effects. On the one hand, the wound - adhering layer of the surgical patch described in the present invention can increase the adhesion performance with tissues through water absorption; on the other hand, during the preparation of the patch by removing water, the van der Waals interaction between hydrophobic chains is enhanced due to the closer distance, prompting the fibrinogen patch to have strong mechanical properties. The form of the surgical patch layer described in the present invention plays an important role in its overall performance.

[0150] The adhesion energy of the unmodified fibrinogen solution is 6.5 J / m 2 , and the shear strength is 750 Pa. It can be seen that there is no obvious difference between the fibrinogen solution containing hydrophobic groups and the unmodified fibrinogen solution in terms of solution viscosity and mechanical properties.

[0151] Comparative Example 3

[0152] (1) Gelatin patch layer modified with hydrophobic groups and unmodified gelatin patch layer

[0153] Gelatin patch layer modified with hydrophobic groups:

[0154] ① Take a 100 mg / mL gelatin solution (PBS buffer solution), stir and ultrasonically disperse it evenly;

[0155] ② Under light - shielding conditions, while stirring the gelatin solution, add 200 μL of 0.4 M N - (hexanoyloxy) succinimide dropwise, and disperse it under a triple mixing process of vortexing for 5 min and ultrasonication for 5 min. React at 37 °C for 4 h to obtain a gelatin solution containing hydrophobic groups;

[0156] ③ Dialyze the obtained gelatin solution containing hydrophobic groups at 37 °C for 72 h;

[0157] ④ Freeze the obtained gelatin solution containing hydrophobic groups, concentrate it to 100 mg / mL at a concentration temperature of 37 °C; then perform freeze - drying to obtain a gelatin patch layer modified with hydrophobic groups. The patch layer prepared in this example contains 20 mg of modified gelatin per square centimeter.

[0158] Unmodified gelatin patch layer:

[0159] ① Take a 100 mg / mL gelatin solution (PBS buffer solution), stir and ultrasonically disperse it evenly;

[0160] ② Under light - shielding conditions, while stirring the gelatin solution, add 200 μL of PBS solution dropwise, and disperse it under a triple mixing process of vortexing for 5 min and ultrasonication for 5 min. React at 37 °C for 4 h to obtain an unmodified gelatin solution;

[0161] ③ Dialyze the obtained unmodified gelatin solution at 37 °C for 72 h;

[0162] ④ Freeze the obtained unmodified gelatin solution, concentrate it to 100 mg / mL at a concentration temperature of 37 °C; then perform freeze - drying to obtain an unmodified gelatin patch layer. The patch layer prepared in this example contains 20 mg of gelatin per square centimeter.

[0163] (2) Albumin patch layer modified with hydrophobic groups and unmodified albumin patch layer

[0164] Albumin patch layer modified with hydrophobic groups:

[0165] ① Take a 100 mg / mL bovine serum albumin solution (PBS buffer solution), stir and ultrasonically disperse it evenly;

[0166] ② Under light - avoiding conditions, the bovine serum albumin solution was added drop - by - drop under stirring conditions to 200 μL of 0.4 M N - (hexyloxy) succinimide, and dispersed under a triple - mixing process of vortexing for 5 min and ultrasonic treatment for 5 min. The reaction was carried out at 37 °C for 4 h to obtain an albumin solution containing hydrophobic groups;

[0167] ③ The obtained albumin solution containing hydrophobic groups was dialyzed at 4 °C for 72 h;

[0168] ④ The obtained albumin solution containing hydrophobic groups was frozen, concentrated to 100 mg / mL, and the concentration temperature was 37 °C; then freeze - dried to obtain a hydrophobic - group - modified albumin patch layer. The patch layer prepared in this example contains 20 mg of modified albumin per square centimeter.

[0169] Unmodified albumin patch layer:

[0170] ① Take a bovine serum albumin solution (PBS buffer solution) with a mass fraction of 100 mg / mL, stir and disperse it evenly by ultrasonic treatment;

[0171] ② Under light - avoiding conditions, 200 μL of PBS solution was added drop - by - drop to the bovine serum albumin solution under stirring conditions, and dispersed under a triple - mixing process of vortexing for 5 min and ultrasonic treatment for 5 min. The reaction was carried out at 37 °C for 4 h to obtain an unmodified albumin solution;

[0172] ③ The obtained unmodified albumin solution was dialyzed at 4 °C for 72 h;

[0173] ④ The obtained unmodified albumin solution was frozen, concentrated to 100 mg / mL, and the concentration temperature was 37 °C; then freeze - dried to obtain an unmodified albumin patch layer. The patch layer prepared in this example contains 20 mg of albumin per square centimeter.

[0174] In this comparative example, for the gelatin patch layer with hydrophobic - group modification and the unmodified gelatin patch layer, as well as the albumin patch layer with hydrophobic - group modification and the unmodified albumin patch layer, there were no obvious changes in the mechanical properties and tissue adhesion properties of the patch layers before and after hydrophobic - group modification. Moreover, whether it was gelatin and albumin before modification or gelatin and albumin after modification, they did not really form a patch - layer structure after freeze - drying, but were in a powder form, rather than the wound - adhesion layer (i.e., fibrinogen patch) described in the present invention.

[0175] This indicates that when the hydrophobic group is modified onto the fibrinogen molecule, a patch can be formed after lyophilization instead of powder, and the fibrinogen patch layer after lyophilization has strong mechanical properties. Under the same conditions, gelatin and albumin do not exhibit corresponding phenomena. We speculate that the morphology and enhanced mechanical properties of the fibrinogen patch are related to its own compositional characteristics. Fibrinogen consists of two symmetrical halves, each half containing three polypeptide chains, namely Aα, Bβ, and γ, and is a protein molecule with a linear structure. Due to its special composition and structure, unexpected improvement in mechanical properties is obtained after modification with hydrophobic groups.

[0176] Comparative Example 4

[0177] Three kinds of absorbable surgical adhesive products purchased through commercial channels: Johnson & Johnson Surgicel Fibrillar, Shanghai RAAS Fibrin Glue, and Xiang'en Gelatin Sponge.

[0178] The three surgical adhesive products selected in this comparative example are surgical adhesives that are widely used in the prior art and have relatively good performance among existing similar products. Their tissue adhesion performance and hemostatic performance need to be further improved.

[0179] Comparing the three surgical adhesive products (absorbable, for in vitro use; Fibrin Glue, Surgicel Fibrillar, Gelatin Sponge) of Example 1, Comparative Example 1, and Comparative Example 4, it can be found that the wound adhesion layer of the surgical patch described in the present invention is significantly higher than the three surgical adhesive products of Comparative Example 1 and Comparative Example 4 in terms of shear strength and adhesion energy ( Figure 7 and Figure 8 ). At the same time, the patch described in the present invention is also significantly superior to the commercial fibrin glue (Fibrin Glue) in terms of mechanical properties and is expected to become a new type of tissue sealant.

[0180] In the hemostasis experiment on the liver of New Zealand white rabbits, the hemostatic functions of sealants in the same / similar form (patch / sponge) were compared. The wound adhesion layer of the surgical patch described in the present invention (Example 1) was compared with the unmodified fibrinogen wound adhesion layer of Comparative Example 1 and the surgical adhesive products (Surgicel Fibrillar, Gelatin Sponge) of Comparative Example 4. Due to the excellent mechanical strength and adhesion performance of the fibrinogen patch described in the present invention, it shows a stronger ability to adhere to wounds, resulting in a shorter hemostasis time and less blood loss, demonstrating excellent hemostatic performance ( Figure 9 ).

[0181] In summary, the wound adhesion layer of the surgical patch of the present invention is significantly superior to the existing surgical adhesives in terms of wound adhesion and hemostatic performance. At the same time, after the surgical patch of the present invention is implanted into damaged tissues, it can effectively prevent adhesion between the damaged tissues and the normal abdominal tissues. Further, after preventing tissue adhesion, it has good biocompatibility and can be absorbed in about 4 weeks. The surgical patch of the present invention performs excellently in terms of adhesion performance, anti-tissue adhesion, biocompatibility, etc., and has great potential in clinical applications.

Claims

1. A surgical patch with both tissue adhesion and anti-adhesion functions, characterized in that, the patch comprises a wound adhesion layer and a base layer. The wound adhesion layer comprises fibrinogen and a stabilizer. Some lysine residues of the fibrinogen contain hydrophobic groups; the stabilizer is used to maintain the activity of fibrinogen; the base layer is a hydrophilic polymer porous scaffold; the lysine residues containing hydrophobic groups on the fibrinogen in the wound adhesion layer account for 2%-70% of the total number of lysine residues.

2. The surgical patch according to claim 1, characterized in that, the base layer comprises one or more of regenerated oxidized cellulose, chitosan, hyaluronic acid, collagen, and polylactic acid.

3. The surgical patch according to claim 1, characterized in that, the hydrophobic group is a hydrocarbon group containing one or more groups of carbonyl, carbon-carbon double bond, ester group, amide bond, and phenyl group.

4. The surgical patch according to claim 1, characterized in that, the wound adhesion layer contains not less than 2 mg of fibrinogen containing hydrophobic groups per square centimeter.

5. The surgical patch according to claim 1, characterized in that, the thickness of the wound adhesion layer is 0.1-1 mm; the thickness of the surgical patch is 0.1-3 mm.

6. The surgical patch according to claim 1, characterized in that, the wound adhesion layer further comprises a pharmaceutically active ingredient.

7. A preparation method of the surgical patch with both tissue adhesion and anti-adhesion functions according to claim 1, characterized in that, the specific steps include: The first step: using fibrinogen containing hydrophobic groups and a stabilizer as raw materials to prepare the wound adhesion layer; the lysine residues containing hydrophobic groups on the fibrinogen account for 2%-70% of the total number of lysine residues; The second step: spraying, dipping or casting a hydrophilic polymer gel on the wound adhesion layer, and freeze-drying to obtain the porous base layer, thereby obtaining the surgical patch with both tissue adhesion and anti-adhesion functions.

8. The preparation method according to claim 7, characterized in that, the preparation steps of the wound adhesion layer include: 1) Ultrasonically treating the mixed solution of fibrinogen and stabilizer, and the mass fraction of the obtained fibrinogen solution is 5-200 mg / mL; 2) Dropwise adding a hydrophobic modification reagent to the fibrinogen solution under stirring conditions, and reacting at 37 °C for 0.5-5 h to obtain a fibrinogen solution containing hydrophobic groups; 3) Dialyzing the obtained fibrinogen solution containing hydrophobic groups at 4-37 °C for 5-72 h; 4) Concentrating the obtained fibrinogen solution containing hydrophobic groups to 50-200 mg / mL, and the concentration temperature is 4-37 °C; and freeze-drying, and the freeze-drying temperature is -85 to -35 °C to obtain the wound adhesion layer; the hydrophobic modification reagent contains hydrophobic groups, and the hydrophobic modification reagent cannot be an acid anhydride with hydrophobic groups. The hydrophobic group is a hydrocarbon group containing one or more groups of carbonyl, carbon-carbon double bond, ester group, amide bond, and phenyl group.

9. The preparation method according to claim 8, characterized in that, The hydrophobic group is used to modify the fibrinogen lysine residue; the hydrophobic modification reagent contains a succinimide group, and the succinimide group is used to react with the primary amine of the lysine residue to form a stable amide bond.

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