Method for modifying ultra-thin hydrophilic lubricating coating on surface of biological material and application of ultra-thin hydrophilic lubricating coating

Abstract

The invention relates to a method for modifying the surface of a biological material with an ultrathin hydrophilic lubricating coating and application thereof, and the method for modifying the surface of the biological material with the ultrathin hydrophilic lubricating coating comprises the following steps: mixing a plasma-treated biological material with a precursor solution, and carrying out an in-situ polymerization reaction, the surface of the biological material is modified with an ultrathin hydrophilic lubricating coating; the precursor solution comprises dopamine or a salt thereof, a zwitterionic monomer and a Tris buffer solution. The ultrathin hydrophilic lubricating coating prepared by the method disclosed by the invention can reduce the friction coefficient of the surface of a biological material, and has relatively strong hydrophilic lubricating performance; according to the present invention, the ultra-thin hydrophilic lubricating coating can be formed on the surfaces of different biological materials, the method is suitable for the surface modification of most biological materials, the process is simple and easy to perform, the hydrophilic lubricating property is good, and the surface lubricating property of the biomedical material can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biomaterial surface modification, and in particular relates to a method for modifying a biomaterial surface with an ultra-thin hydrophilic lubricating coating and an application thereof. Background Art

[0002] Since the materials of interventional medical devices are not lubricating, the friction between them and human tissues is large when they move in the body, which will increase the pain of patients during the process of using medical devices to detect and treat diseases. For example, when a capsule endoscope moves in the stomach and intestines, it will cause damage to human tissues and organs due to the large friction. The large friction will also affect the movement of the capsule endoscope and affect the inspection results.

[0003] At present, the friction of medical devices can be reduced by lubricating the surface. The main methods for modifying the surface of polymer materials to make them hydrophilic and enhancing their lubrication ability are: surface coating, high-energy radiation, plasma modification, surface oxidation, grafting modification, etc. However, these common methods have the disadvantages of complex operation process, special preparation equipment, high energy consumption, and special requirements for the base material. Therefore, a simpler, more convenient, non-toxic, harmless, and biocompatible lubricating coating preparation method is needed. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating and its application. The ultra-thin hydrophilic lubricating coating prepared by the method of the present invention can reduce the friction coefficient of the surface of the biomaterial and has strong hydrophilic lubricating properties.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, the method comprising: mixing a plasma-treated biomaterial with a precursor solution, performing an in-situ polymerization reaction, and obtaining a biomaterial with a surface modified with an ultra-thin hydrophilic lubricating coating; the precursor solution comprises dopamine or a salt thereof, a zwitterionic monomer, and a Tris buffer.

[0007] Dopamine is a catecholamine neurotransmitter present in the central nervous system and the main component of mussel adhesive protein. It can spontaneously polymerize in a weakly alkaline environment and spontaneously deposit on the surface of biomaterials, with good adhesion properties. There are a large number of hydrophilic hydroxyl and amino groups on the surface of polydopamine (PDA), which can greatly improve the wettability of the material surface and can serve as an adhesive site to assist the covalently or non-covalently bonded target polymer to form a co-deposited coating.

[0008] In the present invention, dopamine monomer undergoes oxidative polymerization reaction in a weakly alkaline environment to form a polydopamine linking layer on the surface of the biomaterial, and at the same time acts as a polymerization initiator to generate a large number of free radicals to initiate the polymerization of zwitterionic monomers. The wet adhesion effect of polydopamine enables the zwitterionic polymer with lubricating effect to adhere well to the surface of the biomaterial to form a stable hydrophilic lubricating coating. Plasma treatment can increase the hydroxyl and carboxyl groups on the surface of the biomaterial, enhance the chemical activity and surface energy of the surface of the biomaterial, and facilitate the combination between the biomaterial and the lubricating coating. The ultra-thin hydrophilic lubricating coating prepared by the method of the present invention can reduce the friction coefficient of the surface of the biomaterial and has strong hydrophilic lubricating properties.

[0009] Preferably, the atmosphere of the plasma treatment is oxygen; the power of the plasma treatment is 100-400 W, for example, it can be 100 W, 120 W, 150 W, 180 W, 200 W, 220 W, 250 W, 280 W, 300 W, 320 W, 350 W, 380 W, 400 W, etc.; the time of plasma treatment is 15-60 min, for example, it can be 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc.

[0010] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0011] The power and time of plasma treatment determine the kinetic energy of incident ions and the number of free radicals formed on the surface of the material. In the present invention, the plasma treatment is set with a specific power and time, and the formed ultra-thin hydrophilic lubricating coating has a lower friction coefficient and stronger hydrophilic lubricating performance.

[0012] Preferably, the concentration of dopamine or its salt in the precursor solution is 1-5 mg / mL, for example, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.5 mg / mL, 4 mg / mL, 4.5 mg / mL, 5 mg / mL, etc.

[0013] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0014] The oxidative polymerization of the dopamine monomer further triggers the polymerization reaction of the zwitterionic monomer, and the concentration of the dopamine monomer affects the generation of free radicals, thereby affecting the degree of polymerization of the zwitterionic monomer. In the present invention, the dopamine monomer is set in a specific concentration range, and the formed ultra-thin hydrophilic lubricating coating has a lower friction coefficient and stronger hydrophilic lubricating performance.

[0015] Preferably, the mass ratio of dopamine or its salt to the zwitterionic monomer is 1:(10-25), for example, it can be 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, etc.

[0016] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0017] The content of zwitterionic monomers is crucial to the formation of hydrophilic lubricating coatings. The content of zwitterionic monomers is not the more the better, but with the increase of zwitterionic monomer content, the hydrophilic lubricating properties of the coating show a trend of first increasing and then decreasing. In the present invention, the content of zwitterionic monomers is set within a specific range, and the formed ultra-thin hydrophilic lubricating coating has a lower friction coefficient and stronger hydrophilic lubricating properties.

[0018] Preferably, the zwitterionic monomer includes any one of sulfobetaine methacrylate, 2-methacryloyloxyethyl phosphorylcholine or carboxybetaine methacrylate, or a combination of at least two thereof.

[0019] Preferably, the zwitterionic monomer includes a combination of sulfobetaine methacrylate and 2-methacryloyloxyethyl phosphorylcholine, sulfobetaine methacrylate and carboxybetaine methacrylate, or 2-methacryloyloxyethyl phosphorylcholine and carboxybetaine methacrylate.

[0020] The two zwitterionic monomers in the present invention have a synergistic effect. Compared with a single zwitterionic monomer, the formed ultra-thin hydrophilic lubricating coating has a lower friction coefficient and stronger hydrophilic lubricating performance.

[0021] Preferably, the mass ratio of sulfobetaine methacrylate to 2-methacryloyloxyethyl phosphorylcholine, sulfobetaine methacrylate to carboxybetaine methacrylate, or 2-methacryloyloxyethyl phosphorylcholine to carboxybetaine methacrylate is independently (5-15):(5-15).

[0022] The specific point values ​​in the first one (5-15) can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, etc.; the specific point values ​​in the second one (5-15) can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, etc.

[0023] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0024] The zwitterionic monomers in the present invention have a more excellent synergistic effect within a specific mass ratio range.

[0025] Preferably, the concentration of the Tris buffer is 8-12 mM, for example, it can be 8 mM, 8.5 mM, 9 mM, 9.5 mM, 10 mM, 10.5 mM, 11 mM, 11.5 mM, 12 mM, etc.; the pH of the Tris buffer is 8-9, for example, it can be 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, etc.

[0026] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0027] Preferably, the biomaterial comprises any one of polycarbonate, polypropylene, polytetrafluoroethylene, polyvinylidene chloride, silicone rubber, polydimethylsiloxane, polyurethane, polyethylene, polyethylene terephthalate, polylactic acid or polycaprolactone.

[0028] The method of the present invention can form an ultra-thin hydrophilic lubricating coating on the surface of different biomaterials, and is suitable for surface modification of most biomaterials; the process is simple and easy, the hydrophilic lubricity is good, and the surface lubricity of biomedical materials can be effectively improved.

[0029] Preferably, the time of the in situ polymerization reaction is 8-24h, for example, it can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24h, etc.; the temperature of the in situ polymerization reaction is 20-30℃, for example, it can be 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, etc.

[0030] Other specific point values ​​within the above numerical ranges can be selected and will not be described in detail here.

[0031] Preferably, the in-situ polymerization reaction further includes washing and drying steps.

[0032] Preferably, the washing solvent comprises ethanol and / or deionized water.

[0033] Preferably, the drying method includes drying by oven drying or drying with nitrogen.

[0034] In a second aspect, the present invention provides the use of the method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating as described in the first aspect in the preparation of a medical device.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The ultra-thin hydrophilic lubricating coating prepared by the method of the present invention can reduce the friction coefficient of the surface of the biomaterial and has strong hydrophilic lubricating properties. Among them, the dopamine monomer undergoes an oxidative polymerization reaction in a weakly alkaline environment to form a polydopamine linking layer on the surface of the biomaterial, and at the same time acts as a polymerization initiator to generate a large number of free radicals to initiate the polymerization of zwitterionic monomers. The wet adhesion effect of polydopamine enables the zwitterionic polymer with lubricating effect to adhere well to the surface of the biomaterial to form a stable hydrophilic lubricating coating. Plasma treatment can increase the hydroxyl and carboxyl groups on the surface of the biomaterial, enhance the chemical activity and surface energy of the surface of the biomaterial, and facilitate the combination between the biomaterial and the lubricating coating.

[0037] (2) The method of the present invention can form an ultra-thin hydrophilic lubricating coating on the surface of different biomaterials, and is suitable for surface modification of most biomaterials; the process is simple and easy, the hydrophilic lubricity is good, and it can effectively improve the surface lubrication properties of biomedical materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a picture of a polycarbonate substrate with an ultra-thin hydrophilic lubricating coating (PDA-PSBMA) modified on its surface in Example 1;

[0039] Figure 2 This is an X-ray photoelectron spectrum of the ultra-thin hydrophilic lubricating coating (PDA-PSBMA) modified on the surface of the polycarbonate substrate in Example 1;

[0040] Figure 3 This is a scanning electron microscope image of the ultra-thin hydrophilic lubricating coating (PDA-PSBMA) modified on the surface of the polycarbonate substrate of Example 1;

[0041] Figure 4 This is a scanning electron microscope image of the polydopamine coating (PDA) modified on the surface of the polycarbonate substrate of Comparative Example 2. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present invention, the technical solution of the present invention is further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0043] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0044] Example 1

[0045] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, and the specific steps are as follows:

[0046] (1) The polycarbonate substrate was treated with plasma at a power of 300 W for 30 min in an oxygen atmosphere;

[0047] (2) Prepare a precursor solution: 40 mg of dopamine hydrochloride and 600 mg of sulfobetaine methacrylate (SBMA) were dissolved in 20 mL of Tris buffer solution (10 mM, pH = 8.5);

[0048] (3) The plasma-treated polycarbonate substrate was mixed with the precursor solution for 16 hours to perform an in-situ polymerization reaction. The polycarbonate substrate was taken out and rinsed with deionized water and dried with nitrogen to obtain an ultra-thin hydrophilic lubricating coating (PDA-PSBMA) modified on the surface of the polycarbonate substrate. The product appearance is as follows Figure 1 shown.

[0049] Example 2

[0050] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, and the specific steps are as follows:

[0051] (1) The polypropylene substrate was treated with plasma at 400 W power for 15 min in an oxygen atmosphere;

[0052] (2) Prepare a precursor solution: 100 mg dopamine hydrochloride and 2500 mg 2-methacryloyloxyethyl phosphorylcholine (MPC) were dissolved in 20 mL Tris buffer solution (8 mM, pH = 8);

[0053] (3) The plasma-treated polypropylene substrate was mixed with the precursor solution for 8 hours to carry out an in-situ polymerization reaction. The polypropylene substrate was taken out and rinsed with deionized water and dried with nitrogen gas to obtain an ultra-thin hydrophilic lubricating coating (PDA-PMPC) modified on the surface of the polypropylene substrate.

[0054] Example 3

[0055] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, and the specific steps are as follows:

[0056] (1) Treat the polytetrafluoroethylene substrate with 100 W plasma power for 60 min in an oxygen atmosphere;

[0057] (2) Prepare a precursor solution: 20 mg of dopamine hydrochloride and 200 mg of carboxybetaine methacrylate (CBMA) were dissolved in 20 mL of Tris buffer solution (12 mM, pH = 9);

[0058] (3) The plasma-treated polytetrafluoroethylene substrate was mixed with the precursor solution for 24 hours to carry out an in-situ polymerization reaction. The polytetrafluoroethylene substrate was taken out and rinsed with deionized water and dried with nitrogen gas to obtain an ultra-thin hydrophilic lubricating coating (PDA-PCBMA) modified on the surface of the polytetrafluoroethylene substrate.

[0059] Example 4

[0060] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "sulfobetaine methacrylate (SBMA)" is replaced with an equal amount of "2-methacryloyloxyethyl phosphorylcholine (MPC)", and other raw materials and steps remain unchanged.

[0061] Example 5

[0062] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Embodiment 1 only in that "sulfobetaine methacrylate (SBMA)" is replaced with an equal amount of "carboxybetaine methacrylate (CBMA)", and other raw materials and steps remain unchanged.

[0063] Example 6

[0064] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "600 mg of sulfobetaine methacrylate (SBMA)" is replaced by "300 mg of sulfobetaine methacrylate (SBMA) and 300 mg of 2-methacryloyloxyethyl phosphorylcholine (MPC)", and other raw materials and steps remain unchanged.

[0065] Example 7

[0066] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "600 mg sulfobetaine methacrylate (SBMA)" is replaced with "150 mg sulfobetaine methacrylate (SBMA) and 450 mg carboxybetaine methacrylate (CBMA)", and other raw materials and steps remain unchanged.

[0067] Example 8

[0068] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "600 mg of sulfobetaine methacrylate (SBMA)" is replaced with "450 mg of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 150 mg of carboxybetaine methacrylate (CBMA)", and other raw materials and steps remain unchanged.

[0069] Example 9

[0070] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "600 mg sulfobetaine methacrylate (SBMA)" is replaced with "60 mg sulfobetaine methacrylate (SBMA) and 540 mg 2-methacryloyloxyethyl phosphorylcholine (MPC)", and other raw materials and steps remain unchanged.

[0071] Example 10

[0072] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "600 mg sulfobetaine methacrylate (SBMA)" is replaced with "200 mg sulfobetaine methacrylate (SBMA)", and other raw materials and steps remain unchanged.

[0073] Embodiment 11

[0074] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "600 mg sulfobetaine methacrylate (SBMA)" is replaced with "1200 mg sulfobetaine methacrylate (SBMA)", and other raw materials and steps remain unchanged.

[0075] Example 12

[0076] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "40 mg dopamine hydrochloride and 600 mg sulfobetaine methacrylate (SBMA)" are replaced with "10 mg dopamine hydrochloride and 150 mg sulfobetaine methacrylate (SBMA)", and other raw materials and steps remain unchanged.

[0077] Example 13

[0078] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that "40 mg dopamine hydrochloride and 600 mg sulfobetaine methacrylate (SBMA)" are replaced with "120 mg dopamine hydrochloride and 1800 mg sulfobetaine methacrylate (SBMA)", and other raw materials and steps remain unchanged.

[0079] Embodiment 14

[0080] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Embodiment 1 only in that "plasma treatment at 300 W power for 30 min" is replaced by "plasma treatment at 80 W power for 90 min", and other raw materials and steps remain unchanged.

[0081] Embodiment 15

[0082] This embodiment provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Embodiment 1 only in that "plasma treatment at a power of 300 W for 30 min" is replaced by "plasma treatment at a power of 450 W for 12 min", and other raw materials and steps remain unchanged.

[0083] Comparative Example 1

[0084] This comparative example provides a method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, which differs from Example 1 only in that in step (1), the polycarbonate substrate is not plasma treated, and other raw materials and steps remain unchanged.

[0085] Comparative Example 2

[0086] This comparative example provides a method for modifying the surface of a biomaterial with a polydopamine coating, which differs from Example 1 only in that sulfobetaine methacrylate (SBMA) is not added in step (2), and other raw materials and steps remain unchanged, thereby obtaining a polydopamine coating (PDA) modified on the surface of a polycarbonate substrate.

[0087] Test Example 1

[0088] (1) X-ray Photoelectron Spectroscopy (XPS) Characterization: XPS analysis was performed on the ultra-thin hydrophilic lubricating coating modified on the surface of the polycarbonate substrate in Example 1. The test results are as follows: Figure 2 As shown, an obvious S2p ​​peak appeared at 166.3 eV, indicating that the S content in the coating was high, indicating that the PDA-PSBMA coating was successfully modified on the surface of the polycarbonate substrate;

[0089] (2) Scanning electron microscope (SEM) analysis: The ultra-thin hydrophilic lubricating coating modified on the surface of the polycarbonate substrate of Example 1 and the polydopamine coating modified on the surface of the polycarbonate substrate of Comparative Example 2 were subjected to SEM analysis using a JSM-IT800 scanning electron microscope. The test results are as follows: Figure 3 and Figure 4 As shown, PDA-PSBMA or PDA aggregates are distributed on the surface of the polycarbonate substrate.

[0090] Test Example 2

[0091] (1) Test samples: coatings modified with biomaterial surfaces of Examples 1-15 and Comparative Examples 1-2;

[0092] (2) Coating thickness test: The coating thickness of the sample was measured using a spectroscopic ellipsometer and an atomic force microscope;

[0093] (3) Wetting performance test: The static water contact angle of the sample coating was measured using a DSA-100 contact angle meter;

[0094] (4) Lubrication performance test: In order to simulate the rigid-soft contact interface, a polydimethylsiloxane (PDMS) hemisphere was used instead of a rigid slider to reduce the contact pressure. The sample coating was tested using a CSM friction tester with a test amplitude of 5 mm and a 1 Hz reciprocating cycle to test the friction coefficient of the sample coating.

[0095] (5) The test results are shown in Table 1:

[0096] Table 1

[0097] sample Coating thickness (nm) Water contact angle (°) Friction coefficient Example 1 32 20 0.013 Example 2 28 23 0.028 Example 3 27 24 0.035 Example 4 30 21 0.014 Example 5 29 22 0.014 Example 6 41 11 0.004 Example 7 38 13 0.005 Example 8 37 13 0.005 Example 9 35 18 0.009 Example 10 23 34 0.068 Embodiment 11 24 30 0.059 Example 12 19 39 0.072 Example 13 22 31 0.063 Embodiment 14 25 30 0.051 Embodiment 15 23 33 0.065 Comparative Example 1 20 42 0.093 Comparative Example 2 15 93 0.11

[0098] It can be seen from Examples 1-5 that the ultra-thin hydrophilic lubricating coating prepared by the method of the present invention can reduce the friction coefficient of the surface of the biomaterial and has strong hydrophilic lubrication performance; it can be seen from Examples 6-8 that there is a synergistic effect between the zwitterionic monomers; it can be seen from Example 9 that the setting of the mass ratio between the zwitterionic monomers is crucial to the hydrophilic lubrication performance of the coating; it can be seen from Examples 10-11, 12-13, and 14-15 that the content of the zwitterionic monomer, the concentration of the dopamine monomer, the power and time of the plasma treatment also affect the hydrophilic lubrication performance of the coating.

[0099] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the method and application of a biomaterial surface modified ultra-thin hydrophilic lubricating coating of the present invention, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0100] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0101] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating, characterized in that: The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating comprises: mixing a plasma-treated biomaterial with a precursor solution, and performing an in-situ polymerization reaction to obtain a biomaterial with a surface modified with an ultra-thin hydrophilic lubricating coating; the precursor solution comprises dopamine or a salt thereof, a zwitterionic monomer, and a Tris buffer.

2. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to claim 1, characterized in that: The atmosphere of the plasma treatment is oxygen; the power of the plasma treatment is 100-400W, and the time of the plasma treatment is 15-60min.

3. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to claim 1 or 2, characterized in that: The concentration of dopamine or its salt in the precursor solution is 1-5 mg / mL.

4. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to any one of claims 1 to 3, characterized in that: The mass ratio of the dopamine or its salt to the zwitterionic monomer is 1:(10-25).

5. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to any one of claims 1 to 4, characterized in that: The zwitterionic monomer includes any one or a combination of at least two of sulfobetaine methacrylate, 2-methacryloyloxyethyl phosphorylcholine or carboxybetaine methacrylate; Preferably, the zwitterionic monomer comprises a combination of sulfobetaine methacrylate and 2-methacryloyloxyethyl phosphorylcholine, sulfobetaine methacrylate and carboxybetaine methacrylate, or 2-methacryloyloxyethyl phosphorylcholine and carboxybetaine methacrylate; Preferably, the mass ratio of sulfobetaine methacrylate to 2-methacryloyloxyethyl phosphorylcholine, sulfobetaine methacrylate to carboxybetaine methacrylate, or 2-methacryloyloxyethyl phosphorylcholine to carboxybetaine methacrylate is independently (5-15):(5-15).

6. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to any one of claims 1 to 5, characterized in that: The concentration of the Tris buffer is 8-12 mM, and the pH of the Tris buffer is 8-9.

7. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to any one of claims 1 to 6, characterized in that: The biomaterial includes any one of polycarbonate, polypropylene, polytetrafluoroethylene, polyvinylidene chloride, silicone rubber, polydimethylsiloxane, polyurethane, polyethylene, polyethylene terephthalate, polylactic acid or polycaprolactone.

8. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to any one of claims 1 to 7, characterized in that: The time of the in-situ polymerization reaction is 8-24 hours, and the temperature of the in-situ polymerization reaction is 20-30°C.

9. The method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to any one of claims 1 to 8, characterized in that: The in-situ polymerization reaction further includes washing and drying steps; Preferably, the washing solvent comprises ethanol and / or deionized water; Preferably, the drying method includes drying by oven drying or drying with nitrogen.

10. Use of the method for modifying the surface of a biomaterial with an ultra-thin hydrophilic lubricating coating according to any one of claims 1 to 9 in the preparation of medical devices.

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