Physiological pH-responsive antibacterial and bacterial adhesion-resistant coating as well as preparation method and application of physiological pH-responsive antibacterial and bacterial adhesion-resistant coating

Abstract

The invention discloses a physiological pH response antibacterial and bacterial adhesion prevention coating and a preparation method and application thereof.The coating contains an amino acid-based zwitterionic polymer functional layer, and the functional layer contains an amino acid-based zwitterionic polymer; and antibacterial metal ions complexed with the amino acid-based zwitterionic polymer. The coating not only has excellent hydrophilicity, forms a hydration layer on the surface of a material after being combined with water molecules, inhibits adhesion of proteins, further inhibits adhesion of bacteria and formation of bacterial biofilms, but also can release antibacterial metal ions under physiological pH, realizes an antibacterial effect, can slowly release the antibacterial metal ions, and has a good antibacterial effect. The long-acting antibacterial effect is realized. The coating can be constructed on the surfaces of various materials such as medical high polymer materials, medical ceramics, medical stainless steel and medical titanium alloys, and has a good application prospect in the field of implantation and intervention of medical materials.

Description

Technical Field

[0001] The present invention relates to the field of surface modification of medical materials and functional coatings, and more specifically to a physiological pH-responsive antibacterial and anti-bacterial adhesion coating, and its preparation method and application. Background Art

[0002] Bacterial infection on the surface of medical materials is one of the main types of nosocomial infection, which seriously threatens the life safety of patients, increases the medical burden on patients, and consumes medical resources. Generally, bacterial infection on the surface of medical materials can be simply divided into four stages: (1) First, after the medical material is implanted / intervened in the human body, the surface is adsorbed by proteins, and the protein undergoes conformational changes after adsorption, providing a basis for the next bacterial adhesion; (2) Planktonic bacteria adsorb and adhere to the protein layer on the surface of the material and begin to divide and proliferate; (3) After the bacteria divide and proliferate to a certain extent, they activate related factors in the body and secrete extracellular matrix, thereby forming a mature bacterial biofilm; (4) The mature bacterial biofilm further releases planktonic bacteria to the outside, starting a new round of bacterial biofilm growth. It should be noted that once a mature bacterial biofilm is formed, the ability of bacteria in the film to resist antibiotics and other antibacterial drugs, as well as the body's own immune system, will be greatly enhanced, leading to persistent bacterial infection. Therefore, giving medical material surfaces functionalization and preventing bacterial adhesion, proliferation and bacterial biofilm formation on the surface of medical materials after implantation / intervention in the human body are crucial to reducing bacterial infection on the surface of hospital materials.

[0003] At present, there are two main strategies for functionalizing the surface of hospital materials to reduce bacterial infection on the surface. One strategy is the anti-bacterial adhesion coating strategy, which mainly constructs a hydrophilic and neutrally charged coating on the surface of the material to form a hydration layer on the surface of the material, acting as a "physical barrier" to inhibit the adhesion of proteins on the surface of the material, thereby preventing the adhesion of bacteria on the surface of the material and the formation of bacterial biofilms. For example, in the Chinese patent application with publication number CN 112745508 A, it is disclosed that a double-layer hydrophilic structure is constructed on the surface of medical rubber, with a bottom layer of polyamino acid and a surface layer of polyethylene glycol (PEG) to inhibit bacterial adhesion. This type of coating has no antibacterial function and is a "defense" type coating that can only inhibit bacterial adhesion. Once bacteria break through and adhere to the surface of the material, they can still cause bacterial biofilms. Another strategy is the antibacterial coating strategy, which constructs a coating containing an antibacterial structure on the surface of the material, such as antibacterial metal ions or their nanoparticles, or antibacterial polymers (such as polylysine, quaternary ammonium salts, antibacterial peptides, chitosan, etc.), and kills bacteria adhering to the surface of the material through the antibacterial structure. Although this type of coating structure can kill bacteria, it cannot prevent bacterial adhesion, especially the debris and proteins of dead surface bacteria adhering to the surface of the material, which not only provides a basis for subsequent bacterial adhesion, but also inhibits the antibacterial structure in the surface coating from exerting its antibacterial effect, and ultimately still causes the formation of bacterial biofilm, thereby causing infection.

[0004] Based on this, researchers have tried to combine the two strategies, combining antibacterial structures and antibacterial adhesion structures to develop coatings that are both antibacterial and antibacterial. For example, the literature (Wang, Y.; Zou, Y.; Wu, Y.; Wei, T.; Lu, K.; Li, L.; Lin, Y.; Wu, Y.; Huang, C.; Zhang, Y.; et al. ACS Appl. Mater. Interfaces 2021, 13 (41), 48403-48413) discloses a coating of polymerized tannic acid on the surface of a material and combined with copper, and then grafted with amino-containing polyethylene glycol to achieve a coating that is antibacterial and antibacterial under photothermal stimulation. This technology requires external stimulation (photothermal) to achieve antibacterial effects, which is not conducive to actual clinical operation and application. Another example is a Chinese patent application with publication number CN104710644A, which discloses a double-layer antibacterial coating. The bottom layer is a neutrally charged hydrophilic antibacterial adhesion layer, and the upper layer is a polymer antibacterial brush containing a cationic quaternary ammonium salt. However, it should be noted that since most proteins have negative charges under physiological conditions, the antibacterial polymer brush is positively charged and easily adsorbs proteins, while the antibacterial adhesion layer for antibacterial adhesion is a hydrophilic layer that is close to neutral. Regardless of how the structures of the two functional layers are arranged in space, the antibacterial structure and the antibacterial adhesion structure inevitably have mutual charge and adsorption constraints. That is, if the antibacterial layer is on the top layer, it is still easy to adsorb proteins and cause bacterial adhesion, while if the antibacterial adhesion layer is on the top layer, it will affect the cationic structure of the bottom antibacterial layer, thereby affecting the coating's ability to perform its intended antibacterial and antibacterial adhesion functions.

[0005] In summary, it remains a challenge to develop an ideal functional coating that is both antibacterial (kills bacteria) and prevents bacterial adhesion under physiological conditions to prevent and reduce bacterial infection on the surface of medical materials. Summary of the Invention

[0006] In view of the deficiency that the two structures in the current antibacterial and anti-bacterial adhesion coatings restrain each other in charge, resulting in the inability to achieve both functions simultaneously, the present invention provides an antibacterial and anti-bacterial adhesion coating that responds to physiological pH, and its preparation method and application.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides a physiological pH-responsive antibacterial and anti-bacterial adhesion coating, wherein the coating comprises an amino acid-based zwitterionic polymer functional layer, wherein the functional layer comprises an amino acid-based zwitterionic polymer and antibacterial metal ions complexed with the amino acid-based zwitterionic polymer.

[0009] The coating contains a functional layer of amino acid-based zwitterionic polymer. The amino acid-based zwitterionic polymer not only has excellent hydrophilicity, but also forms a hydration layer on the surface of the material after binding with water molecules, inhibiting the adhesion of proteins and thus inhibiting the adhesion of bacteria and the formation of bacterial biofilms. At the same time, the amino groups and carboxylates in the amino acid-based zwitterionic polymer also complex antibacterial metal ions. At physiological pH, the complexed antibacterial metal ions are released, thereby achieving both antibacterial and anti-bacterial adhesion under physiological conditions.

[0010] Furthermore, the amino acid-based zwitterionic polymer is formed by homopolymerization, copolymerization or partial crosslinking of one or more amino acid-based zwitterionic monomers, or by copolymerization or partial crosslinking of amino acid-based zwitterionic monomers and non-ionized hydrophilic monomers; wherein,

[0011] The amino acid-based zwitterionic monomer is selected from One or more of, wherein R is H or CH3;

[0012] The non-ionizable hydrophilic monomer is selected from (AAm for short), (abbreviated as NVP),

[0013] (NIPAM for short), (abbreviated as N2HPAAm) and (abbreviated as HEMA) in which R′ is H or CH3.

[0014] Furthermore, the antibacterial metal ions are selected from one or more of silver ions, copper ions and zinc ions.

[0015] A second aspect of the present invention provides a method for preparing the above-mentioned physiological pH-responsive antibacterial and anti-bacterial adhesion coating, the preparation method comprising the following steps:

[0016] S1 performs surface treatment on the substrate to construct a structural layer capable of initiating polymerization on the substrate surface;

[0017] S2: immersing the surface of the substrate surface-treated in S1 into an aqueous solution of a raw material for forming the amino acid-based zwitterionic polymer to perform a polymerization reaction to form an amino acid-based zwitterionic polymer layer on the surface of the substrate;

[0018] S3: complexing the amino acid-based zwitterionic polymer layer on the substrate surface obtained in step S2 with antibacterial metal ions to obtain the physiological pH-responsive antibacterial and anti-bacterial adhesion coating.

[0019] Further, the material of the substrate is one or a combination of metal, inorganic non-metal and polymer material. In some specific examples, the metal is selected from one of titanium alloy, magnesium alloy, stainless steel and aluminum alloy. The inorganic non-metal is selected from one of silicon, glass and ceramic. The polymer material is one of polyolefin, polyurethane, polyester, polyimide, polyvinyl chloride and silicone rubber.

[0020] Further, when the material of the substrate is mainly metal and / or inorganic non-metal, the polymerization-activatable structure layer in step S1 is an atom transfer radical polymerization-activatable structure layer,

[0021] The preparation method of the atom transfer radical polymerization-activatable structure layer preferably comprises the steps of sequentially performing surface hydrophilization treatment on the substrate, constructing a coupling agent layer and an initiator layer on the surface. The specific preparation method is preferably:

[0022] 1) Surface hydrophilization treatment: place the substrate in an otter wash or SC1 wash, heat and clean for 5-30 min, then ultrasonically clean the substrate with deionized water and air dry;

[0023] 2) Constructing a coupling agent layer: place the substrate in an ethanol-water mixed solution containing 1wt%-10wt% silane coupling agent, react for 2-24 h, then ultrasonically clean the substrate with anhydrous ethanol and air dry, then place the substrate in a nitrogen atmosphere and heat to 90-120°C in an oven, further react for 0-60 min to solidify the coupling agent layer and enhance the interfacial bonding force;

[0024] 3) Constructing an initiator layer: place the substrate in super-dry dichloromethane containing 0.01-0.1 mol / L 2-bromoisobutyryl bromide, and add super-dry triethylamine in an equimolar amount to 2-bromoisobutyryl bromide, react for 0.5-6 h, then ultrasonically clean with dichloromethane, air dry, and obtain a substrate containing an atom transfer radical polymerization-activatable structure layer.

[0025] Further, when the material of the substrate is mainly polymer material, the polymerization-activatable structure layer in step S1 is an atom transfer radical polymerization-activatable structure layer or a functional initiator layer,

[0026] The preparation method of the atom transfer radical polymerization-activatable structure layer preferably comprises the steps of sequentially performing surface hydrophilization activation treatment on the substrate, constructing a coupling agent layer and an initiator layer on the surface. The specific preparation method is preferably:

[0027] 1) Surface hydrophilization activation of the polymer material: perform plasma pretreatment on the substrate for 1-10 min;

[0028] 2) Constructing a coupling agent layer: Placing the plasma-pretreated substrate in a mixed solution of ethanol and water containing 1% to 10% silane coupling agent for 2 to 24 hours, ultrasonically cleaning the substrate with anhydrous ethanol and drying it, then heating the substrate in an oven to 90 to 120° C. under nitrogen protection and further reacting for 0 to 60 minutes to solidify the coupling agent layer and enhance interfacial bonding strength;

[0029] 3) Constructing an initiator layer: placing the substrate in ultra-dry dichloromethane or ultra-dry anhydrous acetonitrile containing 0.01 to 0.1 mol / L 2-bromoisobutyryl bromide, and adding ultra-dry triethylamine in an amount equimolar to 2-bromoisobutyryl bromide. The reaction is carried out for 0.5 to 6 hours, followed by ultrasonic cleaning with dichloromethane and air drying to obtain a substrate containing an atom transfer radical polymerization initiator polymerization structure layer.

[0030] Furthermore, the silane coupling agent is selected from one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, 3-(2-aminoethyl)-aminopropyltriethoxysilane, N-phenylaminomethyltriethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane and N-(n-butyl)-γ-aminopropyltrimethoxysilane, or a combination of several thereof.

[0031] Furthermore, the method for preparing the functional initiator layer preferably comprises the following steps: performing surface hydrophilization and activation treatment on the substrate, and introducing the functional initiator layer. The specific preparation method is preferably:

[0032] 1) Surface hydrophilization and activation of polymer materials: The substrate is subjected to plasma pretreatment for 1 to 10 minutes;

[0033] 2) Immersing the plasma pretreated substrate in an organic solvent (one or a combination of ethanol, isopropanol, and acetone) containing a hydrophobic initiator (one or a combination of benzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4-phenylbenzophenone, or 2-isopropylthioxanthone) for 5 to 30 minutes, removing the substrate, gently rinsing it with the organic solvent, and drying it under a nitrogen flow to obtain a substrate containing a functional initiator layer.

[0034] Furthermore, in step S2, the aqueous solution of the raw material for forming the amino acid-based zwitterionic polymer contains monomers for forming the amino acid-based zwitterionic polymer, a cross-linking agent, and an initiator.

[0035] Furthermore, the monomer forming the amino acid-based zwitterionic polymer is an amino acid-based zwitterionic monomer, or a mixture of an amino acid-based zwitterionic monomer and a non-ionized hydrophilic monomer.

[0036] Furthermore, the molar ratio of the amino acid-based zwitterionic monomer to the non-ionized hydrophilic monomer in S2 is 1:(0-0.5).

[0037] Furthermore, the total molar concentration of the amino acid-based zwitterionic monomers and non-ionized hydrophilic monomers in S2 in the aqueous solution is 0.1 to 2 mol / L.

[0038] Furthermore, the molar ratio of the total molar number of the amino acid-based zwitterionic monomer and the non-ionized hydrophilic monomer to the cross-linking agent in S2 is 1:(0-0.02).

[0039] Furthermore, the cross-linking agent is selected from (PEGDMA) and / or (abbreviated as MBAA), wherein R″ is H or CH3, and n=an integer from 1 to 50.

[0040] Furthermore, in the aqueous solution, the total concentration of monomers forming the amino acid-based zwitterionic polymer is 0.1-2 mol / L; the molar ratio of the sum of monomers forming the amino acid-based zwitterionic polymer to the crosslinking agent is 1:(0-0.02).

[0041] Furthermore, when the structural layer capable of initiating polymerization in step S1 is an initiating polymerization layer containing an atom transfer radical polymerization structure, in the aqueous solution in S2, the initiator is a combination of a nitrogen-containing multidentate ligand, an oxidizing metal salt and a water-soluble reducing agent, and the nitrogen-containing multidentate ligand is one or more of 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, tris(2-pyridylmethyl)amine and tris[2-(dimethylamino)ethyl]amine; the oxidizing metal salt is ferric chloride, ferric bromide, cobalt chloride, One or a combination of cobalt bromide, copper bromide, copper chloride, nickel chloride or nickel bromide; the water-soluble reducing agent is one or a combination of sodium pyruvate, ascorbic acid, sodium sulfite, and sodium bisulfite; the molar ratio of the oxidizing metal salt, the nitrogen-containing multidentate ligand, the water-soluble reducing agent to the total molar number of monomers forming the amino acid-based zwitterionic polymer is 1:5-20:5-20:1000-10000; the polymerization reaction in S2 is reacted at 20-70°C for 0.5-20h.

[0042] Furthermore, when the structural layer capable of initiating polymerization in step S1 is a layer containing a functional initiator, in the aqueous solution in S2, the initiator is a hydrophilic initiator (one of Irgacure-2959, α-ketoglutaric acid, ammonium persulfate or potassium persulfate), and the polymerization reaction conditions in S2 are heating to 60-80° C. for 1 h to 8 h (when the initiator is ammonium persulfate or potassium persulfate), or irradiating the reaction solution under ultraviolet light for 0.5 to 2 h (when the initiator is Irgacure-2959 or α-ketoglutaric acid), and the light intensity is 10 to 500 mW / cm 2 Preferably, the molar ratio of the initiator in S2 to the total molar number of monomers forming the amino acid-based zwitterionic polymer is 0.005 to 0.01:1.

[0043] Furthermore, the specific method of step S3 is:

[0044] The substrate obtained in S2 is immersed in an aqueous solution of an organic base, the pH is adjusted to 7.5-9.0, and soaked for 0.5-2 hours. Then, a solution containing antibacterial metal ions is added and reacted for 0.5-2 hours. Then, the substrate is taken out, washed with deionized water, and dried.

[0045] Furthermore, in step S3, the organic base is selected from one or a combination of tris(hydroxymethyl)aminomethane, tris(hydroxymethyl)aminomethane hydrochloride, ammonia water, triethylamine, and tetramethylethylenediamine.

[0046] Furthermore, in the solution containing antibacterial metal ions, the source of the antibacterial metal ions is one or a combination of zinc chloride, zinc nitrate, copper chloride, copper nitrate and silver nitrate.

[0047] Furthermore, the concentration of the aqueous solution of the organic base is 0.01 to 0.2 mol / L, and the molar ratio of the organic base to the antibacterial metal ion is 0.5 to 5:1.

[0048] In a third aspect, the present invention provides the use of the physiological pH-responsive antibacterial and anti-bacterial adhesion coating described above in the preparation of implantable medical devices.

[0049] Furthermore, the implantable medical device is selected from one or more of a urinary catheter, a respiratory catheter, a fistula tube, a drainage tube, a vascular stent, a venous indwelling needle, a hydrophilic guidewire, a non-woven dressing and a patch.

[0050] The beneficial effects of the present invention are as follows:

[0051] The coating provided by the present invention contains a functional layer of amino acid-based zwitterionic polymer, which not only has good hydrophilic properties and inhibits the adhesion of proteins and bacteria, but also can destroy the complex structure of amino groups and carboxyl groups in the amino acid-based zwitterionic polymer with antibacterial metal ions at physiological pH, release antibacterial metal ions, and simultaneously achieve antibacterial function without the need for external stimulation (such as light stimulation, heat stimulation). Due to the complexation of amino groups and carboxyl groups in the amino acid-based zwitterionic polymer with metal ions, and the distribution of metal ions, the coating can be applied to the coating of the present invention. It slowly precipitates in the longitudinal space of the coating under physiological conditions, and has good long-term antibacterial properties on the surface. After immersion in PBS for 28 days, the antibacterial rate against Escherichia coli and Staphylococcus aureus is still higher than 90%; the coating has an adhesion inhibition rate of no less than 99% for red blood cells and platelets; the coating is covalently bonded to the substrate surface, has good interfacial bonding, is not easy to fall off, and can be constructed on the surfaces of various substrates, with a wide range of applications; the coating has good biocompatibility, a hemolysis rate of less than 2%, a cytotoxicity of no more than level 2, and an intradermal reaction score of no more than 1.0. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0053] Figure 1 The anti-bacterial adhesion performance of the surface of the medical polyurethane sheet in Example 1 is shown; the adhesion of Staphylococcus aureus to an uncoated medical polyurethane sheet (A) and a coated medical polyurethane sheet (B); and the adhesion of Escherichia coli to an uncoated medical polyurethane sheet (C) and a coated medical polyurethane sheet (D).

[0054] Figure 2 The water contact angles of the untreated silicon wafer (A) and the coated silicon wafer (B) in Example 2 are shown.

[0055] Figure 3 The thickness test results of the coated silicon wafer in Example 2 are shown (A is an atomic force microscope test image; B is a thickness curve) and the confirmation of surface copper (C).

[0056] Figure 4 The adhesion properties of red blood cells and platelets on the surface of the medical titanium alloy sheet in Example 3 are shown, including the adhesion of platelets to an uncoated medical titanium alloy sheet (A) and a coated medical titanium alloy sheet (B); and the adhesion of red blood cells to an uncoated medical titanium alloy sheet (C) and a coated medical titanium alloy sheet (D). DETAILED DESCRIPTION

[0057] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following detailed description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0058] Example 1

[0059] A method for preparing a physiological pH-responsive antibacterial and anti-bacterial adhesion coating comprises the following steps:

[0060] S1. Placing a medical polyurethane sheet in a plasma cleaning machine for plasma pretreatment for 1 minute; then immediately immersing the sheet in an isopropyl alcohol solution containing 10 wt% benzophenone for 30 minutes; removing the sheet, gently rinsing it with isopropyl alcohol, and drying it under a stream of nitrogen;

[0061] S2. Immerse the medical polyurethane sheet treated with S1 in a composite aqueous solution containing 0.5 mol / L amino acid-based zwitterionic monomer, 0.25 mol / L non-ionized hydrophilic monomer (NVP), 7.5 mmol / L PEGDMA (R" is CH3, n = 1) and 3.75 mmol / L Gluco-2959 initiator, and irradiate under ultraviolet light for 0.5 h at an illumination intensity of 100 mW / cm 2 After the reaction is completed, take out the medical polyurethane sheet and wash it thoroughly in deionized water and dry it;

[0062] Wherein, the above-mentioned amino acid-based zwitterionic monomer is (R is H).

[0063] S3. Immerse the medical polyurethane sheet obtained in S2 into a 10 mmol / L tris(hydroxymethyl)aminomethane aqueous solution, adjust the pH to 8.5, soak for 1 hour, then add an equal volume of 20 mmol / L zinc nitrate solution, react for 2 hours, then take out, wash with deionized water, and dry.

[0064] The medical polyurethane sheet obtained in Example 1 was tested for antibacterial properties according to the standard ISO 22196, using Staphylococcus aureus and Escherichia coli as the test bacteria; the antibacterial biofilm performance against Escherichia coli and Staphylococcus aureus was tested according to ISO 4768 (observed by scanning electron microscopy (SEM), without crystal violet staining); the cytotoxicity was tested according to the standard GB / T 16886.5-2017, using L929 mouse fibroblasts; the intradermal reaction was tested according to GB / T 16886.23 (the control was the solvent group); and the hydrophilicity was tested using a contact angle meter.

[0065] The test showed that the contact angle of the medical polyurethane sheet obtained in Example 1 was 19.2°, indicating good hydrophilicity. The surface of the uncoated medical polyurethane sheet had no antibacterial biofilm properties against the two bacteria, and the surface was covered with a large number of Staphylococcus aureus (such as Figure 1 A) and E. coli adhesion (as shown in Figure 1 The coated medical polyurethane sheet has good anti-adhesion effect on Staphylococcus aureus and Escherichia coli, and there is basically no bacterial adhesion on the surface; Figure 1 B) and Escherichia coli (as shown in Figure 1 The antibacterial rates of the two drugs (shown in D) were 99.92% and 99.98% respectively, the cytotoxicity was grade 1, and the intradermal reaction score was 0.1.

[0066] Example 2

[0067] A method for preparing a physiological pH-responsive antibacterial and anti-bacterial adhesion coating comprises the following steps:

[0068] S1. Place the silicon wafer in SC1 washing solution, heat to 80°C for 30 minutes, then ultrasonically clean with deionized water, naturally dry, and then place the silicon wafer in 95v% ethanol solution containing 10v% γ-aminopropyltriethoxysilane. After reacting for 24 hours, ultrasonically clean with anhydrous ethanol and dry. Then, place the silicon wafer in an oven heated to 120°C under nitrogen protection, react for a further 30 minutes, then take it out and add ultra-dry dichloromethane containing 0.1mol / L 2-bromoisobutyryl bromide and 0.1mol / L ultra-dry triethylamine. React for 0.5 hours, finally ultrasonically clean with dichloromethane and dry.

[0069] S2, immersing the silicon wafer treated in S1 into a composite solution containing 0.5 mol / L amino acid-based zwitterionic monomer, 1 mmol / L 2,2'-bipyridine, 0.1 mmol / L copper chloride, and 2 mmol / L ascorbic acid, sealing the reaction vessel, reacting at room temperature for 20 h, then taking out and thoroughly washing in deionized water and drying;

[0070] Wherein, the above-mentioned amino acid-based zwitterionic monomer is (R is H);

[0071] S3. Immerse the silicon wafer obtained in S2 into a 50 mmol / L tris(hydroxymethyl)aminomethane aqueous solution, adjust the pH to 8.7, soak for 0.5 h, then add an equal volume of 25 mmol / L copper chloride solution, react for 2 h, then take out, rinse with deionized water, and dry.

[0072] The antibacterial performance of the silicon wafer obtained in Example 2 was tested according to the standard ISO 22196, and the test bacteria were Staphylococcus aureus and Escherichia coli; in addition, the silicon wafer obtained in Example 2 was immersed in PBS and immersed at 37°C for 28 days, and then the antibacterial performance was tested again according to the standard ISO 22196; the hydrophilicity was tested using a contact angle meter (the untreated silicon wafer was used as a control), the coating thickness was tested using an atomic force microscope, and X-ray photoelectron spectroscopy was used to confirm whether the silicon wafer surface contained copper and its high-resolution spectrum to confirm the valence state; the cytotoxicity was tested according to the standard GB / T 16886.5-2017; and the intradermal reaction was tested according to GB / T16886.23 (the control was the solvent group).

[0073] After testing, the contact angle of the silicon wafer obtained in Example 2 was 18.2° (as shown in FIG. Figure 2 The contact angle of the untreated silicon wafer surface is 98.5° (as shown in B). Figure 2 Atomic force microscopy test shows that the surface coating thickness is about 150nm (as shown in Figure A). Figure 3 X-ray photoelectron spectroscopy shows that the surface of the silicon wafer contains copper, and it is Cu 2+ , no valence change occurs during the reaction (such as Figure 3 The antibacterial rates against Staphylococcus aureus and Escherichia coli were 99.97% and >99.99%, respectively; after immersion in PBS at 37°C for 28 days, the antibacterial rates against Staphylococcus aureus and Escherichia coli were 92.51% and 96.78%, respectively; the cytotoxicity was grade 1, and the intradermal reaction score was 0.2.

[0074] Example 3

[0075] A method for preparing a physiological pH-responsive antibacterial and anti-bacterial adhesion coating comprises the following steps:

[0076] S1. Place the medical titanium alloy sheet in piranha wash solution, heat to 110°C for 30 minutes, then ultrasonically clean with deionized water. After natural drying, place the silicon sheet in a 95v% ethanol solution containing 5v% γ-aminopropyltrimethoxysilane, react for 20 hours, ultrasonically clean with anhydrous ethanol, and dry. Then, place the medical titanium alloy sheet in an oven under nitrogen protection and heat to 120°C. After further reaction for 15 minutes, take it out and add ultra-dry dichloromethane containing 0.05mol / L 2-bromoisobutyryl bromide and 0.0.05mol / L ultra-dry triethylamine. React for 2 hours, finally ultrasonically clean with dichloromethane and dry.

[0077] S2, immersing the medical titanium alloy sheet treated in S1 into a composite solution containing 0.5 mol / L amino acid-based zwitterionic monomer, 0.1 mol / L AAm, 5 mmol / L tris(2-pyridylmethyl)amine, 0.1 mmol / L copper chloride, and 1 mmol / L ascorbic acid, sealing the reaction vessel, reacting at room temperature for 20 h, then taking out and thoroughly washing in deionized water, and drying;

[0078] Wherein, the above-mentioned amino acid-based zwitterionic monomer is (R is H);

[0079] S3. Immerse the medical titanium alloy sheet obtained in S2 into a 0.2 mol / L tris(hydroxymethyl)aminomethane aqueous solution, adjust the pH to 8.5, soak for 0.5 h, then add an equal volume of 0.2 mol / L copper chloride solution, react for 2 h, then take out, wash with deionized water, and dry.

[0080] The medical titanium alloy sheet obtained in Example 3 was tested for antibacterial properties according to the standard ISO 22196, using Staphylococcus aureus and Escherichia coli as the test bacteria; the hydrophilicity was tested using a contact angle meter; the hydrophilicity was tested using a contact angle meter according to the reference (Clin. Hemorheol. Microcirc. 2015, 61, 225-236) to test the anti-adhesion effect of the coated medical titanium alloy sheet surface on platelets and red blood cells (the medical titanium alloy sheet without coating was used as a control), the cytotoxicity was tested according to GB / T 16886.5, and the cells used were L929 mouse fibroblasts; the intradermal reaction was tested according to GB / T 16886.23 (the control was the solvent group).

[0081] The test results show that the antibacterial rates of the medical titanium alloy sheet obtained in Example 3 against Staphylococcus aureus and Escherichia coli are 99.93% and >99.99% respectively, the water contact angle is 16.8°, the cytotoxicity is level 1, the intradermal reaction score is 0.2, and a large number of platelets (such as Figure 4 A) and red blood cells (as Figure 4 C in the middle), while the surface of the coated medical titanium alloy sheet has almost no platelets (as shown in Figure 4 B) and erythrocyte adhesion (as shown in Figure 4 (as shown in D in the figure).

[0082] Example 4

[0083] A method for preparing a physiological pH-responsive antibacterial and anti-bacterial adhesion coating comprises the following steps:

[0084] S1. Place a medical PVC sheet in a plasma cleaning machine for plasma pretreatment for 5 minutes, then immediately immerse it in an isopropyl alcohol solution containing 10 wt% 2-isopropylthioxanthone for 30 minutes, remove the medical PVC sheet, gently rinse it with isopropyl alcohol, and dry it under a nitrogen stream;

[0085] S2, immerse the S2-treated medical PVC sheet in a composite aqueous solution containing 0.5 mol / L amino acid-based zwitterionic monomer, 0.1 mol / L non-ionized hydrophilic monomer (AAm), 6 mmol / L PEGDMA (R" is H, n = 50) and 3 mmol / L Irgacure-2959 initiator, and irradiate under ultraviolet light for 1 h with an illumination intensity of 50 mW / cm 2 After the reaction is completed, take out the medical PVC sheet and wash it thoroughly in deionized water and dry it;

[0086] Wherein, the above-mentioned amino acid-based zwitterionic monomer is (R is CH3);

[0087] S3. Immerse the medical PVC sheet obtained in S2 into a 0.2 mol / L tris(hydroxymethyl)aminomethane aqueous solution, adjust the pH to 8.2, soak for 0.5 h, then add an equal volume of 0.2 mol / L zinc chloride solution, react for 2 h, then take out, wash with deionized water, and dry.

[0088] The medical PVC sheet obtained in Example 4 was tested for antibacterial properties according to ISO 22196, using Staphylococcus aureus and Escherichia coli as the test bacteria. Its hydrophilicity was tested using a contact angle meter. Its cytotoxicity was tested according to GB / T 16886.5, using L929 mouse fibroblasts. The intradermal reaction was tested according to GB / T 16886.23 (the control was the solvent group).

[0089] After testing, the medical PVC sheet obtained in Example 4 had antibacterial rates of 99.67% and 99.89% against Staphylococcus aureus and Escherichia coli, respectively, a water contact angle of 18.1°, a cytotoxicity of level 1, and an intradermal reaction score of 0.3.

[0090] Example 5

[0091] A method for preparing a physiological pH-responsive antibacterial and anti-bacterial adhesion coating comprises the following steps:

[0092] S1. Soak the inner cavity of a medical TPE infusion tube in a composite solution of 5 wt% 4-chlorobenzophenone in isopropyl alcohol and acetone (volume ratio 1:1) for 30 minutes. Remove the medical TPE infusion tube, gently rinse the inner cavity with isopropyl alcohol, and dry it with nitrogen gas.

[0093] S2. Add the inner cavity of the medical TPE infusion tube treated with S2 into a composite aqueous solution containing 1 mol / L amino acid-based zwitterionic monomer, 5 mmol / L PEGDMA (R" is CH3, n = 1) and 5 mmol / L Irgacure-2959 initiator, and irradiate under ultraviolet light for 1 h with an illumination intensity of 200 mW / cm 2 After the reaction is completed, deionized water is passed into the inner cavity of the medical TPE infusion tube to fully clean the inner cavity, and then nitrogen or air is passed through to dry it;

[0094] Wherein, the above-mentioned amino acid-based zwitterionic monomer is (R is H);

[0095] S3. Add a 0.1 mol / L tris(hydroxymethyl)aminomethane aqueous solution to the inner cavity of the medical TPE infusion tube obtained in S2, adjust the pH to 8.5, soak for 0.5 h, aspirate the tris(hydroxymethyl)aminomethane aqueous solution in the inner cavity and mix it with an equal volume of 0.05 mol / L zinc nitrate solution, then add the mixed solution to the inner cavity of the medical TPE infusion tube, react for 2 h, then pass deionized water into the inner cavity of the medical TPE infusion tube, thoroughly clean the inner cavity, and then pass nitrogen or air to dry it.

[0096] The medical TPE infusion tube obtained in Example 5 was cut longitudinally, and the inner surface was tested for antibacterial properties with reference to ISO 22196, using Staphylococcus aureus and Escherichia coli. The cytotoxicity of the medical TPE infusion tube was tested according to GB / T 16886.5, using L929 mouse fibroblasts. The intradermal reaction of the medical TPE infusion tube was tested with reference to GB / T 16886.23 (the control was the solvent group).

[0097] After testing, the medical TPE infusion tube obtained in Example 5 had antibacterial rates of 99.27% ​​and 99.91% against Staphylococcus aureus and Escherichia coli, respectively, a cytotoxicity of grade 1, and an intradermal reaction score of 0.1.

[0098] Example 6

[0099] A method for preparing a physiological pH-responsive antibacterial and anti-bacterial adhesion coating comprises the following steps:

[0100] S1. Plasma pretreatment of a medical polypropylene patch in a plasma cleaning machine for 10 minutes. Immediately thereafter, the patch was immersed in a 95% by volume ethanol solution containing 10% by volume 4-amino-3,3-dimethylbutyltrimethoxysilane. After reacting for 24 hours, the patch was ultrasonically cleaned with anhydrous ethanol and air-dried. The patch was then placed in an oven under nitrogen protection and heated to 90°C. After further reacting for 30 minutes, the patch was removed and added to ultra-dry anhydrous acetonitrile containing 0.1 mol / L 2-bromoisobutyryl bromide and 0.1 mol / L ultra-dry triethylamine. The patch was reacted for 4 hours. Finally, the patch was washed with anhydrous acetonitrile and air-dried.

[0101] S2. Immerse the medical polypropylene patch treated in S1 into a composite solution containing 0.8 mol / L amino acid-based zwitterionic monomer, 0.2 mol / L non-ionized hydrophilic monomer (NIPAM), 2.5 mmol / L 2,2′-bipyridine, 0.25 mmol / L copper chloride, and 2 mmol / L sodium sulfite. Seal the reaction container and react at room temperature for 12 h. Then, remove the patch and rinse thoroughly in deionized water and air-dry.

[0102] Wherein, the above-mentioned amino acid-based zwitterionic monomer is (R is H);

[0103] S3. Immerse the medical polypropylene patch obtained in S2 in a 50 mmol / L aqueous solution of tetramethylethylenediamine, adjust the pH to 8.5, soak for 1 hour, then add an equal volume of 20 mmol / L silver nitrate solution, react for 2 hours, then take out, wash with deionized water, and dry.

[0104] The medical polypropylene patch obtained in Example 6 was tested for antibacterial properties according to GB / T 20944.2 and cytotoxicity according to GB / T 16886.5 using L929 mouse fibroblasts. The intradermal reaction was tested according to GB / T 16886.23 (the control was the solvent group).

[0105] After testing, the medical polypropylene patch obtained in Example 6 had an antibacterial rate of 99.90% and 99.97% against Staphylococcus aureus and Escherichia coli, respectively, a cytotoxicity of grade 1, and an intradermal reaction score of 0.2.

[0106] Example 7

[0107] A method for preparing a physiological pH-responsive antibacterial and anti-bacterial adhesion coating comprises the following steps:

[0108] S1. Plasma pretreatment of a medical silicone catheter in a plasma cleaning machine for 1 minute. Immediately thereafter, the catheter was immersed in a 95% by volume ethanol solution containing 10% by volume γ-aminopropyltrimethoxysilane. After reacting for 6 hours, the catheter was ultrasonically cleaned with anhydrous ethanol and air-dried. The catheter was then placed in an oven heated to 120° C. under nitrogen protection. After further reacting for 30 minutes, the catheter was removed and added to ultra-dry anhydrous acetonitrile containing 0.05 mol / L 2-bromoisobutyryl bromide and 0.05 mol / L ultra-dry triethylamine. The reaction lasted for 4 hours. Finally, the catheter was washed with anhydrous acetonitrile and air-dried.

[0109] S2. Immerse the medical silicone catheter treated with S1 in a composite solution containing 1 mol / L amino acid-based zwitterionic monomer, 0.1 mol / L non-ionized hydrophilic monomer (HEMA), 1.25 mmol / L tris(2-pyridylmethyl), 0.25 mmol / L copper chloride, and 2 mmol / L sodium bisulfite. Seal the reaction vessel and react at room temperature for 20 h. Then remove the catheter and rinse it thoroughly in deionized water and air dry.

[0110] Wherein, the above-mentioned amino acid-based zwitterionic monomer is (R is H);

[0111] S3. Immerse the medical silicone catheter obtained in S2 into a 100 mmol / L tetramethylethylenediamine aqueous solution, adjust the pH to 8.5, soak for 0.5 h, then add an equal volume of 50 mmol / L copper nitrate solution, react for 2 h, then take out, rinse with deionized water, and dry.

[0112] The medical silicone catheter obtained in Example 7 was tested for antibacterial properties according to ISO 22196, using Staphylococcus aureus and Escherichia coli as the test bacteria. Its cytotoxicity was tested according to GB / T 16886.5, using L929 mouse fibroblasts. Its intradermal reaction was tested according to GB / T 16886.23 (the control was the solvent group).

[0113] After testing, the medical silicone catheter obtained in Example 7 had antibacterial rates of 99.89% and 99.94% against Staphylococcus aureus and Escherichia coli, respectively, a cytotoxicity of grade 1, and an intradermal reaction score of 0.1.

[0114] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A physiological pH responsive antibacterial and anti-bacterial adhesion coating, characterized in that: The coating contains an amino acid-based zwitterionic polymer functional layer, which contains an amino acid-based zwitterionic polymer and antibacterial metal ions complexed with the amino acid-based zwitterionic polymer.

2. The coating according to claim 1, characterized in that The amino acid-based zwitterionic polymer is formed by homopolymerization, copolymerization or partial crosslinking of one or more amino acid-based zwitterionic monomers, or by copolymerization or partial crosslinking of amino acid-based zwitterionic monomers and non-ionized hydrophilic monomers; wherein, The amino acid-based zwitterionic monomer is selected from One or more of, wherein R is H or CH3; The non-ionizable hydrophilic monomer is selected from One or more of the following, wherein R′ is H or CH3.

3. The coating according to claim 1, characterized in that The antibacterial metal ions are selected from one or more of silver ions, copper ions and zinc ions.

4. The method for preparing the physiological pH responsive antibacterial and anti-bacterial adhesion coating according to any one of claims 1 to 3, characterized in that: The steps include: S1 performs surface treatment on the substrate to construct a structural layer capable of initiating polymerization on the substrate surface; S2: immersing the surface of the substrate surface-treated in S1 into an aqueous solution of a raw material for forming the amino acid-based zwitterionic polymer to perform a polymerization reaction to form an amino acid-based zwitterionic polymer layer on the surface of the substrate; S3: complexing the amino acid-based zwitterionic polymer layer on the substrate surface obtained in step S2 with antibacterial metal ions to obtain the physiological pH-responsive antibacterial and anti-bacterial adhesion coating.

5. The preparation method according to claim 4, characterized in that The material of the substrate is one or a composite of metal, inorganic non-metal and polymer materials.

6. The preparation method according to claim 5, characterized in that When the material of the substrate is mainly metal and / or inorganic non-metal, the structural layer capable of initiating polymerization in step S1 is a structural layer containing atom transfer radical polymerization initiating polymerization. The method for preparing the structural layer preferably comprises the steps of: performing surface hydrophilization treatment on the substrate, and constructing a coupling agent layer and an initiator layer on the surface.

7. The preparation method according to claim 5, characterized in that When the substrate is mainly made of polymer material, the polymerizable structural layer in step S1 is a polymerization initiation layer containing an atom transfer radical polymerization structure or a functional initiator layer. The method for preparing the polymerization initiation layer preferably comprises the steps of: performing surface hydrophilization and activation treatment on the substrate, and constructing a coupling agent layer and an initiator layer on the surface; The method for preparing the functional initiator layer preferably comprises the steps of performing surface hydrophilization and activation treatment on the substrate and introducing the functional initiator layer.

8. The preparation method according to claim 4, characterized in that In step S2, the aqueous solution of the raw material for forming the amino acid-based zwitterionic polymer contains monomers for forming the amino acid-based zwitterionic polymer, a cross-linking agent, and an initiator; Preferably, the cross-linking agent is selected from and / or Wherein, R″ is H or CH3, and n=an integer from 1 to 50; Preferably, in the aqueous solution, the monomer forming the amino acid-based zwitterionic polymer is an amino acid-based zwitterionic monomer, or a mixture of an amino acid-based zwitterionic monomer and a non-ionized hydrophilic monomer, wherein the molar ratio of the amino acid-based zwitterionic monomer to the non-ionized hydrophilic monomer is 1:(0-0.5), the total molar concentration of the amino acid-based zwitterionic monomer and the non-ionized hydrophilic monomer in the aqueous solution is 0.1-2 mol / L, and the molar ratio of the total molar number of the amino acid-based zwitterionic monomer and the non-ionized hydrophilic monomer to the cross-linking agent is 1:0-0.

02.

9. Use of the physiological pH-responsive antibacterial and anti-bacterial adhesion coating according to any one of claims 1 to 3 in the preparation of implantable medical devices.

10. The use according to claim 9, characterized in that The implantable medical device is selected from one or more of a urinary catheter, a respiratory catheter, a fistula tube, a drainage tube, a vascular stent, a venous indwelling needle, a hydrophilic guidewire, a non-woven dressing and a patch.

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