Preparation of hydrophobic silver nanoparticle doped coating

Abstract

The invention provides a preparation method of a hydrophobic silver nanoparticle doped coating, which comprises the following specific steps: preparing silicon shell silver chloride nanoparticles (AgCl (at) SiO2NPs) by taking cetyltrimethylammonium chloride (CTAC), silver nitrate, sodium chloride and tetraethyl orthosilicate (TEOS) as raw materials through a one-pot method, and introducing carbon-carbon double bonds by 3-(methacryloyloxy) propyltrimethoxysilane (MPS) under an acidic condition. In the subsequent distillation-precipitation polymerization process, 4-chloromethyl styrene (VBC) is grafted with chloromethyl, and finally, perfluoropolyether methyl acrylate (PFPEMA) is introduced through atom transfer radical polymerization (ATRP) to form AgCl (at) SiO2-F NPs. Nanoparticles are added into polydimethylsiloxane (PDMS) to be evenly mixed, a silica gel catheter is used for pulling and curing to form the hydrophobic nanoparticle coating SR-F. The hydrophobic nanoparticle coating SR-F is mature in step, firm in film and good in hydrophobicity, and experimental results show that the coating has long-acting antibacterial ability.

Description

Technical Field

[0001] The invention relates to the field of medical silicone rubber catheters, and in particular to a method for preparing a long-lasting antibacterial medical silicone rubber catheter coating. Background Art

[0002] Surface modification of nanoparticle antimicrobial coatings can alter the structure and state of the particle surface, imparting new properties to the material. These novel properties of nanoparticles create the potential for the development of numerous innovative materials and expand their applications. Surface grafting with polymer brushes is one of the most effective methods for achieving surface modification, as surface properties can be predictably altered by tethering various functional polymers to the target surface, and these permanently attached polymers ensure long-term stability. Atom transfer radical polymerization (ATRP), in particular, offers an efficient synthetic route to functional surfaces with designed properties by allowing control over the composition and structure of the grafted polymer.

[0003] Hydrophobic materials have shown great potential in various applications and have therefore attracted the attention of many researchers around the world. One of the most practical consequences of hydrophobicity is self-cleaning behavior. Therefore, hydrophobicity is regarded as the main reason for their good potential in various applications, including anti-biofouling coatings, anti-corrosion surfaces, antibacterial coatings, etc.

[0004] Polydimethylsiloxane (PDMS) is a good choice for developing composite materials in coating form because its backbone ((Si-O-Si)n) has high bond energy and large bond angle , with good thermal stability and elasticity, as well as hydrophobic properties. In the manufacture of hydrophobic surfaces, PDMS and nanomaterials (such as Fe3O4, SiO2, ZnO and AgCl) are a new trend, in which nanoparticles introduce surface roughness, PDMS acts as a binder and a material with low surface free energy. PDMS and nanoparticle blends can be made into highly hydrophobic surface polymer coatings for antifouling applications.

[0005] We provide a method for modifying the surface of nanoparticles by introducing PFPEMA into the nanoparticles through ATRP polymerization. The modified nanoparticles are then blended with PDMS, pulled with a silicone catheter, and then cured to form a hydrophobic nanoparticle coating SR-F, resulting in a medical catheter coating that can release bacteria and resist bacterial adhesion for a long time. Summary of the Invention

[0006] The present invention mainly includes two parts: one is to synthesize nanoparticles AgCl@SiO2-F NPs with hydrophobic groups; the other is to form a hydrophobic nanoparticle coating SR-F by blending the modified nanoparticles with PDMS, pulling them with a silicone catheter and then curing them.

[0007] The purpose of the present invention is to provide a method for preparing a novel antibacterial medical catheter coating material.

[0008] 1. Technical solution of the present invention:

[0009] The preparation method of AgCl@SiO2-F NPs is as follows:

[0010] 1. CTAC was rapidly dissolved in water with vigorous stirring, followed by the addition of silver nitrate and sodium chloride. After reacting at 40°C for 3.5 hours, additional CTAC and aqueous HCl were introduced, and TEOS was added dropwise to the solution. After reacting at 40°C for 12 hours, the product was centrifuged and dried to yield AgCl@SiO2 NPs.

[0011] 2. Mix deionized water, hydrochloric acid solution and anhydrous ethanol evenly, then disperse the nanoparticles in the solution, add MPS to the reaction system, react at room temperature for 24 hours, and then centrifuge and dry the product to obtain AgCl@SiO2-MPS NPs.

[0012] 3. Disperse VBC, ethylene glycol dimethacrylate (EGDMA) and azobisisobutyronitrile in acetonitrile solution, and then disperse the nanoparticles in the solution. Boil the reaction mixture and maintain it under reflux conditions. After about 10 mL of acetonitrile is evaporated from the reaction system within about 2 hours, the reaction is stopped and the product is centrifuged and dried to obtain AgCl@SiO2-PVBC NPs.

[0013] 4. After fully dissolving perfluoropolyether alcohol (HOPFPEOH) and hydrofluoroether (HFE), an excess of methacryloyl chloride was added and stirred at room temperature for 48 hours to obtain the monomer PFPEMA for subsequent ATRP polymerization. The nanoparticles were mixed into a mixture of HFE and tetrahydrofuran, followed by the addition of methyl methacrylate (MMA), purified cuprous bromide (CuBr), and PFPEMA. N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) was added under a nitrogen atmosphere for 30 minutes. After reacting at 40°C for 24 hours, the mixture was centrifuged and dried to obtain AgCl@SiO2-F NPs.

[0014] The medical catheter coating of the present invention is obtained by co-melting AgCl@SiO2-F NPs, PDMS, and the surface of a silicone catheter. The preparation method of the antibacterial medical catheter coating comprises the following steps:

[0015] AgCl@SiO2-F NPs were dispersed in a tetrahydrofuran solution. PDMS monomer, dienesiloxane, and PDMS curing agent, hydrogenatedsiloxane, were then added to each reaction system and stirred at 55°C for 6 hours to thoroughly mix. A prepared silicone catheter was immersed in the solution for 30 seconds and slowly withdrawn, forming a thin film on the surface. The solution was then left at room temperature to evaporate the solvent and placed in a vacuum drying oven at 70°C for 6 hours to cure into a film. After removing bubbles, the resulting antibacterial medical catheter coating, SR-F, was obtained.

[0016] Technical analysis of the present invention:

[0017] Silver ions are the primary active substance in antimicrobial processes, inhibiting the growth of bacteria, fungi, and viruses. Therefore, silver chloride nanoparticles are a preferred choice for antimicrobial applications because they provide a constant concentration of silver ions in solution. ATRP polymerization introduces PFPEMA into functional polymer brushes, which increase the hydrophobic surface and reduce bacterial adhesion. PDMS can firmly adhere to the surface of medical catheters, combining with nanomaterials to enhance hydrophobicity and antimicrobial properties.

[0018] In summary, the present invention provides a method for preparing a hydrophobic silver nanoparticle-doped coating, and coating the coating on the surface of a silicone catheter to design an effective, long-lasting antibacterial silicone catheter coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 TEM test image of prepared nanoparticles.

[0020] Figure 2 Infrared characterization of the prepared nanoparticles.

[0021] Figure 3 This is the XPS test diagram of the prepared nanoparticles.

[0022] Figure 4 This is the water contact angle diagram of the prepared medical catheter coating.

[0023] Figure 5 This is a diagram of bacterial coating on the prepared medical catheter coating. DETAILED DESCRIPTION

[0024] Example 1

[0025] Preparation of nanoparticles

[0026] The preparation method of nanoparticles includes four steps:

[0027] 1. Preparation of AgCl@SiO2 NPs: 0.06 g of CTAC was rapidly dissolved in water under vigorous stirring, followed by the addition of AgNO3 (1 mL, 0.5 mol / L) and NaCl (1 mL, 0.5 mol / L). After reacting at 40°C for 3.5 hours, another 0.06 g of CTAC and aqueous HCl (1 mL, 0.1 mol / L) were introduced, and then 6 mL of TEOS was added dropwise to the solution. After reacting at 40°C for 12 hours, the product was centrifuged and dried to obtain AgCl@SiO2 NFS.

[0028] 2. Preparation of AgCl@SiO2-MPS NPs: 25 mL of deionized water and 120 mL of anhydrous ethanol were mixed evenly, and 0.1 mol / L hydrochloric acid solution was added dropwise to adjust the pH of the solution to 3.5. Then, 0.1 g of nanoparticles were dispersed in the solution. 2 mL of MPS was added to the reaction system. After reacting at room temperature for 24 h, the product was centrifuged and dried to obtain AgCl@SiO2-MPS NPs.

[0029] 3. Preparation of AgCl@SiO2-PVBC NPs: 0.2 mL of VBC, 0.3 mL of ethylene glycol dimethacrylate (EGDMA), and 10 mg of azobisisobutyronitrile were dispersed in 40 mL of acetonitrile solution. Then, 0.1 g of AgCl@SiO2-MPS NPs was dispersed in the solution. The reaction mixture was boiled and maintained under reflux conditions. About 10 mL of acetonitrile was evaporated from the reaction system within about 2 h, and the reaction was stopped. The product was centrifuged and dried to obtain AgCl@SiO2-PVBC NPs.

[0030] Preparation of AgCl@SiO2-F NPs: 4 g of perfluoropolyether alcohol (HOPFPEOH) was thoroughly dissolved in 4 mL of hydrofluoroether (HFE), followed by the addition of 0.6 g of methacryloyl chloride and stirring at room temperature for 48 h to obtain the monomer PFPEMA for subsequent ATRP polymerization. 0.1 g of AgCl@SiO2-PVBC NPs was mixed with a mixture of 4 mL of HFE and 2 mL of tetrahydrofuran. Subsequently, 0.4 g of methyl methacrylate (MMA), 10 mg of purified cuprous bromide (CuBr), and 2 g of PFPEMA were added to the reaction system. Under a nitrogen atmosphere for 30 min, 0.14 g of N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) was added. The mixture was reacted at 40°C for 24 h and then centrifuged to dry to obtain AgCl@SiO2-F NPs.

[0031] Characterization of Nanoparticles:

[0032] TEM test was performed on AgCl NPs and AgCl@SiO2 NPs. Figure 1It can be seen that the surface of AgCl@SiO2 NPs forms a core-shell structure. The infrared characterization of AgCl@SiO2-MPSNPs, AgCl@SiO2-PVBC NPs and AgCl@SiO2-F NPs was carried out. Figure 2 , AgCl@SiO2-F NPs increased by 1210 cm -1 The absorption vibration peak near the PFPEMA is related to the characteristic absorption peak of the fluorinated group (-CF2-), that is, Figure 2 The nanoparticles were characterized by XPS. Figure 3 In the figure, AgCl@SiO2-F NPs showed the characteristic peak of F1s element compared with other nanoparticles, indicating that PFPEMA was successfully grafted on the surface.

[0033] Example 2

[0034] Preparation of antibacterial medical catheter coatings:

[0035] 0.1g of AgCl@SiO2-FNPs was dispersed in 2mL of tetrahydrofuran solution. Subsequently, 1g of the PDMS monomer, dienesiloxane, and 0.1g of the PDMS curing agent, hydrogenated siloxane, were added to each reaction system and stirred at 55°C for 6 hours to thoroughly mix. A prepared silicone rubber catheter was immersed in the solution for 30 seconds and slowly withdrawn, forming a thin film on the surface of the catheter. The solution was then allowed to evaporate at room temperature and then cured in a vacuum drying oven at 70°C for 6 hours to form a film. After air bubbles were removed, the resulting antibacterial and anti-adhesive medical catheter coating, SR-F, was obtained.

[0036] Characterization of Antimicrobial Medical Catheter Coatings:

[0037] The water contact angle of the SR-F coating was characterized. Figure 4 As a result, the water contact angle of the surface dispersed nanoparticle coating can reach 135°.

[0038] Example 3

[0039] Antibacterial testing:

[0040] In this experiment, 10 6The antibacterial activity of SR-F against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was verified using CFU / mL and incubated for different incubation times. The film catheter material was rinsed with PBS, air-dried, and then sterilized in a clean bench for 2 hours using UV light. The film catheter material was placed in a Petri dish, 20 μL of the bacterial solution was dripped onto the surface of the antibacterial film catheter, and a 0.5 cm × 0.5 cm sterilized PE sheet was placed over the bacterial solution. The incubation of the bacterial solution requires a certain humidity, so a bottle cap containing sterile saline was placed in the Petri dish and incubated in a constant temperature incubator for a specified time. The film catheter material was removed and placed in a small beaker containing 2 mL of PBS solution and sonicated for 2 minutes to disperse the attached bacteria. 50 μL of the solution from the beaker was then applied to a solid culture medium for smearing, and then placed in a constant temperature incubator for smearing. For the blank control group, 20 μL of the bacterial solution was added to the PBS solution, and 50 μL of the bacterial solution was applied to the solid culture medium for smearing. The remaining steps were repeated.

[0041] Antimicrobial test characterization: as attached Figure 5 , whether it is E.coli or S.aureus, the percentage of Ag is above 99% after 25 min of contact time, which indicates that Ag + The release of SR-F gradually played an antibacterial role. This experiment verified that SR-F has good antibacterial properties.

Claims

1. Preparation of a hydrophobic silver nanoparticle doped coating.

2. The preparation of a hydrophobic silver nanoparticle doped coating according to claim 1, characterized in that: AgCl@SiO2 NPs were modified by introducing MPS to form carbon-carbon double bonds.

3. The preparation of a hydrophobic silver nanoparticle doped coating according to claim 1, characterized in that: By introducing VBC, chloromethyl groups were grafted onto the nanoparticles to form AgCl@SiO2-VBC NPs.

4. The preparation of a hydrophobic silver nanoparticle doped coating according to claim 1, characterized in that: PFPEMA was introduced via ATRP polymerization to form AgCl@SiO2-F NPs.

5. The preparation of a hydrophobic silver nanoparticle doped coating according to claim 1, characterized in that: Preparation of hydrophobic nanoparticle coating SR-F with antibacterial and hydrophobic properties.

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