Titanium dioxide-molybdenum disulfide ultrasonic triggering antibacterial coating as well as preparation method and application thereof

Abstract

The invention discloses a titanium dioxide-molybdenum disulfide ultrasonic triggering antibacterial coating and a preparation method and application thereof.The preparation method comprises the following steps that a titanium sheet serves as a working electrode, the working electrode, a counter electrode and electrolyte form an electrochemical anodic oxidation system, electrochemical anodic oxidation is conducted for 5-60 min under 10-50 V, and the titanium sheet loaded with titanium dioxide nanotubes is obtained; in a nitrogen or inert gas atmosphere, the titanium sheet loaded with the titanium dioxide nanotube is subjected to heat preservation at 400-500 DEG C for 0.5-1 h and cooled to the room temperature, and a first substance is obtained; and molybdenum disulfide is used as a target material, the first substance is subjected to magnetron sputtering for 0.5-4 min in the inert gas atmosphere, and the titanium dioxide-molybdenum disulfide ultrasonic triggering antibacterial coating is obtained on a titanium sheet. The titanium dioxide-molybdenum disulfide ultrasonic triggering antibacterial coating disclosed by the invention can generate heat and active oxygen under the triggering of ultrasonic waves, and can inhibit bacterial growth and cause bacterial death through the comprehensive action of the active oxygen and the heat, so that the antibacterial effect is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of antibacterial coatings, and specifically relates to a titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating and a preparation method and application thereof. Background Art

[0002] Due to the presence of bacteria, the problem of postoperative infection of implants has become a global problem that needs to be solved urgently. A large number of relevant studies and clinical experiments have proved that titanium and titanium alloys are the most ideal metal materials for human implants to date. The advantages of titanium can be summarized as: light weight, low elastic modulus, non-magnetic, non-toxic, good corrosion resistance, high strength, and good toughness. There are currently some methods to give the surface of titanium implants antibacterial properties, such as changing the micro-nano structure of the surface of titanium implants, limiting bacterial activity through factors such as size to achieve the purpose of antibacterial; or through various processing methods to dope metal / non-metal atoms on the surface of the implant, using chemical properties to improve the antibacterial ability of the implant surface; and allowing the implant surface to carry drugs to play a drug antibacterial role, however, these implants cannot be intervened in vitro after entering the body, and have certain limitations. Summary of the invention

[0003] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for preparing a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating. The titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating obtained by the preparation method can achieve an antibacterial effect through ultrasound triggering.

[0004] Another object of the present invention is to provide a titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating obtained by the above preparation method.

[0005] Another object of the present invention is to provide the use of the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating in antibacterial applications for non-diagnostic or therapeutic purposes.

[0006] The purpose of the present invention is achieved through the following technical solutions.

[0007] A method for preparing a titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating comprises the following steps:

[0008] Step 1, using a titanium sheet as a working electrode, forming an electrochemical anodization system with a working electrode, a counter electrode and an electrolyte, and electrochemically anodizing for 5 to 60 minutes at 10 to 50 V to obtain a titanium sheet loaded with titanium dioxide nanotubes, wherein the counter electrode is one of a platinum metal electrode and a carbon electrode, the electrolyte is a mixture of a non-conductive solvent, water and a fluorine-containing compound, the fluorine-containing compound is at least one of ammonium fluoride and hydrofluoric acid, and the ratio of the non-conductive solvent, the fluorine-containing compound and water is 100: (0.1 to 1.5): (0.1 to 3) by mass;

[0009] In step 1, the length of the titanium dioxide nanotubes is 4 to 6 μm.

[0010] In step 1, the titanium sheet is ultrasonicated in water, acetone and ethanol in sequence before electrochemical anodization, and then polished with sandpaper.

[0011] In step 1, the non-conductive solvent is at least one of ethylene glycol, glycerol, dimethyl sulfoxide and acetic acid.

[0012] Step 2, in a nitrogen or inert gas atmosphere, keeping the titanium sheet loaded with titanium dioxide nanotubes at 400-500° C. for 0.5-1 h, and cooling to room temperature to obtain a first substance;

[0013] In step 2, the titanium sheet loaded with titanium dioxide nanotubes is washed in ethanol or water before being kept warm to remove residual electrolyte.

[0014] In step 2, the temperature is raised to 400-500° C. at a rate of 5-10° C. / min.

[0015] Step 3, using molybdenum disulfide as a target, magnetron sputtering the first substance in an inert gas atmosphere for 0.5 to 4 minutes to obtain a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating on the titanium sheet.

[0016] In step 3, the power of magnetron sputtering is 200-300W.

[0017] The titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating obtained by the above preparation method.

[0018] The above titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating is used in antibacterial applications for non-diagnostic or therapeutic purposes.

[0019] In the above technical solution, antibacterial is triggered by ultrasound, and the frequency of the ultrasound is 1 to 3 MHz.

[0020] The titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating of the present invention can generate heat and active oxygen under the triggering of ultrasonic waves, and through the combined action of active oxygen and heat, can inhibit bacterial growth and cause bacterial death, thereby improving the antibacterial effect. In addition, the implant loaded with the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating can respond to in vitro ultrasonic stimulation after being implanted in the body, triggering the antibacterial effect, thereby achieving in vitro artificial intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the SEM of the surface of the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating prepared in Example 1;

[0022] Figure 2This is the SEM of the cross section of the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating prepared in Example 1;

[0023] Figure 3 TEM of the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating prepared in Example 1;

[0024] Figure 4 The antibacterial results of the control group, titanium sheet group, titanium sheet group (with ultrasound triggering), TiO2-MoS2 group, and TiO2-MoS2 group (with ultrasound triggering);

[0025] Figure 5 for Figure 4 Statistical chart of the number of colonies in the antibacterial results. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0027] In the following examples, the titanium sheet was purchased from Huijiarui Technology (Tianjin) Co., Ltd. (the purchased specifications were: high-purity titanium sheet, 1.0*200*200mm), first cut to a length of 10mm and a width of 10mm, then ultrasonically cleaned in water, acetone and ethanol for 15min each, and finally polished with 80, 240, 400, 800, 1500 and 2000 mesh sandpaper, rinsed with water, and left to dry in the air before use.

[0028] In the following examples, water is deionized water.

[0029] Staphylococcus aureus: ATCC 25923.

[0030] In the following examples, the culture medium is a mixture of deionized water, sodium chloride, peptone and yeast powder. 10 g of sodium chloride, 10 g of peptone and 5 g of yeast powder are mixed, and deionized water is added to make the volume to 1 L.

[0031] Staphylococcus aureus and the culture solution were mixed and cultured at 37° C. for 24 hours to obtain a bacterial culture solution.

[0032] Coupling agent (medical ultrasonic coupling agent, Kefu): Ningjin County Jinyang Medical Materials Factory (medical device registration certificate number: Ludexibei 20150097).

[0033] Example 1

[0034] A method for preparing a titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating comprises the following steps:

[0035] Step 1, using a titanium sheet as a working electrode, forming an electrochemical anodization system with the working electrode, a counter electrode and an electrolyte, and electrochemically anodizing for 15 minutes at 50V to obtain a titanium sheet loaded with titanium dioxide nanotubes (i.e., titanium dioxide nanotubes are grown on the titanium sheet), wherein the counter electrode is a platinum metal electrode, the thickness of the titanium sheet is 1mm, the length of the titanium dioxide nanotubes is 4-6μm, the electrolyte is a mixture of a non-conductive solvent, water and a fluorine-containing compound, the fluorine-containing compound is ammonium fluoride, the ratio of the non-conductive solvent, the fluorine-containing compound and water is 100:0.426:2 by mass, and the non-conductive solvent is ethylene glycol;

[0036] Step 2, washing (rinsing) the titanium sheet loaded with titanium dioxide nanotubes in ethanol to remove residual electrolyte, placing the titanium sheet loaded with titanium dioxide nanotubes in a tube furnace under a nitrogen atmosphere, keeping the temperature at 450° C. for 0.5 h (the rate of heating to 450° C. is 5° C. / min), and naturally cooling to room temperature 20-25° C. to obtain a first substance;

[0037] Step 3: Place the first substance in a magnetron sputtering device, use molybdenum disulfide as a target, and magnetron sputter the first substance at 300 W for 1 minute in an argon atmosphere to obtain a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating on the titanium sheet.

[0038] Example 2

[0039] A method for preparing a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating is basically the same as that in Example 1, except that the "electrochemical anodization at 50 V for 15 min" in step 1 of Example 1 is replaced by "electrochemical anodization at 30 V for 15 min".

[0040] Example 3

[0041] A method for preparing a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating is basically the same as that in Example 1, except that the "electrochemical anodization at 50 V for 15 min" in step 1 of Example 1 is replaced by "electrochemical anodization at 50 V for 5 min".

[0042] Example 4

[0043] A method for preparing a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating is basically the same as that in Example 1, except that "keeping at 450° C. for 0.5 h" in step 2 of Example 1 is replaced by "keeping at 450° C. for 1 h".

[0044] Example 5

[0045] A method for preparing a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating is basically the same as that in Example 1, the only difference is that: in step 3 of Example 1, "magnetron sputtering at a power of 300 W for 1 min" is replaced by "magnetron sputtering at a power of 300 W for 2 min".

[0046] Figure 1 This is the SEM image of the surface of the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating prepared in Example 1. Figure 2 This is the SEM of the cross section of the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating prepared in Example 1. Figure 3 TEM of the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating prepared in Example 1. Figures 1 to 3 It can be observed that the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating produces titanium dioxide nanotubes, and the titanium dioxide nanotubes have been blocked by molybdenum disulfide. The titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coatings prepared in Examples 2 to 5 are basically the same as the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coatings prepared in Example 1.

[0047] The titanium sheet and the titanium sheet loaded with the titanium dioxide-molybdenum disulfide ultrasonic triggered antibacterial coating prepared in Example 1 were sterilized under ultraviolet light for 60 minutes and the antibacterial test was performed:

[0048] Control group: Staphylococcus aureus concentration was 2.5*10 5 CFU / mL of bacterial culture solution was applied on a 90 mm diameter culture dish and placed in an incubator at 37°C for 24 h;

[0049] Titanium tablet group: Staphylococcus aureus concentration is 2.5*10 7 CFU / mL of bacterial culture solution was dropped on the middle of the titanium sheet surface and allowed to stand for 20 min. The concentration of Staphylococcus aureus on the titanium sheet surface was diluted with the culture solution to 2.5*10 5 CFU / mL, then aspirate 20 μL and apply it to a 90 mm diameter culture dish, and culture it in a constant temperature incubator at 37°C for 24 hours.

[0050] Titanium sheet group (with ultrasound trigger): Staphylococcus aureus concentration is 2.5*10 7 CFU / mL of bacterial culture solution was dropped on the middle position of the titanium sheet surface and treated at a frequency of 1 MHz for 20 min under ultrasonic conditions (the temperature of the bacterial culture solution on the titanium sheet surface was monitored by infrared temperature measurement. It was found that as the ultrasound progressed, the temperature of the bacterial culture solution increased. At the 5th minute of the ultrasound, the temperature of the bacterial culture solution rose to 40°C). The culture solution was used to dilute the concentration of Staphylococcus aureus on the titanium sheet surface to 2.5*10 5CFU / mL, then aspirate 20 μL and apply it on a 90 mm diameter culture dish, and culture it in a constant temperature incubator at 37°C for 24 hours.

[0051] TiO2-MoS2 group: Staphylococcus aureus concentration was 2.5*10 7 CFU / mL of bacterial culture solution was dropped on the surface of the titanium dioxide-molybdenum disulfide ultrasonic triggered antibacterial coating prepared in Example 1, and allowed to stand for 20 min (the temperature of the bacterial culture solution on the surface of the titanium dioxide-molybdenum disulfide ultrasonic triggered antibacterial coating was monitored by infrared temperature measurement, and it was found that the temperature of the bacterial culture solution was always room temperature). The culture solution was used to dilute the concentration of Staphylococcus aureus on the surface of the titanium dioxide-molybdenum disulfide ultrasonic triggered antibacterial coating to 2.5*10 5 CFU / mL, then aspirate 20 μL and apply it on a 90 mm diameter culture dish, and culture it in a constant temperature incubator at 37°C for 24 hours.

[0052] TiO2-MoS2 group (with ultrasound trigger): Staphylococcus aureus concentration was 2.5*10 7 CFU / mL of bacterial culture solution was dropped on the surface of the titanium dioxide-molybdenum disulfide ultrasonic triggered antibacterial coating prepared in Example 1, and treated at a frequency of 1 MHz for 20 min under ultrasonic conditions (the temperature of the bacterial culture solution on the surface of the titanium dioxide-molybdenum disulfide ultrasonic triggered antibacterial coating was monitored by infrared temperature measurement, and it was found that the temperature of the bacterial culture solution increased with the ultrasound, and the temperature of the bacterial culture solution increased to 50°C at the 5th minute of the ultrasound). The culture solution was used to dilute the concentration of Staphylococcus aureus on the surface of the titanium dioxide-molybdenum disulfide ultrasonic triggered antibacterial coating to 2.5*10 5 CFU / mL, then aspirate 20 μL and apply it on a 90 mm diameter culture dish, and culture it in a constant temperature incubator at 37°C for 24 hours.

[0053] The culture dish is filled with culture medium, which is a mixture of deionized water, sodium chloride, peptone, agar and yeast powder. 10g of sodium chloride, 15g of agar, 10g of peptone and 5g of yeast powder are mixed, and then deionized water is added to make the volume to 1L.

[0054] The power density of the ultrasound is 1.5 W / cm 2 , 50% duty cycle.

[0055] The antibacterial results of the control group, titanium sheet group, titanium sheet group (with ultrasound triggering), TiO2-MoS2 group and TiO2-MoS2 group (with ultrasound triggering) cultured in a constant temperature box are as follows: Figure 4 As shown. Figure 4 It can be seen that the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating prepared in Example 1 has excellent antibacterial properties against Staphylococcus aureus under the triggering of ultrasound.

[0056] Figure 5 for Figure 4 Statistical chart of the number of colonies in the antibacterial results ( Figure 5 The vertical axis is the number of colonies), and the antibacterial rate is calculated by the number of colonies. It can be seen that without ultrasonic triggering, the antibacterial ability of the titanium sheet against Staphylococcus aureus is low, and the antibacterial rate is less than 5%; the antibacterial rate of the titanium sheet under ultrasonic triggering is less than 30%.

[0057] The titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating prepared in Example 1 has limited antibacterial ability against Staphylococcus aureus without ultrasonic triggering, with an antibacterial rate of 10%. The titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating prepared in Example 1 has an antibacterial rate of up to 98.7% under ultrasonic triggering, and the antibacterial improvement effect is significant.

[0058] The calculation formula for the above antibacterial rate is: Antibacterial rate = ((control group-experimental group) / control group)*100%, wherein the "experimental group" is one of the titanium sheet group, titanium sheet group (with ultrasonic triggering), TiO2-MoS2 group and TiO2-MoS2 group (with ultrasonic triggering).

[0059] The titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating obtained in Example 1 was immersed in deionized water and subjected to ultrasound at a frequency of 1 MHz (1.5 W / cm 2 , 50% duty cycle) for ESR test. The test results show that the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating can produce three kinds of active oxygen under the triggering of ultrasound. The three kinds of active oxygen are superoxide anion (·O2 - ), singlet oxygen ( 1 O2) and hydroxyl radicals (·OH). Combined with the temperature increase of the bacterial culture solution on the surface of the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating under ultrasonic conditions, it can be inferred that the antibacterial effect brought by the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating of the present invention may be due to the reactive oxygen species generated by it causing damage to cell membrane lipids, enhancing membrane permeability and causing leakage of intracellular substances, breaking DNA bonds and destroying gene expression, inducing functional protein inactivation, etc., ultimately leading to inhibition of bacterial growth and promotion of bacterial death. The heat generated by the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating can change the cell membrane permeability of bacteria adhering to its surface, and help the reactive oxygen species enter the cell body.

[0060] This research was supported by the National Natural Science Foundation of China (General Project No. 52075371).

[0061] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A method for preparing a titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating, characterized in that: The following steps are involved: Step 1, using a titanium sheet as a working electrode, forming an electrochemical anodization system with a working electrode, a counter electrode and an electrolyte, and electrochemically anodizing for 5 to 60 minutes at 10 to 50 V to obtain a titanium sheet loaded with titanium dioxide nanotubes, wherein the counter electrode is one of a platinum metal electrode and a carbon electrode, the electrolyte is a mixture of a non-conductive solvent, water and a fluorine-containing compound, the fluorine-containing compound is at least one of ammonium fluoride and hydrofluoric acid, and the ratio of the non-conductive solvent, the fluorine-containing compound and water is 100: (0.1 to 1.5): (0.1 to 3) by mass; Step 2, in a nitrogen or inert gas atmosphere, keeping the titanium sheet loaded with titanium dioxide nanotubes at 400-500° C. for 0.5-1 h, and cooling to room temperature to obtain a first substance; Step 3, using molybdenum disulfide as a target, magnetron sputtering the first substance in an inert gas atmosphere for 0.5 to 4 minutes to obtain a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating on the titanium sheet.

2. The preparation method according to claim 1, characterized in that: In step 1, the length of the titanium dioxide nanotubes is 4 to 6 μm.

3. The preparation method according to claim 1, characterized in that: In step 1, the titanium sheet is ultrasonicated in water, acetone and ethanol in sequence before electrochemical anodization, and then polished with sandpaper.

4. The preparation method according to claim 1, characterized in that: In step 1, the non-conductive solvent is at least one of ethylene glycol, glycerol, dimethyl sulfoxide and acetic acid.

5. The preparation method according to claim 1, characterized in that: In step 2, the titanium sheet loaded with titanium dioxide nanotubes is washed in ethanol or water before being kept warm.

6. The preparation method according to claim 1, characterized in that: In step 2, the temperature is raised to 400-500° C. at a rate of 5-10° C. / min.

7. The preparation method according to claim 1, characterized in that: In step 3, the power of magnetron sputtering is 200-300W.

8. Titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating obtained by the preparation method according to any one of claims 1 to 7.

9. Use of the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating as claimed in claim 8 in antibacterial applications for non-diagnostic or therapeutic purposes.

10. The use according to claim 9, characterized in that: Antibacterial triggered by ultrasound.

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