Titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating and its preparation method and application

Abstract

The present invention discloses a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating and its preparation method and application. The preparation method comprises the following steps: using a titanium sheet as a working electrode, forming an electrochemical anodizing system with a working electrode, a counter electrode and an electrolyte, electrochemically anodizing for 5 to 60 minutes at 10 to 50V to obtain a titanium sheet loaded with titanium dioxide nanotubes, and keeping the titanium sheet loaded with titanium dioxide nanotubes at 400 to 500°C for 0.5 to 1 hour under a nitrogen or inert gas atmosphere, cooling to room temperature to obtain a first substance; using molybdenum disulfide as a target material, magnetron sputtering the first substance for 0.5 to 4 minutes under an inert gas atmosphere to obtain a titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating on the titanium sheet. 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. Through the combined action of active oxygen and heat, bacterial growth can be inhibited and bacterial death can be caused, thereby improving the antibacterial effect.

Description

Technical Field

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

[0002] Due to the presence of bacteria, the problem of post-operative 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 titanium implants antibacterial properties, such as changing the micro-nano structure of the titanium implant surface to limit 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 implant surface, using chemical properties to improve the antibacterial ability of the implant surface; and allowing the implant surface to carry drugs to play an 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 shortcomings of the existing technology, the purpose 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 this preparation method can trigger an antibacterial effect through ultrasound.

[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 an application 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 at 10 to 50 V for 5 to 60 minutes 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, and the electrolyte is a mixture of a non-conductive solvent, water, and a fluorine-containing compound, wherein 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 the 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, heat the titanium sheet loaded with titanium dioxide nanotubes at 400-500° C. for 0.5-1 hour, and cool 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 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 effect is triggered by ultrasound, and the frequency of ultrasound is 1 to 3 MHz.

[0020] The titanium dioxide-molybdenum disulfide ultrasound-triggered antimicrobial coating of the present invention generates heat and reactive oxygen species when triggered by ultrasound. The combined effects of reactive oxygen species and heat inhibit bacterial growth and cause bacterial death, enhancing the antimicrobial effect. Furthermore, after implantation, the implant loaded with the titanium dioxide-molybdenum disulfide ultrasound-triggered antimicrobial coating responds to external ultrasonic stimulation, triggering an antimicrobial effect, achieving in vitro human intervention. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 2This is the SEM image 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) are shown;

[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 with reference to specific embodiments.

[0027] In the following examples, titanium sheets were purchased from Huijiarui Technology (Tianjin) Co., Ltd. (the purchased specifications were: high-purity titanium sheets, 1.0*200*200 mm), first cut to a length of 10 mm and a width of 10 mm, and then ultrasonically cleaned in water, acetone, and ethanol for 15 min each, and finally polished with 80, 240, 400, 800, 1500, and 2000 grit sandpaper, rinsed with water, and allowed to dry in 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 ultrasound 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 at 50V for 15 minutes 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 1 mm, the length of the titanium dioxide nanotubes is 4 to 6 μm, and the electrolyte is a mixture of a non-conductive solvent, water, and a fluorine-containing compound, the fluorine-containing compound is ammonium fluoride, and 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: The titanium sheet loaded with titanium dioxide nanotubes is washed (rinsed) in ethanol to remove residual electrolyte. The titanium sheet loaded with titanium dioxide nanotubes is placed in a tube furnace under a nitrogen atmosphere and heated at 450° C. for 0.5 h (the heating rate to 450° C. is 5° C. / min). The titanium sheet is then naturally cooled 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 a power of 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 "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 "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 0.5h" in step 2 of Example 1 is replaced by "keeping at 450°C for 1h".

[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, except that "magnetron sputtering at a power of 300 W for 1 min" in step 3 of Example 1 is replaced with "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 ultrasound-triggered antibacterial coating produces titanium dioxide nanotubes, which are blocked by molybdenum disulfide. The titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coatings prepared in Examples 2 to 5 are basically the same as the titanium dioxide-molybdenum disulfide ultrasound-triggered antibacterial coating prepared in Example 1.

[0047] The titanium sheet and the titanium sheet loaded with the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating prepared in Example 1 were sterilized under ultraviolet light for 60 minutes and then subjected to antibacterial testing:

[0048] Control group: Staphylococcus aureus was added at a concentration of 2.5*10 5 CFU / mL of bacterial culture solution was applied to a 90 mm diameter Petri dish and cultured 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 culture solution to 2.5*10 5 CFU / mL, and then aspirate 20 μL to apply on a 90 mm diameter culture dish, and culture in a constant temperature box 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 under ultrasonic conditions for 20 min (the temperature of the bacterial culture solution on the titanium sheet surface was monitored by infrared temperature measurement, and it was found that the temperature of the bacterial culture solution increased with the progress of ultrasound, and the temperature of the bacterial culture solution rose to 40°C at the 5th minute of ultrasound). The culture solution was used to dilute the concentration of Staphylococcus aureus on the titanium sheet surface to 2.5*10 5CFU / mL, and then aspirate 20 μL to spread on a 90 mm diameter culture dish, and culture in a constant temperature box 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 onto the surface of the titanium dioxide-molybdenum disulfide ultrasonically 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 ultrasonically 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 ultrasonically triggered antibacterial coating to 2.5*10 5 CFU / mL, and then aspirate 20 μL to spread on a 90 mm diameter culture dish, and culture in a constant temperature box 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 onto the surface of the titanium dioxide-molybdenum disulfide ultrasonically 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 ultrasonically triggered antibacterial coating was monitored by infrared temperature measurement, and it was found that the temperature of the bacterial culture solution increased with the ultrasonic treatment, and the temperature of the bacterial culture solution increased to 50°C at the 5th minute of the ultrasonic treatment). The culture solution was used to dilute the Staphylococcus aureus concentration on the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating to 2.5*10 5 CFU / mL, and then aspirate 20 μL to spread on a 90 mm diameter culture dish, and culture in a constant temperature box at 37 ° C for 24 hours.

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

[0054] The power density of the ultrasound is 1.5W / 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 ultrasound triggering.

[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%, where 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 ultrasonically tested 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 ultrasonic 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 about by the titanium dioxide-molybdenum disulfide ultrasonically triggered antibacterial coating of the present invention may be due to the reactive oxygen species it produces causing damage to cell membrane lipids, enhancing membrane permeability and causing leakage of intracellular substances, breaking DNA bonds and destroying gene expression, triggering functional protein inactivation, etc., ultimately leading to the 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 adhered to its surface, helping reactive oxygen species to enter the cell body.

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

[0061] The above is an exemplary description of the present invention. 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 other skilled in the art without expending creative labor falls within the scope of protection 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 at 10 to 50 V for 5 to 60 minutes 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, and the electrolyte is a mixture of a non-conductive solvent, water, and a fluorine-containing compound, wherein 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 the water is 100: (0.1 to 1.5): (0.1 to 3) by mass; Step 2: In a nitrogen or inert gas atmosphere, heat the titanium sheet loaded with titanium dioxide nanotubes at 400-500° C. for 0.5-1 hour, and cool 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 activity is triggered by ultrasound.

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