Preparation method and application of photothermal-catalytic antibacterial composite nanomaterial

Abstract

The invention belongs to the technical field of nano materials, and particularly relates to a preparation method of a photo-thermal-catalytic antibacterial titanium alloy implant as well as a product and application of the photo-thermal-catalytic antibacterial titanium alloy implant. According to the present invention, the method for the hydrothermal synthesis of the MoS2 nano-material through the sodium molybdate dehydrate and the thiourea is found, the MoS2 nano-material prepared through the method has good photothermal conversion ability, and the photothermal conversion efficiency of the flower-like MoS2 nano-material is the highest; and the flower-like morphology is introduced to a titanium alloy bracket for growth, so that the photo-thermal-catalytic antibacterial nano material (Ti-MoS2) is obtained. Ti-MoS2 is not only a good photothermal conversion material, but also can be used as a medical implant; and the titanium alloy stent can also be used as catalase to catalyze H2O2 to generate. OH, so that the titanium alloy stent has the synergistic antibacterial performance of a photo-thermal therapy (PTT) and a chemical dynamic therapy (CDT).

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomaterials, and particularly relates to a preparation method, a product and an application of a photothermal-catalytic antibacterial titanium alloy nano-implant. Background Art

[0002] With the improvement of medical technology, biomedical materials are widely used in surgical operations. With the increasing number of diseases such as trauma, osteoporosis, and osteoarticular diseases, the demand for orthopedic implants and related medical devices is increasing day by day. As the most widely used implant material in the biomedical field, about 10% will fail 10 years or even 20 years in advance. However, one of the main factors leading to the failure of biomaterial implants is bacterial infection of biomaterials (Neoh K G, Hu X, Zheng D. et al. Balancing osteoblast functions and bacterial adhesion on functionalized titanium surfaces [J]. Biomaterials, 2012, 33(10): 2813-2822. Tarazi JM, Chen Z, Scuderi GR, Mont MA. The Epidemiology of Revision Total Knee Arthroplasty. J Knee Surg. 2021 Nov; 34(13): 1396-1401. doi: 10.1055 / s-0041-1735282. Epub 2021 Sep 10. PMID: 34507367.). Bacteria attach to the implant and form a multicellular community called a biofilm. This special bacterial biofilm structure significantly increases the drug resistance of bacteria to antibiotics and even enhances their resistance to the host immune system, making it difficult to completely eliminate the related biofilm infections caused by bacterial infections on the implant. During the course of traditional antibiotics, the biofilm will prevent the penetration of antibacterial agents and escape the attack of the host immune system, and induce the inactivation of antibiotics, enhance quorum sensing, and increase the activity of bacterial efflux pumps through enzymatic and chelation reactions. Even after several cycles of treatment, recurrent tolerance symptoms usually occur, accompanied by a high mortality rate. The drug resistance of bacteria encapsulated by the biofilm is 10-1000 times that of ordinary bacteria, and the presence of the biofilm is the root cause of persistent infections. Thus, implant-related infections are still one of the main reasons for the failure of related surgeries. Therefore, selecting a suitable implant and enhancing the surface antibacterial property of the implant are the problems that need to be solved currently.

[0003] Due to their high mechanical strength and excellent fatigue resistance, metallic materials are currently the most widely used load-bearing implants in clinical practice. Among them, compared with stainless steel and cobalt-chromium alloy materials, medical titanium alloy materials are widely used in clinical medicine, such as dentistry and bone transplantation, because of their high strength, low elastic modulus, good fatigue performance, and density closest to human bone. However, as an implant material, titanium has problems such as poor wear resistance, biocompatibility, and susceptibility to contamination (Gahlert M, Roehling S. Peri-implantitis and ceramic implants: first clinical observations[J]. Implantologie, 2015, 23(3): 305-310. B, Terheyden H, Y, Purcz NM, Hertrampf K, Tabakov A, Behrens E, Wiltfang J. A comparison of biocompatibility and osseointegration of ceramic and titanium implants: an in vivo and in vitro study. Int J Oral Maxillofac Surg. 2012 May; 41(5): 638-45. doi: 10.1016 / j.ijom.2012.02.004. Epub 2012 Mar 8. PMID: 22406235.), the bacterial infections and biocompatibility problems caused by medical titanium alloy implants and the like pose huge challenges to long-term and widespread clinical applications. Therefore, it is necessary to perform surface modification and sterilization treatment on titanium implants before implantation into the human body. Common modification methods include composite coatings, mechanical modification, ultrafast laser surface modification, chemical modification methods, etc. By changing the properties of the surface of titanium alloy implants, the reaction between planktonic microorganisms or bacteria in the surrounding environment and the implant surface is prevented, thereby blocking the initial stage of biofilm formation and preventing the formation of biofilms, achieving the antibacterial effect on the surface of titanium implants. At present, the surface modification and sterilization of titanium implants are implemented asynchronously, and most sterilization methods have certain deficiencies, such as destroying the surface structure of the implant, causing carbon pollution, and reducing bone bonding. In addition, the human body will have a certain corrosive effect on the implant. If not handled properly, metal ions will diffuse into human tissues, which may cause serious bone resorption and lead to implant failure. Selecting appropriate nanomaterials for surface modification of titanium implants is particularly crucial.

[0004] Studies have shown that nano antibacterial materials, as new antibacterial tools, can reduce adverse effects such as bacterial drug resistance after antibiotic treatment. Among them, photothermal therapy (PTT) and chemodynamic therapy (CDT) are widely used as alternative therapies to antibiotics. Molybdenum disulfide belongs to transition metal dichalcogenides and is composed of vertically stacked hexagonal flakes, similar to graphite. MoS with different shapes and sizes 2 nanomaterials are widely used in fields such as energy storage, catalysis, electronic devices, and biomedical applications. MoS 2 nanospheres have a large specific surface area, can efficiently adsorb material molecules, and MoS 2 nanoparticles exhibit good biocompatibility and can be used as nano medical materials; MoS 2 nm spheres have strong light absorption ability in the near-infrared (NIR) region, can efficiently convert light energy into heat energy, and achieve antibacterial photothermal therapy. At the same time, MoS 2 nanosheets can inhibit the growth and ROS-independent oxidation of microorganisms by attaching a film. However, single photothermal therapy lacks targeting specificity, and the penetration depth of the excitation light is limited, resulting in limited catalytic antibacterial activity of molybdenum disulfide itself, and it is necessary to form a synergistic antibacterial strategy by compounding with other materials.

[0005] To prevent bacterial infection, one effective method is to improve the antibacterial activity of medical titanium alloy implants; at the same time, to increase the biocompatibility of titanium implants and promote bone tissue regeneration and repair, a composite material with good biocompatibility is introduced (Zhao L, Chu PK, Zhang Y, Wu Z. Antibacterial coatings on titanium implants. J Biomed Mater Res B Appl Biomater. 2009 Oct; 91(1): 470 - 80. doi: 10.1002 / jbm.b.31463. PMID: 19637369.). Therefore, constructing a functionalized coating based on titanium implants to improve the bactericidal effect of biomedical materials or enhance the anti-bacterial adhesion effect on the surface of biomaterials not only has high antibacterial activity against bacterial infection, but also increases the biocompatibility of the material, which is the key research direction for breakthroughs in implant antibacterial biomaterials. Aiming at the problem of bacterial invasion and infection on the surface of titanium alloy implants, and at the same time, the problem of limited antibacterial activity of MoS 2 nanomaterials in the medical field itself, therefore, it is urgent to construct a photothermal-catalytic antibacterial nanomaterial with MoS 2 attached to titanium alloy implants. Summary of the Invention

[0006] In order to overcome the problems existing in the above-mentioned prior art, the present invention discovers a method for hydrothermally synthesizing MoS from sodium molybdate dihydrate and thiourea2 Method for nanomaterials, and the obtained MoS 2 nanomaterials have good photothermal conversion ability, and the flower-shaped MoS 2 nanomaterials have the highest photothermal conversion efficiency; at the same time, applying the flower-shaped MoS 2 nanomaterials to titanium alloy scaffolds can achieve the synergistic antibacterial effect of photothermal-catalysis, and based on this, the present invention is completed.

[0007] In a first aspect, the present invention provides a kind of MoS 2 nanomaterials, and the MoS 2 nanomaterials are obtained by the following preparation method, and the preparation method includes the following steps:

[0008] S1. Dissolve a sulfur salt compound and a molybdenum salt compound in deionized water to obtain a pre-solution;

[0009] S2. Drop an acid solution into the pre-solution obtained in step S1 to adjust the pH value, and stir evenly with or without adding a solvent;

[0010] S3. Pour the solution obtained in S2 into a stainless steel Teflon-lined autoclave, and the autoclave reacts at a certain temperature for a period of time; after the autoclave cools naturally, centrifuge the generated solution, then wash it with water, and finally disperse it in deionized water to obtain MoS 2 nanomaterials;

[0011] Among them, according to the shape of the MoS 2 nanomaterials, a surfactant can be added or not added. When the shape of the MoS 2 nanomaterials is large spherical MoS 2 nanomaterials or microspherical MoS 2 nanomaterials, a surfactant needs to be added; when the shape of the MoS 2 nanomaterials is flower-shaped, then a surfactant does not need to be added.

[0012] Further, in the step S1, the sulfur salt compound is selected from one or more of thioacetamide, L-cysteine, (NH 4 ) 2 MoS 4 and thiourea, and preferably thiourea.

[0013] Further, in the step S1, the molybdenum salt compound is selected from one or more of ammonium molybdate, ammonium molybdate tetrahydrate, (NH 4 ) 2 MoO 4 、ammonium paramolybdate, MoCl 5 and sodium molybdate, and preferably sodium molybdate.

[0014] Further, the molar ratio of the sulfate compound to the molybdate compound in the step S1 is 4-25:0.1-4 mmol, preferably 5-20:1-2 mmol, more preferably 7.5-18:1.5 mmol.

[0015] Further, the volume of deionized water in the step S1 is 5-40 mL, preferably 25-36 mL.

[0016] Further, the pH range in the step S2 is 0.5-7.5, preferably 7.0.

[0017] Further, the surfactant in the step S2 is selected from polyvinylpyrrolidone (K30-PVP) and / or cetyltrimethylammonium bromide (CTAB), preferably polyvinylpyrrolidone (K30-PVP).

[0018] Further, the volume of the surfactant in the step S2 is 1-7.5 mmol, preferably 2.25 mmol-5 mmol.

[0019] Further, the method of stirring evenly in the step S2 includes stirring with a glass plate, stirring with a rotor and / or ultrasonicating with an ultrasonic instrument.

[0020] Further, the reaction temperature of the autoclave in the step S3 is 150-250 °C, preferably 150-200 °C.

[0021] Further, the reaction time of the autoclave in the step S3 is 12-96 h, preferably 12-24 h.

[0022] Further, the rotation speed of centrifugation in the step S4 is 8000-15000 rpm, preferably 8000-12000 rpm.

[0023] Further, the duration of centrifugation in the step S4 is 5-20 min, preferably 5-10 min.

[0024] Further, the MoS 2 nano-material is preferably flower-like MoS 2 nano-material.

[0025] Further, the average particle size of the flower-like MoS 2 nano-material is 50.0-210.0 nm, preferably 50.0-100.0 nm, preferably 50.0-150.0 nm, preferably 50.0-200.0 nm, preferably 100.0-200.0 nm, preferably 100.0-150.0 nm, preferably 120.0-140.0 nm.

[0026] Further, the flower-like MoS2 The average specific surface area of the nanomaterial is 15.0 - 25.0 m 2 / g, preferably 15.0 - 20.0 m 2 / g, preferably 20.0 - 25.0 m 2 / g.

[0027] In a second aspect, the present invention provides a photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ), which is a composite material with a flower-like MoS 2 nanomaterial wrapped around the outside of a titanium metal implant. The preparation method of the photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ) comprises the following steps:

[0028] M1. Add the raw materials for preparing the dispersion liquid of the flower-like MoS 2 nanomaterial to form a pre-liquid;

[0029] M2. Place the pre-liquid in step M1 and the cleaned titanium metal implant together in a stainless steel Teflon-lined autoclave, react in an oven, and after the reaction is completed, take out the titanium metal implant;

[0030] M3. Wash the titanium alloy stent obtained after the reaction in M2 with deionized water and absolute ethanol, and after drying, obtain the photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 -attached titanium alloy implant sample (Ti-MoS 2 ).

[0031] Furthermore, the pre-liquid in step M1 is obtained as described in the steps of the first aspect of the present invention.

[0032] Furthermore, the oven temperature in step M2 is 120 - 250 °C, preferably 120 - 200 °C.

[0033] Furthermore, the reaction time in the oven in step M2 is 1 - 48 h, preferably 9 - 24 h.

[0034] Furthermore, the titanium metal implant in step M2 is one or more of an artificial joint, a vascular stent, an orthodontic implant, and a heart valve.

[0035] Furthermore, the drying temperature in step M3 is 150 - 260 °C, preferably 150 - 200 °C.

[0036] Furthermore, the drying time in step M3 is 1 - 24 h, preferably 1 - 10 h.

[0037] Furthermore, the photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2) The excitation light is 525 - 880 nm, preferably 625 - 808 nm.

[0038] In a third aspect, the present invention provides an application of a photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ) in the preparation of medical implants.

[0039] Furthermore, the photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ) is the same as described in the second aspect of the present invention.

[0040] Furthermore, the medical implant includes one or more of artificial joints, vascular stents, dental implants, and heart valve implants.

[0041] Furthermore, the photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ) has the synergistic surface antibacterial performance of photothermal therapy (PTT) and chemodynamic therapy (CDT), and can reduce bacterial adhesion, resist bacterial infection, and promote the regeneration and repair of tissues.

[0042] In a fourth aspect, the present invention provides an application of a photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ) in the preparation of antibacterial materials.

[0043] Furthermore, the photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ) is the same as described in the second aspect of the present invention.

[0044] Furthermore, the photothermal-catalytic antibacterial nanomaterial (Ti-MoS 2 ) has the synergistic surface antibacterial performance of photothermal therapy (PTT) and photodynamic therapy (CDT), and can reduce bacterial adhesion, resist bacterial infection, and promote the regeneration and repair of tissues.

[0045] Furthermore, the antibacterial material is a material that inhibits bacterial growth.

[0046] Furthermore, the bacteria include autotrophic bacteria and heterotrophic bacteria;

[0047] Even further, the inhibited bacteria include Gram-negative bacteria and Gram-positive bacteria;

[0048] Even further, the inhibited bacterial morphologies include cocci, bacilli, and spirilla;

[0049] Even further, the inhibited bacteria include Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter, Mycobacterium tuberculosis, Helicobacter pylori, Vibrio cholerae, Candida albicans, Streptococcus mutans, Actinomyces, Pseudomonas aeruginosa, Salmonella typhi, Mycobacterium, and Bacillus subtilis, etc.

[0050] Beneficial effects

[0051] In view of the disadvantages that the surface of titanium alloy implants is easily invaded by bacteria, which increases the tolerance symptoms, psychological burden and cost burden of patients, flower-like MoS 2 is selected as the antibacterial nanomaterial for in-situ growth on the surface of titanium alloy scaffolds, enabling the titanium alloy scaffolds to have the synergistic antibacterial properties of PTT and CDT. First, sodium molybdate dihydrate and thiourea are hydrothermally synthesized into MoS 2 nanoparticles, and the flower-like MoS 2 nanomaterials are determined to be the best morphology, and this flower-like morphology is extended to grow on the titanium alloy scaffold to obtain Ti-MoS 2 . Ti-MoS 2 has good photothermal effect and photothermal conversion efficiency under the excitation of 808 nm near-infrared light. Among them, the photothermal effect can heat up to 70.0 °C, and the photothermal conversion efficiency can reach 18.6%. In the antibacterial test, the sterilization effect is 78.95%. Therefore, Ti-MoS 2 is not only a good photothermal conversion material and can be used as a medical implant; it can also act as a peroxidase-like enzyme to catalyze H 2 O 2 to generate ·OH, enabling the titanium alloy scaffold to have the synergistic antibacterial properties of PTT and CDT. Brief description of the drawings

[0052] Figure 1 SEM and TEM characterization morphologies of large spherical MoS 2 , microspherical MoS 2 and flower-like MoS 2 .

[0053] Note: a.b are SEM images of large spherical MoS 2 at different magnifications (2 μm and 1 μm), c is the TEM image (500 nm) of large spherical MoS 2 ; d.e are SEM images of microspherical MoS 2 at different magnifications (1 μm and 500 nm), f is the TEM image (500 nm) of microspherical MoS 2 ; g.h are SEM images of flower-like MoS 2 at different magnifications (2 μm and 500 nm), i is the TEM image (200 nm) of flower-like MoS 2 .

[0054] Figure 2 XRD diffraction patterns and particle size analysis of three different morphologies of MoS 2 nanomaterials.

[0055] Figure 3Optical absorption curves and photothermal effects of three different morphologies of MoS 2

[0056] Figure 4 Specific surface areas of three groups of MoS with different morphologies 2

[0057] Figure 5 Bacterial plate coating results of MoS with different morphologies 2

[0058] Figure 6 SEM characterization of titanium alloy scaffolds before / after growing flower-like MoS 2

[0059] Note: a is the SEM visual characterization of the titanium alloy scaffold before growing flower-like MoS 2 , b, c, and d are SEM images of 1 mm, 3 μm, and 1 μm respectively; e is the SEM visual characterization of the titanium alloy scaffold after growing flower-like MoS 2 on the surface, and f, g, and h are SEM images of 1 mm, 3 μm, and 1 μm respectively.

[0060] Figure 7 Photothermal effects of Ti-MoS under wet and dry conditions 2

[0061] Figure 8 Absorbance values of the catalytic MB reaction solution varying with time and absorbance values of the solution after 70 minutes of the catalytic MB solution reaction in different experimental groups for Ti-MoS 2

[0062] Figure 9 Comparison of bactericidal effects between Ti and Ti-MoS experimental groups under different conditions 2 Specific implementation manners

[0063] The following further describes the specific implementation manners of the present invention. It should be noted here that the description of these implementation manners is for helping to understand the present invention, but does not constitute a limitation to the present invention. In addition, the technical features involved in the following described implementation manners can be combined with each other as long as they do not conflict with each other.

[0064] The experimental methods in the following examples are all conventional methods unless otherwise specified, and the test materials used in the following examples are all commercially available through conventional channels unless otherwise specified.

[0065] Term

[0066] ​​​​​​​Chemical antibacterial action: It can be divided into photocatalytic antibacterial and metal ion dissolution antibacterial, etc. Photocatalytic antibacterial refers to that under the catalytic action of light, antibacterial materials generate reactive oxygen species or reactive holes to inhibit or even kill the growth and reproduction of bacteria. Metal ion dissolution antibacterial refers to that antibacterial materials dissolve out metal ions to produce toxicity and maintain a high bactericidal concentration in the surrounding environment to destroy the metabolic activities of bacteria.

[0067] Physical antibacterial action: Utilize the self-structure of antibacterial materials to achieve antibacterial by restricting the growth behavior of bacteria and destroying the integrity of the bacterial cell membrane.

[0068] Photothermal therapy (PTT): As a treatment mode that converts the energy of near-infrared light (NIR) into local high temperature, it kills MDR bacteria through the irreversible oxidation of the phospholipid layer of the bacterial cell membrane, the destruction of the cell membrane structure, protein denaturation, and cytoplasmic pyknosis, and does not cause drug resistance.

[0069] Photodynamic therapy (CDT): Combine a photosensitizer with oxygen, and under appropriate excitation light, attack bacteria through the generated reactive oxygen species (ROS) without generating drug resistance.

[0070] Chemodynamic therapy (CDT): An emerging cancer treatment strategy that uses CDT drugs to convert hydrogen peroxide (H2O2) into the most harmful reactive oxygen species (ROS) hydroxyl radicals (OH) through Fenton / Fenton-like reactions, thereby inducing apoptosis and necrosis.

[0071] Example 1 Preparation of MoS with different morphologies by hydrothermal method 2 Nanomaterial dispersion

[0072] 1.1 Large spherical MoS 2 Preparation process of nanomaterial dispersion

[0073] Add raw materials to obtain a pre-liquid: Add 7.5 mmol CS(NH 2 ) 2 (thiourea, molecular weight 76.12, 570 mg) and 1.5 mmol Na 2 MoO 4 ·2H 2 O (sodium molybdate, molecular weight 242, 363 mg) to 25 mL of deionized water, add 215 μL of 36% concentrated hydrochloric acid to adjust the pH value of the solution, and then add 5 mmol of polyvinylpyrrolidone (K30-PVP) (molecular weight 58000, 300 mg) to the system. After stirring at room temperature for 30 min, obtain the pre-liquid;

[0074] Reaction: Pour the solution into a 50 mL stainless steel Teflon-lined autoclave, and the autoclave reacts at 200 °C for 24 h;

[0075] Washing material: After the reaction kettle is naturally cooled, the generated solution is centrifuged at a speed of more than 12,000 for 10 min, washed with water 1-2 times, and finally dispersed in 5 mL of deionized water to obtain large spherical MoS 2 nanomaterial dispersion.

[0076] 1.2 Preparation process of microspherical MoS2 nanomaterial dispersion

[0077] Adding raw materials to obtain the pre-liquid: Add 7.5 mmol of CS(NH 2 ) 2 (thiourea, molecular weight 76.12 g / mol, 570 mg) and 1.5 mmol of Na 2 MoO 4 ·2H 2 O (sodium molybdate, molecular weight 242, 363 mg), add 215 μL of 36% concentrated hydrochloric acid to adjust the pH value of the solution, and then add 2.25 mmol of K30-PVP (molecular weight 58,000, 0.1305 g) to the system and stir at room temperature for 30 min to obtain the pre-liquid;

[0078] Reaction: Pour the solution into a 50 mL stainless steel Teflon-lined autoclave, and the autoclave reacts at 200 °C for 24 h;

[0079] Washing material: After the autoclave is naturally cooled, the generated solution is centrifuged at a speed of more than 12,000 for 10 min and washed with water 1-2 times, and finally dispersed in 5 mL of deionized water to obtain microspherical MoS 2 nanomaterial dispersion.

[0080] 1.3 Preparation process of flower-like MoS 2 nanomaterial dispersion (7.5 mmol thiourea)

[0081] Adding raw materials to obtain the pre-liquid: Add 7.5 mmol of CS(NH 2 ) 2 (thiourea, molecular weight 76.12 g / mol, 570 mg) and 1.5 mmol of Na 2 MoO 4 ·2H 2 O (sodium molybdate, molecular weight 242 g / mol, 363 mg), add 600 μL of 36% concentrated hydrochloric acid to adjust the pH value of the solution, and stir at room temperature for 30 min to obtain the pre-liquid;

[0082] Reaction: Pour the pre-liquid into a 50 mL stainless steel Teflon-lined autoclave, and the autoclave reacts at 200 °C for 24 h;

[0083] Washing material: After the autoclave is naturally cooled, the resulting solution is centrifuged at a speed of more than 12,000 rpm for 10 min, washed with water 1-2 times, and finally dispersed in 5 mL of deionized water to obtain a flower-shaped MoS 2 nanomaterial dispersion.

[0084] 1.4 Flower-shaped MoS 2 Preparation process of nanomaterial dispersion (18 mmol thiourea)

[0085] Adding raw materials to obtain a pre-solution: Add 18 mmol of CS(NH 2 ) 2 (thiourea, molecular weight 76.12 g / mol, 570 mg) and 1.5 mmol of Na 2 MoO 4 ·2H 2 O (sodium molybdate, molecular weight 242 g / mol, 363 mg) to 30 mL of deionized water, add 36% concentrated hydrochloric acid to adjust the pH value of the solution to 7.0, and ultrasonicate in an ultrasonic cleaner for 1 h to obtain a pre-solution;

[0086] Reaction: Pour the solution into a 50 mL stainless steel Teflon-lined autoclave and react at 200 °C for 24 h;

[0087] Washing material: After the autoclave is naturally cooled, the resulting solution is centrifuged at a speed of more than 12,000 rpm for 10 min, washed with water 1-2 times, and finally dispersed in 5 mL of deionized water to obtain a flower-shaped MoS 2 nanomaterial dispersion.

[0088] Example 2 Comparison of physicochemical parameters of MoS 2 nanomaterials with different morphologies

[0089] 2.1 Measurement of particle size and length

[0090] 2.1.1 Instruments

[0091] Take pictures with a scanning microscope (HITACHI, S-4800, Japan) and a transmission microscope (JEM-1200EX, JEOL, Japan), and use Image J software to count the particle size.

[0092] 2.1.1 Steps

[0093] (1) Dilute the sample solution in Example 1 to an appropriate concentration, make it evenly distributed by ultrasonication, drop 100 μL of the sample solution on a silicon wafer, let it stand at room temperature and dry, and test the scanning electron microscope;

[0094] (2) Dilute the sample solution in Example 1 to an appropriate concentration, make it evenly distributed by ultrasonic treatment, drop 10 μL of the sample solution on a copper grid, leave it to dry at room temperature, and test the transmission electron microscope;

[0095] (3) Use Image J software to statistically analyze the particle sizes in the scanning electron microscope images and transmission electron microscope images.

[0096] 2.2 Specific surface area measurement

[0097] 2.2.1 Instruments

[0098] Full-automatic specific surface area and porosity analyzer BET (Micromeritics TriStar II 3flex)

[0099] 2.2.2 Procedures (1) Centrifuge the sample solution in Example 1 (12000 r / min, 10 min), remove the upper solution to obtain the precipitate; (2) Place the precipitate in an oven (80 °C) for 24 h;

[0100] (3) Collect the dried molybdenum sulfide powder and crush the powder;

[0101] (4) Weigh 100 mg of the sample amount, put it into the full-automatic specific surface area and porosity analyzer BET for testing, and obtain the specific surface area value of the sample.

[0102] 2.3 Photothermal effect measurement

[0103] 2.3.1 Instruments

[0104] Infrared thermal imager (TiS65, Fluke, USA).

[0105] 2.3.2 Procedures

[0106] (1) Prepare three aqueous solutions of MoS with different morphologies at concentrations of 1 mg / mL, 0.5 mg / mL, and 0.25 mg / mL (the preparation procedures are as described in Example 1, and ultrasonic oscillation the solution before use to make it evenly dispersed); 2 aqueous solution for standby (preparation

[0107] (2) Use a pipette to accurately measure 500 μL of the MoS

[0108] (2) Use a pipette to accurately measure 500 μL of the MoS 2 aqueous solution into the round holes of a 48-well cell culture plate;

[0109] (3) Set an 808 nm laser source with 1 W / cm 2 to vertically irradiate the round holes of the cell culture plate filled with the spherical MoS 2 aqueous solution;

[0110] (4) Record the initial temperature of the temperature rise with an infrared thermal imager, and record the temperature of the aqueous solution every 30 s until the laser source is immediately removed after 6 min of temperature rise, and then record the temperature of the aqueous solution every 30 s until the temperature drops for 6 min. This process can be repeated;

[0111] (5) According to the steps in (3) and (4), replace the aqueous solution of MoS 2 nanomaterials with different morphologies with the same volume of deionized water or aqueous solutions of spherical MoS 2 nanomaterials with other concentrations, and perform the same temperature rise and fall recordings;

[0112] (6) Import the recorded data into the mapping software Origin, plot the temperature rise and fall curves of the aqueous solutions of MoS 2 nanomaterials with different morphologies, and perform corresponding linear fittings to obtain the linear slope to facilitate the calculation of the photothermal conversion efficiency of MoS 2 nanomaterials with different morphologies;

[0113] (7) The calculation steps of the photothermal conversion efficiency (η) are as follows: Calculate the value of η according to equation (1):

[0114]

[0115] Among them, h A is the heat transfer coefficient, ΔTmax,mix is the maximum temperature difference of the MoS 2 aqueous solution, is the maximum temperature difference of water under the same external environment, I is the laser power of the 808 nm laser is 1 W / cm 2 , A is the absorbance of MoS 2 at 808 nm, which can be obtained through light absorption tests at the same concentration.

[0116] In the formula, the value of h A can be calculated by equation (2):

[0117]

[0118] Among them, t / lnθ is the slope of the linear fitting curve, is the mass of deionized water used in the experiment, is the constant 4.2×10 3 J / kg·℃.

[0119] 2.4 Test results

[0120] The average particle size of the flower-like MoS 2 nanomaterials is 136.6 nm; compared with the large spherical MoS 2 nanomaterials and micro-spherical MoS 2Specific surface area of nanomaterials, flower-like MoS 2 The nanomaterials have the largest average specific surface area, with a specific surface area of 19.5 m 2 / g, which increases the contact area of the materials in this morphology. The flower-like MoS 2 nanomaterials can be heated to 70.0 °C under light source excitation, and the average light conversion efficiency reaches 18.6% (Table 1). From the above results, it can be seen that the MoS 2 nanomaterials have good photothermal conversion ability, and the flower-like MoS 2 nanomaterials have the highest photothermal conversion efficiency.

[0121] Table 1 Comparison of physical parameters of MoS 2 nanomaterials with different morphologies

[0122]

[0123] 2.5 Antibacterial effect

[0124] As Figure 5 shown, for the bacterial plate coating of MoS 2 nanomaterials with different morphologies, compared with the antibacterial effects of large spherical MoS 2 nanomaterials and microspherical MoS 2 nanomaterials, the flower-like MoS 2 nanomaterials have the best antibacterial effect and are the best morphology in this antibacterial test. Therefore, the flower-like shape is selected as the best morphology for the MoS 2 nanomaterial coating attached to the titanium metal implant.

[0125] Example 3 Preparation of titanium alloy stent (Ti-MoS 2 ) with flower-like MoS 2 nanomaterials grown on the surface

[0126] The preparation steps of the titanium alloy stent (Ti-MoS 2 ) with flower-like MoS 2 nanomaterials grown on the surface are as follows:

[0127] W1 As described in Example 1.4, prepare the precursor solution of flower-like MoS 2 nanomaterials;

[0128] W2 Place the precursor solution of flower-like MoS 2 nanomaterials obtained in W1 and the cleaned titanium alloy stent in a 50 mL stainless steel Teflon-lined autoclave;

[0129] W3 Place the autoclave in an oven at 200 °C and react for 9 h;

[0130] After the W4 reaction ended, the reaction kettle was allowed to cool naturally. The titanium alloy stent was taken out of the reaction kettle and washed with deionized water and absolute ethanol.

[0131] W5 Subsequently, it was dried at 80 °C for 8 h to obtain a titanium alloy stent (Ti-MoS 2 with flower-like MoS 2 ) nanomaterial grown on its surface.

[0132] Example 4 Photothermal effect of flower-like MoS 2 nanomaterial titanium alloy stent (Ti-MoS 2 )

[0133] "Wet test": Immerse Ti-MoS 2 in water and irradiate it with an 808 nm laser to test its photothermal effect.

[0134] "Dry test": Place Ti-MoS 2 in air and irradiate it with an 808 nm laser to test its photothermal effect.

[0135] 4.1 Instruments

[0136] Infrared thermal imager (TiS65, Fluke, USA)

[0137] 4.2 Wet test procedure:

[0138] 1) Put Ti-MoS 2 into a 24-well plate and add 0.5 mL of water;

[0139] 2) Set an 808 nm laser source with 1 W / cm 2 to vertically irradiate the round hole of the 24-well plate containing the immersed Ti-MoS 2 ;

[0140] 3) Use the infrared thermal imager to record the starting temperature of the temperature rise and record the temperature of the aqueous solution every 30 s until 6 min after the temperature rise, then immediately remove the laser source, and then record the temperature of the aqueous solution every 30 s until 6 min after the temperature drop. This process can be repeated;

[0141] 4) Import the recorded data into the graphing software Origin to plot the heating and cooling curves of the Ti-MoS 2 aqueous solution.

[0142] 4.3 Dry test procedure:

[0143] (1) Place Ti-MoS 2 in air;

[0144] (2) Set 1 W / cm 2808nm laser source, making it vertically irradiate Ti-MoS 2 ;

[0145] (3) Use an infrared thermal imager to record the starting temperature of the temperature rise and record the temperature of Ti-MoS 2 every 30 s until the laser source is immediately removed after 6 min of temperature rise, and then record the temperature of the aqueous solution every 30 s until the temperature drops for 6 min. This process can be repeated;

[0146] (4) Import the recorded data into the mapping software Origin to plot the heating and cooling curves of Ti-MoS 2 .

[0147] 4.4 Test results

[0148] Under the "wet measurement" condition, compared with the control group, the temperature of the titanium stent without grown MoS 2 (marked as Ti) slightly increased under 808nm laser irradiation, and the temperature increase effect of Ti-MoS 2 was very obvious under 808nm laser irradiation. After 4 min of laser irradiation, the temperature of Ti-MoS 2 could rise to 46 °C. Under the "dry measurement" condition, similar results were also obtained. The temperature rise of the control group Ti was not obvious under laser irradiation, while the temperature rise effect of Ti-MoS 2 was very significant and could reach 100 °C. It should be noted that when "wet measurement", the sample was immersed in water. Due to the large specific heat capacity of water, the temperature rise effect was less than that under the "dry measurement" condition (Table 2).

[0149] Table 2 Comparison of photothermal effects between wet measurement and dry measurement of Ti-MoS 2

[0150] Wet measurement Dry measurement PBS 28℃ 28℃ Ti 34℃ 38℃ <![CDATA[Ti-MoS 2 > 46℃ 100℃

[0151] Example 5 Catalytic effect of flower-like MoS 2 nanomaterial titanium alloy stent (Ti-MoS 2 )

[0152] 5.1 Instruments

[0153] Lambda 950 UV-Vis spectrophotometer of Perkin-Elmer Company, USA 5.2 Procedures:

[0154] 1) Prepare a methylene blue (MB) solution with a concentration of 5 ppm (10 mg / L) (10 mg / L) and a 1 mM hydrogen peroxide solution;

[0155] 2) Set different test groups, which are respectively recorded as: MB group (Group 1), MB + H​2 O 2 Group (2 groups), MB + Ti group (3 groups), MB + Ti - MoS 2 Group (4 groups), MB + H 2 O 2 + Ti - MoS 2 Group (5 groups) and MB + H 2 O 2 + Ti - MoS 2 + 808nm group (6 groups), and the specific component settings are shown in Table 3;

[0156] 3) After configuring different test groups, let them stand for 70 min, and then measure the absorption values of different groups in the wavelength range of 300 nm - 900 nm by ultraviolet - visible spectroscopy.

[0157] Table 3 Verification of the catalytic performance of Ti - MoS 2 Grouping of catalytic performance experiments

[0158]

[0159] Among them, by comparing Group 1 and Group 2, verify whether the H 2 O 2 solution has the property of self - decomposing to produce reactive oxygen species; by comparing Group 1 with Groups 3 and 4, verify whether Ti and Ti - MoS 2 have an adsorption phenomenon on MB, resulting in an accidental decrease in the concentration of the MB solution; by comparing Group 1 and Group 4, verify whether Ti has the property of catalase - like; by comparing Group 2 and Group 5, verify whether Ti - MoS 2 has the property of catalase - like; by comparing Group 5 and Group 6, verify whether the photothermal effect of Ti - MoS 2 and its catalytic effect as a catalase - like have a synergistic effect.

[0160] 5.3 Test results

[0161] Adding H 2 O 2 to the MB solution did not affect the absorption curve of MB, indicating that the H 2 O 2 solution does not decompose itself to produce ·OH; when Ti or Ti - MoS 2 is added to the MB solution, the absorption value of the solution decreases slightly. It is speculated that during the experiment, Ti and Ti - MoS 2 have a small amount of adsorption effect on MB, resulting in a slight decrease in the concentration of the MB solution; when both Ti - MoS 2 and H 2 O 2 exist in the MB solution, the absorption value of the solution drops significantly, indicating that Ti - MoS 2It can effectively catalyze H 2 O 2 , and the generated ·OH causes the solution to promote the degradation of MB. From the above experimental results, it can be seen that MoS grown on the surface of the Ti scaffold 2 has the catalytic effect of mimicking catalase and can effectively catalyze H 2 O 2 to generate ·OH. MoS 2 has good photothermal conversion ability. Under the irradiation of 808 nm near-infrared light, it can convert light into heat, and this good photothermal effect can promote the generation of ·OH. Therefore, the irradiation of 808 nm laser can significantly promote the effect of mimicking catalase of Ti-MoS 2 and achieve more efficient degradation of MB.

[0162] Example 6 Antibacterial effect of flower-like MoS 2 nanomaterial titanium alloy scaffold (Ti-MoS 2 )

[0163] 6.1 Test samples

[0164] Bacteria: Mycobacterium smegmatis (M.smeg)

[0165] 6.2 Test steps:

[0166] (1) Preparation of 7H9 broth (1 L liquid medium):

[0167] Weigh 4.7 g of 7H9 medium, dissolve it in 900 mL of deionized water, add 2 mL of glycerol, 2.5 mL of Tween 80, and autoclave at 121 °C for 8 min. After cooling, store it in a 4 °C refrigerator for later use. When using, take it out and equilibrate to room temperature, and add OADC enrichment broth at a ratio of 10:1 (to prevent contamination, OADC is prepared and used immediately).

[0168] (2) Preparation of 7H11 agar plate (1 L solid medium):

[0169] Weigh 21 g of 7H11 medium, dissolve it in 900 mL of deionized water, add 5 mL of glycerol, 1 g L-1 asparagine, and autoclave at 121 °C for 8 min. Take out the medium and place it in a 56 °C water bath for at least 30 min; after the medium has been in the water bath for at least 30 min, then place the OADC equilibrated to room temperature in a 56 °C water bath for 5 min. Subsequently, take 100 min of OADC and add it to the medium, mix well and pour into plates. Each grid in the four-grid contains 4.5 mL. Place it in a ventilated sterile workbench for 4 h, put it in a bag and place it in a 37 °C incubator and let it stand overnight. After detecting no contamination, place it in a safety cabinet and equilibrate to room temperature, then seal the petri dish and place it upside down in a 4 °C refrigerator for storage and later use.

[0170] (3) Bacterial culture:

[0171] Take the preserved Mycobacterium smegmatis strain and inoculate it into 7H9 + OADC liquid medium at a ratio of 1:100. Incubate it in a constant temperature incubator at 37°C and shake it in a shaker at 110 rpm / min. After overnight incubation, measure the culture by a spectrophotometer. When the optical density (OD) at 600 ≈ 0.6, subculture it at a ratio of 1:100. When the OD600 of the second-generation bacteria after resuscitation is ≈ 0.6, the subsequent bactericidal activity detection experiment can be carried out. At the same time, directly add 20% sterile glycerol during the culture, aliquot it into cryotubes for cell storage, and store it at -80°C.

[0172] (4) Experimental group parameter configuration:

[0173] To verify the photothermal performance and catalytic performance of Ti-MoS 2 before testing, sterilize Ti-MoS 2 and the untreated titanium alloy stent at 121°C under high temperature and high pressure. Set different experimental groups for the experiment, and set three replicate experiments for each group. Among them, the concentration of the H 2 O 2 solution used is 2 mM. Before testing, irradiate Ti-MoS 2 and the untreated titanium alloy stent with ultraviolet light for 30 min to achieve the purpose of sterilization.

[0174] (5) Grouping:

[0175] PBS group (control), PBS + H 2 O 2 group, PBS + 808 nm group, Ti group, Ti + 808 nm group, Ti + H 2 O 2 nm group, Ti-MoS 2 group, Ti-MoS 2 + H 2 O 2 group, Ti-MoS 2 + 808 nm group and Ti-MoS 2 + H 2 O 2 + 808 nm group.

[0176] (6) Coating the plate:

[0177] Place the samples of different experimental groups in a 12-well cell culture plate, and drop 1 ml of Mycobacterium smegmatis in the logarithmic growth phase on the surface of the samples, and add PBS solution (control group) and an equal volume of H 2 O 2Solution treatment (final concentration 2 mM). Meanwhile, for the laser treatment group, 808 nm near-infrared laser will be used, and the near-infrared laser with a power density of 1 W / cm 2 will be irradiated for 20 min. After the irradiation is completed, the 12-well plate will be incubated in a 37 °C constant temperature incubator for 6 h and 24 h. Finally, the antibacterial results of Ti-MoS 2 will be determined using the plate coating method.

[0178] (7) Observation and counting:

[0179] After incubating in the constant temperature incubator for 6 h, use a pipette to slowly elute the Mycobacterium smegmatis adhering to the sample surface and mix well. Take 50 μL of the bacterial solution (the remaining bacterial solution is stored frozen for later use) and add it to 450 μL of PBS solution for 10-fold dilution. Dilute it in a 10-fold ratio, with a total of 9 concentrations, respectively denoted as (0, 1, 2, 3, 4, 5, 6, 7, 8), and each concentration is 0.5 mL; respectively take 50 μL of the diluted bacterial solution and spread it on a petri dish for cultivation. After 2 - 3 days, observe and photograph the colonies growing on the surface of the culture medium. At the same time, calculate the antibacterial efficiency of different experimental groups according to the following formula: Antibacterial efficiency (%) = (number of bacterial colonies in the control group - number of bacterial colonies in the experimental group) / number of bacterial colonies in the control group × 100%.

[0180] 6.3 Test results

[0181] Compared with the PBS control group, the number of bacterial colonies in the four groups of PBS + H 2 O 2 , Ti + 808 nm, Ti + H 2 O 2 + 808 nm, Ti-MoS 2 is basically the same, indicating that the treatments of Ti, Ti-MoS 2 , 808 nm laser and H 2 O 2 do not have a significant impact on the number of viable bacteria. Under 808 nm laser irradiation, compared with the control group, the number of bacteria in the Ti-MoS 2 group is significantly reduced, and the antibacterial efficiency is 36.84%. This is mainly because the MoS 2 nm layer on the surface of the titanium alloy stent has a photothermal effect under 808 nm laser irradiation, and the high temperature generated kills some bacteria.

[0182] For the Ti-MoS 2 + H 2 O 2 group, due to the simultaneous presence of Ti-MoS 2 and H 2 O 2 in the bacterial solution, MoS 2 can catalyze H2 O 2 Generates a large amount of ·OH, which in turn kills bacteria. Therefore, Ti-MoS 2 +H 2 O 2 exhibits an obvious antibacterial effect, and the antibacterial efficiency reaches 73.68%. In particular, for the Ti-MoS 2 +H 2 O 2 +808 nm group, Ti-MoS 2 can simultaneously serve as a photothermal conversion material and a peroxidase-like enzyme, so it can achieve both photothermal sterilization and chemodynamic sterilization, and the antibacterial efficiency reaches 78.95%, which is the group with the highest antibacterial efficiency among all groups (Table 4). Therefore, by growing a molybdenum sulfide nm layer on the surface of the titanium alloy stent, it can effectively produce photothermal and chemodynamic effects and achieve effective combined antibacterial.

[0183] Table 4 Antibacterial effect tests of each experimental group under different conditions

[0184]

[0185]

Claims

1. A MoS2 nanomaterial, wherein the preparation method of the MoS2 nanomaterial comprises the following steps: S1. Dissolving the sulfur salt compound and the molybdenum salt compound in deionized water to obtain a pre-solution; S2. The acid solution is added dropwise to the pre-liquid obtained in step S1 to adjust the pH value, and the mixture is stirred evenly with or without adding a solvent; S3. The solution obtained in S2 is poured into a stainless steel Teflon-lined autoclave, and the autoclave is reacted at a certain temperature for a period of time; After the reactor is cooled naturally, the generated solution is centrifuged, then washed with water, and finally dispersed in deionized water to obtain MoS2 nanomaterials; Among them, depending on the shape of the MoS2 nanomaterial, a surfactant may be added or not. When the shape of the MoS2 nanomaterial is a large spherical MoS2 nanomaterial or a microspherical MoS2 nanomaterial, a surfactant needs to be added; when the shape of the MoS2 nanomaterial is a flower shape, no surfactant needs to be added.

2. The method for preparing MoS2 nanomaterials as claimed in claim 1, wherein in step S1, the sulfide salt compound is selected from one or more of thioacetamide, L-cysteine, (NH4)2MoS4 and thiourea, preferably thiourea; and the molybdenum salt compound is selected from one or more of ammonium molybdate, ammonium molybdate tetrahydrate, (NH4)2MoO4, ammonium paramolybdate, MoCl5 and sodium molybdate, preferably sodium molybdate.

3. According to the method for preparing MoS2 nanomaterials as described in claim 1, the molar ratio of the sulfur salt precursor and the molybdenum salt precursor in step S1 is 4-25:0.1-4 mmol, preferably 5-20:1-2 mmol, and more preferably 7.5-18:1.5 mmol.

4. The method for preparing MoS2 nanomaterials as claimed in claim 1, wherein in step S2, the surfactant is selected from polyvinyl pyrrolidone (K30-PVP) and / or hexadecyltrimethylammonium bromide (CTAB), preferably polyvinyl pyrrolidone (K30-PVP); the volume of the surfactant is 1 to 7.5 mol, preferably 2.25 mmol to 5 mmol.

5. The method for preparing MoS2 nanomaterials as claimed in claim 1, wherein the reaction temperature of the high-pressure reactor in step S3 is 150-250°C, preferably 150-200°C; and the reaction time of the high-pressure reactor is 12-96h, preferably 12-24h.

6. The MoS2 nanomaterial as claimed in claim 1 is preferably a flower-shaped MoS2 nanomaterial; the average particle size of the flower-shaped MoS2 nanomaterial is 50.0-210.0 nm, preferably 50.0-100.0 nm, preferably 50.0-150.0 nm, preferably 50.0-200.0 nm, preferably 100.0-200.0 nm, preferably 100.0-150.0 nm, preferably 120.0-140.0 nm; the average specific surface area of ​​the flower-shaped MoS2 nanomaterial is 15.0-25.0 m 2 / g, preferably 15.0 to 20.0 m 2 / g, preferably 20.0 to 25.0 m 2 / g.

7. A photothermal-catalytic antibacterial nanomaterial (Ti-MoS2), the composite material is a titanium metal implant wrapped with a flower-shaped MoS2 nanomaterial, and the preparation method of the photothermal-catalytic antibacterial nanomaterial (Ti-MoS2) comprises the following steps: M1. Add raw materials for preparing flower-shaped MoS2 nanomaterial dispersion to form a pre-liquid; the pre-liquid is obtained as described in claim 1; M2. Place the pre-fluid and the cleaned titanium implant in step M1 together in a stainless steel Teflon-lined autoclave and react in an oven. After the reaction is complete, remove the titanium implant; M3. The titanium alloy stent obtained after the reaction in M2 was washed with deionized water and anhydrous ethanol, and after drying, a photothermal-catalytic antibacterial nanomaterial (Ti-MoS2) sample with flower-like MoS2 attached to the titanium alloy implant was obtained.

8. The method for preparing photothermal-catalytic antibacterial nanomaterial (Ti-MoS2) as described in claim 7, wherein the oven temperature in step M2 is 120-250°C, preferably 200°C; the reaction time in the oven is 1-48h, preferably 9-24h.

9. Application of a photothermal-catalytic antibacterial nanomaterial (Ti-MoS2) in the preparation of medical implants; the medical implants include one or more of artificial joints, vascular stents, orthopedic implants and heart valve implants.

10. Application of a photothermal-catalytic antibacterial nanomaterial (Ti-MoS2) in the preparation of antibacterial materials; the photothermal-catalytic antibacterial nanomaterial (Ti-MoS2) has the synergistic surface antibacterial properties of photothermal therapy (PTT) and photodynamic therapy (CDT), which can reduce bacterial adhesion, resist bacterial infection and promote tissue regeneration and repair.

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