A nanorod array coating capable of ultrasonic-mediated antibacterial and having high osteointegration, and a preparation method and application thereof

Abstract

The present invention provides a nanorod arrayed coating capable of ultrasonic-mediated antibacterial action and having high osteointegration, and a preparation method and application thereof. First, a porous titanium dioxide coating containing phosphorus and calcium is prepared on the surface layer of titanium or its alloy by micro-arc oxidation, then a hydroxyapatite nanorod-configured coating is in-situ grown by a hydrothermal treatment method, and then a hydroxyapatite nanorod array coated with a poly-Mg-O amorphous film is prepared by a magnesium thermal reduction method, and finally a biomedical material with a nanorod arrayed coating capable of ultrasonic-mediated antibacterial action and having high osteointegration is obtained. The coating surface layer prepared by the present invention has dual functions of anti-infection and bone regeneration; at the initial stage of implantation, bacteria can be rapidly killed by ultrasound, and at the same time, an alkaline environment and various osteogenic ions are provided, improving the bone tissue healing and regeneration ability in the middle and late stages. It avoids the occurrence of implant failure caused by an adverse bone microenvironment, coating peeling induced by poor membrane / substrate binding force, and side reactions such as osteolysis or excessive inflammation induced by the coating peeling.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and particularly relates to a nanorod array coating capable of ultrasonic-mediated antibacterial and having high osteointegration, a preparation method thereof, and an application thereof. Background Art

[0002] Titanium and its alloys are widely used in the repair and replacement of hard tissues such as artificial bones, joints, and dental implants due to their good mechanical properties, corrosion resistance, and biocompatibility. However, titanium is biochemically inert. After implantation into the body, it is not easy to form a bone bond with tissues, and at the same time, it has no antibacterial property. During the implantation process, due to the invasion of bacteria, the implantation site will be infected, leading to the failure of the implant. These have become the main problems restricting the clinical application of titanium and its alloys. Among many methods for surface modification of titanium-based materials, hydroxyapatite (HA) coatings prepared by micro-arc oxidation and hydrothermal treatment have more advantages than other modified coatings. The HA coating has a high bone apatite induction ability, can significantly enhance the adhesion and proliferation of mesenchymal stem cells and osteoblasts. More importantly, its substrate TiO 2 can generate reactive oxide species (ROS, mainly including ·O 2- , ·OH, and H 2 O 2 ) under external stimulation to destroy the components of bacteria or viruses. Among them, ROS can be induced by external stimulation, such as ultraviolet, near-infrared, and ultrasonic waves. At the same time, it will slowly disappear after the stimulation ends. During this process, no loaded drug is released, avoiding cytotoxicity caused by improper drug release dose, thus effectively inhibiting bone tissue gangrene caused by bacterial infection.

[0003] In existing studies, ROS is mainly generated by TiO 2 through the following several methods. (1) Ultraviolet irradiation: ROS is generated by TiO 2 through ultraviolet irradiation. However, excessive ultraviolet rays will cause a series of damages to human functions, and ultraviolet light cannot penetrate deep into tissues, bringing difficulties to practical applications; (2) Near-infrared light (NIR) excitation: NIR causes less damage to human tissues. However, although the penetration depth of near-infrared light in the human body is slightly larger than that of ultraviolet light, it still cannot penetrate deep tissues, and higher heat will be generated during irradiation, burning the irradiated area; (3) Ultrasonic excitation: Compared with NIR, ultrasonic waves have a deeper penetration depth in the human body, no radiation, and high precision. ROS is only generated at the site where the photosensitizer exists, and it has no harm to surrounding tissues. Therefore, it can be safely used for in vivo antibacterial treatment. However, TiO 2Its wide bandgap and rapid electron-hole pair separation result in a low ROS yield under ultrasonic excitation and poor antibacterial effect, greatly reducing the activity of osteoblasts under extreme pathological conditions (such as infectious osteoporotic fractures), and the treatment effect is not good.

[0004] Therefore, there is an urgent need for an intraosseous implant that combines anti-infection and bone regeneration to rapidly kill bacteria in the early stage of implantation and promote bone formation in the long term to achieve high bone integration in such pathological conditions. Summary of the Invention

[0005] The purpose of the present invention is to provide a nanorod arrayed coating that can be ultrasonically mediated for antibacterial and has high bone integration, as well as its preparation method and application, aiming at infectious fractures under osteoporotic conditions, to overcome the problems such as low antibacterial rate of TiO 2 under ultrasound and insufficient bone-forming ability of HA. The process of the present invention is stable and highly controllable; the prepared bioactive coating has dual functions of anti-infection and bone regeneration; moreover, as an implant, it can efficiently kill bacteria in the initial stage of implantation, inhibit bacteria in the middle and late stages of implantation, and promote bone tissue healing and regeneration, avoiding the sharp decline of osteoblast activity caused by infection, the expansion of the infection focus, and local tissue necrosis.

[0006] The present invention is realized through the following technical solutions:

[0007] A preparation method of a nanorod arrayed coating that can be ultrasonically mediated for antibacterial and has high bone integration, comprising the following steps:

[0008] Step 1: Perform micro-arc oxidation on a titanium-based substrate in an electrolyte containing phosphate ions and calcium ions to form a microporous titanium dioxide coating on the surface of the titanium-based substrate, and the titanium-based substrate is pure titanium or a titanium alloy;

[0009] Step 2: Prepare a hydroxyapatite nanorod-configured coating on the microporous titanium dioxide coating obtained in Step 1 by a hydrothermal treatment method;

[0010] Step 3: Coat a Mg-O amorphous film on the hydroxyapatite nanorod-configured coating obtained in Step 2 by a magnesium thermal reduction method to obtain a nanorod arrayed coating that can be ultrasonically mediated for antibacterial and has high bone integration.

[0011] Further, the specific content of Step 1 is:

[0012] Use the pure titanium or titanium alloy substrate as the anode and the stainless steel electrolytic cell as the cathode, perform micro-arc oxidation at a temperature of 300K, and then alternately wash and dry with alcohol and deionized water to form a microporous titanium dioxide coating on the surface of the titanium-based substrate.

[0013] Further, the parameters of the micro-arc oxidation are as follows: arc frequency 110 Hz, positive pressure 450 V, duty cycle 7.5%; the electrolyte comprises: sodium hydroxide 0.005 mol / L, calcium acetate 0.2 mol / L, β-glycerophosphate disodium salt pentahydrate 0.02 mol / L.

[0014] Further, step 2 specifically includes:

[0015] Step 2.1: Put the microporous titanium dioxide coating obtained in step 1 into an aqueous sodium hydroxide solution with a concentration of 0.01 mol / L, and seal it for the first hydrothermal treatment.

[0016] Step 2.2: Add sodium calcium edetate, β-glycerophosphate disodium salt pentahydrate and sodium hydroxide into water, stir evenly, and then seal the product of step 2.1 for the second hydrothermal treatment. After washing and drying the product, it is reserved for use.

[0017] Further, in step 2.2, the concentration of sodium calcium edetate is 0.12 mol / L, the concentration of β-glycerophosphate disodium salt pentahydrate is 0.02 mol / L, and the concentration of sodium hydroxide is 0.125 mol / L.

[0018] Further, the temperature of the first hydrothermal treatment is 360 K and the time is 2 h.

[0019] Further, the temperature of the second hydrothermal treatment is 385 K and the time is 20 h.

[0020] Further, step 3 is specifically:

[0021] Parallelly place several products obtained in step two in a crucible, weigh magnesium powder and pour it into another crucible. The ratio of the surface area of the product to the magnesium powder is 4.62 cm 2 :(0.01 - 0.10) g. Parallelly place the two crucibles in a quartz tube, and make the crucible containing magnesium powder closer to the air inlet. After placing the crucibles, place the quartz tube in the furnace chamber of a tube furnace. Connect the quartz tube, the air inlet and the vacuum pump. Turn on the vacuum pump. After ensuring good sealing of the quartz tube, introduce argon. The argon flow rate is 300 sccm. Set the reaction curve of the tube furnace as follows: heat up from room temperature to 650 °C in 110 min, keep warm for 1 - 10 min, then cool down to room temperature with the furnace, stop ventilation, turn off the vacuum pump, take out the sample, rinse it with deionized water and dry it.

[0022] A nano-rod array coating that can be ultrasonically mediated for antibacterial and has high osteointegration is prepared by the above preparation method.

[0023] Application of a nano-rod array coating that can be ultrasonically mediated for antibacterial and has high osteointegration as an implant coating material.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The preparation method of the nanorod array structured coating with both antioxidant and self-generated oxygen functions on the titanium-based surface of the present invention first uses the micro-arc oxidation process to prepare a porous titanium dioxide coating containing phosphorus and calcium on the surface layer of titanium or its alloy, and then uses the hydrothermal treatment method to in-situ grow a hydroxyapatite (HA) nanorod structured coating on the porous titanium dioxide coating containing phosphorus and calcium. Finally, the magnesium thermal reduction method is used to prepare a hydroxyapatite nanorod array (B-HA) coated with a Mg-O amorphous film to obtain a biomedical material with an anti-infective and bone regeneration coating with a nanorod array. The micro-arc oxidation method is used to in-situ prepare a multi-porous TiO 2 layer, so that the coating has a strong interfacial bond with the substrate; and the components of the micro-arc oxidation electrolyte and the hydrothermal solution are simple, do not contain easily decomposed components, the process is stable, controllable, and has strong repeatability. The magnesium thermal reduction method is selected to perform secondary surface modification on HA. One is to form a large number of oxygen vacancies in an inert gas environment, and the other is to achieve the coating of the Mg-O amorphous film, thereby ensuring that the substrate TiO 2 can generate a large amount of reactive oxygen species with cytotoxicity under low-pulse ultrasound to quickly kill bacteria, overcoming the problem of low ROS yield caused by the wide bandgap of traditional TiO 2 and the rapid recombination of electron-hole pairs; in addition, the degradation of the Mg-O amorphous film makes the environment at the lesion site weakly alkaline, which inhibits the reproduction and outbreak of bacteria again. At the same time, the degradation of the amorphous film also releases Mg 2+ , and after degradation, the inner layer of hydroxyapatite nanorods is exposed, and Ca 2+ , PO 4 3- are continuously released. The three ions synergistically promote the increase in the activity of osteoblasts, providing a good environment for subsequent bone regeneration. A nanorod array structured coating that can be mediated by ultrasound for antibacterial and has high bone integration is constructed.

[0026] In this preparation method, the components of the micro-arc oxidation electrolyte and the hydrothermal solution are simple, do not contain easily decomposed components, the process is stable, controllable, and has strong repeatability; the magnesium thermal reduction method has simple steps and stable process, and is not dangerous in an argon environment, making this process applicable to large-scale production and preparation. The raw materials used to prepare this coating, such as NaOH, β-GP, EDTA-Ca, and magnesium powder, are all non-toxic and safe, have no side effects on the human body, and the raw materials can be directly purchased on the market and are easy to obtain, thus ensuring the popularization and application of this technology.

[0027] Furthermore, the ratio between the surface area of the product and the magnesium powder is controlled at 4.62 cm 2:(0.01 - 0.10) g. If the mass of magnesium powder is too high, the Mg-O amorphous film will completely cover the surface of the HA nanorod array coating. If the mass is too small, the Mg-O amorphous film cannot firmly adhere to the HA nanorods and be dense and uniform. The heat preservation temperature is 650 - 700 °C. If the temperature is too low, magnesium powder cannot form magnesium vapor, so the Mg-O amorphous film cannot be formed on the HA nanorod array coating. If the temperature is too high, the experimental risk increases and the service life of the tube furnace decreases.

[0028] Furthermore, the heat preservation time for magnesium thermal reduction is 1 - 10 min. Within this time range, a uniformly coated Mg-O amorphous film can be formed on the surface of the HA nanorod array. If the reduction time is too short, the concentration of magnesium vapor is too low, so a uniformly dense and tightly bound Mg-O amorphous film cannot be formed on the HA nanorod array coating. If the reduction time is too long, the HA nanorod array is completely covered by the Mg-O amorphous film, changing the original array configuration and unable to achieve the effect of promoting osteoblast adhesion.

[0029] A nanorod array coating with ultrasonic-mediated antibacterial and high osteointegration properties prepared by the above preparation method has a bilayer structure. The surface layer is a nanorod array with a bone matrix-like configuration coated with a Mg-O amorphous film, and the inner layer (adjacent to the substrate) is a multi-porous TiO 2 coating containing phosphorus, calcium, and abundant oxygen vacancies. The surface layer of the HA nanorod array coated with the Mg-O amorphous film has both anti-infection and bone regeneration effects. It can generate a large amount of ROS in a short time through externally applied low-pulse ultrasound, thereby efficiently killing bacteria, providing an alkaline environment to inhibit bacterial outburst, and releasing Mg 2+ , Ca 2+ , PO 4 3- The three ions can effectively promote the proliferation and adhesion of osteoblasts, and at the same time inhibit the differentiation of the monocyte / macrophage lineage into osteoclasts and the activity of osteoclasts. Moreover, the coating is tightly bonded to the titanium-based substrate. The raw materials used are non-toxic and safe, have no side effects on the human body, and are easily available, making it easy to promote and apply.

[0030] When the above nanorod array coating with ultrasonic-mediated antibacterial and high osteointegration properties is used as an implant coating material, the inner layer (adjacent to the substrate) is a multi-porous TiO 2 coating containing phosphorus and calcium. This configured surface layer can significantly promote the functions of osteoblast-related cells. In addition, the surface layer of the HA nanorod array after magnesium thermal reduction and TiO 2The substrate has dual functions of anti-infection and bone regeneration. For extreme conditions such as osteoporotic fractures, it can efficiently kill bacteria in the initial stage of implantation in combination with low-pulse ultrasound, providing an ideal environment for the proliferation and adhesion of osteoblasts in the middle and late stages of implantation, thereby greatly enhancing the ability of the titanium-based implant to promote bone tissue healing and regeneration under extreme conditions. In addition, the coating can be tightly combined with the titanium matrix, avoiding the occurrence of coating peeling induced by poor membrane / substrate bonding force and the associated side effects such as osteolysis or excessive inflammation. Description of the Drawings

[0031] Figure 1 SEM (Scanning Electron Microscopy) photographs of the surface morphology of the HA nanorod-configured coating prepared by micro-arc oxidation-hydrothermal treatment in Example 1. (a) is the low-magnification morphology diagram of the HA nanorod-configured coating, and (b) is the high-magnification morphology diagram of the HA nanorod-configured coating;

[0032] Figure 2 SEM photographs of the surface morphology of the titanium implant with the B-HA coating prepared in Example 1. (a) is the low-magnification morphology diagram of the B-HA coating, and (b) is the high-magnification morphology diagram of the B-HA nanorod coating;

[0033] Figure 3 SEM photographs of the surface morphology of the titanium implant with the B-HA coating prepared in Example 2. (a) is the low-magnification morphology diagram of the B-HA coating, and (b) is the high-magnification morphology diagram of the B-HA nanorod coating;

[0034] Figure 4 SEM photographs of the surface morphology of the titanium implant with the B-HA coating prepared in Example 3. (a) is the low-magnification morphology diagram of the B-HA coating, and (b) is the high-magnification morphology diagram of the B-HA nanorod coating;

[0035] Figure 5 Energy Dispersive X-ray Spectroscopy (EDS) diagrams of the titanium implants with the B-HA coating prepared in Examples 1 and 2. (a) and (b) are the EDS diagrams of the titanium implants with the B-HA coating prepared in Examples 1 and 2, respectively.

[0036] Figure 6 Transmission Electron Microscopy (TEM) pictures of the titanium implant with the B-HA coating prepared in Example 2. (a) is the low-magnification morphology diagram of a single B-HA coating nanorod prepared in Example 2, (b) is the high-resolution picture at ① in (a), and (c) is the selected area electron diffraction pattern at ① in (a);

[0037] Figure 7 X-ray Diffraction (XRD) patterns of the titanium implants with the HA coating and the B-HA coating prepared in Examples 1 and 2;

[0038] Figure 8X-ray photoelectron spectroscopy (XPS) of a titanium implant with an HA coating and a B-HA coating in Example 2, where (a)-(d) are the high-resolution spectra at O 1s, Ti 2p, P 2p, and Mg 1s, respectively. Detailed implementation mode

[0039] The implementation scheme of the present invention will be described in detail below in conjunction with the embodiments. This implementation case is the preferred scheme of the present invention and cannot limit the scope of the present invention. In the following embodiments, the methods and experimental equipment used are all conventional methods and instruments unless otherwise specified.

[0040] Example 1

[0041] A preparation method of a biomedical material with an ultrasonically mediated antibacterial and highly osteointegrated nano-rod array coating, comprising the following steps:

[0042] Step 1, micro-arc oxidation of titanium and its alloys:

[0043] The micro-arc oxidation parameters are set as follows: the micro-arc oxidation arc frequency is 110 Hz, the power supply is a positive pressure of 450 V, and the duty cycle is 7.5%. During the micro-arc oxidation process, pure titanium or a titanium alloy is used as the anode, and a stainless steel electrolytic cell is used as the cathode. The composition and concentration of the electrolyte are: sodium hydroxide (NaOH) 0.005 mol / L, calcium acetate (Ca(CH 3 COO) 2 ) 0.2 mol / L, β-glycerophosphate disodium pentahydrate (β-GP) 0.02 mol / L. During the preparation process, a cooling system is used to control the temperature of the micro-arc oxidation electrolyte at 300 K. After micro-arc oxidation, a specimen coated with a microporous titanium dioxide coating is obtained. The prepared specimen is washed with alcohol and deionized water and then placed in a drying oven for standby.

[0044] Step 2, hydrothermally treating the porous TiO 2 coating containing phosphorus and calcium to obtain an HA nano-rod configured coating:

[0045] Step 2.1, primary hydrothermal treatment

[0046] First, prepare the solution required for the primary hydrothermal treatment. The solution is an aqueous sodium hydroxide solution with a concentration of 0.01 mol / L. The titanium sheet coated with a titanium dioxide coating after micro-arc oxidation is placed in a reaction kettle, and then an aqueous sodium hydroxide solution capable of completely immersing the sample surface is added to each reaction kettle. The reaction kettle is tightened and placed in an oven. Finally, the temperature and time parameters are set. The temperature is adjusted to 360 K and the time is set to 2 h.

[0047] Step 2.2, secondary hydrothermal treatment

[0048] Calcium disodium ethylenediaminetetraacetate, disodium β - glycerophosphate pentahydrate and sodium hydroxide were added to water. After stirring evenly, the product of step 2.1 was sealed for secondary hydrothermal treatment. Among them, the concentration of calcium disodium ethylenediaminetetraacetate was 0.12 mol / L, the concentration of disodium β - glycerophosphate pentahydrate was 0.02 mol / L, and the concentration of sodium hydroxide was 0.125 mol / L; the secondary hydrothermal temperature was set at 385 K and the time was set at 20 h. After two hydrothermal treatments, a titanium sheet coated with a HA nanorod - configured coating was obtained. The sample was taken out from the autoclave, rinsed with deionized water and then placed in a drying oven for standby.

[0049] Step 3: Preparation of Mg - O amorphous film - coated hydroxyapatite (HA) nanorod arrays (B - HA)

[0050] Three products from step 2 (the surface area of the product was 4.62 cm 2 ) were placed in parallel in a crucible. 0.1 g of magnesium powder was weighed and poured into another crucible. The two crucibles were placed in parallel in a quartz tube, and the crucible containing magnesium powder was placed closer to the gas inlet. After placing the crucibles, the quartz tube was placed in the furnace chamber of a tube furnace. The quartz tube was connected to the gas inlet and a vacuum pump. The vacuum pump was turned on. After ensuring that the quartz tube was well - sealed, argon gas was introduced, and the argon gas flow rate was 300 sccm. The reaction curve of the tube furnace was set as follows: heating from room temperature to 650 °C in 110 min, holding for 1 min and then cooling to room temperature with the furnace. The gas supply was stopped, the vacuum pump was turned off, and after the sample was taken out, rinsed with deionized water and dried, a nanorod - arrayed coating that could be ultrasonically mediated for antibacterial and had high osteointegration could be obtained.

[0051] Example 2

[0052] A preparation method of a biomedical material with a nanorod - arrayed coating that can be ultrasonically mediated for antibacterial and has high osteointegration includes the following steps:

[0053] Step 1: Micro - arc oxidation of titanium and its alloys:

[0054] The micro - arc oxidation parameters were set as follows: the micro - arc oxidation arc frequency was 110 Hz, the power supply was at a positive pressure of 450 V, and the duty cycle was 7.5%. During micro - arc oxidation, pure titanium or a titanium alloy was used as the anode, and a stainless - steel electrolytic cell was used as the cathode. The composition and concentration of the electrolyte were: sodium hydroxide (NaOH) 0.005 mol / L, calcium acetate (Ca(CH 3 COO) 2 ) 0.2 mol / L, disodium β - glycerophosphate pentahydrate (β - GP) 0.02 mol / L. During the preparation process, a cooling system was used to control the temperature of the micro - arc oxidation electrolyte at 300 K. After micro - arc oxidation, a specimen coated with a microporous titanium dioxide coating was obtained. The prepared specimen was cleaned with alcohol and deionized water and then placed in a drying oven for standby.

[0055] Step 2. Hydrothermally treat the porous TiO coating containing phosphorus and calcium to obtain a HA nanorod-configured coating: 2

[0056] Step 2.1. Primary hydrothermal treatment

[0057] First, prepare the solution required for the primary hydrothermal treatment. The solution is an aqueous sodium hydroxide solution with a concentration of 0.01 mol / L. Place the titanium sheet coated with a titanium dioxide coating after micro-arc oxidation into the reaction kettle. Then, add the aqueous sodium hydroxide solution that can completely submerge the surface of the sample into each reaction kettle. Tighten the reaction kettle and place it in the oven. Finally, set the temperature and time parameters. Adjust the temperature to 360 K and set the time to 2 h.

[0058] Step 2.2. Secondary hydrothermal treatment

[0059] Add calcium disodium ethylenediaminetetraacetate, disodium β-glycerophosphate pentahydrate, and sodium hydroxide to water. After stirring evenly, conduct secondary hydrothermal treatment on the product of Step 2.1 in a sealed manner. Among them, the concentration of calcium disodium ethylenediaminetetraacetate is 0.12 mol / L, the concentration of disodium β-glycerophosphate pentahydrate is 0.02 mol / L, and the concentration of sodium hydroxide is 0.125 mol / L; set the secondary hydrothermal temperature to 385 K and the time to 20 h. After the two hydrothermal treatments, obtain a titanium sheet coated with a HA nanorod-configured coating. Take out the sample from the reaction kettle, rinse it with deionized water, and then place it in the drying oven for standby.

[0060] Step 3. Prepare a magnesium oxide amorphous film-coated hydroxyapatite (HA) nanorod array (B-HA)

[0061] Place the products of the three steps in Step 2 (the surface area of the product is 4.62 cm 2 ) parallel in the crucible. Weigh 0.1 g of magnesium powder and pour it into another crucible. Place the two crucibles parallel in the quartz tube, and make the crucible containing magnesium powder closer to the air inlet. After placing the crucibles, place the quartz tube in the furnace chamber of the tube furnace. Connect the quartz tube, the air inlet, and the vacuum pump. Turn on the vacuum pump. After ensuring that the quartz tube is well sealed, introduce argon. The argon flow rate is 300 sccm. Set the reaction curve of the tube furnace as follows: heat from room temperature to 650 °C in 110 min, keep it warm for 10 min, and then cool it to room temperature with the furnace. Stop ventilation, turn off the vacuum pump. After taking out the sample, rinse it with deionized water and dry it to obtain a nanorod-arrayed coating that can be ultrasonically mediated for antibacterial and has high osteointegration.

[0062] Example 3

[0063] ​A preparation method of a biomedical material with a nanorod array coating that can be ultrasonically mediated for antibacterial and has high osteointegration, comprising the following steps:

[0064] Step 1, micro-arc oxidation of titanium and its alloys:

[0065] The micro-arc oxidation parameters are set as follows: the micro-arc oxidation arc frequency is 110 Hz, the power supply is a positive pressure of 450 V, and the duty cycle is 7.5%. During the micro-arc oxidation process, pure titanium or a titanium alloy is used as the anode, and a stainless steel electrolytic cell is used as the cathode. The composition and concentration of the electrolyte are: sodium hydroxide (NaOH) 0.005 mol / L, calcium acetate (Ca(CH 3 COO) 2 ) 0.2 mol / L, β-glycerophosphate disodium pentahydrate (β-GP) 0.02 mol / L. During the preparation process, a cooling system is used to control the temperature of the micro-arc oxidation electrolyte at 300 K. After micro-arc oxidation, a specimen coated with a microporous titanium dioxide coating is obtained. The prepared specimen is washed with alcohol and deionized water and then placed in a drying oven for standby.

[0066] Step 2, hydrothermally treat the porous TiO 2 coating containing phosphorus and calcium to obtain an HA nanorod-configured coating:

[0067] Step 2.1, primary hydrothermal treatment

[0068] First, prepare the solution required for the primary hydrothermal treatment. The solution is an aqueous sodium hydroxide solution with a concentration of 0.01 mol / L. The titanium sheet coated with a titanium dioxide coating after micro-arc oxidation is placed in a reaction kettle. Then, an aqueous sodium hydroxide solution capable of completely submerging the sample surface is added to each reaction kettle. The reaction kettle is tightened and placed in an oven. Finally, the temperature and time parameters are set. The temperature is adjusted to 360 K, and the time is set to 2 h.

[0069] Step 2.2, secondary hydrothermal treatment

[0070] Calcium disodium ethylenediaminetetraacetate, β-glycerophosphate disodium pentahydrate, and sodium hydroxide are added to water. After stirring evenly, the product of Step 2.1 is sealed for secondary hydrothermal treatment. Among them, the concentration of calcium disodium ethylenediaminetetraacetate is 0.12 mol / L, the concentration of β-glycerophosphate disodium pentahydrate is 0.02 mol / L, and the concentration of sodium hydroxide is 0.125 mol / L; the secondary hydrothermal temperature is set to 385 K, and the time is set to 20 h. After two hydrothermal treatments, a titanium sheet coated with an HA nanorod-configured coating is obtained. The sample is taken out of the reaction kettle, rinsed with deionized water, and then placed in a drying oven for standby.

[0071] Step 3, prepare a hydroxyapatite (HA) nanorod array (B-HA) coated with an Mg-O amorphous film

[0072] Place the products from step 2 (product surface area is 4.62 cm 2 ) parallel in the crucible. Weigh 0.01 g of magnesium powder and pour it into another crucible. Place the two crucibles parallel in the quartz tube, and make the crucible with magnesium powder closer to the gas inlet. After placing the crucibles, place the quartz tube in the furnace chamber of the tube furnace. Connect the quartz tube, the gas inlet, and the vacuum pump. Turn on the vacuum pump. After ensuring good sealing of the quartz tube, introduce argon. The argon flow rate is 300 sccm. Set the reaction curve of the tube furnace as follows: heat from room temperature to 650 °C in 110 min, hold for 10 min, and then cool to room temperature with the furnace. Stop the gas supply, turn off the vacuum pump. After taking out the sample, rinse it with deionized water and dry it to obtain a nanorod array coating that can be ultrasonically mediated for antibacterial and has high osteointegration.

[0073] Example 4

[0074] A preparation method of a biomedical material with a nanorod array coating that can be ultrasonically mediated for antibacterial and has high osteointegration, comprising the following steps:

[0075] Step 1, micro-arc oxidation of titanium and its alloys:

[0076] Set the micro-arc oxidation parameters as follows: the micro-arc oxidation arc frequency is 110 Hz, the power supply is a positive pressure of 450 V, and the duty cycle is 7.5%. During the micro-arc oxidation process, use pure titanium or titanium alloy as the anode and a stainless steel electrolytic cell as the cathode. The composition and concentration of the electrolyte are: sodium hydroxide (NaOH) 0.005 mol / L, calcium acetate (Ca(CH 3 COO) 2 ) 0.2 mol / L, β-glycerophosphate disodium pentahydrate (β-GP) 0.02 mol / L. During the preparation process, use a cooling system to control the temperature of the micro-arc oxidation electrolyte at 300 K. After micro-arc oxidation, obtain a specimen coated with a microporous titanium dioxide coating. After cleaning the prepared specimen with alcohol and deionized water, put it in a drying oven for standby.

[0077] Step 2, hydrothermally treat the porous TiO 2 coating containing phosphorus and calcium to obtain a HA nanorod-configured coating:

[0078] Step 2.1, primary hydrothermal treatment

[0079] First, prepare the solution required for the primary hydrothermal treatment. The solution is an aqueous sodium hydroxide solution with a concentration of 0.01 mol / L. Put the titanium sheet coated with titanium dioxide after micro-arc oxidation into the reaction kettle. Then add the aqueous sodium hydroxide solution that can completely immerse the sample surface into each reaction kettle. Tighten the reaction kettle and put it into the oven. Finally, set the temperature and time parameters. Adjust the temperature to 360 K and set the time to 2 h.

[0080] Step 2.2, secondary hydrothermal treatment

[0081] Add sodium calcium edetate, disodium β - glycerophosphate pentahydrate and sodium hydroxide into water. After stirring evenly, perform secondary hydrothermal treatment on the product of Step 2.1 in a sealed manner. Among them, the concentration of sodium calcium edetate is 0.12 mol / L, the concentration of disodium β - glycerophosphate pentahydrate is 0.02 mol / L, and the concentration of sodium hydroxide is 0.125 mol / L; the secondary hydrothermal temperature is set at 385 K and the time is set at 20 h. After two hydrothermal treatments, a titanium sheet coated with a HA nanorod - configured coating is obtained. Take the sample out of the autoclave, rinse it with deionized water and then put it in a drying oven for standby.

[0082] Step 3, prepare Mg - O amorphous film - coated hydroxyapatite (HA) nanorod arrays (B - HA)

[0083] Place the products of the three in Step 2 (the surface area of the product is 4.62 cm 2 ) parallel in a crucible. Weigh 0.05 g of magnesium powder and pour it into another crucible. Place the two crucibles parallel in a quartz tube, and make the crucible containing magnesium powder closer to the gas inlet. After placing the crucibles, place the quartz tube in the furnace chamber of a tube furnace. Connect the quartz tube, the gas inlet and the vacuum pump. Turn on the vacuum pump. After ensuring that the quartz tube is well - sealed, introduce argon. The argon flow rate is 300 sccm. Set the reaction curve of the tube furnace as follows: heat from room temperature to 650 °C in 110 min, keep it at this temperature for 10 min, and then cool it to room temperature with the furnace. Stop ventilation, turn off the vacuum pump. After taking out the sample, rinse it with deionized water and dry it to obtain a nanorod - arrayed coating that can be ultrasonically mediated for antibacterial and has high osteointegration.

[0084] Example 5

[0085] A preparation method of a biomedical material with a nanorod - arrayed coating that can be ultrasonically mediated for antibacterial and has high osteointegration, comprising the following steps:

[0086] Step 1, micro - arc oxidation of titanium and its alloys:

[0087] Set the micro - arc oxidation parameters as follows: the micro - arc oxidation arc frequency is 110 Hz, the power supply is at a positive pressure of 450 V, and the duty cycle is 7.5%. During micro - arc oxidation, use pure titanium or a titanium alloy as the anode and a stainless - steel electrolytic cell as the cathode. The composition and concentration of the electrolyte are: sodium hydroxide (NaOH) 0.005 mol / L, calcium acetate (Ca(CH 3 COO) 2)0.2 mol / L, 0.02 mol / L of disodium β - glycerophosphate pentahydrate (β - GP). During the preparation process, a cooling system was used to control the temperature of the micro - arc oxidation electrolyte at 300 K. After micro - arc oxidation, a specimen coated with a microporous titanium dioxide coating was obtained. The prepared specimen was cleaned with alcohol and deionized water and then placed in a drying oven for standby.

[0088] Step 2: Hydrothermally treat the porous TiO 2 coating to obtain a HA nanorod - configured coating:

[0089] Step 2.1: Primary hydrothermal treatment

[0090] First, prepare the solution required for the primary hydrothermal treatment. The solution is an aqueous sodium hydroxide solution with a concentration of 0.01 mol / L. The titanium sheet coated with a titanium dioxide coating after micro - arc oxidation is placed in a reaction kettle. Then, add an aqueous sodium hydroxide solution that can completely submerge the surface of the sample into each reaction kettle. Tighten the reaction kettle and place it in an oven. Finally, set the temperature and time parameters. The temperature is adjusted to 360 K and the time is set to 2 h.

[0091] Step 2.2: Secondary hydrothermal treatment

[0092] Calcium disodium ethylenediaminetetraacetate, disodium β - glycerophosphate pentahydrate, and sodium hydroxide are added to water. After stirring evenly, the product of Step 2.1 is sealed for secondary hydrothermal treatment. Among them, the concentration of calcium disodium ethylenediaminetetraacetate is 0.12 mol / L, the concentration of disodium β - glycerophosphate pentahydrate is 0.02 mol / L, and the concentration of sodium hydroxide is 0.125 mol / L; the secondary hydrothermal temperature is set to 385 K and the time is set to 20 h. After two hydrothermal treatments, a titanium sheet coated with a HA nanorod - configured coating is obtained. The sample is taken out of the reaction kettle, rinsed with deionized water, and then placed in a drying oven for standby.

[0093] Step 3: Prepare a Mg - O amorphous film - coated hydroxyapatite (HA) nanorod array (B - HA)

[0094] Take 3 products from Step 2 (the surface area of the product is 4.62 cm 2) It is placed parallel in the crucible. Weigh 0.1 g of magnesium powder and pour it into another crucible. Place the two crucibles parallel in the quartz tube, and make the crucible containing magnesium powder closer to the gas inlet. After placing the crucibles, place the quartz tube in the furnace chamber of the tube furnace. Connect the quartz tube, the gas inlet, and the vacuum pump. Turn on the vacuum pump. After ensuring that the quartz tube is well sealed, introduce argon gas, with an argon gas flow rate of 300 sccm. Set the reaction curve of the tube furnace as follows: heat from room temperature to 650 °C in 110 min, hold for 5 min, and then cool to room temperature with the furnace. Stop ventilation, turn off the vacuum pump. After taking out the sample, rinse it with deionized water and dry it to obtain a nano-rod array coating that can be ultrasonically mediated for antibacterial and has high osteointegration.

[0095] The prepared titanium alloy sample with a B-HA coating includes a TiO 2 coating and a B-HA coating. As Figure 1 , it is the scanning picture of the hydroxyapatite nano-rod coating obtained after micro-arc oxidation and hydrothermal treatment in Examples 1 and 2. As Figure 2 , it is the scanning electron microscope picture of the B-HA coating obtained in Example 1. It can be seen that the configuration of the nano-rods changes from regular hexagonal prisms to irregular circles with a thicker diameter. As Figure 3 , it is the scanning electron microscope picture of the B-HA coating obtained in Example 2. Compared with Example 1, the diameter of the nano-rods increases, indicating that when the content of magnesium powder is certain, the thickness of the surface Mg-O amorphous film increases with the extension of the magnesiothermic reduction time, and more magnesium ions will be released during its degradation process, providing a more lasting alkaline environment. As Figure 4 , it is the scanning electron microscope picture of the B-HA coating obtained in Example 3. Compared with Example 2, the diameter of the nano-rods decreases, indicating that when the magnesiothermic reduction time is certain, the thickness of the surface Mg-O amorphous film decreases with the reduction of the magnesium powder content. As Figure 5 , in the EDS diagram, it can be seen that after micro-arc oxidation, two hydrothermal treatments and magnesiothermic reduction, calcium, phosphorus, and magnesium elements do exist in the coating, and with the extension of the magnesiothermic reduction time, the proportion of magnesium element increases. As Figure 6 , it is the transmission electron microscope image of the B-HA coating obtained in Example 2. The high-resolution image shows the crystal planes representing HA and the amorphous coating layer. The electron diffraction image also shows the relevant crystal planes representing HA and a faint amorphous halo appears, representing the existence of the Mg-O amorphous film. As Figure 7 , it can be seen from the XRD characterization diagram that after micro-arc oxidation and hydrothermal treatment, a titanium alloy with an HA coating is obtained. Since the surface Mg-O film belongs to an amorphous substance, it can be seen that with the extension of the annealing time, the intensity of the HA-related characteristic peaks becomes lower and lower, which to a certain extent shows that the Mg-O amorphous film is successfully wrapped on the surface of the HA nano-rods. As Figure 8, XPS of the hydroxyapatite nanorod coating prepared in Example 1 and the B-HA coating obtained in Example 2 shows that magnesium ions exist in the divalent form in the B-HA coating. After magnesium loses electrons, phosphorus gains electrons, and the phosphorus peak shifts to a lower valence. Since the B-HA coating is obtained by magnesiothermic reduction in an argon atmosphere, the oxygen vacancy content in the substrate TiO 2 layer is higher than that of the HA coating. At the same time, the deconvolution results also show that its adsorbed oxygen content is greater than that of the HA coating. These provide sufficient raw material conditions for B-HA to generate a large amount of ROS in a short time under ultrasonic stimulation. The above results indicate that a titanium alloy implant with a nanorod-arrayed coating that can be ultrasonically mediated for antibacterial and has high osteointegration has been successfully prepared.

[0096] Many examples can be cited for the embodiments. Limited by space, they are not listed one by one here. In short, within the scope provided by the present invention, after treatment by micro-arc oxidation, hydrothermal treatment, and magnesiothermic reduction, a double-layer structure coating can be obtained on the surface of titanium and its alloys: the inner layer is a microporous TiO 2 layer containing phosphorus, calcium, and a large number of oxygen vacancies, which is an oxide film containing calcium and phosphorus elements in-situ grown on the titanium surface. It can improve the biocompatibility of titanium and its alloy implants to a certain extent. The large number of oxygen vacancies enables it to cooperate with low-pulse ultrasound to generate a large amount of ROS for efficient sterilization in a short time; the surface layer is a nanostructured coating of hydroxyapatite configured with an Mg-O amorphous film. The hydroxyapatite component is closer to the composition of human bone. After being coated with the Mg-O amorphous film, it forms an irregular cylindrical nanorod configuration, which can increase the specific surface area in contact with cells, further improve biocompatibility, and promote cell adhesion and proliferation to a certain extent; in addition, the HA nanorod array coating after magnesiothermic reduction has dual functions of anti-infection and bone regeneration under ultrasonic stimulation, and can effectively target extreme conditions, such as the infected fracture area under osteoporosis. At the initial stage of implantation, bacteria can be quickly killed by ultrasound, while providing an alkaline environment and a variety of osteogenic ions, providing an ideal environment for the proliferation and adhesion of osteoblasts in the middle and late stages, thereby greatly enhancing the ability of the implant to promote bone tissue healing and regeneration under infected osteoporosis fractures. After the surface of titanium and titanium alloys is coated with this double coating, it has high bonding strength and good bioactivity. Moreover, due to its good antibacterial and ability to promote the proliferation, adhesion, and mineralization of osteoblasts in simulated body fluid, it can significantly enhance the antibacterial and bone tissue healing and regeneration abilities of titanium and titanium alloy implants under extreme conditions.

[0097] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various modifications and decorations without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims.

Claims

1. A preparation method of a nanorod arrayed coating that can be mediated by ultrasound for antibacterial and has high osteointegration, characterized in that, it includes the following steps: Step 1: Perform micro-arc oxidation on a titanium-based substrate in an electrolyte containing phosphate ions and calcium ions to form a microporous titanium dioxide coating on the surface of the titanium-based substrate, and the titanium-based substrate is pure titanium or a titanium alloy; Step 2: Prepare a hydroxyapatite nanorod-configured coating on the microporous titanium dioxide coating obtained in Step 1 by a hydrothermal treatment method; The specific steps of Step 2 include: Step 2.1: Put the microporous titanium dioxide coating obtained in Step 1 into an aqueous sodium hydroxide solution with a concentration of 0.01 mol / L, and seal it for a first hydrothermal treatment; Step 2.2: Add calcium disodium ethylene diamine tetraacetate, disodium β-glycerophosphate pentahydrate, and sodium hydroxide to water, stir evenly, and then seal the product of Step 2.1 for a second hydrothermal treatment. After washing and drying the product, it is reserved for use; In Step 2.2, the concentration of calcium disodium ethylene diamine tetraacetate is 0.12 mol / L, the concentration of disodium β-glycerophosphate pentahydrate is 0.02 mol / L, and the concentration of sodium hydroxide is 0.125 mol / L; Step 3: Use the magnesium thermal reduction method to coat the hydroxyapatite nanorod-configured coating obtained in Step 2 with an Mg-O amorphous film. Specifically: Place a number of the products from Step 2 in parallel in a crucible, weigh magnesium powder and pour it into another crucible. The ratio of the surface area of the product to the magnesium powder is 4.62 cm 2 :(0.01 - 0.10) g. Place the two crucibles in parallel in a quartz tube, and make the crucible containing magnesium powder closer to the gas inlet. After placing the crucibles, place the quartz tube in the furnace chamber of a tube furnace. Connect the quartz tube to the gas inlet and a vacuum pump. Turn on the vacuum pump. After ensuring good sealing of the quartz tube, introduce argon gas, with an argon gas flow rate of 300 sccm. Set the reaction curve of the tube furnace as follows: Heat from room temperature to 650 °C over 110 min, hold for 1 - 10 min, and then cool to room temperature with the furnace. Stop the gas supply, turn off the vacuum pump, take out the sample, rinse it with deionized water and dry it to obtain a nanorod array coating that can be ultrasonically mediated for antibacterial and has high osteointegration properties.

2. The preparation method of a nanorod arrayed coating that can be mediated by ultrasound for antibacterial and has high osteointegration according to claim 1, characterized in that, the specific steps of Step 1 are: Use a pure titanium or titanium alloy substrate as the anode and a stainless steel electrolytic cell as the cathode to perform micro-arc oxidation at a temperature of 300 K, and then alternately wash and dry it with alcohol and deionized water to form a microporous titanium dioxide coating on the surface of the titanium-based substrate.

3. The preparation method of a nanorod arrayed coating that can be mediated by ultrasound for antibacterial and has high osteointegration according to claim 2, characterized in that, the parameters of the micro-arc oxidation are: arc frequency 110 Hz, positive pressure 450 V, duty cycle 7.5%; the electrolyte includes: 0.005 mol / L of sodium hydroxide, 0.2 mol / L of calcium acetate, and 0.02 mol / L of disodium β-glycerophosphate pentahydrate.

4. The preparation method of a nanorod arrayed coating that can be mediated by ultrasound for antibacterial and has high osteointegration according to claim 1, characterized in that, the temperature of the first hydrothermal treatment is 360 K and the time is 2 h.

5. The preparation method of a nanorod arrayed coating that can be mediated by ultrasound for antibacterial and has high osteointegration according to claim 1, characterized in that, the temperature of the second hydrothermal treatment is 385 K and the time is 20 h.

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