A micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles and its preparation method

Abstract

This invention provides a micro / nano titanium-based dental implant loaded with gold-modified mesoporous silica composite particles and its preparation method, belonging to the field of dental implant material technology. The preparation method of the dental implant includes: (1) polishing and cleaning a pure titanium sheet to obtain a titanium-based dental implant; (2) acid etching the titanium-based dental implant; (3) anodizing the titanium-based dental implant to obtain a pretreated titanium-based dental implant; (4) preparing mesoporous silica nanoparticles; (5) preparing a suspension of gold-modified mesoporous silica composite particles; (6) immersing the pretreated titanium-based dental implant in the suspension of gold-modified mesoporous silica composite particles, followed by vacuum treatment and placement to obtain the implant. The micro / nano titanium-based dental implant loaded with gold-modified mesoporous silica composite particles of this invention simultaneously possesses high osteogenic activity and long-lasting antibacterial effects, achieving the effect of promoting early implant osseointegration and providing long-lasting antibacterial prevention of peri-implantitis.

Description

Technical Field

[0001] This invention belongs to the field of dental implant material technology, specifically relating to a micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles and its preparation method. Background Technology

[0002] Titanium is currently widely used in dentistry as a dental implant material. However, titanium itself is biologically inert. To improve its bioactivity, modifying the surface of titanium-based implants to achieve early and higher osseointegration strength has become a core issue in dental implant material research.

[0003] Peri-implantitis is one of the leading causes of implant failure. Implant material antibacterial properties through surface modification are an effective way to prevent and treat peri-implantitis. Currently, implant surface modification is widely used either to promote early and higher bone integration strength and shorten the treatment cycle, or to improve antibacterial properties for long-term antibacterial effects, thereby reducing infection rates.

[0004] In existing technologies, to promote bone integration rate, various osteogenic differentiation factors are often loaded onto the implant surface, mainly including bone morphogenetic protein, transforming growth factor, insulin-like growth factor, miRNA, and siRNA. Implants modified by this method are not easy to preserve and the preparation process is complex. To improve antibacterial properties, metal antibacterial coatings or antibacterial drugs are often prepared on the implant surface. However, this type of method cannot effectively promote the biological closure of the implant-soft tissue interface, and the treatment cycle is relatively long. Summary of the Invention

[0005] The purpose of this invention is to provide a micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles and its preparation method. This dental implant has both high osteogenic activity and long-lasting antibacterial effect, which can promote early implant osseointegration and provide long-lasting antibacterial protection against peri-implantitis.

[0006] The technical solution adopted to achieve the above objectives is to provide a micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles, comprising the following steps:

[0007] (1) Pure titanium sheet is used as the implant matrix and polished and cleaned to obtain titanium-based dental implant;

[0008] (2) The titanium-based dental implant is acid-etched to form a micron-pitted surface.

[0009] (3) The titanium-based dental implant obtained in step (2) is anodized to form a micro-nano morphological surface, thus obtaining a pretreated titanium-based dental implant;

[0010] (4) Preparation of mesoporous silica nanoparticles;

[0011] (5) Preparation of a suspension of nano-gold modified mesoporous silica composite particles;

[0012] (6) The pretreated titanium-based dental implant is immersed in a suspension of nano-gold modified mesoporous silica composite particles for 0.8 to 1.2 hours. After removal, it is vacuum treated and then placed at 35 to 38°C overnight to obtain the final product.

[0013] The beneficial effects of the above-mentioned technical solution in this invention are as follows: First, the surface of a pure titanium sheet is polished and cleaned, then acid-etched to form a micro-pitted surface to simulate the natural roughness of bone. Next, anodizing is used to prepare a precisely controlled titanium dioxide (TiO2) nanotube structure on the basis of the micro-pits to mimic the collagen fiber structure of bone tissue, thereby forming a micro / nano composite gradient morphology surface more similar to natural bone tissue. Based on this, gold nanoparticles (AuNPs) and mesoporous silica nanoparticles (MSNs) are combined to form gold-modified mesoporous silica composite particles. Then, utilizing the hydrophilicity of the titanium dioxide nanotube structure, vacuum processing is used to uniformly load the gold-modified mesoporous silica composite particles into the titanium dioxide nanotube structure to achieve surface modification of titanium, forming a micro / nano composite gradient morphology more similar to the surface of natural bone tissue. Finally, a micro / nano titanium-based dental implant with dual photothermal and dynamic functions, loaded with gold-modified mesoporous silica composite particles, is prepared. The gold nanoparticles have photothermal therapy effects and can be irradiated by near-infrared light. By loading gold nanoparticles onto the surface of titanium implants, they exert a strong and effective antibacterial effect. This allows them to penetrate deep tissues through near-infrared light irradiation, achieving long-term maintenance and infection resistance for the implant. Simultaneously, gold nanoparticles possess a non-specific bacterial toxicity mechanism (they do not bind to specific receptors in bacterial cells), which, compared to current systemic or local antibiotic applications, not only makes it difficult for bacteria to develop resistance but also broadens the range of antibacterial activity. AuNPs loaded onto the titanium surface form a sustained-release coating, which, compared to systemic antibiotic application or coating preparation, provides long-term stability and prevents the development of drug-resistant bacteria. However, directly loading gold nanoparticles onto the surface of titanium implants is difficult. Therefore, this invention uses mesoporous silica nanoparticles capable of adsorbing or loading large amounts of bioactive substances to load gold nanoparticles. The silicon ions released by the mesoporous silica nanoparticles can participate in regulating various cellular activities and promote osteogenic differentiation. The gold-modified mesoporous silica composite particles can provide a sustained-release effect for the gold nanoparticles and also promote the osteogenic differentiation effect of silicon ions. The micro / nano composite surface morphology and size, silicon ion release, and photothermal and photocatalytic activity of gold nanoparticles of the present invention better promote early bone healing between implants and surrounding bone tissue, while also endowing the implant surface with antibacterial ability.

[0014] Preferably, the polishing and cleaning in step (1) includes the following steps: polishing the pure titanium sheet with 400 to 7000 grit sandpaper until the surface of the pure titanium sheet has a mirror effect, and then ultrasonically cleaning it with acetone, anhydrous ethanol and deionized water in sequence, with each cleaning time being 10 to 20 minutes, and then drying it at room temperature.

[0015] Preferably, the acid etching in step (2) includes the following steps: placing the titanium-based dental implant in a 0.5% wt hydrofluoric acid aqueous solution with the front side facing up, letting it stand for 20 to 40 minutes, rinsing it with water for 10 to 15 minutes after removal, and then ultrasonically cleaning it with acetone, anhydrous ethanol and deionized water in sequence, with each cleaning time being 10 to 20 minutes, and then drying it at room temperature after removal.

[0016] The beneficial effects of the above technical solution of the present invention are as follows: acid etching of titanium-based dental implants with 0.5% wt hydrofluoric acid aqueous solution can form a uniform micron-shaped pit morphology on its surface.

[0017] Preferably, the anodizing in step (3) includes the following steps:

[0018] S1: Add hydrofluoric acid with a volume concentration of 40% and phosphoric acid with a volume concentration of 85% sequentially to water to form an anodic oxidation electrolyte; the volume ratio of water, hydrofluoric acid and phosphoric acid is 70-80:1:4-5.

[0019] S2: Hold the titanium-based dental implant obtained in step (2) with titanium wire;

[0020] S3: Set the electrolytic cell voltage to 18-22V, connect the carbon rod to the cathode and the titanium wire obtained in S2 to the anode, and place the carbon rod and titanium wire in the anodic oxidation electrolyte in sequence, and stir and oxidize for 25-35 minutes at a speed of 250-350 rpm.

[0021] S4: Take out the titanium wire and soak it in water for 4-6 minutes. Then, clean it with acetone, anhydrous ethanol and deionized water in sequence using ultrasonic cleaning. Each cleaning time is 4-6 minutes. After taking it out, dry it at room temperature under an inert atmosphere.

[0022] The beneficial effects of the above technical solution adopted in this invention are as follows: the anodic oxidation electrolyte is composed of water with a volume ratio of 70-80:1:4-5, hydrofluoric acid with a volume concentration of 40%, and phosphoric acid with a volume concentration of 85%, which can further form a uniform micro-nano morphology on the surface of titanium-based dental implants with micron-pit morphology.

[0023] Preferably, the preparation of mesoporous silica nanoparticles in step (4) includes the following steps:

[0024] S1: Dissolve the template agent in water at 45-55℃, heat to 75-85℃, and then add the alkali solution and mix well;

[0025] S2: Dissolve the silicon source in methanol, then add the solution obtained in S1, stir to dissolve for 1.5-2.5 h, cool and centrifuge, take the precipitate and dry it at 55-65℃ for 23-25 ​​h, then calcine it at 500-600℃ for 4.5-5.5 h;

[0026] S3: Dissolve the solid obtained in S2 in toluene, add 3-aminopropyltriethoxysilane, and reflux condense at 75-85°C for 1.5-2.5 h;

[0027] S4: Centrifuge the solution obtained in S3 at 7500-8500 rpm for 15-20 min, and dry the precipitate at 55-65℃ for 23-25 ​​h.

[0028] The beneficial effects of the above technical solution of the present invention are as follows: the template agent is placed in water, a silicon source is added in an alkaline environment, and the silicon source is polymerized by hydrothermal reaction to form a mesoporous silica nanoparticle structure. Then, 3-aminopropyltriethoxysilane is used to make the mesoporous silica nanoparticles carry amino groups. The amino groups are used to achieve the subsequent encapsulation of gold nanoparticles by the mesoporous silica nanoparticles. Finally, the template agent is removed by reflux to obtain mesoporous silica nanoparticles with amino groups.

[0029] More preferably, the alkali solution is a 4M sodium hydroxide solution; the template agent is hexadecyltrimethylammonium bromide; the silicon source is tetraethyl orthosilicate; and the ratio of template agent, alkali solution and silicon source is 0.3-0.5g:1mL:2.5-2.7mL.

[0030] Preferably, the preparation of the nano-gold modified mesoporous silica composite particle suspension in step (5) includes the following steps:

[0031] S1: Add the stabilizer to the tetrachloroauric acid solution and stir at 90-110°C for 15-25 minutes;

[0032] S2: Cool the solution obtained in S1 to room temperature, add the dispersant while stirring, centrifuge at 12000-14000 rpm for 25-35 min, take the precipitate, wash it, and prepare a 0.125 wt% gold nanoparticle suspension.

[0033] S3: Mix the mesoporous silica nanoparticles obtained in step (4) with a 0.125 wt% gold nanoparticle suspension and shake for 11-13 h to obtain a nano-gold modified mesoporous silica composite particle suspension.

[0034] More preferably, the stabilizer is a 3% (w / w) trisodium citrate solution; the dispersant is polyvinylpyrrolidone with a weight-average molecular weight of 54,000 to 56,000; and the material-to-liquid ratio of the mesoporous silica nanoparticles to the 0.125 wt% gold nanoparticle suspension is 0.075 to 0.1 g: 1 mL.

[0035] The beneficial effects of the above technical solution of the present invention are as follows: using a 3% (w / w) trisodium citrate solution as a stabilizer can form a stable complex with tetrachloroauric acid solution; using polyvinylpyrrolidone with a weight-average molecular weight of 54,000 to 56,000 as a dispersant helps the compound dissolve or disperse in the solution, so as to encapsulate or load mesoporous silica nanoparticles and gold nanoparticles in the subsequent process, so as to form a uniformly dispersed suspension of nano-gold modified mesoporous silica composite particles.

[0036] Preferably, the pressure during vacuum treatment is -15 psi and the treatment time is 2 to 5 minutes.

[0037] The present invention also provides a micro / nano titanium-based dental implant with photothermal and dynamic dual functions, prepared by the above preparation method, consisting of loaded gold nanoparticles modified with mesoporous silica composite particles.

[0038] The present invention has the following beneficial effects:

[0039] (1) The micro-nano titanium-based dental implant prepared by the present invention has a micro-nano structure and is loaded with gold nano-modified mesoporous silica composite particles on its surface. It has photothermal and dynamic dual functions and can simultaneously promote early implant osseointegration and long-term antibacterial effect, and prevent peri-implantitis.

[0040] (2) The micro-nano titanium-based dental implants prepared by the present invention, which are loaded with gold nanoparticles modified with mesoporous silica composite particles, have the natural roughness of bone and the collagen fiber structure of bone tissue. They are similar to the morphology of natural bone tissue and have good cell compatibility with mesenchymal stem cells.

[0041] (3) The preparation method of the micro-nano titanium-based dental implant loaded with gold nanoparticles modified mesoporous silica composite particles of the present invention is simple, the prepared dental implant is easy to preserve, and is suitable for industrial production. Attached Figure Description

[0042] Figure 1 This is a transmission electron microscope (TEM) image of mesoporous silica nanoparticles.

[0043] Figure 2 This is a transmission electron microscope (TEM) image of the gold nanoparticle-modified mesoporous silica composite particles.

[0044] Figure 3 Here is a scanning electron microscope image of the surface of the dental implant prepared in Example 1;

[0045] Figure 4 This is a scanning electron microscope image of the surface of the dental implant prepared in Comparative Example 1;

[0046] Figure 5 This is a scanning electron microscope image of the surface of the dental implant prepared in Comparative Example 2;

[0047] Figure 6 This is an EDS elemental analysis diagram of the surface of the dental implant prepared in Example 1;

[0048] Figure 7 These are contact angle diagrams of water on the surfaces of dental implants prepared in Example 1 and Comparative Examples 1-2;

[0049] Figure 8 This is a temperature-time curve of the dental implant surface prepared in Example 1 during the photothermal response process;

[0050] Figure 9 This is a histogram showing the antibacterial rate distribution of dental implants prepared in Example 1 and Comparative Examples 1-2;

[0051] Figure 10 This is a diagram showing the effect of the dental implant surface prepared in Example 1 on the ALP activity of osteoblasts;

[0052] Figure 11 This is a diagram showing the effect of the dental implant surface prepared in Comparative Example 1 on the ALP activity of osteoblasts.

[0053] Figure 12 This is a diagram showing the effect of the dental implant surface prepared in Comparative Example 2 on the ALP activity of osteoblasts.

[0054] Figure 13 This is a diagram showing the effect of the dental implant surface prepared in Example 1 on collagen secretion by osteoblasts;

[0055] Figure 14 This is a diagram showing the effect of the dental implant surface prepared in Comparative Example 1 on collagen secretion by osteoblasts.

[0056] Figure 15 This is a diagram showing the effect of the dental implant surface prepared in Comparative Example 2 on collagen secretion by osteoblasts.

[0057] Figure 16 This is a diagram showing the effect of the dental implant surface prepared in Example 1 on osteoblast matrix mineralization;

[0058] Figure 17 This is a diagram showing the effect of the dental implant surface prepared in Comparative Example 1 on osteoblast matrix mineralization.

[0059] Figure 18 This is a diagram showing the effect of the dental implant surface prepared in Comparative Example 2 on osteoblast matrix mineralization.

[0060] Figure 19 This is a biocompatibility diagram of the dental implant surface prepared in Example 1 with mesenchymal stem cell cells;

[0061] Figure 20 This is a biocompatibility diagram of the dental implant surface prepared in Comparative Example 1 with mesenchymal stem cell cells;

[0062] Figure 21 This is a diagram showing the compatibility between the dental implant surface prepared in Comparative Example 2 and mesenchymal stem cell cells. Detailed Implementation

[0063] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0064] Example 1

[0065] A method for preparing a micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles includes the following steps:

[0066] (1) Pure titanium sheet is selected as the implant matrix. The pure titanium sheet is polished with 400-7000 grit diamond sandpaper under running water cooling until the surface of the pure titanium sheet has a mirror effect. Then, it is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 15 minutes. After taking it out, it is dried at room temperature to obtain titanium-based dental implant.

[0067] (2) Place the titanium-based dental implant in a 0.5% wt hydrofluoric acid aqueous solution with the front side facing up and let it stand for 30 minutes. After taking it out, rinse it with water for 15 minutes, and then clean it with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 15 minutes. After taking it out, dry it at room temperature to form a micron-shaped pit surface.

[0068] (3) The titanium-based dental implant obtained in step (2) is anodized to form a micro-nano morphology surface;

[0069] (4) Add 5 mL of 40% hydrofluoric acid and 23 mL of 85% phosphoric acid to 372 mL of deionized water to form an anodic oxidation electrolyte.

[0070] (5) Clamp the titanium-based dental implant obtained in step (2) with the pre-bent titanium wire;

[0071] (6) Turn on the power, set the electrolytic cell voltage to 20V, connect the cathode to the carbon rod, and connect the anode to the titanium wire obtained in step (5). Place the carbon rod and titanium wire in the anodic oxidation electrolyte in sequence, so that the front of the titanium-based dental implant held by the titanium wire is opposite to the carbon rod. Stir at a speed of 250rpm, oxidize for 30min and then disconnect the anode to form a micro-nano morphology surface.

[0072] (7) Remove the titanium wire holding the titanium-based dental implant and soak it in deionized water for 5 minutes. Then clean it with acetone, anhydrous ethanol and deionized water in sequence, with each cleaning time being 5 minutes. After removal, dry it at room temperature under nitrogen atmosphere to obtain the pretreated titanium-based dental implant.

[0073] (8) Add 0.84 g of hexadecyltrimethylammonium bromide to 400 mL of deionized water at 50 °C, pour it into a flask and stir until clear, then heat to 80 °C and add 2 mL of 4 M sodium hydroxide solution and mix well.

[0074] (9) Dissolve 5.2 mL of tetraethyl orthosilicate in 26 mL of methanol, add it dropwise to the solution obtained in step (8), stir to dissolve for 2 h, cool to room temperature, centrifuge at 8000 rpm, take the precipitate and dry at 60 °C for 24 h, and then calcine at 550 °C for 5 h.

[0075] (10) Weigh 0.5g of the solid obtained in step (9) and dissolve it in 50mL of toluene. Add 2mL of 3-aminopropyltriethoxysilane and reflux condense at 80℃ for 2h.

[0076] (11) Centrifuge the solution obtained in step (10) at 8000 rpm for 15 min, take the precipitate and dry it at 60℃ for 24 h to obtain mesoporous silica nanoparticles.

[0077] (12) Pour 100 mL of 0.01 wt% tetrachloroauric acid solution into the flask, then pour 3 mL of 3% trisodium citrate solution into the flask, and stir the solution continuously at 100 °C for 20 min until the solution turns dark red.

[0078] (13) Cool the solution obtained in step (12) to room temperature, add 400 mg of polyvinylpyrrolidone with a weight average molecular weight of 55,000 to the flask while stirring, centrifuge at 13,000 rpm for 30 min, take the precipitate and wash it 3 times with deionized water, then add 8 mL of deionized water to prepare a 0.125 wt% gold nanoparticle suspension.

[0079] (14) Weigh 0.07 g of mesoporous silica nanoparticles and 800 μL of 0.125 wt% gold nanoparticle suspension, mix and shake for 12 h to obtain nano-gold modified mesoporous silica composite particle suspension.

[0080] (15) The pretreated titanium-based dental implant was immersed in 10 mL of nano-gold modified mesoporous silica composite particle suspension for 1 h. After being taken out, it was placed in a plastic vacuum desiccator (pressure of -15 psi) for vacuum treatment for 3 min, and then placed at 37 °C overnight to obtain the product.

[0081] Example 2

[0082] A method for preparing a micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles includes the following steps:

[0083] (1) Pure titanium sheet is selected as the implant matrix. The pure titanium sheet is polished with 400-7000 grit diamond sandpaper under running water cooling until the surface of the pure titanium sheet has a mirror effect. Then, it is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 10 minutes. After taking it out, it is dried at room temperature to obtain titanium-based dental implant.

[0084] (2) Place the titanium-based dental implant in a 0.5% wt hydrofluoric acid aqueous solution with the front side facing up and let it stand for 20 minutes. After taking it out, rinse it with water for 10 minutes, and then clean it with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 10 minutes. After taking it out, dry it at room temperature to form a micron-shaped pit surface.

[0085] (3) The titanium-based dental implant obtained in step (2) is anodized to form a micro-nano morphology surface;

[0086] (4) Add 5 mL of 40% hydrofluoric acid and 20 mL of 85% phosphoric acid to 350 mL of deionized water to form an anodic oxidation electrolyte.

[0087] (5) Clamp the titanium-based dental implant obtained in step (2) with the pre-bent titanium wire;

[0088] (6) Turn on the power, set the electrolytic cell voltage to 18V, connect the cathode to the carbon rod, and connect the anode to the titanium wire obtained in step (5). Place the carbon rod and titanium wire in the anodic oxidation electrolyte in sequence, so that the front of the titanium-based dental implant held by the titanium wire is opposite to the carbon rod. Stir at a speed of 350rpm, oxidize for 25 minutes and then disconnect the anode to form a micro-nano morphology surface.

[0089] (7) Remove the titanium wire holding the titanium-based dental implant and soak it in deionized water for 4 minutes. Then clean it with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 4 minutes. After removal, dry it at room temperature under nitrogen atmosphere to obtain the pretreated titanium-based dental implant.

[0090] (8) Add 0.6 g of hexadecyltrimethylammonium bromide to 400 mL of deionized water at 45 °C, pour it into a flask and stir until clear, then heat to 80 °C and add 2 mL of 4 M sodium hydroxide solution and mix well.

[0091] (9) Dissolve 5 mL of tetraethyl orthosilicate in 26 mL of methanol, add it dropwise to the solution obtained in step (8), stir to dissolve for 1.5 h, cool to room temperature, centrifuge at 8000 rpm, take the precipitate and dry it at 55 °C for 25 h, and then calcine it at 500 °C for 5.5 h.

[0092] (10) Weigh 0.5g of the solid obtained in step (9) and dissolve it in 50mL of toluene. Add 2mL of 3-aminopropyltriethoxysilane and reflux condense at 75°C for 2.5h.

[0093] (11) Centrifuge the solution obtained in step (10) at 7500 rpm for 20 min, take the precipitate and dry it at 55℃ for 25 h to obtain mesoporous silica nanoparticles.

[0094] (12) Pour 100 mL of 0.01 wt% tetrachloroauric acid solution into the flask, then pour 3 mL of 3% trisodium citrate solution into the flask, and stir the solution continuously at 90 °C for 15 min until the solution turns dark red.

[0095] (13) Cool the solution obtained in step (12) to room temperature, add 400 mg of polyvinylpyrrolidone with a weight average molecular weight of 54,000 to the flask while stirring, centrifuge at 12,000 rpm for 25 min, take the precipitate and wash it 3 times with deionized water, then add 8 mL of deionized water to prepare a 0.125 wt% gold nanoparticle suspension.

[0096] (14) Weigh 0.06 g of mesoporous silica nanoparticles and 800 μL of 0.125 wt% gold nanoparticle suspension, mix and shake for 11 h to obtain nano-gold modified mesoporous silica composite particle suspension.

[0097] (15) The pretreated titanium-based dental implant was immersed in 10 mL of nano-gold modified mesoporous silica composite particle suspension for 1.2 h. After being taken out, it was placed in a plastic vacuum desiccator (pressure of -15 psi) for vacuum treatment for 2 min, and then placed at 35 °C overnight to obtain the product.

[0098] Example 3

[0099] A method for preparing a micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles includes the following steps:

[0100] (1) Pure titanium sheet is selected as the implant matrix. The pure titanium sheet is polished with 400-7000 grit diamond sandpaper under running water cooling until the surface of the pure titanium sheet has a mirror effect. Then, it is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 20 minutes. After taking it out, it is dried at room temperature to obtain titanium-based dental implant.

[0101] (2) Place the titanium-based dental implant in a 0.5% wt hydrofluoric acid aqueous solution with the front side facing up and let it stand for 40 minutes. After taking it out, rinse it with water for 15 minutes, and then clean it with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 20 minutes. After taking it out, dry it at room temperature to form a micron-shaped pit surface.

[0102] (3) The titanium-based dental implant obtained in step (2) is anodized to form a micro-nano morphology surface;

[0103] (4) Add 5 mL of 40% hydrofluoric acid and 25 mL of 85% phosphoric acid to 400 mL of deionized water to form an anodic oxidation electrolyte.

[0104] (5) Clamp the titanium-based dental implant obtained in step (2) with the pre-bent titanium wire;

[0105] (6) Turn on the power, set the electrolytic cell voltage to 22V, connect the cathode to the carbon rod, and connect the anode to the titanium wire obtained in step (5). Place the carbon rod and titanium wire in the anodic oxidation electrolyte in sequence, so that the front of the titanium-based dental implant held by the titanium wire faces the carbon rod. Stir at a speed of 300rpm, oxidize for 35 minutes and then disconnect the anode to form a micro-nano morphology surface.

[0106] (7) Remove the titanium wire holding the titanium-based dental implant and soak it in deionized water for 6 minutes. Then clean it with acetone, anhydrous ethanol and deionized water in sequence, each time for 6 minutes. After removal, dry it at room temperature under nitrogen atmosphere to obtain the pretreated titanium-based dental implant.

[0107] (8) Add 1g of hexadecyltrimethylammonium bromide to 400mL of deionized water at 55℃, pour it into a flask and stir until clear, then heat to 85℃, and add 2mL of 4M sodium hydroxide solution and mix well.

[0108] (9) Dissolve 5.4 mL of tetraethyl orthosilicate in 26 mL of methanol, add it dropwise to the solution obtained in step (8), stir to dissolve for 2.5 h, cool to room temperature, centrifuge at 8000 rpm, take the precipitate and dry it at 65 °C for 23 h, and then calcine it at 600 °C for 4.5 h.

[0109] (10) Weigh 0.5g of the solid obtained in step (9) and dissolve it in 50mL of toluene. Add 2mL of 3-aminopropyltriethoxysilane and reflux condense at 85℃ for 1.5h.

[0110] (11) Centrifuge the solution obtained in step (10) at 8500 rpm for 15 min, take the precipitate and dry it at 65℃ for 23 h to obtain mesoporous silica nanoparticles.

[0111] (12) Pour 100 mL of 0.01 wt% tetrachloroauric acid solution into the flask, then pour 3 mL of 3% trisodium citrate solution into the flask, and stir the solution continuously at 110 °C for 25 min until the solution turns dark red.

[0112] (13) Cool the solution obtained in step (12) to room temperature, add 400 mg of polyvinylpyrrolidone with a weight average molecular weight of 56,000 to the flask while stirring, centrifuge at 14,000 rpm for 35 min, take the precipitate and wash it three times with deionized water, then add 8 mL of deionized water to prepare a 0.125 wt% gold nanoparticle suspension.

[0113] (14) Weigh 0.08 g of mesoporous silica nanoparticles and 800 μL of 0.125 wt% gold nanoparticle suspension, mix and shake for 13 h to obtain nano-gold modified mesoporous silica composite particle suspension.

[0114] (15) The pretreated titanium-based dental implant was immersed in 10 mL of nano-gold modified mesoporous silica composite particle suspension for 0.8 h. After being taken out, it was placed in a plastic vacuum desiccator (pressure -15 psi) for vacuum treatment for 5 min, and then placed at 38 °C overnight to obtain the product.

[0115] Comparative Example 1

[0116] A method for preparing a smooth titanium-based dental implant includes the following steps:

[0117] Pure titanium sheets were selected as the implant matrix. The pure titanium sheets were polished with 400-7000 grit diamond sandpaper under running water cooling until the surface of the pure titanium sheets had a mirror effect. Then, they were ultrasonically cleaned with acetone, anhydrous ethanol and deionized water in sequence, with each cleaning time being 15 minutes. After removal, they were dried at room temperature to obtain a smooth titanium-based dental implant.

[0118] Comparative Example 2

[0119] A method for preparing a micro / nano titanium-based dental implant includes the following steps:

[0120] (1) Pure titanium sheet is selected as the implant matrix. The pure titanium sheet is polished with 400-7000 grit diamond sandpaper under running water cooling until the surface of the pure titanium sheet has a mirror effect. Then, it is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 15 minutes. After taking it out, it is dried at room temperature to obtain titanium-based dental implant.

[0121] (2) Place the titanium-based dental implant in a 0.5% wt hydrofluoric acid aqueous solution with the front side facing up and let it stand for 30 minutes. After taking it out, rinse it with water for 15 minutes, and then clean it with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 15 minutes. After taking it out, dry it at room temperature to form a micron-shaped pit surface.

[0122] (3) The titanium-based dental implant obtained in step (2) is anodized to form a micro-nano morphology surface;

[0123] (4) Add 5 mL of 40% hydrofluoric acid and 23 mL of 85% phosphoric acid to 372 mL of deionized water to form an anodic oxidation electrolyte.

[0124] (5) Clamp the titanium-based dental implant obtained in step (2) with the pre-bent titanium wire;

[0125] (6) Turn on the power, set the electrolytic cell voltage to 20V, connect the cathode to the carbon rod, and connect the anode to the titanium wire obtained in step (5). Place the carbon rod and titanium wire in the anodic oxidation electrolyte in sequence, so that the front of the titanium-based dental implant held by the titanium wire is opposite to the carbon rod. Stir at a speed of 250rpm, oxidize for 30min and then disconnect the anode to form a micro-nano morphology surface.

[0126] (7) Take out the titanium wire holding the titanium-based dental implant and soak it in deionized water for 5 minutes. Then clean it with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 5 minutes. After taking it out, dry it at room temperature under nitrogen atmosphere to obtain micro-nano titanium-based dental implant.

[0127] Experimental Example

[0128] 1. The surface morphology and surface elemental analysis of the dental implants prepared in Examples 1 and 1-2, including mesoporous silica nanoparticles, gold-modified mesoporous silica composite particles, and comparative examples 1-2, were observed. The results are as follows: Figures 1-6 As shown. Figures 3-5 It is known that acid etching and anodizing can achieve micro / nano-structural modification of smooth titanium surfaces. On the surface of micro / nano titanium-based dental implants loaded with gold-modified mesoporous silica composite particles (Au@MSNs), a large number of nanoscale particles are visible loaded on the surface and inside nanotubes with a diameter of approximately 100 nm. Figure 6 Elemental analysis shows that the surface of the micro / nano titanium-based dental implant loaded with Au@MSNs contains a certain amount of Si and Au elements in addition to O and Ti, indicating that the preparation method of the dental implant of the present invention can achieve Au@MSNs loading on the surface of the titanium-based dental implant.

[0129] 2. The hydrophilicity of the dental implant surfaces prepared in Examples 1 and 1-2 was tested. Deionized water was dropped onto the surface of each sample using an injection tube from an EasyDrop Standard (KRUSS GmbH, Germany). Images were captured 10 seconds after the droplets contacted the sample surface using a microscope. The results are as follows: Figure 7 As shown, compared to the smooth titanium-based dental implant (Comparative Example 1), the surface of the micro / nano titanium-based dental implant loaded with Au@MSNs in this invention maintains the high hydrophilicity of the micro / nano titanium structure surface (Comparative Example 2), with a contact angle of 5.4°±1.32°, showing good hydrophilic activity.

[0130] 3. The photothermal response of the titanium-based dental implant surface loaded with Au@MSNs prepared in Example 1 was tested; using an 808nm laser (1W / cm²). 2 The surface of a micro / nano titanium-based dental implant loaded with Au@MSNs was irradiated. The surface temperature at different irradiation times was recorded using an infrared thermometer, and temperature-time curves were plotted. The results are as follows: Figure 8 As shown. By Figure 8 It can be seen that under the irradiation of near-infrared light (808nm laser), the surface temperature of the micro-nano titanium-based dental implant loaded with Au@MSNs prepared in Example 1 showed a basically linear increase within 5 minutes, and reached the temperature that could completely inhibit bacterial growth, showing good photothermal and photocatalytic activity.

[0131] 4. The antibacterial properties of the dental implants prepared in Example 1 and Comparative Examples 1-2 were determined. Common oral streptococci were used as verification bacteria. The dental implants prepared in Example 1 and Comparative Examples 1-2 were inserted into solid trypsin-soybean agar medium contaminated with bacteria. The smooth titanium (ST)-based dental implant prepared in Comparative Example 1 served as a blank control group. Antibacterial treatment was performed daily using timed infrared light irradiation, with 10 minutes of near-infrared light applied every 8 hours. The infrared light wavelength was 808 nm, and the applied power was 1 W / cm². 2 The culture was continued for 5 days. After 5 days, the implants were removed, and the culture medium around the implants was separated. The culture medium was dispersed in tryptone-soybean broth medium to prepare a diluted bacterial suspension. An equal-sized culture medium without the antibacterial test area was used as a negative control, and the sterile tryptone-soybean broth suspension was used as a positive control. The absorbance of the bacterial suspension at 600 nm was measured. The relative inhibition rate was calculated using the formula: Inhibition rate = (A... 阴性 -A 样本 ) / (A 阴性 -A 阳性 ), where A is the absorbance of the solution; the results are as follows Figure 9As shown, compared with the micro-nano titanium-based dental implant (Comparative Example 2), the surface antibacterial rate of the micro-nano titanium-based dental implant loaded with Au@MSNs (Example 1) increased by more than double, reaching an antibacterial rate of about 90%, showing good antibacterial performance.

[0132] 5. Further investigation was conducted on the biological activity of the micro / nano titanium-based dental implant surface loaded with Au@MSNs by studying osteoblast ALP activity, collagen secretion, and matrix mineralization.

[0133] A. ALP alkaline phosphatase secretion detection: Dental implants prepared in Example 1 and Comparative Examples 1-2 were placed in a 24-well plate, and their surfaces were sealed with 2×10⁻⁶ plates. 4 MC3T3-E1 osteogenic progenitor cells were seeded per well and cultured. After 48 hours of seeding, the culture medium was replaced with osteogenic induction medium and cultured for 7 days. The specific formulation of this medium was as follows: containing 10% fetal bovine serum, 10 mM sodium β-glycerophosphate, 0.1 μM dexamethasone, 0.2 mM vitamin C, and the remainder α-MEM modified medium. After culture, the cells were transferred to new 24-well plates and fixed on ice with 4% paraformaldehyde solution for 15 min. ALP secretion was detected using the NBT / BCIP alkaline phosphatase activity kit, with sample added and color development for 20 min according to the kit instructions. After air drying at room temperature, the cells were observed and photographed under a stereomicroscope. The results are shown below. Figures 10-12 As shown.

[0134] B. Detection of Cellular Collagen Secretion: The surface treatment, cell culture, and seeding methods for the dental implants prepared in Examples 1 and Comparative Examples 1-2 were the same as those used in the ALP alkaline phosphatase secretion detection. Osteogenic induction culture was terminated after 2 weeks; the cells were then transferred to new 24-well plates, fixed with 4% paraformaldehyde solution on ice for 30 min, stained with 1% Sirius red / picric acid solution at room temperature for 24 h, the staining solution was discarded, and the cells were allowed to air dry at room temperature; the cell collagen secretion was observed using a stereomicroscope, and the results are as follows: Figures 13-15 As shown.

[0135] C. Extracellular matrix mineralization detection: The surface treatment, cell culture, and seeding methods for the dental implants prepared in Examples 1 and Comparative Examples 1-2 were the same as those used in the ALP alkaline phosphatase secretion detection. After 2 weeks of osteogenic induction culture, the culture was terminated. The implants were then transferred to new 24-well plates, fixed on ice with 4% paraformaldehyde solution for 30 min, and stained at room temperature with Alizarin Red solution (14.41 g Alizarin Red powder dissolved and mixed thoroughly in 100 mL of deionized water, pH adjusted to 4.1 and filtered) for 20 min. The staining solution was discarded, and the implants were allowed to air dry at room temperature. The extracellular matrix mineralization was observed using a stereomicroscope. The results are as follows: Figures 16-18 As shown.

[0136] Depend on Figures 10-18It can be seen that the surface of the micro-nano titanium-based dental implant loaded with Au@MSNs significantly enhances osteoblast ALP activity, collagen secretion capacity and matrix mineralization, indicating that the micro-nano titanium-based dental implant loaded with Au@MSNs is more conducive to improving the biological activity of osteoblast osteogenic differentiation.

[0137] 6. The biocompatibility of the dental implant surfaces prepared in Examples 1 and 1-2 was tested. Mesenchymal stem cells were seeded onto the surfaces of the dental implants prepared in Examples 1 and 1-2 and incubated for 3 days. Staining was then performed. The results are as follows: Figures 19-21 As shown. By Figures 19-21 It can be seen that the ratio of live to dead cells in the dental implants prepared in Example 1 and Comparative Examples 1-2 is basically the same, with a live to dead cell ratio of about 95%. This indicates that the surface of the micro-nano titanium-based dental implant loaded with Au@MSNs (Example 1) does not interfere with the proliferation of mesenchymal stem cells and has good cell compatibility with mesenchymal stem cells.

[0138] In summary, the micro / nano titanium-based dental implants loaded with Au@MSNs obtained by this invention have dual photothermal and dynamic functions. While possessing antibacterial properties, they significantly enhance the osteogenic activity of osteoblasts, exhibiting both high osteogenic activity and long-lasting antibacterial effects.

[0139] The present invention has been described according to the above embodiments. It should be understood that the above embodiments do not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent transformation fall within the scope of the present invention.

Claims

1. A method for preparing a micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles, characterized in that, Includes the following steps: (1) Pure titanium sheet is used as the implant matrix and polished and cleaned to obtain titanium-based dental implant; (2) The titanium-based dental implant is acid-etched to form a micron-pitted surface. (3) The titanium-based dental implant obtained in step (2) is anodized to form a micro-nano morphological surface, thus obtaining a pretreated titanium-based dental implant; (4) Preparation of mesoporous silica nanoparticles; (5) Preparation of a suspension of nano-gold modified mesoporous silica composite particles; (6) The pretreated titanium-based dental implant is immersed in a suspension of nano-gold modified mesoporous silica composite particles for 0.8-1.2 h, then removed and vacuum treated, and then placed at 35-38℃ overnight to obtain the product; The preparation of mesoporous silica nanoparticles in step (4) includes the following steps: S1: Dissolve the template agent in water at 45~55℃, heat to 75~85℃, and then add the alkali solution and mix well; S2: Dissolve the silicon source in methanol, then add the solution obtained from S1, stir to dissolve for 1.5~2.5 h, cool and centrifuge, take the precipitate and dry it at 55~65℃ for 23~25 h, then calcine it at 500~600℃ for 4.5~5.5 h; S3: Dissolve the solid obtained in S2 in toluene, add 3-aminopropyltriethoxysilane, and reflux condense at 75-85°C for 1.5-2.5 h; S4: Centrifuge the solution obtained in S3 at 7500~8500 rpm for 15~20 min, and dry the precipitate at 55~65℃ for 23~25 h; The preparation of the nano-gold modified mesoporous silica composite particle suspension in step (5) includes the following steps: S1: Add the stabilizer to the tetrachloroauric acid solution and stir at 90~110℃ for 15~25 min; S2: Cool the solution obtained in S1 to room temperature, add the dispersant while stirring, centrifuge at 12000~14000 rpm for 25~35 min, take the precipitate, wash it, and prepare a 0.125wt% gold nanoparticle suspension. S3: Mix the mesoporous silica nanoparticles obtained in step (4) with a 0.125wt% gold nanoparticle suspension and shake for 11-13 h to obtain a gold nanoparticle modified mesoporous silica composite particle suspension.

2. The method for preparing micro / nano titanium-based dental implants loaded with gold-modified mesoporous silica composite particles as described in claim 1, characterized in that, The polishing and cleaning in step (1) includes the following steps: polish the pure titanium sheet with 400~7000 grit sandpaper until the surface of the pure titanium sheet has a mirror effect, and then clean it with acetone, anhydrous ethanol and deionized water in sequence. Each cleaning time is 10~20 minutes. After taking it out, dry it at room temperature.

3. The method for preparing micro / nano titanium-based dental implants loaded with gold-modified mesoporous silica composite particles as described in claim 1, characterized in that, The acid etching in step (2) includes the following steps: placing the titanium-based dental implant in a 0.5% wt hydrofluoric acid aqueous solution with the front side facing up, letting it stand for 20 to 40 minutes, rinsing it with water for 10 to 15 minutes after removal, and then ultrasonically cleaning it with acetone, anhydrous ethanol and deionized water in sequence, with each cleaning time being 10 to 20 minutes, and then drying it at room temperature after removal.

4. The method for preparing micro / nano titanium-based dental implants loaded with gold-modified mesoporous silica composite particles as described in claim 1, characterized in that, The anodizing process in step (3) includes the following steps: S1: Hydrofluoric acid with a volume concentration of 40% and phosphoric acid with a volume concentration of 85% are added sequentially to water to form an anodic oxidation electrolyte; the volume ratio of water, hydrofluoric acid and phosphoric acid is 70~80:1:4~5. S2: Hold the titanium-based dental implant obtained in step (2) with titanium wire; S3: Set the electrolytic cell voltage to 18~22 V, connect the carbon rod to the cathode and the titanium wire obtained in S2 to the anode, and place the carbon rod and titanium wire in the anodic oxidation electrolyte in sequence, and stir and oxidize for 25~35 min at a speed of 250~350 rpm. S4: Take out the titanium wire and soak it in water for 4-6 minutes. Then, clean it with acetone, anhydrous ethanol and deionized water in sequence, with each cleaning time being 4-6 minutes. After cleaning, dry it at room temperature under an inert atmosphere.

5. The method for preparing micro / nano titanium-based dental implants loaded with gold nanoparticles modified mesoporous silica composite particles as described in claim 1, characterized in that, The alkaline solution is a 4 M sodium hydroxide solution; the template agent is hexadecyltrimethylammonium bromide; the silicon source is tetraethyl orthosilicate; the ratio of template agent, alkaline solution and silicon source is 0.3~0.5 g:1 mL:2.5~2.7 mL.

6. The method for preparing micro / nano titanium-based dental implants loaded with gold-modified mesoporous silica composite particles as described in claim 1, characterized in that, The stabilizer is a 3% (w / w) trisodium citrate solution; the dispersant is polyvinylpyrrolidone with a weight-average molecular weight of 54,000-56,000; the material-to-liquid ratio of the mesoporous silica nanoparticles to the 0.125 wt% gold nanoparticle suspension is 0.075-0.1 g:1 mL.

7. The method for preparing micro / nano titanium-based dental implants loaded with gold nanoparticles modified mesoporous silica composite particles as described in claim 1, characterized in that, The vacuum treatment process involves a pressure of -15 psi and a treatment time of 2 to 5 minutes.

8. A micro / nano titanium-based dental implant loaded with gold nanoparticles modified with mesoporous silica composite particles, prepared by the preparation method according to any one of claims 1 to 7.

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