A surface-modified medical titanium material with antibacterial effect, preparation method and application thereof

Abstract

The present invention provides a surface-modified medical titanium material with antibacterial effect, a preparation method and an application thereof, and belongs to the technical field of surface modification of metal materials. The surface-modified medical titanium material of the present invention is modified on the surface of pure titanium to achieve antibacterial effect, specifically by using gold nanoparticles as a carrier to load polyhexamethylene biguanide hydrochloride, thereby obtaining a modified titanium material with both antibacterial effect and extremely low cytotoxicity. The preparation method of the surface-modified medical titanium material comprises the following steps: using piranha lotion to obtain a plurality of hydroxyl functional groups on the titanium surface, then using 3-aminopropyltrimethoxysilane for grafting and loading, and then using gold nanoparticles and polyhexamethylene biguanide hydrochloride respectively to obtain a titanium modified material loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride through electrostatic adsorption. The pure titanium modified material prepared by the present invention has a significant antibacterial effect and has no toxic effect on cells, and can effectively prevent and treat postoperative infection of titanium implants.

Description

Technical Field

[0001] The present invention belongs to the technical field of surface modification of metal materials, and in particular relates to a surface-modified medical titanium material with antibacterial effect, a preparation method thereof and an application thereof. Background Art

[0002] With an aging population and increasing social activity, fractures and bone defects caused by transportation, sports, and industry are increasing, leading to a growing demand for bone replacement and repair materials. Biomedical titanium, with its advantages such as low density, low elastic modulus, excellent corrosion and fatigue resistance, and excellent biocompatibility, has become the material of choice for hard tissue implants. However, titanium lacks antimicrobial properties and is susceptible to bacterial infection. Bacteria adhere to the surface of titanium implants and secrete polysaccharide complexes such as polysaccharide matrix, fibrin, and lipoprotein, forming a biofilm. This biofilm not only absorbs nutrients from the surrounding environment, but also evades the body's defenses and provides strong resistance to most antibiotics. Consequently, once a bacterial infection occurs, treatment is extremely difficult, leading to the failure of titanium implants. Since the surface of titanium implants is in direct contact with the human environment, bacterial behavior is regulated by the surface properties of titanium. Therefore, constructing antimicrobial films on titanium surfaces to prevent bacterial adhesion and proliferation has become a hot topic in titanium implant material research.

[0003] Gold nanoparticles (GNPs) are widely used in biomedical fields such as photothermal therapy, controlled drug delivery, and bioimaging due to their low toxicity, plasmon resonance absorption properties, and ease of surface functionalization. Therefore, loading GNPs onto medical-grade pure titanium surfaces can effectively enhance the bone integration of titanium materials. For example, Chinese Patent 103451705A discloses the wet chemical loading of gold nanoparticles onto titanium oxide nanotubes. Gold nanoparticle-modified substrates exhibit excellent biocompatibility, promoting protein adhesion and the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells. The negatively charged surface of gold nanoparticles allows for the stable attachment of polyhexamethylene biguanide hydrochloride (PHMB) to the titanium surface via electrostatic adsorption. Thus, the gold nanoparticles act as a bridge between titanium and PHMB, resulting in significant antibacterial activity for the resulting gold nanoparticle-PHMB-modified titanium surface. This titanium surface modification process offers advantages such as ease of operation, stability, low cost, and ease of application.

[0004] PHMB is an antibacterial agent that is positively charged. After adsorbing with negatively charged bacteria, it can block the bacterial respiratory tract and inhibit bacterial division. The biguanide group in polyhexamethylene biguanide hydrochloride can also bind to the phosphatidylglycerol bilayer on the bacterial surface, causing damage to the bacterial cell wall, reduced membrane fluidity, leakage of ions, adenosine triphosphate, and proteins, and ultimately bacterial death. However, free PHMB is concentration-dependent in clinical antibacterial treatment. High doses of PHMB can cause the collapse of normal cell membrane structure, form transmembrane pores, rupture the cell membrane, leak intracellular substances, and cause certain toxic side effects to the human body. Therefore, how to reduce the effective concentration of PHMB while using its antibacterial properties has not yet been reported. Summary of the Invention

[0005] In response to the deficiencies in the prior art, the present invention discloses a surface-modified medical titanium material with antibacterial effect, a preparation method thereof, and an application thereof, to solve the problem of poor antibacterial performance of existing medical titanium metal materials. By performing antibacterial surface modification treatment on the surface of pure titanium, specifically using gold nanoparticles as a carrier to load polyhexamethylene biguanide hydrochloride, a modified titanium material with both antibacterial properties and low cytotoxicity is obtained.

[0006] A surface-modified medical titanium material with antibacterial properties is a modified material in which gold nanoparticles and polyhexamethylene biguanide hydrochloride are loaded on the surface of pure titanium, obtained by sequentially immersing pure titanium in a gold nanoparticle suspension and a polyhexamethylene biguanide hydrochloride solution;

[0007] The method for preparing the surface-modified medical titanium material having antibacterial effect comprises the following steps:

[0008] Step S1: Pure titanium surface pretreatment

[0009] The pure titanium was ultrasonically cleaned at least twice in a cleaning solution, then ultrasonically cleaned with deionized water, dried, immersed in a piranha cleaning solution, then ultrasonically cleaned with deionized water, and dried to obtain a pure titanium sample;

[0010] Step S2: Preparation of gold nanoparticles

[0011] The chloroauric acid solution was heated to boiling, and then sodium citrate solution was added, and the heating and boiling were continued for 10-30 minutes to obtain a gold nanoparticle suspension;

[0012] Step S3: Loading of gold nanoparticles

[0013] The pure titanium sample obtained in step S1 is ultrasonically treated in an aqueous solution of 3-aminopropyltrimethoxysilane (APS), and then the pure titanium sample is immersed in a suspension of gold nanoparticles coated with negatively charged citrate ions obtained in step S2, and the suspension is allowed to stand to obtain a titanium sample loaded with gold nanoparticles;

[0014] Step S4: Loading of polyhexamethylene biguanide hydrochloride (PHMB)

[0015] The titanium sample loaded with gold nanoparticles was immersed in a polyhexamethylene biguanide hydrochloride (PHMB) solution and allowed to stand, then washed and dried to obtain a surface-modified medical titanium material.

[0016] The cleaning solution in step S1 comprises hydrofluoric acid, concentrated nitric acid and deionized water, and the volume ratio of hydrofluoric acid, concentrated nitric acid and deionized water is (1-3): (4-6): 34;

[0017] The piranha washing solution in step S1 is composed of concentrated sulfuric acid and hydrogen peroxide, and the volume ratio of concentrated sulfuric acid to hydrogen peroxide is (2.5-3.5):1; the soaking time in the piranha washing solution is 2-5 hours;

[0018] The ultrasonic cleaning time in step S1 is 5-10 minutes;

[0019] The volume ratio of the chloroauric acid solution to the sodium citrate solution in step S2 is 100:3-8;

[0020] The mass concentration of the chloroauric acid solution in step S2 is 0.5-2%, and the mass concentration of the sodium citrate solution is 1-3%;

[0021] The volume fraction of 3-aminopropyltrimethoxysilane in the 3-aminopropyltrimethoxysilane aqueous solution in step S3 is 3-8%;

[0022] The ultrasonic time in step S3 is 1-3 hours;

[0023] The standing time in step S3 is 12-48 hours;

[0024] The mass volume concentration of the polyhexamethylene biguanide hydrochloride (PHMB) solution in step S4 is 15-30 mg / ml;

[0025] The standing time in step S4 is 12-24 hours.

[0026] The above-mentioned surface-modified medical titanium material with antibacterial effect is used as a titanium implant in the biomedical field.

[0027] The beneficial effects of the present invention are:

[0028] 1. The use of a piranha solution in the present invention generates numerous -OH functional groups on the titanium surface, facilitating the subsequent grafting of 3-aminopropyltrimethoxysilane (APS). Aqueous 3-aminopropyltrimethoxysilane (APS) can undergo stepwise hydrolysis in an aqueous environment to form silanol structures. Siloxane oligomers formed by dehydration condensation of the silanols can further react with the -OH groups on the titanium surface treated with the piranha solution to form Si-O covalent bonds, thereby grafting APS onto the titanium surface. Because APS contains positively charged -NH2 groups, the APS-grafted titanium surface exhibits a high positive charge in a liquid environment. The gold nanoparticles have a negative surface charge, while PHMB has a positive charge. The gold nanoparticles and polyhexamethylene biguanide hydrochloride are sequentially loaded via electrostatic adsorption, ultimately yielding a titanium-modified material loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride.

[0029] 2. The pure titanium modified material loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride prepared by the present invention has significant antibacterial effects against Escherichia coli and Staphylococcus aureus, effectively preventing and treating postoperative infections of titanium implants. Due to the excellent biocompatibility of the gold nanoparticles and the trace loading of polyhexamethylene biguanide hydrochloride, the pure titanium modified material loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride reduces the toxic side effects of high-concentration polyhexamethylene biguanide hydrochloride on cells, resulting in the modified titanium surface having no significant toxic effects on cells.

[0030] 3. The polyhexamethylene biguanide hydrochloride used in the present invention is a cationic antibacterial agent. It is fixed to the surface of biomedical pure titanium material using electrostatic self-assembly technology. The method is simple and efficient, the preparation process is stable and controllable, the operation is simple, the cost is low, and it is easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figures are scanning electron microscope images of the pure titanium surface after modification according to the present invention. In the figures, Ti represents the scanning electron microscope image of the titanium surface treated with piranha lotion, Ti-GNP represents the scanning electron microscope image of the titanium surface loaded with gold nanoparticles, and Ti-GNP-PHMB represents the scanning electron microscope image of the titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride.

[0032] Figure 2 EDS images of the titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride;

[0033] Figure 3Figure 3 is a graph showing the Zeta potential of pure titanium surface modified by the present invention as a function of electrolyte pH. In the graph, Ti represents the Zeta potential curve of titanium surface treated with piranha lotion as a function of electrolyte pH, Ti-APS represents the Zeta potential curve of titanium surface treated with piranha lotion and 3-aminopropyltrimethoxysilane as a function of electrolyte pH, Ti-GNP represents the Zeta potential curve of titanium surface loaded with gold nanoparticles as a function of electrolyte pH, and Ti-GNP-PHMB represents the Zeta potential curve of titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride as a function of electrolyte pH.

[0034] Figure 4 Figure 3 shows the effect of the modified pure titanium surface on the activity of E. coli. In the figure, Ti represents the activity of E. coli on the titanium surface treated with piranha solution, Ti-GNP represents the activity of E. coli on the titanium surface loaded with gold nanoparticles, and Ti-GNP-PHMB represents the activity of E. coli on the titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride.

[0035] Figure 5 Figure 3 shows the effect of the modified pure titanium surface on the activity of Staphylococcus aureus. In the figure, Ti represents the activity of Staphylococcus aureus on the titanium surface treated with piranha lotion, Ti-GNP represents the activity of Staphylococcus aureus on the titanium surface loaded with gold nanoparticles, and Ti-GNP-PHMB represents the activity of Staphylococcus aureus on the titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride.

[0036] Figure 6 : Figures 1 and 2 are scanning electron micrographs of Escherichia coli on a pure titanium surface modified by the present invention. In the figures, Ti represents a scanning electron micrograph of Escherichia coli on a titanium surface treated with piranha lotion, Ti-GNP represents a scanning electron micrograph of Escherichia coli on a titanium surface loaded with gold nanoparticles, and Ti-GNP-PHMB represents a scanning electron micrograph of Escherichia coli on a titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride.

[0037] Figure 7 Figure 3 is a scanning electron microscope image of Staphylococcus aureus on a pure titanium surface modified by the present invention. In the figure: Ti represents a scanning electron microscope image of Staphylococcus aureus on a titanium surface treated with piranha lotion, Ti-GNP represents a scanning electron microscope image of Staphylococcus aureus on a titanium surface loaded with gold nanoparticles, and Ti-GNP-PHMB represents a scanning electron microscope image of Staphylococcus aureus on a titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride.

[0038] Figure 8The present invention provides a scanning electron microscopic image of human osteosarcoma cells cultured on a pure titanium surface modified by the present invention for 24 hours. In the image: Ti represents a scanning electron microscopic image of human osteosarcoma cells cultured on a titanium surface treated with piranha lotion for 24 hours, Ti-GNP represents a scanning electron microscopic image of human osteosarcoma cells cultured on a titanium surface loaded with gold nanoparticles for 24 hours, and Ti-GNP-PHMB represents a scanning electron microscopic image of human osteosarcoma cells cultured on a titanium surface loaded with gold nanoparticles and polyhexamethylene biguanide hydrochloride for 24 hours. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to the accompanying drawings and the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, rather than to limit the present invention.

[0040] The amount of pure titanium used in the technical solution of the present invention is not specifically limited. During the surface modification process of pure titanium, the amount of cleaning solution, piranha lotion, 3-aminopropyltrimethoxysilane and polyhexamethylene biguanide hydrochloride (PHMB) used during immersion is sufficient to ensure that the pure titanium sample can be completely immersed.

[0041] In the embodiment of the present invention, the size of the pure titanium is 10 mm × 10 mm × 1 mm, and the amount of the cleaning solution, piranha lotion, 3-aminopropyltrimethoxysilane, and polyhexamethylene biguanide hydrochloride (PHMB) used is 1-3 ml;

[0042] The mass concentration of hydrofluoric acid in the cleaning solution of the present invention is 44-51%, and the mass concentration of concentrated nitric acid is 65-68%; the piranha cleaning solution is composed of concentrated sulfuric acid with a mass concentration of 95-98% and hydrogen peroxide with a mass concentration of 30%;

[0043] The present invention requires that the surface of the pure titanium be polished before being immersed in a cleaning solution, and then immersed in acetone, ethanol and deionized water in sequence and ultrasonically cleaned for 5-10 minutes each to remove stains on the titanium surface.

[0044] Example 1

[0045] Pure titanium surface pretreatment

[0046] After polishing, pure titanium of 10mm×10mm×1mm was ultrasonically cleaned with acetone, ethanol and deionized water in turn, each for 5 minutes, and then dried and set aside; it was ultrasonically cleaned twice with a mixed acid cleaning solution with a volume ratio of HF:HNO3:H2O=1:5:34, each for 5 minutes, and then ultrasonically cleaned with deionized water for 5 minutes, and then set aside; the pure titanium sample after the above acid treatment was immersed in a piranha cleaning solution of concentrated sulfuric acid and hydrogen peroxide with a volume ratio of 2.5:1 for 2 hours, and then ultrasonically cleaned with deionized water for 5 minutes. The titanium material (Ti) treated with piranha cleaning solution was properly preserved after drying.

[0047] Example 2

[0048] Pure titanium surface pretreatment

[0049] After polishing, pure titanium of 10mm×10mm×1mm was ultrasonically cleaned with acetone, ethanol and deionized water in turn, each for 5 minutes, and then dried and set aside; it was ultrasonically cleaned twice with a mixed acid cleaning solution with a volume ratio of HF:HNO3:H2O=3:6:34, each for 5 minutes, and then ultrasonically cleaned with deionized water for 5 minutes, and then set aside; the pure titanium sample after the above acid treatment was immersed in a piranha cleaning solution of concentrated sulfuric acid and hydrogen peroxide with a volume ratio of 3.5:1 for 5 hours, and then ultrasonically cleaned with deionized water for 5 minutes. The titanium material (Ti) treated with piranha cleaning solution was properly preserved after drying.

[0050] Figure 1 (Ti) is the surface morphology of the medical titanium material obtained by the modification treatment in Example 1. The figure shows that a honeycomb multi-level pore nanostructure appears on the surface of the modified material; Figure 3 (Ti) is the curve of the Zeta potential of the surface of the medical titanium material obtained by the modification treatment in Example 1 as a function of the pH of the electrolyte. It can be seen that the Zeta potential of the surface of the medical titanium material obtained by the modification treatment in Example 1 gradually decreases with the increase of the pH value; since the pH value of the in vivo environment is around 7.4, the Zeta potential of the material at a pH value of 7.4 is of particular interest; it can be seen that the Zeta potential of the Ti surface at a pH value of 7.4 is -54 mV, indicating that the surface of the medical titanium material obtained by the modification treatment in Example 1 forms a surface containing a large number of -OH groups, which is beneficial to the subsequent grafting of APS and the electrostatic adsorption of gold nanoparticles.

[0051] Example 3

[0052] Gold nanoparticle loading

[0053] 100 ml of 0.5% chloroauric acid solution was heated to boiling, and then 5 ml of 1% sodium citrate solution was added, and the mixture was heated for 10 minutes to obtain a gold nanoparticle suspension.

[0054] The titanium material treated in Example 1 was ultrasonically immersed in 2 ml of a 3% by volume 3-aminopropyltrimethoxysilane solution for 1 hour, ultrasonically cleaned with deionized water for 5 minutes, and dried to obtain a titanium material treated with a silane coupling agent (Ti-APS). The titanium material was then immersed in 2 ml of the gold nanoparticle suspension prepared above and allowed to stand for 12 hours. The titanium material was ultrasonically cleaned with deionized water for 5 minutes, and dried to obtain a titanium material loaded with gold nanoparticles (Ti-GNP).

[0055] Example 4

[0056] Gold nanoparticle loading

[0057] 100 ml of 2% chloroauric acid solution was heated to boiling, and then 8 ml of 3% sodium citrate solution was added, and the mixture was heated for 30 minutes to obtain a gold nanoparticle suspension.

[0058] The titanium material treated in Example 1 was ultrasonically immersed in 3 ml of 8% by volume 3-aminopropyltrimethoxysilane solution for 3 h, ultrasonically cleaned with deionized water for 5 min, and dried to obtain a titanium material treated with a silane coupling agent (Ti-APS). The titanium material was then immersed in 2 ml of the gold nanoparticle suspension prepared above and allowed to stand for 48 h. The titanium material was ultrasonically cleaned with deionized water for 5 min, and dried to obtain a titanium material loaded with gold nanoparticles (Ti-GNP).

[0059] Figure 3 (Ti-APS) is a curve showing the change in the surface Zeta potential of the medical titanium material obtained by treatment with 3-aminopropyltrimethoxysilane in Example 3 as a function of the electrolyte pH. It can be seen that the surface Zeta potential of the medical titanium material obtained by modification in Example 3 gradually decreases with increasing pH. Comparing the surface potentials of Ti and Ti-APS, it was found that the surface potential of Ti-APS was higher than that of Ti at the same pH value, indicating that the positively charged -NH2 group in the coupling agent significantly increased the Zeta potential of the APS-modified Ti-APS surface. The gold nanoparticles prepared by the sodium citrate method are coated with negatively charged citrate ions, so the gold nanoparticles can be loaded on the Ti-APS surface by electrostatic attraction. Figure 3 (Ti-GNP) is a curve showing the change of the surface Zeta potential of the medical titanium material modified in Example 3 with the pH of the electrolyte. Comparing the surface potentials of Ti-APS and Ti-GNP, it is found that the surface potential of Ti-GNP is lower than that of Ti-APS at the same pH value, indicating that the surface Zeta potential of Ti-GNP is reduced due to the loading of negatively charged gold nanoparticles. Figure 1(Ti-GNP) is the surface morphology of the medical titanium material obtained by the modification treatment in Example 3. The figure shows that the gold nanoparticles are uniformly loaded on the surface of Ti-GNP.

[0060] Example 5

[0061] The gold nanoparticle-loaded titanium material treated in Example 3 was immersed in 3 ml of a polyhexamethylene biguanide hydrochloride solution having a mass volume concentration of 15 mg / ml and allowed to stand for 12 h. After washing and drying, a surface-modified medical titanium material loaded with gold nanoparticles-polyhexamethylene biguanide hydrochloride (Ti-GNP-PHMB) was obtained.

[0062] Example 6

[0063] The gold nanoparticle-loaded titanium material treated in Example 3 was immersed in 1 ml of a polyhexamethylene biguanide hydrochloride solution having a mass volume concentration of 30 mg / ml and allowed to stand for 24 h. After washing and drying, a surface-modified medical titanium material loaded with gold nanoparticles-polyhexamethylene biguanide hydrochloride (Ti-GNP-PHMB) was obtained.

[0064] Figure 1 (Ti-GNP-PHMB) is the surface morphology of the medical titanium material obtained by the modification treatment in Example 5. The figure shows that the titanium surface loaded with polyhexamethylene biguanide hydrochloride retains a structure similar to that of Ti-GNP, indicating that loading with polyhexamethylene biguanide hydrochloride does not affect the surface morphology of the material treated in Example 3; Figure 2 This is the energy spectrum curve of the medical titanium material obtained by the modification treatment in Example 5. It can be seen from the figure that the surface components of the material contain Ti, O, Si, Au, and Cl elements, among which the Si element comes from the silane coupling agent, the Au element comes from the gold nanoparticles, and the Cl element comes from polyhexamethylene biguanide hydrochloride; Figure 3 (Ti-GNP-PHMB) is the curve of the surface Zeta potential of the titanium material obtained by the modification treatment in Example 5 as a function of the electrolyte pH. By comparing the surface potentials of Ti-GNP and Ti-GNP-PHMB, it is found that the surface potential of Ti-GNP-PHMB is higher than that of Ti-GNP at the same pH value, indicating that the surface Zeta potential value of the Ti-GNP-PHMB surface is increased due to the loading of positively charged polyhexamethylene biguanide hydrochloride.

[0065] The antibacterial activity of the titanium materials modified by the above-mentioned Examples 1, 3 and 5 was evaluated by using Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. The specific method is as follows: the sample to be tested was sterilized in 75% ethanol for 2 hours, and 60 μL of 10 7A bacterial droplet of 100 cfu / ml was placed on the surface of the sterilized sample and incubated in a 37°C constant temperature incubator for 24 hours. Then, AlamarBlue solution was added and the sample was placed in a 37°C constant temperature incubator for another 4 hours. The absorbance was measured at 570 nm and 600 nm using a microplate reader, and the bacterial activity was calculated according to the reagent instructions. The results are as follows: Figure 4 and Figure 5 As shown in the figure, the activity of Escherichia coli and Staphylococcus aureus on the surfaces of Ti-GNP and Ti-GNP-PHMB is lower than that of the Ti sample, while the activity of Escherichia coli and Staphylococcus aureus on Ti-GNP-PHMB is greatly reduced, indicating that the antibacterial effect of Ti-GNP material is weak, while Ti-GNP-PHMB material has higher antibacterial efficiency against Escherichia coli and Staphylococcus aureus.

[0066] The antibacterial activity of the titanium materials modified by the above-mentioned Examples 1, 3 and 5 was further evaluated by observing the morphology of Escherichia coli and Staphylococcus aureus using scanning electron microscopy (SEM). The specific method was as follows: the sample to be tested was sterilized in 75% ethanol for 2 hours, 60 μL of 10 7 A bacterial droplet of 100 cfu / ml was placed on the surface of a sterilized sample and incubated in a 37°C constant temperature incubator for 24 hours. Subsequently, a 2.5% glutaraldehyde solution was added to fix the bacteria. The sample was dehydrated and dried using gradient concentrations of ethanol and hexamethyldisilazane. Finally, the morphology of the bacteria on the sample surface was observed under SEM.

[0067] Figure 6 and Figure 7 Scanning electron microscopy images of Escherichia coli and Staphylococcus aureus cultured on the surfaces of titanium materials modified in Examples 1, 3, and 5 for 24 hours show that the bacteria on the Ti sample have intact surfaces and obvious filopodia, indicating good bacterial activity. Several bacteria on the Ti-GNP sample showed pitting and wrinkling, indicating that the growth of E. coli and Staphylococcus aureus on the Ti-GNP sample was somewhat inhibited. Bacteria on the Ti-GNP-PHMB sample showed bacterial lysis and cytoplasmic efflux, indicating that the titanium material modified in Example 5 has good antibacterial properties.

[0068] The activity test of modified titanium materials was conducted by inoculating human osteosarcoma cells (MG63) to simulate the application of modified medical titanium materials as titanium implants in biomedicine:

[0069] The cytotoxicity of the titanium materials modified by the above-mentioned Examples 1, 3 and 5 was evaluated by an activity test of human osteosarcoma cells (MG63) cultured in vitro for 24 hours. The specific method was as follows: after the sample was sterilized, 2×10 41 ml of cell suspension with a concentration of 100 cells / ml was inoculated on the sample surface and cultured in a constant temperature incubator at 37°C for 24 h. Then, 2.5% glutaraldehyde solution was added to fix the cells. The cells were dehydrated and dried using gradient concentrations of ethanol and hexamethyldisilazane. Finally, the morphology of MG63 on the sample surface was observed under SEM. The results are as follows. Figure 8 As shown;

[0070] Materials with antibacterial properties will basically produce a certain degree of toxicity to cells. Figure 8 It can be seen that the results of the cell experiment show that the Ti-GNP-PHMB sample has an antibacterial effect on Escherichia coli and Staphylococcus aureus, while having no obvious cytotoxicity to cells. In other words, the Ti-GNP-PHMB sample has an inhibitory effect on bacteria, but has no obvious toxicity to human cells; Figure 8 The cell images show that the surface cell appearances of the three samples are similar. The morphology of MG63 cells on Ti, Ti-GNP, and Ti-GNP-PHMB does not change significantly, indicating that the cell activity of the titanium sample in Example 5 after modification with GNP and PHMB does not decrease significantly compared with the sample before modification.

[0071] The above examples are merely partial embodiments of the present invention, but the scope of the present invention is not limited thereto. The various aspects and embodiments of the present invention disclosed herein are merely illustrative of specific ways to make and utilize the present invention. The order of the examples and the specific operations described do not limit the present invention in any way. Any substitutions and variations that can be readily conceived by researchers familiar with the art within the technical scope disclosed herein are intended to be within the scope of the present invention.

Claims

1. A surface-modified medical titanium material with antibacterial effect, characterized in that: The surface-modified medical titanium material with antibacterial effect is a modified material in which gold nanoparticles and polyhexamethylene biguanide hydrochloride are loaded on the surface of pure titanium, obtained by sequentially immersing pure titanium in a gold nanoparticle suspension and a polyhexamethylene biguanide hydrochloride solution; The components and volume fractions of the gold nanoparticle suspension are: chloroauric acid solution: sodium citrate solution = 100: 3-8; The mass concentration of the chloroauric acid solution is 0.5-2%; the mass concentration of the sodium citrate solution is 1-3%; The mass volume concentration of the polyhexamethylene biguanide hydrochloride solution is 15-30 mg / ml; The method for preparing the surface-modified medical titanium material with antibacterial effect comprises the following steps: Step S1: Loading of gold nanoparticles The pretreated pure titanium sample is ultrasonicated in a 3-aminopropyltrimethoxysilane aqueous solution, and then the pure titanium sample is immersed in a gold nanoparticle suspension and allowed to stand to obtain a titanium sample loaded with gold nanoparticles; the ultrasonication time is 1-3 hours, and the standing time is 12-48 hours; Step S2: Loading of polyhexamethylene biguanide hydrochloride The titanium sample loaded with gold nanoparticles is immersed in a polyhexamethylene biguanide hydrochloride solution and allowed to stand, and then washed and dried to obtain a surface-modified medical titanium material with antibacterial effect; the standing time is 12-24 hours.

2. The surface-modified medical titanium material with antibacterial effect according to claim 1, characterized in that: The processing process of the pretreated pure titanium sample in step S1 includes: ultrasonically cleaning the pure titanium in a cleaning solution for at least two times, then ultrasonically cleaning it with deionized water, drying it and immersing it in a piranha cleaning solution, then ultrasonically cleaning it with deionized water, and drying it to obtain the pretreated pure titanium sample; the ultrasonic cleaning time is 5-10 minutes.

3. The surface-modified medical titanium material with antibacterial effect according to claim 2, characterized in that: The cleaning solution includes hydrofluoric acid, concentrated nitric acid and deionized water, and the volume ratio of hydrofluoric acid, concentrated nitric acid and deionized water is (1-3): (4-6): 34; the piranha cleaning solution is composed of concentrated sulfuric acid and hydrogen peroxide, and the volume ratio of concentrated sulfuric acid and hydrogen peroxide is (2.5-3.5): 1; the immersion time in the piranha cleaning solution is 2-5 hours.

4. The surface-modified medical titanium material with antibacterial effect according to claim 1, characterized in that: The volume fraction of 3-aminopropyltrimethoxysilane in the 3-aminopropyltrimethoxysilane aqueous solution in step S1 is 3-8%.

5. The surface-modified medical titanium material with antibacterial effect according to claim 1, characterized in that: The preparation process of the gold nanoparticle suspension in step S1 is as follows: heating the chloroauric acid solution to boiling, adding the sodium citrate solution, and continuing to heat and boil for 10-30 minutes to obtain the gold nanoparticle suspension.

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