CN108404222B

CN108404222B - Porous titanium-based nano composite material for hard tissue material and preparation method and application thereof

Info

Publication number: CN108404222B
Application number: CN201810512957.2A
Authority: CN
Inventors: 皮立波; 孙若为; 温景成; 孙一绮; 杨志
Original assignee: Hunan Zaochen Nano Robot Co ltd
Current assignee: Hunan Zaochen Nano Robot Co ltd
Priority date: 2018-05-25
Filing date: 2018-05-25
Publication date: 2021-09-21
Anticipated expiration: 2038-05-25
Also published as: CN108404222A

Abstract

The invention provides a porous titanium-based composite material which comprises a porous titanium-based material, a hydroxyapatite layer compounded on the porous titanium-based material, and chitosan-vancomycin compounded on the hydroxyapatite layer. The invention reduces or eliminates the stress shielding effect through the porous titanium-based material, and has stronger binding force. The porous titanium-based composite material provided by the invention further comprises chitosan-vancomycin compounded on the outer surface, and the combination of the chitosan-vancomycin and the chitosan-vancomycin greatly solves the problems that the graft is easy to be infected after the existing osteogenic grafting operation, so that the graft is inflamed or functionally degenerated, the graft fails, the binding force problem exists and the drug slow-release time is short. The porous titanium-based composite material provided by the invention can well combine HAp, chitosan-functional medicine and a composite coating formed by the HAp, the chitosan-functional medicine and the composite coating by utilizing the porous structure, has better dispersibility and stronger binding force, obviously improves the slow release time, and has a long-term antibacterial effect.

Description

Porous titanium-based nano composite material for hard tissue material and preparation method and application thereof

Technical Field

The invention relates to the technical field of biomedical materials, relates to a porous titanium-based composite material, a preparation method and application thereof, and particularly relates to a porous titanium-based nanocomposite material for hard tissue materials, a preparation method thereof and application thereof in biomedical materials.

Background

With the increasing aging of the population and the dramatic increase in various accidental injuries, the number of patients with hard tissue defects is increasing, and as expected by the economic cooperation and development organization of the united nations, the market value of hard tissue repair products caused thereby will reach $ 8000 billion by 2020.

As an important component of biomedical materials, hard tissue materials play an important role in repairing defective hard tissues (bones, joints, etc.) of the human body and reconstructing lost physiological functions. Bone defect repair is mainly replaced by autologous bone graft, allogeneic bone graft and artificial materials. However, both autologous bone grafting and allogeneic bone grafting have drawbacks, and the manner of "cutting the flesh and supplementing sores" is not an ideal option and is also very limited in source; allograft bone transplantation also carries the risk of immunological rejection and donor-derived infection; therefore, the adoption of hard tissue repair artificial materials is an important method for repairing bone defects at present. Based on the special use environment of the bone substitute material, the requirements on the medical substitute material of human hard tissues are extremely strict, and the bone substitute material not only has good comprehensive mechanical properties, but also has excellent biological activity; the titanium alloy has excellent comprehensive mechanical properties and excellent wear resistance and corrosion resistance, but has higher elastic modulus relative to bone tissues, is easy to generate stress shielding to cause the degradation of the surrounding bone tissues, and belongs to a biological inert material despite good biocompatibility, lacks biological activity, is difficult to directly form chemical bonding with the bone tissues after being implanted, thereby causing lower bonding strength and easy loosening, thereby causing the failure of tissue reconstruction and repair.

Hydroxyapatite [ Ca ]₁₀(PO₄)₆(OH)₂]The HAp is an important biomedical material, has good biocompatibility and bioactivity, has chemical components and crystals similar to mineral apatite in bone tissues, is an important inorganic substance component forming the bone tissues of a human body, can perform interfacial reaction with the bone tissues to form chemical bonding, but has high brittleness, fracture toughness only 1/70-1/40 of titanium alloy, but poor mechanical properties, and greatly limits the application of the HAp in the field of biomedical materials.

Therefore, in the existing technology, in the hard tissue repair process replaced by artificial materials, the hydroxyapatite is combined with metal to form the composite coating, so as to make up the good bioactivity of the hydroxyapatite and facilitate the osteogenesis. For example, patent CN103014801A discloses an electrodeposition preparation method of titanium-based hydroxyapatite biomedical composite material, which is to prepare a hydroxyapatite coating on a titanium-based surface of a pretreated titanium or titanium alloy substrate by a constant-current or constant-voltage electrodeposition method, to improve the affinity and biocompatibility with the body, promote the growth of new bones, and has the advantages of simple preparation process, avoidance of high temperature during reaction, poor comprehensive mechanical properties, considerable comprehensive mechanical properties of metal substrates, less ideal bioactivity, and the like.

Therefore, how to obtain a composite material capable of being used for hard tissues to solve the above-mentioned complicated problems and defects, and to be better applied to the field of biomedical materials has become a problem to be solved by various manufacturers and first-line researchers in the field.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a porous titanium-based composite material, a preparation method and an application thereof, which is a porous titanium-based composite material for hard tissue materials, and the porous titanium-based composite material provided by the present invention can effectively reduce or eliminate the "stress shielding" effect, has good compatibility and bioactivity, has a lasting antibacterial effect, plays a role in cooperative repair and treatment, and improves the success rate of bone tissue repair so as to achieve a good controlled drug release effect.

The invention provides a porous titanium-based composite material which comprises a porous titanium-based material, a hydroxyapatite layer compounded on the porous titanium-based material, and chitosan-vancomycin compounded on the hydroxyapatite layer.

Preferably, the titanium-based material comprises titanium or a titanium alloy;

the aperture of the titanium-based material is 30-60 nm;

the porosity of the titanium-based material is 90-98.6%;

the titanium-based material has the size of (40-60) × (20-40) × (0.5-2 mm).

Preferably, the mass ratio of the titanium-based material to the hydroxyapatite is (10-20): 1;

the mass ratio of the titanium-based material to the chitosan-vancomycin is (40-70): 1;

the hydroxyapatite layer has a fine needle-shaped surface structure;

the chitosan-vancomycin has one or more of a flocculent structure, a petal-shaped structure, an ellipsoid-shaped structure and a blocky structure.

Preferably, the thickness of the hydroxyapatite layer is 6-15 μm;

the diameter of the fine needle is 1-4 mu m;

the chitosan-vancomycin is doped in needle clusters on the surface of the hydroxyapatite layer and/or covers the surface of the apatite layer.

The invention also provides a preparation method of the porous titanium-based composite material, which comprises the following steps:

1) carrying out anodic oxidation process and annealing treatment on the pretreated titanium-based material to obtain the titanium-based material with the porous structure surface;

mixing a chitosan and vancomycin mixed solution, calcium salt, phosphorus salt and water, and adjusting the pH value to obtain a first mixed solution;

2) carrying out electrodeposition on the titanium-based material with the porous structure surface obtained in the step and the first mixed solution to obtain a semi-finished product;

3) and (3) carrying out alkaline soaking treatment on the semi-finished product obtained in the step to obtain the porous titanium-based composite material.

Preferably, the pretreatment process comprises one or more of grinding, cleaning, drying and polishing;

the anodic oxidation process is a constant-pressure anodic oxidation process;

the oxidation voltage of the anodic oxidation is 10-20V;

the time of anodic oxidation is 1-3 h;

the oxidation temperature of the anodic oxidation is 20-30 ℃;

the anodized electrolyte comprises one or more of a hydrofluoric acid solution, an ammonium fluoride glycol organic electrolyte system and a hydrofluoric acid/sulfuric acid/water system;

the annealing temperature is 350-550 ℃;

the annealing time is 2-3 h;

the temperature rise rate of the annealing is 3-5 ℃/min.

Preferably, the mixing comprises the following specific steps:

mixing calcium salt, phosphate and water to obtain a calcium-phosphate mixed solution;

dissolving chitosan tablets in acid liquor, diluting to obtain a chitosan solution, stirring, taking supernatant, adding vancomycin into the supernatant, and mixing again to obtain a suspension;

and continuously mixing the suspension obtained in the step with the calcium phosphate mixed solution, and adjusting the pH value to obtain a first mixed solution.

Preferably, the calcium salt comprises Ca (NO)₃)₂、CaCl₂、Ca(NO₃)₂·4H₂One or more of O;

the phosphorus salt comprises (NH)₄)₂HPO₄、K₂HPO₄、KH₂PO₄And NaH₂PO₄One or more of;

the molar ratio of calcium to phosphorus in the calcium-phosphorus salt mixed solution is 5: 3;

the mass ratio of the calcium salt to the water is 7: (200-250);

the weight average molecular weight of the chitosan is 50-100 KDa;

the deacetylation degree of the chitosan is more than or equal to 95 percent;

the acid solution comprises a glacial acetic acid solution;

the mass concentration of the acid liquor is 1-2 wt%;

the concentration of the chitosan solution is 1-3 mg/mL;

the mass ratio of chitosan to vancomycin in the suspension is 1: (5-10);

the pH value is 4-6.2.

Preferably, the temperature of the electrodeposition is 30-40 ℃;

the electrodeposition is specifically electrodeposition by adopting a step current rise method;

the deposition current of the first step of the electro-deposition is 0.5-1.0A; the deposition time of the first step of the electrodeposition is 5-10 min;

the deposition current of the second step of the electro-deposition is 1.0-1.5A; the deposition time of the second step of the electrodeposition is 5-10 min;

the deposition current of the third step of the electro-deposition is 1.5-3.0A; the deposition time of the third step of the electro-deposition is 20-40 min;

the time of the alkali soaking treatment is 2-3 h;

the concentration of the alkali liquor for the alkali soaking treatment is 1.0-1.5 mol/L;

the alkali liquor for alkali soaking treatment comprises sodium hydroxide solution and/or ammonia water.

The porous titanium-based composite material according to any one of the above technical schemes or the porous titanium-based composite material prepared by the preparation method according to any one of the above technical schemes is applied to biomedical materials.

The invention provides a porous titanium-based composite material which comprises a porous titanium-based material, a hydroxyapatite layer compounded on the porous titanium-based material, and chitosan-vancomycin compounded on the hydroxyapatite layer. Compared with the prior art, the invention aims at the defects that the existing hard tissue material has stress shielding, causes the degradation of the surrounding bone tissue, lacks the bioactivity, is difficult to directly form chemical bonding with the bone tissue after being implanted and the like. The invention considers that the metal sample without surface modification treatment generally has higher elastic modulus, high rigidity and higher elastic modulus relative to bone tissues, is easy to generate stress shielding to cause the degradation of the surrounding bone tissues, and then passes through the porous titanium-based material to react with titaniumPreparing regular TiO with high specific surface on the surface of base material₂The nano porous structure utilizes the porosity to influence the overall density, strength and elastic modulus of the titanium alloy implant, thereby reducing or eliminating the stress shielding effect. And TiO₂The nano porous structure has high specific surface area and rough surface, has good compatibility and bioactivity, and a layer of compact hydroxyapatite (HAp) is deposited on the surface of the porous structure, so that the nano porous structure has stronger binding force, and the defect that the existing composite coating is low in binding strength and easy to loosen, so that the tissue reconstruction and repair are failed is effectively overcome.

The present invention is directed to implant infection, one of the most serious complications in orthopedic and trauma surgeries, which is caused by adhesion of microorganisms on the surface of biomedical materials after surgical transplantation, and is called "Biomaterial-associated infection (BCI)", which not only reduces the success rate of tissue repair, but also may cause critical problems of low function, implantation failure, chronic osteomyelitis and even death in severe cases. The porous titanium-based composite material provided by the invention further comprises chitosan-vancomycin compounded on the outer surface, wherein the chitosan is the only natural cationic polymer in nature, has good performances of no toxicity, biocompatibility, biodegradability, bioadhesion, antibiosis, procoagulant coagulation and the like, has pH responsiveness, and is cationic when the pH is less than 6.3; vancomycin is a glycopeptide antibiotic, kills bacteria by inhibiting the growth and reproduction of the bacteria, is widely used as a functional antibacterial drug for treating and preventing osteomyelitis and deep infection, plays a role in cooperative repair treatment, improves the success rate of bone tissue repair to achieve a good drug controlled release effect, and greatly solves the problems that a transplant body is easy to be infected after an existing-stage bone grafting operation, inflammation or function degradation of the transplant body is caused, and the transplantation fails, so that a composite coating consisting of functional drugs has a binding force problem, and the drug is mostly slowly released for about one month.

The porous titanium-based composite material provided by the invention can well combine HAp, chitosan-functional medicine and a composite coating formed by the HAp, the chitosan-functional medicine and the composite coating by utilizing the porous structure, has better dispersibility and stronger binding force, obviously improves the slow release time, and has a long-term antibacterial effect.

Experimental results show that the matrix of the porous titanium-based composite material prepared by the invention has a honeycomb porous structure, the matrix has a high specific surface area, the pore diameter is 30-60 nm, the porosity reaches 90-98.6%, the multifunctional composite coating is compactly combined with the honeycomb porous structure, the combination effect is good, the initial burst release amount of the composite material is only about 0.23g, the burst release rate is about 28.75%, the cumulative release can be prolonged to more than one month, and the durable antibacterial effect can be well achieved.

Drawings

FIG. 1 is a surface SEM topography of a titanium-based material with a porous structure surface prepared in example 1 of the present invention;

FIG. 2 is an enlarged partial SEM topography map of the surface of the titanium-based material with the porous structure surface prepared in example 1 of the present invention;

FIG. 3 is an electrodeposition experimental apparatus used in an embodiment of the present invention;

FIG. 4 is an SEM topography of a multi-coating composite type functional drug-loaded material prepared in example 1 of the present invention;

FIG. 5 is an SEM topography of a semi-finished product which is not treated with an alkaline bath after electrodeposition in example 3 of the invention;

FIG. 6 is an SEM image of the porous titanium-based composite material after electrodeposition and alkali bath treatment in example 3 of the invention;

FIG. 7 is a graph showing the cumulative release rate of vancomycin drug from the porous titanium-based composite material prepared in example 3 of the present invention.

Detailed Description

For a further understanding of the invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are included merely to further illustrate the features and advantages of the invention and are not intended to limit the invention to the claims.

All of the starting materials of the present invention, without particular limitation as to their source, may be purchased commercially or prepared according to conventional methods well known to those skilled in the art.

All the raw materials of the invention are not particularly limited in purity, and the invention preferably adopts pure medicines or conventional purity in the medical field.

All the noun expressions and acronyms of the invention belong to the conventional noun expressions and acronyms in the field, each noun expression and acronym is clearly and definitely clear in the relevant application field, and a person skilled in the art can clearly, exactly and uniquely understand the noun expressions and acronyms.

The titanium-based material is not particularly limited in the present invention, and may be selected and adjusted by those skilled in the art according to the actual application, product requirements and product properties, and preferably comprises titanium or a titanium alloy, more preferably a titanium alloy, and the titanium alloy may specifically comprise one or more of Ti-6Al-4V, Ti-3Al-2.5V, Ti-6Al-7Nb and Ti-5Al-2.5Fe, more preferably Ti-6Al-4V, Ti-3Al-2.5V, Ti-6Al-7Nb or Ti-5Al-2.5 Fe.

The specific parameters of the porous titanium-based material are not particularly limited, and the parameters of the conventional porous material known to those skilled in the art can be used, and the parameters can be selected and adjusted by those skilled in the art according to the actual application condition, the product requirements and the product performance, and the pore diameter of the porous titanium-based material is preferably 30-60 nm, more preferably 35-55 nm, and more preferably 40-50 nm. The porosity of the porous titanium-based material is preferably 90-98.6%, more preferably 91-97%, and more preferably 93-95%. The size of the titanium-based material is preferably (40-60) × (20-40) × (0.5-2 mm), more preferably (43-58) × (22-38) × (0.8-1.8 mm), more preferably (45-55) × (25-35) × (1.0-1.5 mm), and more preferably (47-52) × (27-32) × (1.1-1.4 mm).

The present invention is not particularly limited in the composite state of the hydroxyapatite layer, and may be defined by a composite known to those skilled in the art, and the present invention is preferably coated, half-coated, laminated or generated, more preferably coated or half-coated, and most preferably coated. The coating is not particularly limited in the present invention, and may be defined by a coating known to those skilled in the art, and the present invention is preferably a full coating. The hydroxyapatite provided by the invention not only forms a layer on the surface of the titanium-based material, but also fills the pores on the surface of the titanium-based material.

The thickness of the hydroxyapatite layer is not particularly limited, and can be selected and adjusted by the skilled in the art according to the actual application condition, the product requirement and the product performance, and the thickness of the hydroxyapatite layer is preferably 6-15 μm, more preferably 8-13 μm, and more preferably 10-11 μm. The adding amount of the hydroxyapatite is not particularly limited, and a person skilled in the art can select the hydroxyapatite according to the actual application condition, the product requirement and the product performance, wherein the mass ratio of the titanium-based material to the hydroxyapatite is preferably (10-20): 1, more preferably (12-18): 1, more preferably (14 to 16): 1.

the surface morphology of the hydroxyapatite layer is not particularly limited in the present invention, and those skilled in the art can select and adjust the surface morphology according to the actual application, product requirements and product performance, and the hydroxyapatite layer of the present invention particularly preferably has a fine needle-like surface structure, and more preferably a specific multiple needle-cluster surface structure. The diameter of the fine needle is preferably 1-4 μm, more preferably 1.5-3.5 μm, and still more preferably 2-3 μm.

The present invention does not particularly limit the complex state of the chitosan-vancomycin, and may be defined as a complex known to those skilled in the art, and the present invention is preferably one or more of doping, coating, half-coating, stacking and embedding, and more preferably, is more preferably one or more of doping, stacking and embedding.

The parameters of the chitosan-vancomycin are not particularly limited in the present invention, and may be conventional parameters well known to those skilled in the art, and those skilled in the art may select and adjust the parameters according to the actual application situation, the product requirements and the product performance. The adding amount of the hydroxyapatite is not particularly limited, a person skilled in the art can select the hydroxyapatite according to the actual application condition, the product requirement and the product performance, and the mass ratio of the titanium-based material to the chitosan-vancomycin is preferably (40-70): 1, more preferably (45-65): 1, more preferably (50 to 60): 1.

the form of the chitosan-vancomycin is not particularly limited, and a person skilled in the art can select and adjust the form according to the actual application condition, the product requirement and the product performance. The chitosan-vancomycin of the present invention preferably has one or more of a flocculent structure, a petal-shaped structure, an ellipsoid-shaped structure and a block-shaped structure, more preferably has a plurality of flocculent structures, petal-shaped structures, ellipsoid-shaped structures and block-shaped structures, and more preferably has flocculent and petal-shaped structures. According to the invention, the appearance of the chitosan-vancomycin can be controlled through the conditions of alkali treatment time, temperature and the like, so that the ellipsoidal structure blooms to form more floccules and petals.

The selection and proportion of the raw materials in the preparation method and the corresponding preferred principle are consistent with the selection and proportion of the materials of the porous titanium-based composite material and the corresponding preferred principle, and the detailed description is omitted here.

The invention firstly carries out anodic oxidation process and annealing treatment on the pretreated titanium-based material to obtain the titanium-based material with the porous structure surface.

The pretreatment process of the titanium-based material is not particularly limited in the present invention, and may be a conventional pretreatment process of such materials, which is well known to those skilled in the art, and can be selected and adjusted by those skilled in the art according to actual production conditions, product requirements and product properties, and the pretreatment process of the present invention preferably includes one or more of grinding, cleaning, drying and polishing, more preferably, a plurality of grinding, cleaning, drying, polishing, cleaning and drying, and more preferably, grinding, cleaning, drying, polishing, cleaning and drying are sequentially performed. The polishing according to the invention is preferably electrochemical polishing.

In order to further improve the performance of the final product, complete and refine the preparation process, the pretreatment process specifically comprises the following steps:

1) sequentially polishing the titanium alloy with the size of 40 multiplied by 20 multiplied by 1mm by using sandpaper of No. 220, No. 400, No. 600, No. 800 and No. 1000, then respectively putting the titanium alloy into acetone, absolute ethyl alcohol and deionized water, respectively carrying out ultrasonic cleaning for 10-15 min, and drying the titanium alloy for later use by cold air after the cleaning is finished;

2) the samples obtained above were mixed in phosphoric acid: sulfuric acid: carrying out electrochemical polishing in polishing solution with the volume ratio of 1:3:10, carrying out electrochemical polishing in an oil bath device at the temperature of 80-90 ℃, simultaneously carrying out magnetic stirring at the stirring speed of 800-1200 r/min, and carrying out polishing by adopting a constant current method at the current density of 25-50A/dm²And (4) polishing for 10-20 s, ultrasonically cleaning the polished sample for 10-15 min by using deionized water, taking out and washing the sample, and drying the sample by using cold air. The non-reactive side was then packaged with scotch tape at 20X 20mm for use to control the reaction area and prevent edge polarization.

The anodizing process is not particularly limited in the present invention, and may be performed by a conventional anodizing process of such materials, which is well known to those skilled in the art, and may be selected and adjusted by those skilled in the art according to actual production conditions, product requirements and product performance, and the anodizing process of the present invention is preferably a constant pressure anodizing process. The specific parameters of the anodic oxidation process are not particularly limited, and the parameters of the conventional anodic oxidation process known by the skilled in the art can be used, and the skilled in the art can select and adjust the parameters according to the actual production condition, the product requirements and the product performance, and the oxidation voltage of the anodic oxidation process is preferably 10-20V, more preferably 12-18V, and more preferably 14-16V. The time of the anodic oxidation is preferably 1-3 h, more preferably 1.2-2.8 h, and more preferably 1.5-2.5 h. The oxidation temperature of the anodic oxidation is preferably 20-30 ℃, more preferably 22-28 ℃, and more preferably 24-26 ℃. The stirring speed of the anodic oxidation process is preferably 800-1200 r/min, more preferably 850-1150 r/min, and more preferably 900-1100 r/min. The anodized electrolyte solution of the present invention preferably comprises one or more of a hydrofluoric acid solution, an ammonium fluoride glycol organic electrolyte system, and a hydrofluoric acid/sulfuric acid/water system, more preferably a hydrofluoric acid solution, an ammonium fluoride glycol organic electrolyte system, or a hydrofluoric acid/sulfuric acid/water system, and most preferably a hydrofluoric acid solution.

The specific parameters of the hydrofluoric acid solution are not particularly limited in the present invention, and those skilled in the art can select and adjust the concentration according to actual production conditions, product requirements and product performance, and the concentration of the hydrofluoric acid solution of the present invention is preferably 0.3 wt% to 0.7 wt%, more preferably 0.35 wt% to 0.65 wt%, more preferably 0.4 wt% to 0.6 wt%, and more preferably 0.45 wt% to 0.55 wt%.

The anodic oxidation process preferably adopts a double-electrode system, preferably takes the pretreated titanium-based material as an anode, more preferably adopts a graphite electrode as a counter electrode, and particularly preferably takes out a sample after anodic oxidation, rapidly washes the sample with a large amount of deionized water, and dries the sample at room temperature.

The annealing treatment is carried out subsequently, specific parameters of the annealing treatment are not particularly limited, and the parameters of the conventional annealing treatment known by the skilled in the art can be selected and adjusted by the skilled in the art according to the actual production condition, the product requirement and the product performance, and the temperature of the annealing treatment is preferably 350-550 ℃, more preferably 375-525 ℃, more preferably 400-500 ℃, and more preferably 425-575 ℃. The annealing time is preferably 2-3 h, more preferably 2.2-2.8 h, and more preferably 2.4-2.6 h. The heating rate of the annealing is preferably 3-5 ℃/min, more preferably 3.2-4.8 ℃/min, and more preferably 3.5-4.5 ℃/min. The annealing treatment is preferably carried out in a tubular annealing furnace in an air atmosphere, and the material is taken out for later use after the annealing treatment is finished and the furnace is cooled to room temperature.

The invention also mixes the chitosan and vancomycin mixed solution, calcium salt, phosphate and water, and adjusts the pH value to obtain a first mixed solution.

The specific choice of the calcium salt is not particularly limited in the present invention, and may be a common calcium salt well known to those skilled in the art, and those skilled in the art can select and adjust the calcium salt according to actual production conditions, product requirements and product performance, and the calcium salt preferably comprises Ca (NO)₃)₂、CaCl₂、Ca(NO₃)₂·4H₂One or more of O, more preferably Ca (NO)₃)₂、CaCl₂Or Ca (NO)₃)₂·4H₂And O. The specific selection of the phosphorus salt is not particularly limited in the present invention, and may be common phosphorus salts known to those skilled in the art, and those skilled in the art can select and adjust the phosphorus salt according to actual production conditions, product requirements and product properties, and the phosphorus salt preferably comprises (NH)₄)₂HPO₄、K₂HPO₄、KH₂PO₄And NaH₂PO₄More preferably (NH)₄)₂HPO₄、K₂HPO₄、KH₂PO₄Or NaH₂PO₄。

The specific selection of the chitosan is not particularly limited, and the chitosan can be commonly used as is well known by the technicians in the field, and the technicians in the field can select and adjust the chitosan according to the actual production condition, the product requirement and the product performance, wherein the weight average molecular weight of the chitosan is preferably 50-100 KDa, more preferably 60-90 KDa, and more preferably 70-80 KDa. The degree of deacetylation of the chitosan of the present invention is preferably 95% or more, more preferably 96% or more, and still more preferably 98% or more.

The specific steps and parameters of the mixing are not particularly limited in the present invention, and the mixing steps and parameters of the conventional raw materials well known to those skilled in the art can be selected and adjusted according to the actual production situation, product requirements and product performance, and in order to ensure the performance of the final product, complete and refine the process flow, the specific steps of the mixing, i.e. the above steps, are preferably:

The dosage of the calcium salt and the phosphorus salt is not particularly limited by the invention, and the dosage is conventional dosage well known to those skilled in the art, and can be selected and adjusted by those skilled in the art according to actual production conditions, product requirements and product performance, in order to ensure better formation of hydroxyapatite and facilitate deposition of formed Hap on a titanium-based porous surface, the molar ratio of calcium to phosphorus in the calcium-phosphorus salt mixed solution is preferably 5: 3.

the amount of the water used in the present invention is not particularly limited, and may be any conventional amount well known to those skilled in the art, and those skilled in the art can select and adjust the amount according to actual production conditions, product requirements and product properties, and the mass ratio of the calcium salt to the water in the present invention is preferably 7: (200-250), more preferably 7: (210-240), more preferably 7: (220-230).

The specific selection and parameters of the acid solution are not particularly limited in the present invention, and may be common acid solutions and parameters well known to those skilled in the art, and those skilled in the art may select and adjust the acid solution according to actual production conditions, product requirements and product performance, and the acid solution in the present invention preferably includes glacial acetic acid solution. The mass concentration of the acid solution is preferably 1wt% to 2wt%, more preferably 1.2 wt% to 1.8 wt%, and more preferably 1.4 wt% to 1.6 wt%.

The concentration of the chitosan solution is preferably 1-3 mg/mL, more preferably 1.2-2.8 mg/mL, more preferably 1.5-2.5 mg/mL, and more preferably 1.8-2.2 mg/mL. The dosage of the chitosan and the vancomycin is not particularly limited, and the dosage is conventional dosage well known to those skilled in the art, and those skilled in the art can select and adjust the dosage according to actual production conditions, product requirements and product performance, the mass ratio of the chitosan to the vancomycin in the suspension, namely the mass ratio of the chitosan to the vancomycin in the final product, is preferably 1: (5-10), more preferably 1: (6-9), more preferably 1: (7-8).

The specific selection of the pH value is not particularly limited, and a person skilled in the art can select and adjust the pH value according to the actual production condition, the product requirements and the product performance, and in order to better ensure the effect of the final product and ensure the pH responsiveness of chitosan, the pH value is preferably 4-6.2, more preferably 4.2-6.0, more preferably 4.5-5.7, more preferably 5-5.5, and particularly 4.5-5.

In order to ensure the performance of the final product, complete and refine the process flow, the specific steps of mixing, namely the steps, can be as follows:

accurately weighing Ca (NO) at room temperature₃)₂·4H₂O and (NH)₄)₂HPO₄Respectively placing the mixture into 150ml beakers, then respectively adding deionized water, after uniformly stirring and dissolving, pouring the mixture into 500ml beakers for mixing to ensure that the ratio of Ca:and (3) P is 5:3 (molar ratio), dissolving chitosan sheets (Mw is 50-100 KDa, DD is more than or equal to 95%) in glacial acetic acid, adding a chitosan solution prepared from deionized water, centrifugally stirring (50ml of a centrifuge tube), taking supernatant, adding a certain amount of vancomycin powder into the supernatant to prepare a high polymer suspension, wherein the mass ratio of vancomycin to chitosan in the suspension is 5-10, adding the prepared high polymer suspension into a water-soluble calcium phosphate solution, adjusting the liquid level height to be 250ml, and finally adjusting the pH of the solution to be 4.5-5.

According to the invention, the titanium-based material with the porous structure surface and the first mixed solution obtained in the above steps are subjected to electrodeposition to obtain a semi-finished product.

The specific steps and parameters of the electrodeposition are not particularly limited in the present invention, and the electrodeposition steps and parameters of the conventional raw materials well known to those skilled in the art can be selected and adjusted according to the actual production conditions, product requirements and product performance, and the electrodeposition in the present invention is particularly preferably performed by using a step current rising method. The temperature of the electrodeposition is preferably 30-40 ℃, more preferably 32-38 ℃, and more preferably 34-36 ℃. The deposition current of the electrodeposition is preferably 0.5-3.0A, more preferably 1-2.5A, and more preferably 1.5-2.0A. The deposition time of the electrodeposition is preferably 30-60 min, more preferably 35-55 min, and more preferably 40-50 min.

The step current rising method for carrying out electrodeposition can be divided into 2-5 sections, or 3-4 sections, or 3 sections.

The specific processes and parameters of the electrodeposition of the present invention may be:

the deposition current of the first step of the electrodeposition is preferably 0.5-1.0A, more preferably 0.6-0.9A, and more preferably 0.7-0.8A. The deposition time of the first step of the electrodeposition is preferably 5-10 min, more preferably 6-9 min, and still more preferably 7-8 min. The deposition current of the second step of the electro-deposition is preferably 1.0-1.5A, more preferably 1.1-1.4A, and more preferably 1.2-1.3A. The deposition time of the second step of the electrodeposition is preferably 5-10 min, more preferably 6-9 min, and still more preferably 7-8 min. The deposition current of the third step of the electro-deposition is preferably 1.5-3.0A, more preferably 1.7-2.8A, and more preferably 2.0-2.5A. The deposition time of the third step of the electrodeposition is preferably 20-40 min, more preferably 22-38 min, and still more preferably 25-35 min.

In order to ensure the deposition effect, complete and refine the process flow, the specific steps of the electrodeposition can be as follows:

putting a 500ml beaker into a constant-temperature heating magnetic stirrer, connecting an anode with a graphite electrode, connecting a cathode with a sample as a working electrode, wherein the electrode spacing is 3cm, placing the working electrode in a deposition solution before deposition, stabilizing for 1-2 min, wherein the electrodeposition temperature is 30-40 ℃, the stirring speed is 800-1200 r/min, simultaneously adopting a step current rise method, firstly depositing for 5-10 min by using 0.5-1.0A current, then raising the current to 1.0-1.5A, then depositing for 5-10 min, finally raising the current to 1.5-3.0A, stabilizing and depositing for 20-40 min, taking out the sample after deposition, cleaning by using deionized water, and naturally air-drying.

Finally, the porous titanium-based composite material, namely the multi-coating composite type functional drug-loaded material, is obtained after the semi-finished product obtained in the step is subjected to alkaline soaking treatment.

The specific steps and parameters of the alkali soaking treatment are not particularly limited, and the steps and parameters of the conventional alkali soaking treatment known to those skilled in the art can be selected and adjusted by those skilled in the art according to the actual production condition, product requirements and product performance, and the time of the alkali soaking treatment in the invention is preferably 2-3 hours, more preferably 2.2-2.8 hours, and more preferably 2.4-2.6 hours. The temperature of the alkali soaking is preferably 36.5-37.5 ℃, more preferably 36.7-37.3 ℃, and more preferably 36.9-37.1 ℃. The concentration of the alkali liquor for the alkali soaking treatment is preferably 1.0-1.5 mol/L, more preferably 1.1-1.4 mol/L, and more preferably 1.2-1.3 mol/L. The alkali solution for alkali soaking treatment according to the present invention preferably includes a sodium hydroxide solution and/or ammonia water, more preferably a sodium hydroxide solution or ammonia water, and still more preferably a sodium hydroxide solution.

In order to ensure the effect of in-situ synthesis of the HAp coating with bioactivity by alkali bath soaking hydrolysis and further improve the performance of a product, complete and refine the process flow, the alkali soaking treatment can comprise the following specific steps:

and (3) carrying out alkali bath soaking treatment on the air-dried sample (semi-finished product) in NaOH solution for 2-3 h to obtain an alkali liquor treatment sample, taking out the alkali liquor treatment sample, washing the surface with deionized water, and naturally air-drying to obtain the coating composite type functional drug-loaded material.

The invention provides a porous titanium-based composite material for a hard tissue material and a preparation method thereof, and aims at solving the problem that the prior art of stress shielding cannot eliminate the problem, and the essence of the porous titanium-based composite material is that a metal sample which is not subjected to surface modification treatment generally has higher elastic modulus and high rigidity, and the elastic modulus is higher relative to bone tissues, so that stress shielding is easily generated to cause the degradation of the surrounding bone tissues. Therefore, the invention can prepare more regular nano holes or nano tubes by controlling the parameters of the anodic oxidation process, and can reduce or eliminate the influence caused by stress shielding as much as possible according to the actual situation.

The invention also aims at the problem that the existing method for preparing HAp by hydrothermal synthesis has good effect, but is carried out at higher temperature and higher pressure, takes time, and mostly deposits HAp on the surface which is not modified, but has lower bonding strength compared with the modified composite coating, and is easy to loosen, thereby causing the failure of tissue reconstruction and repair. The invention makes use of TiO₂The specific surface area of the nano porous structure is high, the modified rough porous structure surface has good compatibility and bioactivity, and a layer of dense CaHPO with strong binding force is deposited on the porous structure surface by an electrodeposition method₄·2H₂And the O calcium phosphate layer is subjected to alkali bath soaking hydrolysis to synthesize the HAp coating with bioactivity in situ, so that the problem of low bonding strength in the prior art is effectively solved.

The invention also aims at the problem that the bone tissue transplantation infection is one of the important reasons causing the failure of the osteogenesis transplantation, silver ions are adopted as an antibacterial agent, potential safety hazards exist, and the functional medicine is adopted for auxiliary treatment, so that although good curative effect can be achieved, the controlled release time of the medicine generally lasts only one or two weeks, and the clinical slow release time is relatively long. The composite coating prepared by the invention can well combine HAp, chitosan-functional medicine and the composite coating formed by the HAp and the chitosan-functional medicine by utilizing a porous structure, has better dispersity and stronger binding force, obviously improves the slow release time, has a long-term antibacterial effect, and greatly solves the problems that the composite coating formed by the functional medicine has the binding force problem and the slow release time of the medicine is mostly about one month, and the composite coating formed by the functional medicine has short time because the composite coating is easily infected after the existing osteogenic transplantation to cause inflammation or function degradation of a transplant body and cause transplantation failure.

The invention also provides application of the porous titanium-based composite material or the porous titanium-based composite material prepared by the preparation method in any one of the technical schemes in biomedical materials.

The biomedical material is more preferably a hard tissue material, has important effects on repairing defective human hard tissues (bones, joints and the like) and reconstructing lost physiological functions and the like, and is mainly used as an artificial material for repairing bone defects.

The invention provides a porous titanium-based composite material for hard tissue materials, a preparation method thereof and application thereof in biomedical materials. The invention adopts an anodic oxidation method to prepare regular TiO with high specific surface on the surface of titanium or titanium alloy₂The nano porous structure utilizes the porosity to influence the overall density, strength and elastic modulus of the titanium alloy implant, and adjusts the aperture size and the porosity by adjusting the anodic oxidation process parameters to match the mechanical properties of host bone tissues, thereby reducing or eliminating the stress shielding effect. Due to TiO₂The specific surface area of the nano porous structure is high, the modified rough porous structure surface has good compatibility and bioactivity, and a layer of dense CaHPO with strong binding force is deposited on the porous structure surface by an electrodeposition method₄·2H₂O calcium phosphorus layer, thenAlkaline bath soaking hydrolysis in situ synthesis of HAp coating with bioactivity. In order to solve the problem of infection after bone tissue transplantation, chitosan-vancomycin is added into the deposition solution obtained by electrodeposition, wherein the chitosan is the only natural cationic polymer in the nature, has good performances of no toxicity, biocompatibility, biodegradability, biological adhesiveness, antibiosis, procoagulant and the like, has pH responsiveness, and is cationic when the pH is less than 6.3; vancomycin is a glycopeptide antibiotic, kills bacteria by inhibiting the growth and reproduction of the bacteria, has been widely used for treating and preventing osteomyelitis and deep infection), has the effect of synergistic repair and treatment, improves the success rate of bone tissue repair, and achieves good controlled drug release effect.

The invention can change the anodic oxidation process parameters according to the actual requirements to adjust the aperture size and the porosity so as to match the mechanical properties of host bone tissues, thereby reducing or eliminating the stress shielding effect, and moreover, the hydroxyapatite antibacterial composite coating can be well deposited by adopting a nano porous structure with small aperture (about 30-60 nm), the dispersibility is better, the binding force is stronger, the drug slow-release time is long, and the durable antibacterial effect can be achieved. Meanwhile, the composite coating prepared by the invention has the advantages of simple process and low cost, and all components in the composite coating are nontoxic or absorbable and degradable to human bodies, so that the composite coating is very safe and suitable for large-scale popularization and application.

For further illustration of the present invention, the following will describe in detail a porous titanium-based composite material and its preparation method and application in conjunction with the following examples, but it should be understood that these examples are carried out on the premise of the technical solution of the present invention, and the detailed embodiments and specific procedures are given only for further illustration of the features and advantages of the present invention, not for limitation of the claims of the present invention, and the scope of protection of the present invention is not limited to the following examples.

A detection step:

the porous titanium-based composite material subjected to alkaline bath soaking and drug loading is placed in a centrifuge tube filled with 3ml of human body Simulated Body Fluid (SBF), then drug release research is carried out in a constant temperature incubator, the culture temperature is 37 ℃, the step release time intervals are 1h, 3h, 9h, 15h, 30h, 60h, 100h, 150h, 300h and 600h, the PBS solution in the original centrifuge tube needs to be reserved for detection each time when an equivalent amount of new PBS solution is replaced, the detection is finished through an ultraviolet spectrophotometer (UV), and the surface morphology of a sample is observed by using a field emission scanning electron microscope (Hitachi SU8010) as the multi-coating composite type functional drug loading material.

Example 1

Sequentially polishing the titanium alloy with the size of 40 multiplied by 20 multiplied by 1mm by using sand paper, then respectively putting the titanium alloy into acetone, absolute ethyl alcohol and deionized water, respectively carrying out ultrasonic cleaning for 10min, and drying the titanium alloy by cold air for later use after the titanium alloy is cleaned; the samples obtained above were mixed in phosphoric acid: sulfuric acid: electrochemical polishing is carried out in polishing solution with the volume ratio of 1:3:10, the electrochemical polishing is carried out in an oil bath device at the temperature of 85 ℃, the stirring speed is 800r/min, the polishing adopts a constant current method, and the current density is 25A/dm²And the polishing time is 10s, the polished sample is ultrasonically cleaned for 10min by deionized water, the sample is taken out and washed clean after the polishing is finished, the sample is dried by cold air, and then the surface which does not participate in the reaction is packaged for standby by using a transparent adhesive tape according to the size of 20 multiplied by 20mm so as to control the reaction area and prevent edge polarization.

The anodic oxidation adopts a constant pressure method, hydrofluoric acid solution is used as electrolyte, wherein the concentration of hydrofluoric acid is 0.5 wt%, the oxidation voltage is 10V, the oxidation time is 1h, the oxidation temperature is 25 ℃, the stirring speed is 1000r/min, a sample is taken out after the anodic oxidation and is rapidly washed by a large amount of deionized water, and the sample is dried at room temperature. And (3) after drying, carrying out annealing treatment, wherein the annealing temperature is 350 ℃, the heat preservation time is 2h, the heating rate is 5 ℃/min, and taking out for later use after furnace cooling to room temperature to obtain the titanium-based material with the porous structure surface.

The titanium-based material having a surface with a porous structure prepared in example 1 of the present invention was characterized.

Referring to fig. 1, fig. 1 is a SEM topography of the surface of the titanium-based material having a porous structure surface prepared in example 1 of the present invention.

Referring to fig. 2, fig. 2 is a partially enlarged SEM topography of the surface of the titanium-based material having a surface with a porous structure prepared in example 1 of the present invention.

As can be seen from the figures 1 and 2, the cellular porous structure has compact arrangement, high porosity, high specific surface area and pore size of about 30-60 nm, and can be used as a good carrier of hydroxyapatite.

7.0845g Ca (NO) was accurately weighed at room temperature₃)₂·4H₂O and 2.3772g (NH)₄)₂HPO₄Respectively placing the mixture into 150ml beakers, then respectively adding 100ml of deionized water, after uniformly stirring and dissolving, pouring the mixture into 500ml beakers for mixing to ensure that the ratio of Ca: and (3) P is 5:3 (molar ratio), dissolving chitosan sheets (Mw is 50-100 KDa, DD is more than or equal to 95%) in 2wt% glacial acetic acid, adding a proper amount of deionized water to prepare a chitosan solution of 2.0mg/ml, centrifuging and stirring (50ml centrifuge tube), taking supernatant, adding a certain amount of vancomycin powder into the supernatant to prepare high-molecular suspension, wherein the mass ratio of vancomycin to chitosan in the suspension is 6, adding the prepared high-molecular suspension into a water-soluble calcium phosphate solution, adjusting the liquid level height to 250ml, and finally adjusting the pH of the solution to be 4.7.

Referring to fig. 3, fig. 3 is a schematic view of an electrodeposition experimental apparatus used in an embodiment of the present invention.

By adopting the electrodeposition experimental device shown in FIG. 3, a 500ml beaker is placed in a constant temperature heating magnetic stirrer, the anode is connected with a graphite electrode, the cathode is connected with a sample as a working electrode, the electrode spacing is 3cm, the working electrode is firstly placed in a deposition solution for stabilization for 2min before deposition, the electrodeposition temperature is 37 ℃, the stirring speed is 900r/min, simultaneously a step-up current method is adopted, 0.7A current is firstly used for deposition for 5min, and then increasing the current to 1.3A, depositing for 5min, finally increasing to 2.0A, stably depositing for 20min, taking out the sample after deposition, cleaning with deionized water, naturally drying, soaking the dried sample in 0.1mol/L NaOH solution in an alkali bath at 37 ℃ for 2h to obtain an alkali solution treated sample, washing the surface with deionized water after taking out, and naturally drying to obtain the porous titanium-based composite material, namely the multi-coating composite type functional drug-carrying material.

The process product and the final product of example 4 of the invention were characterized by scanning electron microscopy.

Referring to fig. 4, fig. 4 is an SEM topography of the multi-coating composite type functional drug-loaded material prepared in example 1 of the present invention.

As can be seen from FIG. 4, the hydroxyapatite layer of the porous titanium-based composite material prepared by the present invention fills the pores on the surface of the titanium-based material and coats the surface of the porous titanium-based material. The chitosan-vancomycin is stacked and covered on the surface of the hydroxyapatite, and has an ellipsoid-shaped structure and a blocky structure. Many small olive-shaped particles on the surface have the size of about 3-7 mu m, the calcium-phosphorus layer at the bottom of the small particles is tightly combined on the whole sample surface, and no obvious fine needle-cluster-shaped hydroxyapatite is observed.

The multi-coating composite type functional drug-loaded material prepared in the embodiment 1 of the invention is detected.

The burst release amount of the multi-coating composite type functional medicine-carrying material prepared in the embodiment 1 of the invention in the first 24 hours is only about 0.33g, the burst release rate is about 41.25%, the accumulated release can be prolonged to more than one month, and the durable antibacterial effect can be better achieved.

Example 2

Sequentially polishing the titanium alloy with the size of 40 multiplied by 20 multiplied by 1mm by using sand paper, then respectively putting the titanium alloy into acetone, absolute ethyl alcohol and deionized water, respectively carrying out ultrasonic cleaning for 15min, and drying the titanium alloy by cold air for later use after the titanium alloy is cleaned; the samples obtained above were mixed in phosphoric acid: sulfuric acid: electrochemical polishing is carried out in polishing solution with the volume ratio of 1:3:10, the electrochemical polishing is carried out in an oil bath device with the temperature of 87 ℃, the stirring speed is 1000r/min, the polishing adopts a constant current method, and the current density is 35A/dm²Polishing for 15s, ultrasonically cleaning the polished sample for 13min by using deionized water, and taking out and punchingCleaning, drying with cold air, and packaging the surface which does not participate in the reaction with transparent adhesive tape at a thickness of 20 × 20mm for later use to control the reaction area and prevent edge polarization.

The anodic oxidation adopts a constant pressure method, hydrofluoric acid solution is used as electrolyte, wherein the concentration of hydrofluoric acid is 0.5 wt%, the oxidation voltage is 20V, the oxidation time is 1h, the oxidation temperature is 25 ℃, the stirring speed is 800r/min, a sample is taken out after the anodic oxidation and is rapidly washed by a large amount of deionized water, and the sample is dried at room temperature. And (3) after drying, carrying out annealing treatment, wherein the annealing temperature is 350 ℃, the heat preservation time is 2h, the heating rate is 5 ℃/min, and taking out for later use after furnace cooling to room temperature to obtain the titanium-based material with the porous structure surface.

7.0845g Ca (NO) was accurately weighed at room temperature₃)₂·4H₂O and 2.3772g (NH)₄)₂HPO₄Respectively placing the mixture into 150ml beakers, then respectively adding 100ml of deionized water, after uniformly stirring and dissolving, pouring the mixture into 500ml beakers for mixing to ensure that the ratio of Ca: and (3) P is 5:3 (molar ratio), dissolving chitosan sheets (Mw is 50-100 KDa, DD is more than or equal to 95%) in 2wt% glacial acetic acid, adding 40ml of deionized water to prepare 2.0mg/ml chitosan solution, centrifugally stirring (50ml of centrifuge tube), taking supernatant, adding a certain amount of vancomycin powder into the supernatant to prepare high-molecular suspension, enabling the mass ratio of vancomycin to chitosan in the suspension to be 8, then adding the prepared high-molecular suspension into water-soluble calcium phosphate solution, adjusting the liquid level height to be 250ml, and finally adjusting the pH of the solution to be 4.5.

By adopting the electrodeposition experimental device shown in FIG. 3, a 500ml beaker is placed in a constant temperature heating magnetic stirrer, the anode is connected with a graphite electrode, the cathode is connected with a sample as a working electrode, the electrode spacing is 3cm, the working electrode is firstly placed in a deposition solution for stabilization for 2min before deposition, the electrodeposition temperature is 35 ℃, the stirring speed is 1200r/min, simultaneously a step-up current method is adopted, 0.5A current is firstly used for deposition for 5min, and then increasing the current to 1.0A, depositing for 5min, finally increasing to 1.5A, stably depositing for 20min, taking out the sample after deposition, cleaning with deionized water, naturally drying, soaking the dried sample in 0.1mol/L NaOH solution in an alkali bath at 37 ℃ for 3h to obtain an alkali solution treated sample, washing the surface with deionized water after taking out, and naturally drying to obtain the porous titanium-based composite material, namely the multi-coating composite type functional drug-carrying material.

The multi-coating composite type functional drug-loaded material prepared in the embodiment 2 of the invention is detected.

The burst release amount of the multi-coating composite type functional medicine-carrying material prepared in the embodiment 2 in the first 24 hours is only about 0.31g, the burst release rate is about 38.75%, the accumulated release can be prolonged to more than one month, and the lasting antibacterial effect can be better achieved.

Example 3

Sequentially polishing the titanium alloy with the size of 40 multiplied by 20 multiplied by 1mm by using sand paper, then respectively putting the titanium alloy into acetone, absolute ethyl alcohol and deionized water, respectively carrying out ultrasonic cleaning for 12min, and drying the titanium alloy by cold air for later use after the titanium alloy is cleaned; the samples obtained above were mixed in phosphoric acid: sulfuric acid: electrochemical polishing is carried out in polishing solution with the volume ratio of 1:3:10, the electrochemical polishing is carried out in an oil bath device at 82 ℃, the stirring speed is 900r/min, the polishing adopts a constant current method, and the current density is 50A/dm²And the polishing time is 15s, the polished sample is ultrasonically cleaned for 15min by deionized water, the sample is taken out and washed clean after the polishing is finished, the sample is dried by cold air, and then the surface which does not participate in the reaction is packaged for standby by using a transparent adhesive tape according to the size of 20 multiplied by 20mm so as to control the reaction area and prevent edge polarization.

The anodic oxidation adopts a constant pressure method, hydrofluoric acid solution is used as electrolyte, wherein the concentration of hydrofluoric acid is 0.7 wt%, the oxidation voltage is 15V, the oxidation time is 2h, the oxidation temperature is 30 ℃, the stirring speed is 1200r/min, a sample is taken out after the anodic oxidation and is rapidly washed by a large amount of deionized water, and the sample is dried at room temperature. And (3) after drying, carrying out annealing treatment, wherein the annealing temperature is 550 ℃, the heat preservation time is 3h, the heating rate is 5 ℃/min, and taking out for later use after furnace cooling to room temperature to obtain the titanium-based material with the porous structure surface.

7.0845g Ca (NO) was accurately weighed at room temperature₃)₂·4H₂O and 2.3772g (NH)₄)₂HPO₄Respectively placing the mixture into 150ml beakers, then respectively adding 100ml of deionized water, and pouring the mixture into 500ml beakers after the mixture is uniformly stirred and dissolvedMixing, and making the ratio of Ca: and (3) P is 5:3 (molar ratio), dissolving chitosan sheets (Mw is 50-100 KDa, DD is more than or equal to 95%) in 2wt% glacial acetic acid, adding 40ml of deionized water to prepare 2.0mg/ml chitosan solution, centrifugally stirring (50ml of centrifuge tube), taking supernatant, adding a certain amount of vancomycin powder into the supernatant to prepare high-molecular suspension, enabling the mass ratio of vancomycin to chitosan in the suspension to be 10, adding the prepared high-molecular suspension into water-soluble calcium phosphate solution, adjusting the liquid level height to be 250ml, and finally adjusting the pH of the solution to be 5.

The distance between two electrodes in an electrodeposition experimental device is 3cm, a working electrode is placed in a deposition solution for stabilization for 1.5min before deposition, the electrodeposition temperature is 40 ℃, the stirring speed is 800r/min, meanwhile, a step current rising method is adopted, 1.0A current is firstly used for deposition for 5min, then the current is raised to 1.5A, then the deposition is carried out for 5min, finally the deposition is carried out to 3.0A for stabilization for 20min, a sample is taken out after the deposition is finished and is cleaned by deionized water, the sample is naturally air-dried, the air-dried sample is subjected to alkali bath soaking treatment for 2.5h at 37 ℃ in 0.1mol/L NaOH solution to obtain an alkali solution treatment sample, the sample is taken out and is washed by the deionized water, and the surface is naturally air-dried to obtain the porous titanium-based composite material, namely the multi-coating composite type functional drug-carrying material.

Referring to fig. 5, fig. 5 is an SEM topography of a semi-finished product without alkaline bath treatment after electrodeposition in example 3 of the present invention.

Referring to FIG. 6, FIG. 6 is an SEM image of the porous titanium-based composite material after electrodeposition and alkali bath treatment in example 3 of the invention.

As can be seen from fig. 5 and 6, the hydroxyapatite layer of the porous titanium-based composite material prepared by the present invention fills the pores on the surface of the titanium-based material and coats the surface of the porous titanium-based material. The surface morphology of the hydroxyapatite layer has a fine needle-shaped surface structure, and a plurality of needle-cluster-shaped surface structures are further formed; the chitosan-vancomycin is not only doped in the fine needle cluster on the surface of the hydroxyapatite, but also can be stacked and covered on the surface of the hydroxyapatite. It has a flocculent structure in the needle cluster, a petal-like structure and an ellipsoid-like structure stacked on the surface.

The multi-coating composite type functional drug-loaded material prepared in the embodiment 3 of the invention is detected.

Referring to fig. 7, fig. 7 is a graph showing the cumulative release rate of vancomycin in the porous titanium-based composite material prepared in example 3 of the present invention.

As can be seen from fig. 7, the burst release amount of the multi-coating composite type functional drug-loaded material prepared in example 3 of the present invention is only about 0.30g within the first 24 hours, the burst release rate is about 37.50%, the cumulative release can be extended to more than one month, and the durable antibacterial effect can be well achieved.

Example 4

Sequentially polishing the titanium alloy with the size of 40 multiplied by 20 multiplied by 1mm by using sand paper, then respectively putting the titanium alloy into acetone, absolute ethyl alcohol and deionized water, respectively carrying out ultrasonic cleaning for 12min, and drying the titanium alloy by cold air for later use after the titanium alloy is cleaned; the samples obtained above were mixed in phosphoric acid: sulfuric acid: electrochemical polishing is carried out in polishing solution with the volume ratio of 1:3:10, the electrochemical polishing is carried out in an oil bath device with the temperature of 80 ℃, the stirring speed is 1200r/min, the polishing adopts a constant current method, and the current density is 45A/dm²And the polishing time is 13s, the polished sample is ultrasonically cleaned for 10min by deionized water, the sample is taken out and washed clean after the polishing is finished, the sample is dried by cold air, and then the surface which does not participate in the reaction is packaged for standby by using a transparent adhesive tape according to the thickness of 20 multiplied by 20mm so as to control the reaction area and prevent edge polarization.

The anodic oxidation adopts a constant pressure method, hydrofluoric acid solution is used as electrolyte, wherein the concentration of hydrofluoric acid is 0.3 wt%, the oxidation voltage is 20V, the oxidation time is 3h, the oxidation temperature is 27 ℃, the stirring speed is 1000r/min, a sample is taken out after the anodic oxidation and is rapidly washed by a large amount of deionized water, and the sample is dried at room temperature. And (3) after drying, carrying out annealing treatment, wherein the annealing temperature is 450 ℃, the heat preservation time is 2h, the heating rate is 5 ℃/min, and taking out for later use after furnace cooling to room temperature to obtain the titanium-based material with the porous structure surface.

7.0845g Ca (NO) was accurately weighed at room temperature₃)₂·4H₂O and 2.3772g (NH)₄)₂HPO₄Respectively placed in 150ml beakers, and thenRespectively adding 100ml of deionized water, after uniformly stirring and dissolving, pouring the mixture into a 500ml beaker for mixing to ensure that the ratio of Ca: and (3) P is 5:3 (molar ratio), dissolving chitosan sheets (Mw is 50-100 KDa, DD is more than or equal to 95%) in 2wt% glacial acetic acid, adding 40ml of deionized water to prepare 2.0mg/ml chitosan solution, centrifugally stirring (50ml of centrifuge tube), taking supernatant, adding a certain amount of vancomycin powder into the supernatant to prepare high-molecular suspension, wherein the mass ratio of vancomycin to chitosan in the suspension is 5, adding the prepared high-molecular suspension into water-soluble calcium phosphate solution, adjusting the liquid level height to 250ml, and finally adjusting the pH of the solution to 4.6.

The distance between two electrodes in an electrodeposition experimental device is 3cm, a working electrode is placed in a deposition solution for stabilization for 2min before deposition, the electrodeposition temperature is 30 ℃, the stirring speed is 1000r/min, meanwhile, a step current rising method is adopted, 1.0A current is firstly used for deposition for 5min, then the current is raised to 1.5A, the deposition is carried out for 5min, finally the deposition is carried out to 2.5A for stabilization for 20min, a sample is taken out after the deposition is finished and is cleaned by deionized water, the sample is naturally air-dried, the air-dried sample is subjected to alkali bath soaking treatment for 3h at 37 ℃ in 0.1mol/L NaOH solution to obtain an alkali solution treatment sample, the sample is taken out and is washed by the deionized water, and the surface is naturally air-dried to obtain the porous titanium-based composite material, namely the multi-coating composite type functional drug-carrying material.

The multi-coating composite type functional drug-loaded material prepared in the embodiment 4 of the invention is detected.

The burst release amount of the multi-coating composite type functional medicine carrying material prepared in the embodiment 4 of the invention in the initial 24 hours is only about 0.34g, the burst release rate is about 42.50%, the accumulated release can be prolonged to more than one month, and the durable antibacterial effect can be better achieved.

While the present invention has been described in detail with respect to a porous titanium-based nanocomposite material for hard tissue materials, a method of making the same, and applications of the same to biomedical materials, the principles and embodiments of the present invention are described herein using specific examples, which are provided only to facilitate an understanding of the methods of the present invention and their core concepts, including the best mode, and to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any combination thereof. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A porous titanium-based composite material is characterized by comprising a porous titanium-based material, a hydroxyapatite layer compounded on the porous titanium-based material, and chitosan-vancomycin compounded on the hydroxyapatite layer;

the aperture of the titanium-based material is 30-60 nm;

the porosity of the titanium-based material is 90-98.6%;

the hydroxyapatite layer has a fine needle-shaped surface structure;

the chitosan-vancomycin has one or more of a flocculent structure, a petal-shaped structure, an ellipsoid-shaped structure and a blocky structure;

the thickness of the hydroxyapatite layer is 6-15 mu m;

the chitosan-vancomycin is doped in needle clusters on the surface of the hydroxyapatite layer and covers the surface of the apatite layer.

2. The porous titanium-based composite material of claim 1, wherein the titanium-based material comprises titanium or a titanium alloy;

the titanium-based material has the size of (40-60) × (20-40) × (0.5-2 mm).

3. The porous titanium-based composite material according to claim 1 or 2, wherein the mass ratio of the titanium-based material to the hydroxyapatite is (10-20): 1;

the mass ratio of the titanium-based material to the chitosan-vancomycin is (40-70): 1.

4. the porous titanium-based composite material according to claim 3, wherein the fine needles have a diameter of 1 to 4 μm.

5. The preparation method of the porous titanium-based composite material is characterized by comprising the following steps:

6. The method of claim 5, wherein the pre-treatment process comprises one or more of grinding, cleaning, drying, and polishing;

the anodic oxidation process is a constant-pressure anodic oxidation process;

the oxidation voltage of the anodic oxidation is 10-20V;

the time of anodic oxidation is 1-3 h;

the oxidation temperature of the anodic oxidation is 20-30 ℃;

the annealing temperature is 350-550 ℃;

the annealing time is 2-3 h;

the temperature rise rate of the annealing is 3-5 ℃/min.

7. The preparation method according to claim 5, wherein the mixing comprises the following specific steps:

8. The method of claim 7, wherein the calcium salt comprises Ca (NO)₃)₂、CaCl₂、Ca(NO₃)₂·4H₂One or more of O;

the mass ratio of the calcium salt to the water is 7: (200-250);

the weight average molecular weight of the chitosan is 50-100 KDa;

the deacetylation degree of the chitosan is more than or equal to 95 percent;

the acid solution comprises a glacial acetic acid solution;

the mass concentration of the acid liquor is 1-2 wt%;

the concentration of the chitosan solution is 1-3 mg/mL;

the mass ratio of chitosan to vancomycin in the suspension is 1: (5-10);

the pH value is 4-6.2.

9. The method according to any one of claims 5 to 8, wherein the temperature of the electrodeposition is 30 to 40 ℃;

the time of the alkali soaking treatment is 2-3 h;

10. Use of the porous titanium-based composite material according to any one of claims 1 to 4 or the porous titanium-based composite material prepared by the preparation method according to any one of claims 5 to 9 in biomedical materials.