Porous Titanium Alloy Implant with Bone Homeostasis Regulation Function and Its Preparation Method

Abstract

The present invention relates to a porous titanium alloy implant with a function of regulating bone homeostasis and a preparation method thereof, belonging to the technical field of porous titanium alloy implants. It solves the technical problems of insufficient stability of the existing porous titanium alloy implants combined with molecular sieves and limited drug loading capacity. The porous titanium alloy implant with a function of regulating bone homeostasis of the present invention comprises a porous titanium alloy implant and an amino-functionalized hierarchical pore molecular sieve coating fixed on the surface of the porous titanium alloy implant. This porous titanium alloy implant with a function of regulating bone homeostasis has strong physical and chemical binding ability between the amino-functionalized hierarchical pore molecular sieve and the porous titanium alloy implant, and has good functions of regulating bone metabolism homeostasis, biological activity and drug loading capacity.

Description

Technical Field

[0001] The present invention belongs to the technical field of porous titanium alloy implants, and particularly relates to a porous titanium alloy implant with a bone homeostasis regulation function and a preparation method thereof. Background Art

[0002] As a highly prevalent disease in the skeletal muscle system, osteoporosis is mainly characterized by a decrease in bone mass accompanied by damage to the microstructure of bone tissue in the affected area, resulting in a significant increase in its brittleness. Its main pathological mechanism is as follows: the osteogenic ability of osteoblasts decreases while the activity of osteoclasts increases, leading to hyperactive bone resorption, which exceeds the speed of osteoblasts forming new bone tissue, thus triggering osteoporosis. This imbalance in bone metabolism homeostasis not only destroys the self-renewal ability of bone tissue but also reduces the integration efficiency of the bone-implant interface, becoming the root cause of early implant subsidence, late loosening, and surrounding fractures.

[0003] Porous titanium alloy implants have the advantages of personalized design, porous structure, light weight, and high strength. These characteristics make them highly favored in the medical field and an ideal choice for implants. However, in specific pathological conditions such as osteoporosis, porous titanium alloys do not have the function of regulating the imbalance of bone metabolism homeostasis. To overcome the limitations of existing porous titanium alloys, research on preparing bioactive coatings with the function of regulating the imbalance of bone metabolism homeostasis on their surfaces has become an effective way to solve the above problems.

[0004] Molecular sieves are a kind of crystalline inorganic materials with regular and uniform pore structures, high porosity and good permeability, and are widely used as catalysts, ion exchangers, drug carriers, etc. Molecular sieves can introduce some specific ions or molecules into the surface and pores of their structures, and can achieve drug loading by binding drugs with exchanged cations. For example, in a Chinese patent "Preparation Method and Application of a Spatial Gradient Molecular Sieve Coating on the Surface of a Porous Titanium Alloy" (Publication No. 117100907B), by exchanging calcium ions in hierarchical pore Y-type molecular sieves and chelating calcium ions with bisphosphonates, the molecular sieves are loaded with bisphosphonates, realizing the local slow release of drugs and showing a long-lasting biological effect. In addition, molecular sieves can form covalent bonds with metal matrices such as titanium and copper through processes such as in-situ hydrothermal crystallization, and have the feasibility of constructing molecular sieve coatings on the surface of titanium alloy implants. However, the surface of conventional molecular sieves is mainly composed of silanol groups, while the surface of titanium alloy implants is mainly composed of titanium oxides, lacking strong chemical bond connections; and the differences in thermal expansion coefficients and mechanical properties between the two lead to easy stress concentration at the interface, thus causing cracks or peeling. At the same time, imperfect coating preparation processes and external environmental factors such as humidity, corrosion, vibration, etc. will further weaken the bonding force between the two. These factors together result in insufficient stability of the combination of molecular sieves and titanium alloy implants. On the other hand, as a drug carrier, molecular sieves with only microporous pore structures can only chelate a small amount of drugs with the cations obtained by ion exchange, and drugs with larger particle sizes cannot enter the interior of microporous molecular sieves, so the drug loading amount is limited. Summary of the Invention

[0005] The present invention provides a porous titanium alloy implant with a bone homeostasis regulation function to solve the technical problems of insufficient stability of the combination of porous titanium alloy implants and molecular sieves and limited drug loading amount in the prior art.

[0006] To achieve the above object, the present invention adopts the following technical solutions.

[0007] In the first aspect, the present invention provides a porous titanium alloy implant with a bone homeostasis regulation function, including a porous titanium alloy implant and an amino-functionalized hierarchical pore molecular sieve coating fixed on the surface of the porous titanium alloy implant;

[0008] The preparation method of the amino-functionalized hierarchical pore molecular sieve includes the following steps:

[0009] (1) Add ammonia water (NH3·H2O), absolute ethanol, deionized water, tetraethyl orthosilicate (TEOS), and 3-aminopropyltriethoxysilane (APTES) with a volume ratio of 2.5-4:70-72.5:9.5-11:3:3 into a reaction vessel in sequence, stir evenly, and continue to stir for 10-14 h, centrifuge and wash with water, dry and calcine in air to obtain an amino-functionalized silicon source;

[0010] (2) According to the molar ratio of Al2O3, SiO2, Na2O, and H2O being 1:1 - 3:2 - 4:150 - 250, sodium hydroxide (NaOH), sodium aluminate (NaAlO2), and the amino-functionalized silicon source prepared in step (1) are sequentially added to deionized water. After stirring for 2 - 3 h, it is added to a reaction vessel for crystallization for more than 25 h. After the crystallization is completed, it is centrifuged and washed with water, and then dried in air to obtain the amino-functionalized hierarchical porous molecular sieve.

[0011] Preferably, in step (1), the volume ratio of ammonia water, absolute ethanol, deionized water, tetraethyl orthosilicate, and 3-aminopropyltriethoxysilane is 3.14:71.4:10:3:3.

[0012] Preferably, in step (1), the centrifugation temperature is 22 - 26 °C, the centrifugation speed is 9000 - 11000 rpm, and the centrifugation time is 4 - 6 min.

[0013] Preferably, in step (1), the drying temperature is 60 - 100 °C, the calcination temperature is 500 - 600 °C, the calcination time is 6 - 12 h, and the heating rate is 1 - 3 °C / min.

[0014] Preferably, in step (2), the molar ratio of Al2O3, SiO2, Na2O, and H2O is 1:2:3.2:200.

[0015] Preferably, in step (2), the centrifugation temperature is 22 - 26 °C, the centrifugation speed is 9000 - 11000 rpm, and the centrifugation time is 4 - 6 min.

[0016] Preferably, in step (2), the crystallization temperature is 60 - 100 °C, the crystallization time is 40 - 48 h, and the drying temperature is 60 - 100 °C; more preferably, the crystallization time is 48 h.

[0017] Preferably, in step (2), the micropore aperture of the amino-functionalized hierarchical porous molecular sieve is 0.4 - 1.9 nm, and the mesopore aperture is 14 - 36 nm.

[0018] In the second aspect, the present invention also provides a preparation method of the above-mentioned porous titanium alloy implant with bone homeostasis regulation function, including the following steps:

[0019] (1) The porous titanium alloy implant is sequentially placed in absolute ethanol, acetone, and deionized water for ultrasonic cleaning. After drying, it is immersed in piranha solution, rinsed with deionized water, and then blown dry with nitrogen to obtain the pretreated porous titanium alloy implant;

[0020] (2) The pretreated porous titanium alloy implant is first placed in a Polydimethyl diallyl ammonium chloride (PDDA) solution for surface modification for 5 - 10 minutes. After taking it out, it is washed with deionized water and dried with nitrogen. Then it is placed in a Polyacrylic acid (PAA) solution for surface modification for 5 - 10 minutes. After taking it out, it is washed with deionized water and dried with nitrogen;

[0021] (3) Repeat the process of step (2) 2 - 4 times to obtain a porous titanium alloy implant with an organic - inorganic bonding layer:

[0022] (4) The porous titanium alloy implant with an organic - inorganic bonding layer is first placed in a Polydimethyl diallyl ammonium chloride solution for surface modification for 5 - 10 minutes. After taking it out, it is washed with deionized water and dried with nitrogen. Then it is immersed in a solution containing amino - functionalized hierarchical porous molecular sieve for surface modification for 5 - 10 minutes. After taking it out, it is washed with deionized water and dried in nitrogen;

[0023] (5) Repeat the process of step (4) 3 - 5 times, and then calcine to obtain a porous titanium alloy implant with bone homeostasis regulation function.

[0024] Preferably, in step (1), the pore size of the porous titanium alloy implant is 400 - 800 μm, and the porosity is 50% - 80%.

[0025] Preferably, in step (1), the ultrasonic cleaning times in absolute ethanol, acetone, and deionized water are 10 - 20 minutes respectively.

[0026] Preferably, in step (1), the drying temperature is 60 - 100 °C, and the time is 20 - 50 minutes.

[0027] Preferably, in step (1), the piranha solution is a mixture of concentrated sulfuric acid and 30% hydrogen peroxide with a volume ratio of 3:1, the soaking time is 15 - 30 minutes, and the concentration of the concentrated sulfuric acid is 95wt% - 98wt%.

[0028] Preferably, in step (2), the concentration of the Polydimethyl diallyl ammonium chloride solution is 0.1wt% - 0.5wt%, the solvent is deionized water, the concentration of the Polyacrylic acid solution is 0.1wt% - 0.5wt%, and the solvent is deionized water.

[0029] Preferably, in step (4), the concentration of the polydiallyldimethylammonium chloride solution is 0.1 wt% - 0.5 wt%, the solvent is deionized water, the concentration of the solution containing the amino-functionalized hierarchical mesoporous molecular sieve is 0.1 wt% - 0.5 wt%, and the solvent is deionized water; more preferably, the concentration of the solution containing the amino-functionalized hierarchical mesoporous molecular sieve is 0.3 wt% - 0.5 wt%.

[0030] Preferably, in step (5), the calcination temperature is 500 - 600 °C, the calcination time is 1 - 6 h, and the heating rate is 1 - 3 °C / min; more preferably, the calcination temperature is 500 - 550 °C, and the calcination time is 2 - 4 h.

[0031] It should be noted that the porous titanium alloy implant in the present invention is a prior art and is usually fabricated by an electron beam melting machine (such as EBM Q10 Plus, Arcam AB, USA). Reference: Hierarchical zeolite coatings featuring a spatial gradient architecture for sequentially-controlled bisphosphonate release in the modulation of osteogenic–osteoclastic balance, Microporous and Mesoporous Materials, 15, April, 2024.

[0032] The principle of the present invention is as follows: The porous titanium alloy implant with the function of regulating bone homeostasis in the present invention has an amino-functionalized hierarchical mesoporous molecular sieve as a coating, so it has a surface modified with amino groups and has the ability to regulate bone homeostasis such as promoting osteogenesis and inhibiting osteoclastogenesis. Moreover, the amino groups can form stable chemical covalent bonds with the hydroxyl groups on the surface of the porous titanium alloy implant, realizing the stable combination of the molecular sieve coating and the porous titanium alloy implant.

[0033] In addition, the present invention coats the amino-functionalized hierarchical mesoporous molecular sieve on the surface of the porous titanium alloy implant to form a coating with a microporous - mesoporous - macroporous spatial gradient structure. This hierarchical pore structure endows the porous titanium alloy implant with the function of regulating bone homeostasis with excellent drug loading performance.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] The porous titanium alloy implant with bone homeostasis regulation function of the present invention is coated with amino-functionalized hierarchical mesoporous molecular sieve. On the one hand, the amino-functionalized hierarchical mesoporous molecular sieve has a surface modified with amino groups, which not only facilitates the realization of the self-regulation of bone metabolism homeostasis by amino groups and plays the bioactive role of the coating, but also enhances the physical and chemical bonding ability between the molecular sieve and the porous titanium alloy implant. On the other hand, the porous titanium alloy implant with bone homeostasis regulation function has a hierarchical pore structure, which is beneficial to improving the drug (zoledronic acid) loading capacity of the porous titanium alloy implant with bone homeostasis regulation function and has important clinical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 Scanning electron microscope (SEM) images of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention, where a is a low-magnification image of the amino-functionalized hierarchical mesoporous molecular sieve, and b is a high-magnification image of the amino-functionalized hierarchical mesoporous molecular sieve.

[0038] Figure 2 Transmission electron microscope (TEM) images of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention. The arrow in the figure indicates the mesoporous structure of the amino-functionalized hierarchical mesoporous molecular sieve.

[0039] Figure 3 X-ray diffractometer (XRD) images of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0040] Figure 4 Nitrogen adsorption-desorption isotherm images of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0041] Figure 5 Nitrogen adsorption-desorption micropore size distribution images of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0042] Figure 6 Nitrogen adsorption-desorption mesopore size distribution images of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0043] Figure 7 Fourier transform infrared absorption spectrometer (FTIR) images of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0044] Figure 8 SEM images of the porous titanium alloy implant used in Example 1 of the present invention. Among them, a is the low-magnification image of the porous titanium alloy implant, and b is the high-magnification image of the porous titanium alloy implant.

[0045] Figure 9 SEM images of the porous titanium alloy implant with bone homeostasis regulation function prepared in Example 1 of the present invention. Among them, a is the low-magnification image, and b is the high-magnification image.

[0046] Figure 10 ALP staining results after co-culturing the porous titanium alloy implant used in the present invention, the non-bone-homeostasis-regulation-function porous titanium alloy implant of Comparative Example 1, and the bone-homeostasis-regulation-function porous titanium alloy implant of Example 1 with bone marrow mesenchymal stem cells for 14 days. Among them, a is the porous titanium alloy implant, b is the non-bone-homeostasis-regulation-function porous titanium alloy implant, and c is the bone-homeostasis-regulation-function porous titanium alloy implant.

[0047] Figure 11 TRAP staining results after co-culturing the porous titanium alloy implant used in the present invention, the non-bone-homeostasis-regulation-function porous titanium alloy implant of Comparative Example 1, and the bone-homeostasis-regulation-function porous titanium alloy implant of Example 1 with pre-osteoclasts for 5 days. Among them, a is the porous titanium alloy implant, b is the non-bone-homeostasis-regulation-function porous titanium alloy implant, and c is the bone-homeostasis-regulation-function porous titanium alloy implant.

[0048] Figure 12 Scanning electron microscope (SEM) images of the non-bone-homeostasis-regulation-function porous titanium alloy implant of Comparative Example 1 and the bone-homeostasis-regulation-function porous titanium alloy implant of Example 1 in the present invention before and after ultrasonic treatment. Among them, a is the SEM image of the non-bone-homeostasis-regulation-function porous titanium alloy implant before ultrasonic treatment, b is the SEM image of the bone-homeostasis-regulation-function porous titanium alloy implant before ultrasonic treatment, c is the SEM image of the non-bone-homeostasis-regulation-function porous titanium alloy implant after ultrasonic treatment, and d is the SEM image of the bone-homeostasis-regulation-function porous titanium alloy implant after ultrasonic treatment.

[0049] Figure 13 Coating retention rate results of the non-bone-homeostasis-regulation-function porous titanium alloy implant of Comparative Example 1 and the bone-homeostasis-regulation-function porous titanium alloy implant of Example 1 in the present invention before and after ultrasonic treatment. In the figure, * indicates a significant difference between the two groups, and the significant difference *p < 0.05.

[0050] Figure 14This is the result of the drug loading capacity of the porous titanium alloy implant without bone homeostasis regulation function in Comparative Example 1 and the porous titanium alloy implant with bone homeostasis regulation function in Example 1 of the present invention. In the figure, *** indicates a significant difference between the two groups, and the significant difference *** p < 0.001.

[0051] Figure 15 This is the scanning electron microscope (SEM) image of Sample 1 prepared in Comparative Example 2 of the present invention. Among them, a is the low-magnification image of Sample 1, and b is the high-magnification image of Sample 1.

[0052] Figure 16 This is the transmission electron microscope (TEM) image of Sample 1 prepared in Comparative Example 2 of the present invention.

[0053] Figure 17 This is the scanning electron microscope (SEM) image of Sample 2 prepared in Comparative Example 3 of the present invention. Among them, a is the low-magnification image of Sample 2, and b is the high-magnification image of Sample 2.

[0054] Figure 18 This is the transmission electron microscope (TEM) image of Sample 2 prepared in Comparative Example 3 of the present invention. Detailed implementation manners

[0055] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the embodiments.

[0056] In the following embodiments, various processes and methods not described in detail are conventional methods well known in the art. The materials, reagents, devices, instruments, equipment, etc. used in the following embodiments can be obtained from commercial channels without special instructions.

[0057] Example 1

[0058] A porous titanium alloy implant with bone homeostasis regulation function, including a porous titanium alloy implant and an amino-functionalized hierarchical pore molecular sieve coating fixed on the surface of the porous titanium alloy implant;

[0059] Among them, the preparation method of the amino-functionalized hierarchical pore molecular sieve coating includes the following steps:

[0060] First, 12.56 ml of ammonia water, 285.6 ml of absolute ethanol, 40 ml of deionized water, 12 ml of tetraethyl orthosilicate and 12 ml of 3-aminopropyltriethoxysilane were successively added to a glass beaker of corresponding volume and stirred evenly, and stirring was continued for 12 h. The obtained milky white solution was centrifuged in a centrifuge at a temperature of 24 °C and a rotation speed of 10,000 rpm for 5 min, and washed 3 times with deionized water. The obtained precipitate was dried in air at 60 - 100 °C, and the obtained white powder was calcined in air at 550 °C for 8 h with a heating rate of 1 - 3 °C / min to obtain an amino-functionalized silicon source, which was light yellow. Then, according to the molar ratio of Al2O3, SiO2, Na2O, and H2O of 1:2:3.2:200, 0.445 g of sodium hydroxide, 0.691 g of sodium aluminate, and 0.4 g of the amino-functionalized silicon source were successively added to 10 g of deionized water. After stirring for 2 - 3 h, it was added to a 25 ml hydrothermal reaction kettle and crystallized at 100 °C for 48 h. The obtained reactant was centrifuged in a centrifuge at a temperature of 24 °C and a rotation speed of 10,000 rpm for 5 min, and washed 3 times with deionized water. The obtained precipitate was dried in air at 60 - 100 °C to obtain an amino-functionalized hierarchical porous molecular sieve.

[0061] The preparation method of the above porous titanium alloy implant with bone homeostasis regulation function is as follows:

[0062] (1) The porous titanium alloy implant (diameter: 10 mm, height: 3 mm, prepared with reference to Hierarchical zeolite coatings featuring a spatial gradient architecture for sequentially-controlled bisphosphonate release in the modulation of osteogenic–osteoclastic balance, Microporous and Mesoporous Materials, 15, April, 2024) was successively placed in absolute ethanol, acetone and deionized water for ultrasonic cleaning for 15 min. After drying in an oven at 100 °C for 40 min, it was immersed in a piranha solution (a mixture of 98 wt% concentrated sulfuric acid and 30% hydrogen peroxide with a volume ratio of 3:1) for 15 - 30 min. After rinsing with deionized water, it was dried with nitrogen to obtain a pretreated porous titanium alloy implant.

[0063] (2) The pretreated porous titanium alloy implant was first placed in a 0.3 wt% solution of polydiallyldimethylammonium chloride for surface modification for 5 min, taken out, washed with deionized water, and dried with nitrogen. Then it was placed in a 0.3 wt% solution of polyacrylic acid for surface modification for 5 min, taken out, washed with deionized water, and dried with nitrogen.

[0064] (3) Repeat the process of step (2) three times to obtain a porous titanium alloy implant with an organic-inorganic bonding layer.

[0065] (4) First, place the porous titanium alloy implant with an organic-inorganic bonding layer in a 0.3 wt% solution of polydiallyldimethylammonium chloride for surface modification for 5 min. After taking it out, wash it with deionized water and dry it with nitrogen. Then, immerse it in a solution containing 0.3 wt% of amino-functionalized hierarchical mesoporous molecular sieve for surface modification for 5 min. After taking it out, wash it with deionized water and dry it in a nitrogen stream.

[0066] (5) Repeat the process of step (4) five times, and then calcine it at 550 °C for 2 h with a heating rate of 3 °C / min to obtain a porous titanium alloy implant with bone homeostasis regulation function.

[0067] Comparative Example 1

[0068] Add 4A molecular sieve to deionized water, stir and mix evenly to prepare a 0.3 wt% solution of non-amino-functionalized hierarchical mesoporous molecular sieve. Subsequently, replace the 0.3 wt% solution of amino-functionalized hierarchical mesoporous molecular sieve with a 0.3 wt% solution of non-amino-functionalized hierarchical mesoporous molecular sieve, and the others are the same as in Example 1 to obtain a porous titanium alloy implant without bone homeostasis regulation function.

[0069] Comparative Example 2

[0070] First, add 12.56 ml of ammonia water, 285.6 ml of absolute ethanol, 40 ml of deionized water, 12 ml of tetraethyl orthosilicate and 12 ml of 3-aminopropyltriethoxysilane to a glass beaker with corresponding volumes in sequence, stir evenly, and continue to stir for 12 h. The obtained milky white solution is centrifuged in a centrifuge at a temperature of 24 °C and a rotation speed of 10,000 rpm for 5 min, and washed 3 times with deionized water. The obtained precipitate is dried in air at 60 - 100 °C, and the obtained white powder is calcined in air at 550 °C for 8 h with a heating rate of 1 - 3 °C / min to obtain an amino-functionalized silicon source, which is light yellow. Then, according to the molar ratio of Al2O3, SiO2, Na2O, H2O being 1:2:3.2:200, add 0.445 g of sodium hydroxide, 0.691 g of sodium aluminate, and 0.4 g of amino-functionalized silicon source to 10 g of deionized water in sequence, stir for 2 - 3 h, then add it to a 25 ml hydrothermal reaction kettle and crystallize at 100 °C for 6 h. The obtained reactant is centrifuged in a centrifuge at a temperature of 24 °C and a rotation speed of 10,000 rpm for 5 min, and washed 3 times with deionized water. The obtained precipitate is dried in air at 60 - 100 °C to obtain Sample 1.

[0071] Comparative Example 3

[0072] First, 12.56 ml of ammonia water, 285.6 ml of absolute ethanol, 40 ml of deionized water, 12 ml of tetraethyl orthosilicate, and 12 ml of 3-aminopropyltriethoxysilane were successively added to a glass beaker with corresponding volumes and stirred evenly, and then stirred continuously for 12 h. The obtained milky white solution was centrifuged in a centrifuge at a temperature of 24 °C and a rotation speed of 10,000 rpm for 5 min, and washed 3 times with deionized water. The obtained precipitate was dried in air at 60 - 100 °C, and the obtained white powder was calcined in air at 550 °C for 8 h with a heating rate of 1 - 3 °C / min to obtain an amino-functionalized silicon source, which was light yellow. Then, according to the molar ratio of Al2O3, SiO2, Na2O, and H2O of 1:2:3.2:200, 0.445 g of sodium hydroxide, 0.691 g of sodium metaaluminate, and 0.4 g of the amino-functionalized silicon source were successively added to 10 g of deionized water. After stirring for 2 - 3 h, it was added to a 25 ml hydrothermal reaction kettle and crystallized at 100 °C for 24 h. The obtained reactant was centrifuged in a centrifuge at a temperature of 24 °C and a rotation speed of 10,000 rpm for 5 min, and washed 3 times with deionized water. The obtained precipitate was dried in air at 60 - 100 °C to obtain Sample 2.

[0073] The amino-functionalized hierarchical porous molecular sieve prepared in Example 1 was detected. Figure 1 In which, a and b are SEM pictures of the amino-functionalized hierarchical porous molecular sieve. From Figure 1 It can be seen that after 48 h of crystallization, the molecular sieve can form a classic LTA structure, indicating that this crystallization time is sufficient to meet the conditions for synthesizing the amino-functionalized hierarchical porous molecular sieve. Figure 2 is the TEM picture of the amino-functionalized hierarchical porous molecular sieve. From Figure 2 It can be seen that after 48 h of crystallization, the obtained molecular sieve can form a mesoporous structure, indicating that this crystallization time is sufficient to meet the conditions for synthesizing the amino-functionalized hierarchical porous molecular sieve. Figure 3 is the XRD picture of the amino-functionalized hierarchical porous molecular sieve. From Figure 3 It can be seen that after 48 h of crystallization, the obtained molecular sieve can show the characteristic diffraction peaks of the molecular sieve, and at the same time, the presence of amino groups does not affect the orderliness of the molecular sieve. Figure 4 is the nitrogen adsorption - desorption isotherm picture of the amino-functionalized hierarchical porous molecular sieve. From Figure 4 It can be seen that after 48 h of crystallization, the obtained molecular sieve has a type IV isotherm, indicating that this molecular sieve has a hierarchical pore structure, and this crystallization time is sufficient to meet the conditions for synthesizing the amino-functionalized hierarchical porous molecular sieve. Figure 5 is the nitrogen adsorption - desorption micropore pore size distribution picture of the amino-functionalized hierarchical porous molecular sieve. Figure 6 is the nitrogen adsorption - desorption mesopore pore size distribution picture of the amino-functionalized hierarchical porous molecular sieve. From Figure 5 and Figure 6It can be seen that the zeolite obtained by crystallization for 48 h has micropore and mesopore diameters, indicating that this crystallization time is sufficient to meet the conditions for synthesizing amino-functionalized hierarchical zeolites. Figure 7 is the FTIR image of the amino-functionalized hierarchical zeolite. From Figure 7 it can be seen that the zeolite obtained by crystallization for 48 h has a characteristic peak at 3472.13 cm -1 . This corresponds to the stretching vibration of the N-H bond, indicating the presence of amino groups on the zeolite surface.

[0074] Figure 15 and Figure 17 are the scanning electron microscope images of sample 1 prepared in Comparative Example 2 and sample 2 prepared in Comparative Example 3, respectively. Figure 16 and Figure 18 are the transmission electron microscope images of sample 1 prepared in Comparative Example 2 and sample 2 prepared in Comparative Example 3, respectively. From Figures 15 - 18 it can be seen that for samples 1 and 2 prepared by crystallization for 6 h and 24 h, the typical regular pore arrangement and uniform pore diameter characteristics of zeolites are lacking, and an ordered crystal framework or periodic pore structure cannot be observed, which does not meet the structural requirements of zeolites.

[0075] SEM detection was carried out on the porous titanium alloy implant used in Example 1 and the porous titanium alloy implant with bone homeostasis regulation function prepared in Example 1. The results are as shown in Figure 8 a and b in, and Figure 9 a and b in, respectively. It can be seen from the figures that the surface of the porous titanium alloy implant with bone homeostasis regulation function is evenly and densely distributed, can completely coat the substrate surface, and the presence of zeolites increases the roughness of the substrate surface.

[0076] The ability of the porous titanium alloy implant with bone homeostasis regulation function prepared in Example 1 to regulate bone metabolic homeostasis was detected.

[0077] The experiments related to the osteogenic process regulation are as follows: In a 24-well plate, 2×10 4 bone marrow mesenchymal stem cells (derived from Sprague-Dawley Rats) were co-cultured with the samples in each well. Using osteogenic induction medium (450 ml of DMEM-F12 medium, 10% fetal bovine serum, 1% penicillin-streptomycin double antibody, 12.8 mg / L vitamin C, 2.16 g / L β-glycerophosphate, 5 mmol / L dexamethasone), after culturing in a 37 °C, 5% CO2 cell culture incubator for 14 days, an alkaline phosphatase (ALP) staining kit was used for qualitative analysis of ALP. The samples were porous titanium alloy implants, non-porous titanium alloy implants with bone homeostasis regulation function in Comparative Example 1, and porous titanium alloy implants with bone homeostasis regulation function in Example 1. The results are as shown inFigure 10 as shown by a, b, and c.

[0078] The experiments related to regulating the osteoclastogenesis process are as follows: In a 6-well plate, 2×10 4 RAW264.7 cells (mouse monocyte-macrophage leukemia cells, derived from tumors induced by Abelson murine leukemia virus in male mice, purchased from the Cell Bank of the Chinese Academy of Sciences, used as pre-osteoclast precursor cells) were co-cultured with the samples in MEM-α medium containing 100 ng / ml osteoclast-inducing factor (RANKL) to induce the directional differentiation of RAW264.7 cells into osteoclasts. After culturing in a 37°C, 5% CO2 cell incubator for 5 days, a tartrate-resistant acid phosphatase (TRAP) staining kit was used to count the number of osteoclasts formed. The samples were a porous titanium alloy implant, a porous titanium alloy implant without the function of regulating bone homeostasis in Comparative Example 1, and a porous titanium alloy implant with the function of regulating bone homeostasis in Example 1. The results are respectively as Figure 11 shown by a, b, and c.

[0079] From Figure 10 and Figure 11 it can be seen that the porous titanium alloy implant with the function of regulating bone homeostasis of the present invention can promote the expression of alkaline phosphatase in BMSCs and at the same time inhibit the formation of osteoclasts, proving that the presence of amino groups can regulate the ability of bone metabolism homeostasis and enable the coating to play a bioactive role.

[0080] The binding ability between the molecular sieve and the porous titanium alloy implant in the porous titanium alloy implant with the function of regulating bone homeostasis prepared in Example 1 and the porous titanium alloy implant without the function of regulating bone homeostasis prepared in Comparative Example 1 was detected. The detection process was as follows: The samples were placed in 15 ml centrifuge tubes, and the centrifuge tubes were placed in an ultrasonic oscillator and continuously operated at a intensity of 50 kHz for 5 min. Subsequently, the ultrasonically treated samples were dried at 60°C for 4 h. SEM was used to observe the surface morphology and area of the surface coatings of the non-ultrasonically treated samples and the ultrasonically treated samples. The results are as Figure 12 shown by a-d and Figure 13 shown. From Figure 12 shown by a-d and Figure 13 it can be seen that the coating retention rate of the porous titanium alloy implant with the function of regulating bone homeostasis is higher before and after ultrasonic treatment, indicating that the presence of amino groups can enhance the physical and chemical binding ability between the molecular sieve and the titanium alloy implant.

[0081] The drug loading capacities of the porous titanium alloy implant with bone homeostasis regulation function prepared in Example 1 and the porous titanium alloy implant without bone homeostasis regulation function prepared in Comparative Example 1 were detected. The detection process was as follows: The samples were placed in 5 ml of 0.5 mg / ml zoledronic acid solution and oscillated at room temperature for 36 h to complete drug loading. Subsequently, the remaining liquid was detected by a high performance liquid chromatograph to analyze the content of the remaining zoledronic acid in the solution. The results are as Figure 14 shown. As can be seen from Figure 14 shown, the porous titanium alloy implant with bone homeostasis regulation function of the present invention can load more zoledronic acid, which proves that the hierarchical pore structure of the porous titanium alloy implant with bone homeostasis regulation function is beneficial to improving its drug loading capacity.

[0082] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the embodiments. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A porous titanium alloy implant with bone homeostasis regulation function, characterized in that, It includes a porous titanium alloy implant and an amino-functionalized hierarchical pore molecular sieve coating fixed on the surface of the porous titanium alloy implant; The preparation method of the amino-functionalized hierarchical pore molecular sieve includes the following steps: (1) Add ammonia water, anhydrous ethanol, deionized water, tetraethyl orthosilicate, and 3-aminopropyltriethoxysilane with a volume ratio of 2.5 - 4:70 - 72.5:9.5 - 11:3:3 into a reaction vessel in sequence, stir evenly, continue to stir for 10 - 14 h, centrifuge and wash with water, dry in air and calcine to obtain an amino-functionalized silicon source; (2) According to the molar ratio of Al2O3, SiO2, Na2O, H2O being 1:1 - 3:2 - 4:150 - 250, add sodium hydroxide, sodium aluminate, and the amino-functionalized silicon source prepared in step (1) to deionized water in sequence. After stirring for 2 - 3 h, add it into a reaction vessel for crystallization for more than 25 h. After the crystallization is completed, centrifuge and wash with water, and dry in air to obtain the amino-functionalized hierarchical pore molecular sieve.

2. The porous titanium alloy implant with bone homeostasis regulation function according to claim 1, characterized in that, In step (1), the volume ratio of the ammonia water, anhydrous ethanol, deionized water, tetraethyl orthosilicate, and 3-aminopropyltriethoxysilane is 3.14:71.4:10:3:3; The centrifugation temperature is 22 - 26 °C, the centrifugation speed is 9000 - 11000 rpm, and the centrifugation time is 4 - 6 min; The drying temperature is 60 - 100 °C, the calcination temperature is 500 - 600 °C, the calcination time is 6 - 12 h, and the heating rate is 1 - 3 °C / min.

3. The porous titanium alloy implant with bone homeostasis regulation function according to claim 1, characterized in that, In step (2), the molar ratio of Al2O3, SiO2, Na2O, H2O is 1:2:3.2:200; The centrifugation temperature is 22 - 26 °C, the centrifugation speed is 9000 - 11000 rpm, and the centrifugation time is 4 - 6 min.

4. The porous titanium alloy implant with bone homeostasis regulation function according to claim 1, characterized in that, In step (2), the crystallization temperature is 60 - 100 °C, the crystallization time is 40 - 48 h, and the drying temperature is 60 - 100 °C.

5. The porous titanium alloy implant with bone homeostasis regulation function according to claim 1, characterized in that, In step (2), the micropore diameter of the amino-functionalized hierarchical pore molecular sieve is 0.4 - 1.9 nm, and the mesopore diameter is 14 - 36 nm.

6. The preparation method of the porous titanium alloy implant with the function of regulating bone homeostasis according to any one of claims 1-5, characterized in that, It includes the following steps: (1) Place the porous titanium alloy implant in anhydrous ethanol, acetone, and deionized water in sequence for ultrasonic cleaning. After drying, soak it in a piranha solution, rinse with deionized water, and blow dry with nitrogen to obtain a pretreated porous titanium alloy implant; (2) First place the pretreated porous titanium alloy implant in a polydiallyldimethylammonium chloride solution for surface modification for 5 - 10 min. After taking it out, wash it with deionized water and blow dry with nitrogen. Then place it in a polyacrylic acid solution for surface modification for 5 - 10 min. After taking it out, wash it with deionized water and blow dry with nitrogen; (3) Repeat the process of step (2) 2 - 4 times to obtain a porous titanium alloy implant with an organic-inorganic bonding layer: (4) The porous titanium alloy implant with an organic-inorganic bonding layer is first placed in a polydiallyldimethylammonium chloride solution for surface modification for 5 - 10 minutes. After taking it out, it is washed with deionized water and dried with nitrogen. Then it is immersed in a solution containing amino-functionalized hierarchical porous molecular sieve for surface modification for 5 - 10 minutes. After taking it out, it is washed with deionized water and dried with nitrogen. (5) Repeat the process of step (4) 3 - 5 times, and then calcine to obtain a porous titanium alloy implant with the function of regulating bone homeostasis.

7. The preparation method of the porous titanium alloy implant with the function of regulating bone homeostasis according to claim 6, characterized in that, In step (1), the pore size of the porous titanium alloy implant is 400 - 800 μm, and the porosity is 50% - 80%; the ultrasonic cleaning times in anhydrous ethanol, acetone, and deionized water are 10 - 20 minutes respectively; the drying temperature is 60 - 100 °C, and the drying time is 20 - 50 minutes; the piranha solution is a mixture of concentrated sulfuric acid and 30% hydrogen peroxide with a volume ratio of 3:1, and the soaking time is 15 - 30 minutes.

8. The preparation method of the porous titanium alloy implant with bone homeostasis regulation function according to claim 6, characterized in that, In step (2), the concentration of the polydiallyldimethylammonium chloride solution is 0.1 wt% - 0.5 wt%, and the solvent is deionized water. The concentration of the polyacrylic acid solution is 0.1 wt% - 0.5 wt%, and the solvent is deionized water.

9. The preparation method of the porous titanium alloy implant with bone homeostasis regulation function according to claim 6, wherein, In step (4), the concentration of the polydiallyldimethylammonium chloride solution is 0.1 wt% - 0.5 wt%, and the solvent is deionized water. The concentration of the solution containing amino-functionalized hierarchical porous molecular sieve is 0.1 wt% - 0.5 wt%, and the solvent is deionized water.

10. The preparation method of the porous titanium alloy implant with bone homeostasis regulation function according to claim 6, characterized in that, In step (5), the calcination temperature is 500 - 600 °C, the calcination time is 1 - 6 h, and the heating rate is 1 - 3 °C / min.

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