Porous titanium alloy implant with bone steady state regulation function and preparation method thereof

Abstract

The invention relates to a porous titanium alloy implant with a bone steady state regulation function and a preparation method of the porous titanium alloy implant, and belongs to the technical field of porous titanium alloy implants. The technical problems that an existing porous titanium alloy implant is insufficient in combination stability with a molecular sieve, and the drug loading capacity is limited are solved. The porous titanium alloy implant with the bone steady state regulation and control function comprises a porous titanium alloy implant body and an amino-functionalized hierarchical pore molecular sieve coating fixed to the surface of the porous titanium alloy implant body. According to the porous titanium alloy implant with the bone steady state regulation and control function, the physical and chemical binding capacity between the amino-functionalized hierarchical pore molecular sieve and the porous titanium alloy implant is high, and the porous titanium alloy implant has a good bone metabolism steady state regulation effect, a good biological activity effect and a good 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 of the musculoskeletal system, osteoporosis is mainly characterized by reduced bone mass accompanied by damage to the microstructure of bone tissue in the affected area, which significantly increases 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 new bone tissue formation by osteoblasts, 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 fundamental cause of early prosthesis subsidence, late loosening, and surrounding fractures.

[0003] Porous titanium alloy implants have advantages such as personalized design, porous structure, and 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, the research on preparing a bioactive coating with the function of regulating the imbalance of bone metabolism homeostasis on its surface 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 load drugs by combining with drugs through 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 long-lasting biological effects. 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, and vibration 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 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) Ammonia water (NH 3 ·H 2O), absolute ethanol, deionized water, tetraethyl orthosilicate (TEOS), and 3-aminopropyltriethoxysilane (APTES) were successively added to a reaction vessel, stirred evenly, and continuously stirred for 10 - 14 h, centrifuged and washed with water, dried under air, and calcined to obtain an amino-functionalized silicon source;

[0010] (2) According to the molar ratio of Al 2 O 3 , SiO 2 , Na 2 O, H 2 O being 1:1 - 3:2 - 4:150 - 250, sodium hydroxide (NaOH), sodium aluminate (NaAlO 2 ), and the amino-functionalized silicon source prepared in step (1) were successively added to deionized water. After stirring for 2 - 3 h, it was added to a reaction vessel for crystallization for more than 25 h. After crystallization was completed, it was centrifuged and washed with water, and dried under air to obtain an amino-functionalized hierarchical pore 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 Al 2 O 3 , SiO 2 , Na 2 O, H 2 O 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 pore molecular sieve is 0.4 - 1.9 nm, and the mesopore aperture is 14 - 36 nm.

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

[0019] (1) The porous titanium alloy implant is successively ultrasonically cleaned in absolute ethanol, acetone and deionized water. After drying, it is immersed in a piranha solution, rinsed with deionized water, and then dried with nitrogen to obtain a pretreated porous titanium alloy implant;

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

[0021] (3) The process of step (2) is repeated 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 surface-modified in a Polydimethyl diallyl ammonium chloride solution for 5 - 10 minutes. After taking it out, it is cleaned 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 cleaned with deionized water and dried in nitrogen;

[0023] (5) The process of step (4) is repeated 3 - 5 times, and then calcined 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 poly(diallyldimethylammonium chloride) solution is 0.1 wt%-0.5 wt%, 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.

[0029] Preferably, in step (4), the concentration of the poly(diallyldimethylammonium chloride) solution is 0.1 wt%-0.5 wt%, the solvent is deionized water, the concentration of the solution containing 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 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 the function of regulating bone homeostasis of the present invention uses amino-functionalized hierarchical mesoporous molecular sieve as the coating. 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 the exertion of the bioactive effect of the coating, but also helps to enhance the physical and chemical binding ability between the molecular sieve and the porous titanium alloy implant. On the other hand, the porous titanium alloy implant with the function of regulating bone homeostasis has a hierarchical pore structure, which is beneficial to improving the drug (zoledronic acid) loading capacity of the porous titanium alloy implant with the function of regulating bone homeostasis 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, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a scanning electron microscope (SEM) picture of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention. Among them, a is a low-magnification picture of the amino-functionalized hierarchical mesoporous molecular sieve, and b is a high-magnification picture of the amino-functionalized hierarchical mesoporous molecular sieve.

[0038] Figure 2 It is a transmission electron microscope (TEM) picture of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention. The arrow in the figure is the mesoporous structure of the amino-functionalized hierarchical mesoporous molecular sieve.

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

[0040] Figure 4 It is a nitrogen adsorption-desorption isotherm picture of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0041] Figure 5 It is a nitrogen adsorption-desorption micropore size distribution picture of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0042] Figure 6 It is a nitrogen adsorption-desorption mesopore size distribution picture of the amino-functionalized hierarchical mesoporous molecular sieve prepared in Example 1 of the present invention.

[0043] Figure 7FTIR image 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, where 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, where 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-functional porous titanium alloy implant of Comparative Example 1, and the bone-homeostasis-regulation-functional 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-functional porous titanium alloy implant, and c is the bone-homeostasis-regulation-functional 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-functional porous titanium alloy implant of Comparative Example 1, and the bone-homeostasis-regulation-functional 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-functional porous titanium alloy implant, and c is the bone-homeostasis-regulation-functional porous titanium alloy implant.

[0048] Figure 12 SEM images of the non-bone-homeostasis-regulation-functional porous titanium alloy implant of Comparative Example 1 and the bone-homeostasis-regulation-functional 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-functional porous titanium alloy implant before ultrasonic treatment, b is the SEM image of the bone-homeostasis-regulation-functional porous titanium alloy implant before ultrasonic treatment, c is the SEM image of the non-bone-homeostasis-regulation-functional porous titanium alloy implant after ultrasonic treatment, and d is the SEM image of the bone-homeostasis-regulation-functional porous titanium alloy implant after ultrasonic treatment.

[0049] Figure 13 Coating retention rate results of the non-bone-homeostasis-regulation-functional porous titanium alloy implant of Comparative Example 1 and the bone-homeostasis-regulation-functional 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 14 The results 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 are shown in the figure. *** 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, comprising 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 Al 2 O 3 、SiO 2 、Na 2 O、H 2 O 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, dried with nitrogen, and then 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)The process of step (2) was repeated 3 times to obtain a porous titanium alloy implant with an organic-inorganic bonding layer.

[0065] (4)The porous titanium alloy implant with an organic-inorganic bonding layer was first placed in a 0.3 wt% solution of polydiallyldimethylammonium chloride for surface modification for 5 min, taken out, washed with deionized water, dried with nitrogen, and then immersed in a solution containing 0.3 wt% of amino-functionalized hierarchical porous molecular sieve for surface modification for 5 min, taken out, washed with deionized water, and dried in a nitrogen stream.

[0066] (5)The process of step (4) was repeated 5 times, and then calcined 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] 4A molecular sieve was added to deionized water, stirred and mixed evenly to prepare a 0.3 wt% solution of non-amino-functionalized hierarchical porous molecular sieve. Subsequently, the 0.3 wt% solution of amino-functionalized hierarchical porous molecular sieve was replaced with a 0.3 wt% solution of non-amino-functionalized hierarchical porous molecular sieve, and the others were the same as in Example 1 to obtain a porous titanium alloy implant without bone homeostasis regulation function.

[0069] Comparative Example 2

[0070] 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 the corresponding volume, stirred evenly, and continued to stir 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 Al 2 O 3 、SiO 2 、Na 2 O、H 2The molar ratio of O is 1:2:3.2:200. 0.445 g of sodium hydroxide, 0.691 g of sodium aluminate, and 0.4 g of 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 6 h. The resulting 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 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 of corresponding volume and stirred evenly, and stirring was continued for 12 h. The resulting 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, 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 Al 2 O 3 、SiO 2 、Na 2 O、H 2 The molar ratio of O is 1:2:3.2:200. 0.445 g of sodium hydroxide, 0.691 g of sodium aluminate, and 0.4 g of 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 resulting 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 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 the molecular sieve obtained after 48 h of crystallization 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 3It can be seen that the molecular sieve obtained after 48 h of crystallization can exhibit characteristic diffraction peaks of the molecular sieve, and the presence of amino groups does not affect the orderliness of the molecular sieve either. Figure 4 Figure for the nitrogen adsorption-desorption isotherm of the amino-functionalized hierarchical pore molecular sieve. From Figure 4 It can be seen that the molecular sieve obtained after 48 h of crystallization has a type-IV isotherm, indicating that the molecular sieve has a hierarchical pore structure, and this crystallization time is sufficient to meet the conditions for synthesizing the amino-functionalized hierarchical pore molecular sieve. Figure 5 Figure for the micropore size distribution of the nitrogen adsorption-desorption of the amino-functionalized hierarchical pore molecular sieve, Figure 6 Figure for the mesopore size distribution of the nitrogen adsorption-desorption of the amino-functionalized hierarchical pore molecular sieve. From Figure 5 and Figure 6 It can be seen that the molecular sieve obtained after 48 h of crystallization has micropore size and mesopore size, indicating that this crystallization time is sufficient to meet the conditions for synthesizing the amino-functionalized hierarchical pore molecular sieve. Figure 7 Figure for the FTIR of the amino-functionalized hierarchical pore molecular sieve. From Figure 7 It can be seen that the molecular sieve obtained after 48 h of crystallization has a characteristic peak at 3472.13 cm -1 −1, which corresponds to the stretching vibration of the N-H bond, indicating the presence of amino groups on the surface of the molecular sieve.

[0074] Figure 15 and Figure 17 Figures for the scanning electron microscopy of sample 1 prepared in Comparative Example 2 and sample 2 prepared in Comparative Example 3 respectively, Figure 16 and Figure 18 Figures for the transmission electron microscopy 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 with crystallization times of 6 h and 24 h, they lack the typical regular pore arrangement and uniform pore size characteristics of the molecular sieve, and an ordered crystal framework or periodic pore structure cannot be observed, not meeting the structural requirements of the molecular sieve.

[0075] SEM detection was carried out on the porous titanium alloy implant used in Example 1 and the porous titanium alloy implant with the function of regulating bone homeostasis 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 the function of regulating bone homeostasis is uniformly and densely distributed, can completely coat the surface of the substrate, and the presence of the molecular sieve increases the roughness of the substrate surface.

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

[0077] The related experiments for regulating the osteogenic process 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. Osteogenic induction medium (450 ml 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) was used to culture in a cell incubator at 37°C and 5% CO 2 2 for 14 days. Then, an alkaline phosphatase (ALP) staining kit was used for qualitative analysis of ALP. The samples were porous titanium alloy implants, the porous titanium alloy implants without the function of regulating bone homeostasis in Comparative Example 1, and the porous titanium alloy implants with the function of regulating bone homeostasis in Example 1. The results are shown as a, b, and c in Figure 10 respectively.

[0078] The related experiments for regulating the osteoclastic process are as follows: In a 6-well plate, 2×10 4 RAW264.7 (mouse mononuclear 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 osteoclast precursor cells) were co-cultured with the samples in each well. MEM-α medium containing 100 ng / ml osteoclast induction factor (RANKL) was used to induce RAW264.7 cells to differentiate into osteoclasts directionally. After culturing in a cell incubator at 37°C and 5% CO 2 2 for 5 days, an anti-tartrate acid phosphatase (TRAP) staining kit was used to count the number of osteoclasts formed. The samples were porous titanium alloy implants, the porous titanium alloy implants without the function of regulating bone homeostasis in Comparative Example 1, and the porous titanium alloy implants with the function of regulating bone homeostasis in Example 1. The results are shown as a, b, and c in Figure 11 respectively.

[0079] It can be seen from Figure 10 and Figure 11 that the porous titanium alloy implants 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 can 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 prepared in Example 1 with bone homeostasis regulation function and the porous titanium alloy implant prepared in Comparative Example 1 without bone homeostasis regulation function was detected. The detection process was as follows: The sample was placed in a 15 ml centrifuge tube, and the centrifuge tube was placed in an ultrasonic oscillator and continuously operated at a strength of 50 kHz for 5 min. Subsequently, the ultrasonically treated sample was dried at 60 °C for 4 h. SEM was used to observe the surface morphology and area of the surface coating of the non-ultrasonically treated sample and the ultrasonically treated sample. The results are as Figure 12 shown in a-d of Figure 13 and as Figure 12 shown in a-d of Figure 13 It can be seen that the coating retention rate of the porous titanium alloy implant with bone homeostasis regulation function before and after ultrasonic treatment is higher, 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 capacity 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 was detected. The detection process was as follows: The sample was placed in a 5 ml 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, and as Figure 14 shown, the porous titanium alloy implant with bone homeostasis regulation function of the present invention can load more zoledronic acid, proving 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 for clear illustration and 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 multi-level pore molecular sieve coating fixed on the surface of the porous titanium alloy implant; The preparation method of the amino-functionalized multi-level pore molecular sieve comprises the following steps: (1) Ammonia water, anhydrous ethanol, deionized water, ethyl orthosilicate and 3-aminopropyltriethoxysilane in a volume ratio of 2.5-4:70-72.5:9.5-11:3:3 are added to a reaction vessel in sequence and stirred evenly, and the stirring is continued for 10-14 hours, centrifuged and washed with water, dried in air and calcined to obtain an amino-functionalized silicon source; (2) Sodium hydroxide, sodium aluminate and the amino-functionalized silicon source prepared in step (1) are sequentially added to deionized water in a molar ratio of Al2O3, SiO2, Na2O and H2O of 1:1-3:2-4:150-250, stirred for 2-3 hours, and then added to a reaction vessel for crystallization for more than 25 hours. After crystallization, the mixture is centrifuged and washed with water, and dried in air to obtain an 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 ammonia water, anhydrous ethanol, deionized water, ethyl orthosilicate and 3-aminopropyltriethoxysilane is 3.14:71.4:10:3:3; The centrifugal temperature is 22-26°C, the centrifugal speed is 9000-11000rpm, and the centrifugal time is 4-6min; The drying temperature is 60-100° C., the calcination temperature is 500-600° C., the calcination time is 6-12 hours, 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 and H2O is 1:2:3.2:200; The centrifugal temperature is 22-26° C., the centrifugal speed is 9000-11000 rpm, and the centrifugal 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 40-48h, 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 amino-functionalized multi-level pore size of the molecular sieve is 0.4-1.9 nm, and the mesopore size is 14-36 nm.

6. The method for preparing the porous titanium alloy implant with bone homeostasis regulation function according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) The porous titanium alloy implant is ultrasonically cleaned in anhydrous ethanol, acetone and deionized water in sequence, dried, immersed in a piranha solution, rinsed with deionized water, and dried with nitrogen to obtain a pretreated porous titanium alloy implant; (2) The pretreated porous titanium alloy implant is first placed in a polydiallyldimethylammonium chloride solution for surface modification for 5-10 min, then taken out and rinsed with deionized water and dried with nitrogen, and then placed in a polyacrylic acid solution for surface modification for 5-10 min, then taken out and rinsed with deionized water and dried with nitrogen; (3) Repeat 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 the organic-inorganic bonding layer is first placed in a polydiallyldimethylammonium chloride solution for surface modification for 5-10 min, then taken out and rinsed with deionized water, dried with nitrogen, and then immersed in a solution containing an amino-functionalized hierarchical pore molecular sieve for surface modification for 5-10 min, then taken out and rinsed with deionized water, and dried with nitrogen; (5) Repeat the process of step (4) 3-5 times, followed by calcination to obtain a porous titanium alloy implant with bone homeostasis regulation function.

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

8. The method for preparing 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 0.1wt%-0.5wt%, and the solvent is deionized water; the concentration of the polyacrylic acid solution is 0.1wt%-0.5wt%, and the solvent is deionized water.

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

10. The method for preparing 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 1-6h, and the heating rate is 1-3°C / min.

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