Mg-doped biphase calcium-phosphorus-based inorganic material as well as preparation method and application thereof

Abstract

The invention relates to an Mg-doped biphase calcium-phosphorus-based inorganic material as well as a preparation method and application thereof. Magnesium hydroxide, calcium hydroxide and phosphoric acid are used as raw materials, a one-step chemical precipitation method is utilized to obtain the Mg-doped biphase calcium-phosphorus-based inorganic material with different hydroxyapatite / beta-TCP proportions by adjusting a reaction process and magnesium doping amount, and the obtained inorganic material has high osteogenic activity of hydroxyapatite; the beta-TCP has high degradability, Mg ions promote osteogenesis and other functions, and osteoblast attachment proliferation can be induced easily.

Description

Technical Field

[0001] The invention relates to the technical field of biofunctional inorganic materials, and in particular to a Mg-doped dual-phase calcium-phosphorus-based inorganic material and a preparation method and application thereof. Background Art

[0002] Clinical treatment of bone defects often includes autologous bone transplantation, allogeneic bone transplantation, artificial bone tissue material replacement, etc., among which artificial bone tissue materials have received great attention from researchers due to their wide sources. The selection of artificial bone tissue materials is also called a hot topic. Hydroxyapatite is an inorganic mineral similar to human bone tissue, which is characterized by good biological activity and biocompatibility and is widely used in the field of bone tissue repair. β-TCP (β-tricalcium phosphate) is also a commonly used bone tissue replacement material. When it is implanted into the human body, the Ca and P released by degradation can enter the living body's circulatory system to form new bone. Magnesium, as a trace element in the human body, participates in many important life activities in the human body, and magnesium can promote tissue regeneration very well. The present invention is intended to provide a bone tissue repair material with clinical application prospects. Summary of the invention

[0003] One of the purposes of the present invention is to provide a method for preparing a Mg-doped dual-phase calcium-phosphorus-based inorganic material. The obtained Mg-doped dual-phase calcium-phosphorus-based inorganic material has the advantages of good biocompatibility, biodegradability, and osteogenic effect.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for preparing a Mg-doped dual-phase calcium-phosphorus-based inorganic material comprises the following steps:

[0006] S1. Adding calcium hydroxide powder and magnesium hydroxide powder into deionized water to prepare a calcium hydroxide / magnesium hydroxide suspension;

[0007] S2, preparing phosphoric acid aqueous solution;

[0008] S3, under stirring conditions, adding the phosphoric acid aqueous solution dropwise to the calcium hydroxide / magnesium hydroxide suspension, during which the pH value of the system is controlled within the range of 9 to 11;

[0009] S4. After the phosphoric acid aqueous solution is added dropwise, continue stirring and reacting for 10 to 30 hours;

[0010] S5. After the reaction is completed, the reaction system is repeatedly filtered and washed with ethanol solution and deionized water, and the collected materials are dried to obtain a Mg-doped dual-phase calcium-phosphorus-based inorganic material.

[0011] Further, the concentration of calcium hydroxide in the calcium hydroxide / magnesium hydroxide suspension formed in step S1 is 0.1-0.2 M. As an example, the concentration of calcium hydroxide in the calcium hydroxide / magnesium hydroxide suspension is 0.1 M, 0.11 M, 0.12 M, 0.13 M, 0.14 M, 0.15 M, 0.16 M, 0.17 M, 0.18 M, 0.19 M, 0.20 M.

[0012] Further, the ratio of the mole of magnesium hydroxide in the calcium hydroxide / magnesium hydroxide suspension formed in step S1 to the total mole of magnesium hydroxide and calcium hydroxide is 1 to 10: 100. As an example, the ratio of the mole of magnesium hydroxide in the calcium hydroxide / magnesium hydroxide suspension to the total mole of magnesium hydroxide and calcium hydroxide is 10: 100, 9: 100, 8: 100, 7: 100, 6: 100, 5: 100, 4: 100, 3: 100, 2: 100, 1: 100.

[0013] Furthermore, the concentration of phosphoric acid in the phosphoric acid aqueous solution in step S2 is 0.1 to 0.3 M. As an example, the concentration of phosphoric acid in the phosphoric acid aqueous solution is 0.1 M, 0.15 M, 0.2 M, 0.25 M, or 0.3 M.

[0014] Further, in step S3, the ratio of the molar amount of phosphorus ions added to the total molar amount of calcium and magnesium ions in the suspension is 1:(1-2). As an example, the ratio of the molar amount of phosphorus ions in the phosphoric acid aqueous solution to the total molar amount of calcium and magnesium ions in the suspension is 1:1, 1:1.23, 1:1.34, 1:1.45, 1:1.56, 1:1.67, 1.69, 1.72, 1:1.78, 1:1.89, 1:2.

[0015] Furthermore, in steps S3 and S4, vigorous stirring is maintained, and the stirring speed can be selected to be 350-500 r / min.

[0016] Furthermore, in step S3, ammonia water is used to adjust the pH value of the system during the reaction process.

[0017] Furthermore, in step S3, the pH value of the control system during the reaction process is 9, 9.5, 10, 10.5, and 11.

[0018] Furthermore, in step S5, washing with deionized water is repeated 1 to 3 times, and washing with ethanol is repeated 1 to 3 times.

[0019] Further, in step S5, washing with deionized water is repeated twice, and washing with ethanol is repeated twice.

[0020] Further, in step S5, drying is performed in a vacuum oven at 60° C. for 12 h.

[0021] Another object of the present invention is to provide a Mg-doped dual-phase calcium-phosphorus-based inorganic material prepared by the above method.

[0022] Another object of the present invention is to provide an application of the above-mentioned Mg-doped dual-phase calcium-phosphorus-based inorganic material in the preparation of bone tissue repair materials.

[0023] The present invention uses calcium hydroxide, magnesium hydroxide and phosphoric acid as raw materials to synthesize Mg-doped dual-phase calcium-phosphorus-based inorganic materials by a wet chemical method. Compared with the prior art using magnesium oxide, calcium phosphate salt and acid solution as raw materials, the product generated by using raw materials such as calcium hydroxide, magnesium hydroxide and phosphoric acid only contains the required magnesium-doped calcium phosphate salt and water, and no other inorganic ions or irrelevant elements exist; and calcium hydroxide and magnesium hydroxide themselves will cause the entire reaction to react under alkaline conditions at the initial stage, providing a hydroxyl-rich chemical environment for the formation of hydroxyapatite.

[0024] The present invention can also prepare Mg-doped biphasic calcium-phosphorus-based inorganic materials with different hydroxyapatite / β-TCP ratios by adjusting reaction process conditions and magnesium doping amounts. Compared with non-doped calcium-phosphorus-based materials, the materials have multiple functions such as high osteogenic activity of hydroxyapatite, high degradability of β-TCP, and osteogenic effects of Mg ions. The obtained Mg-doped biphasic calcium-phosphorus-based inorganic materials have good biocompatibility and biodegradability, can slowly and continuously release Ca ions and Mg ions during the degradation process, and the preparation method is simple and easy to operate, which is conducive to clinical approval and transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a Fourier infrared spectrum of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 1;

[0026] Figure 2 The XRD diffraction pattern of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 1;

[0027] Figure 3 This is the Tem morphology of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 1;

[0028] Figure 4 This is a Fourier infrared spectrum of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2;

[0029] Figure 5 The XRD diffraction pattern of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2;

[0030] Figure 6 The Tem morphology of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2, wherein A, B, C, D, and E correspond to magnesium doping amounts of 1%, 1.5%, 2%, 7.7%, and 10%, respectively;

[0031] Figure 7 The Ca ion and Mg ion release curves of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2; the left figure is the Ca ion release curve, and the right figure is the Mg ion release curve;

[0032] Figure 8 The cell compatibility test results of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 1;

[0033] Fig. 9 These are the cell compatibility test results of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2. DETAILED DESCRIPTION

[0034] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.

[0035] Example 1

[0036] Preparation of Mg-doped dual-phase calcium-phosphorus-based inorganic materials under different pH conditions

[0037] Weigh calcium hydroxide powder and magnesium hydroxide powder and add them to ultrapure water to form a calcium hydroxide / magnesium hydroxide suspension with a concentration of 0.15M; measure 85wt% phosphoric acid solution and dilute it to a phosphoric acid solution concentration of 0.2M. Under the condition of 25°C, the diluted phosphoric acid solution is slowly and uniformly added to the calcium hydroxide / magnesium hydroxide suspension using a constant pressure funnel, and vigorous stirring is maintained during the dropwise addition. The pH value of the reaction system is monitored in real time using a pH meter and ammonia water is added to maintain the pH value of the reaction system after the dropwise addition at about 9. After the dropwise addition is completed, the synthetic product is vigorously and rapidly stirred for 24 hours. After the reaction is completed, the synthetic product is first washed twice with deionized water using a suction filtration device, and then the synthetic product washed with deionized water is washed twice with ethanol using a suction filtration device. Finally, the synthetic product washed with ethanol is placed in a vacuum oven and dried at 60°C for 12 hours to obtain a Mg-doped dual-phase calcium-phosphorus-based inorganic material. The obtained Mg-doped dual-phase calcium-phosphorus-based inorganic material was calcined at 900°C for 2h in a muffle furnace. The sample obtained after calcination was recorded as HAp-1, in which the molar ratio of Mg / (Ca+Mg) was 1.5%, and the ratio of the molar amount of phosphorus ions to the total molar amount of calcium and magnesium ions in the suspension was 1:1.67. The reaction pH was changed to 9.5, 10, and 10.5, and the samples were recorded as HAp-2, HAp-3, and HAp-4, respectively.

[0038] Example 2

[0039] Preparation of Mg-doped dual-phase calcium-phosphorus-based inorganic materials at different Mg-doping levels

[0040] Weigh calcium hydroxide powder and magnesium hydroxide powder and add them to ultrapure water to form a calcium hydroxide / magnesium hydroxide suspension with a concentration of 0.15M; measure 85wt% phosphoric acid solution and dilute it to a phosphoric acid solution concentration of 0.2M. Under the condition of 25°C, the diluted phosphoric acid solution is slowly and uniformly added to the calcium hydroxide / magnesium hydroxide suspension using a constant pressure funnel, and vigorous stirring is maintained during the dropwise addition. The pH value of the reaction system is monitored in real time using a pH meter and ammonia water is added to maintain the pH value of the reaction system at about 10. After the dropwise addition, it is vigorously and rapidly stirred for 24 hours. After the reaction is completed, the synthetic product is first washed twice with deionized water using a suction filtration device, and then the synthetic product washed with deionized water is washed twice with ethanol using a suction filtration device. Finally, the synthetic product washed with ethanol is placed in a vacuum oven and dried at 60°C for 12 hours to obtain a Mg-doped dual-phase calcium-phosphorus-based inorganic material. The obtained Mg-doped dual-phase calcium-phosphorus-based inorganic material was calcined at 900°C in a muffle furnace for 2 h. The sample obtained after calcination was recorded as 1.5% Mg-HAp. The Mg / (Ca+Mg) molar ratio of the reaction system was changed to 1%, 2%, 6.25%, 7.7%, and 10%, respectively. The samples were recorded as 1% Mg-HAp, 2% Mg-HAp, 6.25% Mg-HAp, 7.7% Mg-HAp, and 10% Mg-HAp, respectively.

[0041] Figure 1 This is the Fourier infrared spectrum of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 1. The results show that the Mg-doped dual-phase calcium-phosphorus-based inorganic material has a wavelength of 3446 cm -1 There is an OH stretching vibration peak nearby, and adsorbed water exists at a wave number of 1638 cm -1 Nearby, wave number 1422cm -1 The peaks nearby are attributed to CO3 2- This is because CO2 in the air enters the reaction system during the synthesis process; wave number 1041cm -1 、875cm -1 、610cm -1 、566cm -1 All are PO4 3- vibration absorption peak.

[0042] Figure 2The XRD diffraction pattern of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 1. It can be seen from the analysis of the spectrum that the Mg-doped dual-phase calcium-phosphorus-based inorganic material has both β-TCP and hydroxyapatite, two calcium-phosphorus-based materials. Among them, 28.10°, 31.30°, and 34.73° are diffraction peaks of β-TCP, and 31.80°, 32.20°, and 32.88° are diffraction peaks of hydroxyapatite. By changing the pH conditions, the relative content of β-TCP and hydroxyapatite can be changed. When the pH increases from 9 to 10, the characteristic peak intensity of hydroxyapatite increases, and the characteristic peak intensity of β-TCP decreases; when the pH increases from 10 to 10.5, the characteristic peak intensity of hydroxyapatite decreases, and the characteristic peak intensity of β-TCP increases. This indicates that when the pH increases from 9 to 10, the content of β-TCP decreases, and the content of hydroxyapatite increases; when the pH increases from 10 to 10.5, the content of hydroxyapatite decreases, and the content of β-TCP increases. Therefore, by regulating the pH value of the reaction system, it is expected to obtain Mg-doped dual-phase calcium-phosphorus-based inorganic materials with different β-TCP / hydroxyapatite ratios.

[0043] Figure 3 The Tem morphology of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 1. It can be seen from the figure that the morphology of the Mg-doped dual-phase calcium-phosphorus-based inorganic material synthesized under different pH conditions is similar to that of the standard hydroxyapatite synthesized at room temperature, both of which are short rod-shaped, so the change in pH does not have a significant effect on the morphology of the Mg-doped dual-phase calcium-phosphorus-based inorganic material.

[0044] Figure 4 This is the Fourier infrared spectrum of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2. The results show that the amount of magnesium doping has little effect on the infrared spectrum of the Mg-doped dual-phase calcium-phosphorus-based material.

[0045] Figure 5 This is the XRD diffraction pattern of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2. It can be seen from the figure that when the magnesium doping amount is low-doping such as 1%, 1.5%, and 2%, basically only the diffraction peaks of HA and β-TCP appear in the spectrum. Among them, the diffraction peak intensity of β-TCP is relatively small. As the magnesium doping amount increases, the diffraction peak intensity of HA gradually weakens, and the diffraction peak intensity of β-TCP gradually increases. When the magnesium doping amount is increased to 7.7% or more, there is almost no diffraction peak of HA in the diffraction spectrum, and the diffraction peak of β-TCP occupies the vast majority. Therefore, by regulating the magnesium doping amount of the reaction system, Mg-doped dual-phase calcium-phosphorus-based inorganic materials with different β-TCP / hydroxyapatite ratios can also be obtained.

[0046] Figure 6This is the Tem morphology of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2. It can be seen that the morphology of the Mg-doped dual-phase calcium-phosphorus-based inorganic materials synthesized under different magnesium doping conditions all show short rod-like morphological characteristics. The morphological edges of the Mg-doped dual-phase calcium-phosphorus-based inorganic materials with low magnesium doping amounts of 1%, 1.5%, and 2% are relatively smooth, while the morphological edges of the Mg-doped dual-phase calcium-phosphorus-based inorganic materials with high magnesium doping amounts of 7.7% and 10% are relatively sharp, indicating that magnesium doping can regulate the morphology of calcium-phosphorus-based inorganic materials.

[0047] Figure 7 The Ca ion and Mg ion release curves of the Mg-doped dual-phase calcium-phosphorus-based inorganic material obtained in Example 2. The results show that for the Mg-doped dual-phase calcium-phosphorus-based inorganic material, the release behavior of Ca ions and Mg ions is related to the Mg doping amount. The higher the Mg doping amount, the faster the release rate of Ca ions and Mg ions, and the greater the release amount.

[0048] Figure 8 The live / dead cell staining diagram of the Mg-doped dual-phase calcium-phosphorus-based inorganic material and L929 cells co-cultured for 1 day and 3 days for Example 1 shows that each group shows good cell compatibility, does not inhibit cell proliferation, has no obvious apoptosis phenomenon, and the cell survival rate reaches more than 90%, and the cell phase compatibility is good. Due to the difference in the pH of the synthetic chemical environment, the change of the β-TCP / hydroxyapatite ratio in the Mg-doped dual-phase calcium-phosphorus-based inorganic material is caused, thereby changing the release behavior of inorganic ions, which can affect cell proliferation. Wherein the Mg-doped dual-phase calcium-phosphorus-based inorganic material synthesized under the condition of pH 10 has the best cell proliferation effect.

[0049] Fig. 9 The live / dead cell staining diagram of the Mg-doped biphasic calcium-phosphorus-based inorganic material obtained in Example 2 and co-cultured with L929 cells for 1 day and 3 days; the results show that each group shows good cell compatibility. The Mg-doped biphasic calcium-phosphorus-based inorganic material did not inhibit cell proliferation, there was no obvious cell apoptosis phenomenon, the cell survival rate was more than 90%, and the cell compatibility was good. Due to the different magnesium doping contents, the β-TCP / hydroxyapatite ratio in the Mg-doped biphasic calcium-phosphorus-based inorganic material changed, thereby changing the release behavior of inorganic ions, which can affect cell proliferation. With the increase of magnesium doping, the cell proliferation situation showed a trend of first strengthening and then weakening, among which the Mg-doped biphasic calcium-phosphorus-based inorganic material with a magnesium doping content of 1.5% had the best cell proliferation effect.

[0050] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A method for preparing a Mg-doped dual-phase calcium-phosphorus-based inorganic material, characterized in that: The following steps are involved: S1. Adding calcium hydroxide powder and magnesium hydroxide powder into deionized water to prepare a calcium hydroxide / magnesium hydroxide suspension; S2, preparing phosphoric acid aqueous solution; S3, under stirring conditions, adding the phosphoric acid aqueous solution dropwise to the calcium hydroxide / magnesium hydroxide suspension, during which the pH value of the system is controlled within the range of 9 to 11; S4. After the phosphoric acid aqueous solution is added dropwise, continue stirring and reacting for 10 to 30 hours; S5. After the reaction is completed, the reaction system is repeatedly filtered and washed with ethanol solution and deionized water, and the collected materials are dried to obtain a Mg-doped dual-phase calcium-phosphorus-based inorganic material.

2. The method for preparing the Mg-doped dual-phase calcium-phosphorus-based inorganic material according to claim 1, characterized in that: The concentration of calcium hydroxide in the calcium hydroxide / magnesium hydroxide suspension formed in step S1 is 0.1-0.2M.

3. The method for preparing the Mg-doped dual-phase calcium-phosphorus-based inorganic material according to claim 1, characterized in that: The ratio of the mole of magnesium hydroxide to the total mole of magnesium hydroxide and calcium hydroxide in the calcium hydroxide / magnesium hydroxide suspension formed in step S1 is 1 to 10:

100.

4. The method for preparing the Mg-doped dual-phase calcium-phosphorus-based inorganic material according to claim 1, characterized in that: The phosphoric acid concentration in the phosphoric acid aqueous solution in step S2 is 0.1-0.3M.

5. The method for preparing the Mg-doped dual-phase calcium-phosphorus-based inorganic material according to claim 1, characterized in that: In step S3, the ratio of the molar amount of phosphorus ions in the added phosphoric acid aqueous solution to the total molar amount of calcium and magnesium ions in the suspension is 1:(1-2).

6. The method for preparing the Mg-doped dual-phase calcium-phosphorus-based inorganic material according to claim 1, characterized in that: The stirring speed in steps S3 and S4 is 350-500 r / min.

7. The method for preparing the Mg-doped dual-phase calcium-phosphorus-based inorganic material according to claim 1, characterized in that: In step S3, ammonia water is used to adjust the pH value of the system during the reaction.

8. The method for preparing the Mg-doped dual-phase calcium-phosphorus-based inorganic material according to claim 1, characterized in that: In step S5, washing with deionized water is repeated 1 to 3 times, and washing with ethanol is repeated 1 to 3 times.

9. A Mg-doped dual-phase calcium-phosphorus-based inorganic material, characterized in that: The method is prepared by any one of claims 1 to 8.

10. Use of the Mg-doped dual-phase calcium-phosphorus-based inorganic material as claimed in claim 9 in preparing bone tissue repair materials.

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