Composite tricalcium phosphate / tetracalcium phosphate and application thereof in bone repair material

Abstract

The invention discloses composite tricalcium phosphate / tetracalcium phosphate and application thereof in bone repair materials, and belongs to the field of bone repair materials. The composite tricalcium phosphate / tetracalcium phosphate is porous tricalcium phosphate / tetracalcium phosphate composite powder loaded with a flastem milkvetch seed polysaccharide magnesium complex. The porous tricalcium phosphate / tetracalcium phosphate composite powder is a product obtained by presintering, pore-forming treatment and secondary sintering treatment of a mixture of CaCO3 and (NH4) 2HPO4 with a Ca / P molar ratio of 1.6-1.8, and the flastem milkvetch seed polysaccharide magnesium complex is a complex of flastem milkvetch seed polysaccharide and magnesium chloride. The compound tricalcium phosphate / tetracalcium phosphate provided by the invention can be used as a bone cement raw material, and the use of the compound tricalcium phosphate / tetracalcium phosphate not only can comprehensively improve the physical properties of the bone cement, but also can enhance the bone repair promotion effect of the bone cement.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bone repair materials, in particular to a composite tricalcium phosphate / tetracalcium phosphate and its application in bone repair materials. BACKGROUND

[0002] Bone repair materials are key materials for treating orthopedic diseases such as bone defects and poor fracture healing, and their performance directly affects the repair effect and patient prognosis. At present, the commonly used bone repair materials in clinical practice mainly include metal materials, ceramic materials, polymer materials and composite materials, etc. Among various bone repair materials, calcium phosphate-based ceramic materials have good biocompatibility due to their similar chemical composition to human bone tissue. Among them, tricalcium phosphate (TCP) and tetracalcium phosphate (TTCP) are widely used in the preparation of bone cement, bone scaffolds and other products.

[0003] Research has found that compared with using tricalcium phosphate or tetracalcium phosphate alone to prepare bone cement, using tricalcium phosphate and tetracalcium phosphate in combination can effectively improve the matching of the degradation rate of bone cement and the bone tissue regeneration rate. In order to further improve the bone repair efficiency of bone cement, the existing technology often modifies the bone cement by adding bioactive factors, stem cells, active peptides or antibacterial and anti-inflammatory ingredients and other functional materials. However, the existing composite bone cement preparation scheme has obvious limitations: on the one hand, the introduction of some functional materials will weaken the structural performance of the bone cement after solidification, thereby affecting the convenience of clinical operation and the supporting effect of the bone cement; on the other hand, the promotion effect of the composite bone cement loaded with functional materials on the bone repair process is affected by many factors such as the degradation efficiency of the bone cement, the release efficiency of the functional materials and the bone tissue regeneration rate, and the existing composite bone cement mostly focuses on the long-acting release effect of the functional materials, ignoring the balance of the release efficiency of the functional materials in the entire bone repair process, which may have the problem of insufficient short-term release, thereby restricting the early repair efficiency. To this end, the present application provides a composite tricalcium phosphate / tetracalcium phosphate and its application in bone repair materials. SUMMARY

[0004] The purpose of the present application is to provide a composite tricalcium phosphate / tetracalcium phosphate and its application in bone repair materials to solve the above problems.

[0005] The present application achieves the above-mentioned purposes through the following technical solutions: The present application provides a composite tricalcium phosphate / tetracalcium phosphate, which is a porous tricalcium phosphate / tetracalcium phosphate composite powder loaded with polygonum multiflorum polysaccharide magnesium complex; The porous tricalcium phosphate / tetracalcium phosphate composite powder is a product after pre-sintering, pore preparation and secondary sintering treatment of a mixture of CaCO3 and (NH4)2HPO4 with a Ca / P molar ratio of 1.6-1.8; The sand sage polysaccharide magnesium complex is a complex of sand sage polysaccharide and magnesium chloride.

[0006] The application further provides the composite tricalcium phosphate / tetracalcium phosphate and application thereof in bone repair materials.

[0007] As a further optimization scheme of the application, the preparation method of the composite tricalcium phosphate / tetracalcium phosphate is as follows: after obtaining the sand sage polysaccharide magnesium complex and the porous tricalcium phosphate / tetracalcium phosphate composite powder, the sand sage polysaccharide magnesium complex is dissolved in sterile deionized water, and stirring is performed until complete dissolution, so as to obtain a complex solution with a concentration of 3-5 mg / mL; the porous tricalcium phosphate / tetracalcium phosphate composite powder is added into the sand sage polysaccharide magnesium complex solution at a solid-liquid ratio of 1:(7-10) g / mL, and ultrasonic oscillation treatment is performed at 200-300 W, 30-45 kHz and for 10-15 min; after centrifugation, the precipitate is collected and dried, so as to obtain the composite tricalcium phosphate / tetracalcium phosphate.

[0008] As a further optimization scheme of the application, the preparation method of the porous tricalcium phosphate / tetracalcium phosphate composite powder is as follows: CaCO3 and (NH4)2HPO4 are mixed, and ball milling, vacuum drying and pre-sintering treatment are sequentially performed, so as to obtain a precursor powder; PVA aqueous solution, acrylic acid and H2O2 solution are added into the precursor powder, and the solid-liquid ratio is adjusted to 1:2 by using deionized water; after uniform stirring, a slurry is obtained; the slurry is sequentially subjected to secondary sintering, cooling, ball milling and sieving treatment, so as to obtain the porous tricalcium phosphate / tetracalcium phosphate composite powder.

[0009] As a further optimization scheme of the application, the pre-sintering condition is 800-900 ℃, 2-4 h, and the secondary sintering condition is as follows: the temperature is raised to 200-300 ℃ at a rate of 3-5 ℃ / min, and the temperature is maintained for 1-2 h; then the temperature is raised to 1100-1400 ℃ at a rate of 3-6 ℃ / min, and the temperature is maintained for 4-6 h.

[0010] As a further optimization scheme of the application, when the slurry is prepared, the adding amounts of the PVA aqueous solution, the acrylic acid and the H2O2 solution are 3-8%, 2-5% and 1%-5% of the mass of the precursor powder, respectively.

[0011] As a further optimization scheme of the application, the preparation method of the sand sage polysaccharide magnesium complex is as follows: the sand sage polysaccharide and magnesium chloride are respectively dissolved in water; the magnesium chloride aqueous solution is slowly dropped into the sand sage polysaccharide aqueous solution; after adding anhydrous ethanol into the mixed solution for purification, the precipitate is collected; and the precipitate is sequentially subjected to cleaning, drying, ball milling and sieving treatment, so as to obtain the sand sage polysaccharide magnesium complex.

[0012] As a further optimization scheme of the application, the concentration of the sand sage polysaccharide aqueous solution is 0.5-1 g / mL, and the concentration of the magnesium chloride aqueous solution is 1-1.5 mol / L.

[0013] As a further optimization scheme of the present application, the mixing conditions of the aqueous magnesium chloride solution and the aqueous Hedysari polysaccharide solution are as follows: mixing at a volume ratio of 1:1 at 35-40℃ and pH 8-10, dropwise adding at a speed of 1-2 mL / min, stirring at 200-300 r / min during the mixing process, and continuing for 1-2 h.

[0014] As a further optimization scheme of the present application, the purification conditions are as follows: adding 3 times the volume of anhydrous ethanol to the mixed solution, and centrifuging after cold storage.

[0015] The present application also provides an application of the above-mentioned composite tricalcium phosphate / tetracalcium phosphate in bone repair materials, i.e., the composite tricalcium phosphate / tetracalcium phosphate is used as a bone cement raw material.

[0016] The present application has the following beneficial effects: The present application obtains a composite tricalcium phosphate / tetracalcium phosphate with bone repair function through compounding of the porous TCP / TTCP composite powder and the Hedysari polysaccharide magnesium complex, and the composite tricalcium phosphate / tetracalcium phosphate can improve the curing performance, compressive strength, and injectability of bone cement and other core physical properties after being applied to bone cement. The combined use of Hedysari polysaccharide and magnesium can not only directly strengthen the promotion effect of bone cement on the bone repair process, but also is beneficial to improving the balance of the repair promotion effect and strengthening the early repair efficiency, thereby providing a bone cement raw material with excellent physical properties and biological activity for bone repair treatment. DETAILED DESCRIPTION

[0017] The following further describes the present application, and it is necessary to point out here that the following detailed description is only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0018] 1. Experimental materials The preparation method of Hedysari polysaccharide is as follows: after drying and crushing the Hedysari, the defatting treatment is performed twice by using petroleum ether continuous reflux at 40℃ for 2 h each time, then the obtained defatted Hedysari powder is subjected to ultrasonic water extraction treatment at a material-to-liquid ratio of 1:10, 60℃, 25 kHz, 300 W, and 45 min, the extraction liquid is centrifuged and filtered, and then vacuum concentrated to 1 / 3 of the original volume, to obtain a crude polysaccharide extraction liquid, the crude polysaccharide extraction liquid is repeatedly deproteinized by the Sevag method until no obvious protein layer is present, and then 20% and 25% ethanol are used for fractional precipitation, respectively, the obtained precipitate is washed with anhydrous ethanol and dried (45℃, vacuum drying) to constant weight, to obtain Hedysari polysaccharide.

[0019] The method used in the present application is a conventional method known to those skilled in the art, and the reagents and other materials used are commercially available products unless otherwise specified.

[0020] 2. Experimental method 2.1, Preparation of composite tricalcium phosphate / tetracalcium phosphate Example 1 A composite tricalcium phosphate / tetracalcium phosphate was prepared as follows: (1) Preparation of a magnesium polysaccharide complex of sophora alopecuroides: polysaccharide of sophora alopecuroides and magnesium chloride were dissolved in water to obtain a 0.5 g / mL polysaccharide of sophora alopecuroides solution and a 1.5 mol / L magnesium chloride solution. The magnesium chloride solution was slowly added to the polysaccharide of sophora alopecuroides solution at a volume ratio of 1:1 at a speed of 1 mL / min at 35°C. The pH of the mixed solution was adjusted to 8 using 30% (w / w) sodium hydroxide. The mixture was continuously stirred at 300 r / min for 1 h. Three times the volume of anhydrous ethanol was added to the obtained mixed solution, which was then refrigerated at 4°C for 8 h and then centrifuged (6000 r / min, 15 min). The precipitate was collected and sequentially washed (75% ethanol, stirring and soaking for 30 min, then washing for 3 min), dried (35°C, 8 h), ball-milled, and sieved to obtain a magnesium polysaccharide complex of sophora alopecuroides; (2) Mixing CaCO3 and (NH4)2HPO4 with a Ca / P molar ratio of 1.6, and sequentially ball-milling, drying (80°C, 6 h), and pre-sintering at 900°C for 2 h to obtain a precursor powder; Based on the mass of the precursor powder, 5% PVA aqueous solution (8% mass fraction), 3% acrylic acid, and 3% H2O2 solution (30% mass fraction) were added, and deionized water was used to adjust the solid-liquid ratio to 1:2. The mixture was stirred at 300 r / min for 30 min to obtain a slurry; The slurry was sequentially subjected to secondary sintering treatment, cooling, ball-milling, and sieving to obtain a porous TCP / TTCP composite powder. The secondary sintering treatment conditions were as follows: heating to 200°C at a rate of 3°C / min, maintaining the temperature for 2 h, then heating to 1100°C at a rate of 3°C / min, and maintaining the temperature for 6 h; (3) The magnesium polysaccharide complex of sophora alopecuroides was dissolved in sterile deionized water and stirred until completely dissolved to obtain a complex solution with a concentration of 5 mg / mL. The porous TCP / TTCP composite powder was added to the magnesium polysaccharide complex solution of sophora alopecuroides at a solid-liquid ratio of 1:7 g / mL. The mixture was then sequentially subjected to ultrasonic oscillation treatment at 200 W and 30 kHz for 15 min and centrifugation at 6000 r / min for 5 min. The precipitate was collected and subjected to vacuum drying at 45°C for 4 days to obtain a composite tricalcium phosphate / tetracalcium phosphate.

[0021] Example 2 A composite tricalcium / tetracalcium phosphate is prepared as follows: (1) A polysaccharide-magnesium complex of the milk vetch seed is prepared by dissolving polysaccharide of the milk vetch seed and magnesium chloride in water to obtain a 1 g / mL polysaccharide solution and a 1 mol / L magnesium chloride solution, slowly adding the magnesium chloride solution to the polysaccharide solution at a volume ratio of 1:1 at a speed of 2 mL / min at 40°C, adjusting the pH of the mixed solution to 10 with 30% (w / w) sodium hydroxide, continuously stirring at 300 r / min for 1 h during the mixing, adding 3 times the volume of anhydrous ethanol to the obtained mixed solution, and centrifuging (6000 r / min, 15 min) after cold storage at 4°C for 8 h, collecting the precipitate and sequentially washing (75% ethanol, stirring and soaking for 30 min and then washing for 3 min), drying (35°C, 8 h), ball milling, and sieving to obtain the polysaccharide-magnesium complex of the milk vetch seed; (2) The CaCO3 and (NH4)2HPO4 are mixed at a Ca / P molar ratio of 1.8, and the mixed powder is sequentially subjected to ball milling, drying (80°C, 6 h), and pre-sintering at 900°C for 2 h to obtain a precursor powder; The mass of the precursor powder is taken as a standard, 5% PVA solution (8% by mass), 3% acrylic acid, and 3% H2O2 solution (30% by mass) are added, deionized water is used to adjust the solid-liquid ratio to 1:2, and stirring is performed at 300 r / min for 30 min to obtain a slurry; The slurry is sequentially subjected to secondary sintering, cooling, ball milling, and sieving to obtain a porous TCP / TTCP composite powder, and the secondary sintering is performed by increasing the temperature to 300°C at a rate of 5°C / min, maintaining the temperature for 1 h, and then increasing the temperature to 1400°C at a rate of 6°C / min and maintaining the temperature for 4 h; (3) The polysaccharide-magnesium complex of the milk vetch seed is dissolved in sterile deionized water and stirred until completely dissolved to obtain a complex solution with a concentration of 3 mg / mL, the porous TCP / TTCP composite powder is added to the polysaccharide-magnesium complex solution at a solid-liquid ratio of 1:10 g / mL, and then ultrasonic oscillation treatment is performed at 300 W, 45 kHz, and 10 min, followed by centrifugation at 6000 r / min for 5 min, the precipitate is collected and subjected to vacuum drying at 45°C for 4 days to obtain a composite tricalcium / tetracalcium phosphate.

[0022] Example 3 A composite tricalcium / tetracalcium phosphate is prepared as follows: (1) Preparation of the magnesium complex of polysaccharide from Helicteres isora L. : polysaccharide from Helicteres isora L. and magnesium chloride were dissolved in water to obtain a 0.8 g / mL polysaccharide from Helicteres isora L. aqueous solution and a 1.2 mol / L magnesium chloride aqueous solution, and the magnesium chloride aqueous solution was slowly dropped into the polysaccharide from Helicteres isora L. aqueous solution at a volume ratio of 1:1 and a speed of 1.5 mL / min at 38°C, and then the pH of the mixed solution was adjusted to 9 by using 30% (w / w) sodium hydroxide, and the mixing process was continuously stirred at 250 r / min for 1.5 h, and then 3 times the volume of anhydrous ethanol was added to the obtained mixed solution, and the solution was stored at 4°C for 8 h and then centrifuged (6000 r / min, 15 min), and the precipitate was collected and sequentially washed (75% ethanol, stirring and soaking for 30 min and then washing for 3 min), dried (35°C, 8 h), ball-milled, and sieved to obtain the magnesium complex of polysaccharide from Helicteres isora L. ; (2) CaCO3 and (NH4)2HPO4 were mixed at a Ca / P molar ratio of 1.7, and the mixed powder was sequentially ball-milled, dried (80°C, 6 h), and pre-sintered at 850°C for 3 h to obtain a precursor powder; Based on the mass of the precursor powder, 5% PVA aqueous solution (8% by mass), 3% acrylic acid, and 3% H2O2 solution (30% by mass) were added, and deionized water was used to adjust the solid-liquid ratio to 1:2, and the slurry was stirred at 300 r / min for 30 min to obtain a slurry; The slurry was sequentially subjected to secondary sintering treatment, cooling, ball-milling, and sieving to obtain a porous TCP / TTCP composite powder, and the secondary sintering treatment was performed by increasing the temperature to 250°C at a rate of 4°C / min and maintaining the temperature for 1 h, and then increasing the temperature to 1200°C at a rate of 5°C / min and maintaining the temperature for 5 h; (3) The magnesium complex of polysaccharide from Helicteres isora L. was dissolved in sterile deionized water and stirred until completely dissolved to obtain a complex solution with a concentration of 4 mg / mL, and the porous TCP / TTCP composite powder was added to the magnesium complex of polysaccharide from Helicteres isora L. solution at a solid-liquid ratio of 1:8 g / mL, and then sequentially subjected to ultrasonic oscillation treatment at 250 W and 40 kHz for 12 min and centrifugal treatment at 6000 r / min for 5 min, and the precipitate was collected and subjected to vacuum drying treatment at 45°C for 4 days to obtain a composite tricalcium phosphate / tetracalcium phosphate.

[0023] Blank control A composite tricalcium phosphate / tetracalcium phosphate was prepared by the following method: (1) Preparation of TTCP: CaCO3 and (NH4)2HPO4 were mixed with a Ca / P molar ratio of 2, and the mixed powder was subjected to ball milling and drying (80°C, 6h) in sequence, followed by pre-sintering (850°C, 2h) and secondary sintering (heating to 1400°C at a rate of 4°C / min, and holding for 5h), to obtain a TTCP solid-phase powder; (2) Preparation of β-TCP: CaCO3 and (NH4)2HPO4 were mixed with a Ca / P molar ratio of 1.5, and the mixed powder was subjected to ball milling and drying (80°C, 6h) in sequence, followed by pre-sintering (850°C, 2h) and secondary sintering (heating to 1100°C at a rate of 4°C / min, and holding for 5h), to obtain a β-TCP solid-phase powder; (3) TTCP and β-TCP were mixed in a mass ratio of 1:1, and placed in a ball mill with anhydrous ethanol as the ball milling medium. After ball milling for 3h, the mixture was dried at 80°C for 6h, and then calcined at 800°C for 2h. After cooling, the mixture was ground to obtain a composite tricalcium phosphate / tetracalcium phosphate powder.

[0024] Comparative Example 1 Based on Example 3, the Hedysari polysaccharide was replaced with Eucommia ulmoides polysaccharide to prepare a composite tricalcium phosphate / tetracalcium phosphate.

[0025] Comparative Example 2 Based on Example 3, the Hedysari polysaccharide was replaced with Rehmannia glutinosa polysaccharide to prepare a composite tricalcium phosphate / tetracalcium phosphate.

[0026] Comparative Example 3 Based on Example 3, the magnesium chloride used in step (1) was replaced with an equal amount of strontium chloride to prepare a Hedysari polysaccharide strontium complex. The Hedysari polysaccharide strontium complex was then used to replace the Hedysari polysaccharide magnesium complex in step (3) to prepare a composite tricalcium phosphate / tetracalcium phosphate.

[0027] Comparative Example 4 (1) Preparation of a porous TCP / TTCP composite powder, by the same method as in Example 3; (3) The Hedysari polysaccharide (used in the same amount as the Hedysari polysaccharide magnesium complex in Example 3) was dissolved in sterile deionized water, and stirred until completely dissolved to obtain a Hedysari polysaccharide solution. The porous TCP / TTCP composite powder was added to the Hedysari polysaccharide solution at a solid-liquid ratio of 1:8g / mL, and then subjected to ultrasonic oscillation treatment at 250W, 40kHz for 12min, and centrifugation at 6000r / min for 5min. The precipitate was collected and subjected to vacuum drying at 45°C for 4 days to obtain a composite tricalcium phosphate / tetracalcium phosphate.

[0028] 2.2, Efficacy detection From the composite tricalcium phosphate / tetracalcium phosphate prepared in Example 1-3 and the blank control group, a sample was taken, bone cement was prepared, and corresponding performance tests were conducted: The preparation method of the bone cement was as follows: 0.25 g of MCPM was uniformly mixed with 1.8 g of the sample, 2 mL of citric acid (0.5 mol / L) was added, and the bone cement was obtained after uniform mixing.

[0029] The test items and methods were as follows: (1) Curing time determination: the bone cement was filled into a Φ10 mm x 5 mm cylindrical mold, and after curing, it was demolded. During the process, the Gilmore double needle method was used to determine the curing time; (2) Compression strength determination: the bone cement slurry was filled into a Φ10 mm x 5 mm mold, and after 0.5 h, it was taken out and placed in a 37°C water bath for 72 h of curing. A universal mechanical testing machine was used for testing, with a load of 900 N and a pressing speed of 1 mm / min. Five parallel samples were set for each group, and the average value was taken as the test result; (3) Injectability determination: a 2 mL syringe was taken, and the mass was recorded as m0. The bone cement was filled into the syringe, and at this time the total mass of the syringe was recorded as m1. After 2 min, the slurry was extruded at a constant rate of 150 mm / min until the pushing force was greater than 200 N, at which point the mass of the syringe at this time was recorded as m2. The experiment was repeated 5 times. The injection coefficient (IC) was calculated, and the formula was as follows: ; (4) Immune function detection: the bone cement slurry was made into a circle with a size of Φ19 mm x 2 mm, and Ringer's simulated liquid was used as the medium. According to the solid-liquid ratio of 1 g / 50 mL, the sample was suspended in Ringer's simulated liquid at 37°C, and was oscillated and soaked. 3 mL of the soaking liquid was taken at 2 days, 4 days, and 6 days of soaking, respectively, for standby; Mouse macrophage RAW264.7 cells were scraped with a cell scraper and blown to prepare a single cell suspension. After counting on a counting plate, they were diluted with DMEM medium containing 5% (volume percentage) FBS (fetal bovine serum), and then inoculated into a 96-well plate, with about 5000 cells per well and 100 μL of cell suspension added to each well. Then the 96-well plate was placed in a carbon dioxide incubator for 24 hours. The culture medium in the 96-well plate was then aspirated, and 200 μL of the above soaking liquid was added to 3 parallel wells of the 96-well plate as experimental wells. 3 wells to which 200 μL of DMEM medium was added were set as control wells. After 3 days of culture, the absorbance values of the solutions in the experimental and control wells were detected, and the average value of the three wells was taken as the detection result. Taking the detection result of the control wells as the reference, the relative absorbance of each experimental well was calculated.

[0030] The detection results are shown in the following table, and from the results, it can be seen that: (1) Compared with the blank control, in examples 1-3, the curing time of the bone cement is longer, the compressive strength is greater, and the injectability coefficient is greater, which shows that when the porous TCP / TTCP composite powder loaded with the magnesium complex of polygonatum sibiricum polysaccharide is used as the raw material of bone cement, the physical properties of the bone cement can be effectively strengthened; (2) In comparative examples 1 and 2, the curing speed and compressive strength of the bone cement are comparable to example 3, but the injectability coefficient is significantly reduced. In comparative example 3, the curing speed of the bone cement is significantly accelerated, the compressive strength is comparable to example 3, and the decrease in the injectability coefficient is smaller. In comparative example 4, the compressive strength and injectability coefficient of the bone cement are significantly reduced. The above results comprehensively show that the combination of polygonatum sibiricum polysaccharide and magnesium can take into account the curing performance, compressive performance and injectability of the bone cement, and achieve the effect of strengthening the comprehensive physical properties of the bone cement; (3) The greater the relative absorbance value, the better the cell proliferation of the bone cement immersion liquid. According to the relative absorbance value, compared with example 3, the cell proliferation effect of the bone cement immersion liquid in comparative examples 1-4 is worse than that of example 3 as a whole, and in example 3, the difference in cell proliferation effect of 2-day immersion liquid, 4-day immersion liquid and 6-day immersion liquid is smaller. The results show that in the present application, there is an adaptability advantage between polygonatum sibiricum polysaccharide and magnesium, and the combination of the two can not only strengthen the repair effect of bone cement, but also be beneficial to improving the balance of bone repair process.

[0031] ; The above examples only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the present patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. A composite tricalcium / tetracalcium phosphate, characterized in that: The composite tricalcium phosphate / tetracalcium phosphate is a porous tricalcium phosphate / tetracalcium phosphate composite powder loaded with a polygonum multiflorum polysaccharide magnesium complex; The porous tricalcium phosphate / tetracalcium phosphate composite powder is a product obtained by pre-sintering, pore preparation and secondary sintering of a mixture of CaCO3 and (NH4)2HPO4 with a Ca / P molar ratio of 1.6-1.8; The polygonum multiflorum polysaccharide magnesium complex is a complex of polygonum multiflorum polysaccharide and magnesium chloride.

2. The composite tricalcium / tetracalcium phosphate according to claim 1, characterized in that: The preparation method of the composite tricalcium phosphate / tetracalcium phosphate comprises the following steps: after obtaining the polygonum multiflorum polysaccharide magnesium complex and the porous tricalcium phosphate / tetracalcium phosphate composite powder, dissolving the polygonum multiflorum polysaccharide magnesium complex in sterile deionized water, stirring until completely dissolved, obtaining a complex solution with a concentration of 3-5 mg / mL, adding the porous tricalcium phosphate / tetracalcium phosphate composite powder into the polygonum multiflorum polysaccharide magnesium complex solution at a solid-liquid ratio of 1:(7-10) g / mL, and performing ultrasonic oscillation treatment at 200-300 W, 30-45 kHz and 10-15 min, collecting the precipitate after centrifugation and drying to obtain the composite tricalcium phosphate / tetracalcium phosphate.

3. The composite tricalcium / tetracalcium phosphate according to claim 2, characterized in that: The preparation method of the porous tricalcium phosphate / tetracalcium phosphate composite powder comprises the following steps: mixing CaCO3 and (NH4)2HPO4, and sequentially performing ball milling, vacuum drying and pre-sintering to obtain a precursor powder, adding PVA aqueous solution, acrylic acid and H2O2 solution into the precursor powder, adjusting the solid-liquid ratio to 1:2 with deionized water, uniformly stirring to obtain a slurry, and sequentially performing secondary sintering, cooling, ball milling and sieving on the slurry to obtain the porous tricalcium phosphate / tetracalcium phosphate composite powder.

4. The composite tricalcium / tetracalcium phosphate according to claim 3, characterized in that: The pre-sintering condition is 800-900 ℃ for 2-4 h, and the secondary sintering condition is: heating to 200-300 ℃ at a rate of 3-5 ℃ / min, maintaining for 1-2 h, then heating to 1100-1400 ℃ at a rate of 3-6 ℃ / min, and maintaining for 4-6 h.

5. The composite tricalcium / tetracalcium phosphate according to claim 3, characterized in that: When preparing the slurry, the PVA aqueous solution, the acrylic acid and the H2O2 solution are added in an amount of 3-8%, 2-5% and 1%-5% of the mass of the precursor powder, respectively.

6. The composite tricalcium / tetracalcium phosphate according to claim 2, characterized in that: The preparation method of the polygonum multiflorum polysaccharide magnesium complex comprises the following steps: dissolving polygonum multiflorum polysaccharide and magnesium chloride in water respectively, slowly dropping the magnesium chloride aqueous solution into the polygonum multiflorum polysaccharide aqueous solution, adding anhydrous ethanol into the mixed solution to collect the precipitate, and sequentially performing cleaning, drying, ball milling and sieving on the precipitate to obtain the polygonum multiflorum polysaccharide magnesium complex.

7. A composite tricalcium / tetracalcium phosphate according to claim 6, characterized in that: The concentration of the polygonum multiflorum polysaccharide aqueous solution is 0.5-1 g / mL, and the concentration of the magnesium chloride aqueous solution is 1-1.5 mol / L.

8. The composite tricalcium / tetracalcium phosphate according to claim 6, characterized in that: The mixing condition of the magnesium chloride aqueous solution and the polygonum multiflorum polysaccharide aqueous solution is: mixing at a volume ratio of 1:1 at 35-40 ℃ and pH 8-10, the dropping speed is 1-2 mL / min, and stirring is performed at 200-300 r / min during the mixing process for 1-2 h.

9. The composite tricalcium / tetracalcium phosphate according to claim 6, characterized in that: The purification condition is: adding 3 times the volume of anhydrous ethanol into the mixed solution, and performing centrifugation after cold storage.

10. Use of a composite tricalcium / tetracalcium phosphate according to any one of claims 1 to 9 in a bone repair material, characterized in that: The composite tricalcium phosphate / tetracalcium phosphate is used as a bone cement raw material.