Modified magnesium strontium doped hydroxyapatite whisker and polymethyl methacrylate composite bone cement and preparation method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG FOOD & DRUG VOCATIONAL COLLEGE
- Filing Date
- 2026-06-29
- Publication Date
- 2026-08-04
AI Technical Summary
然而，PMMA骨水泥存在如下缺陷：（1）PMMA骨水泥固化体弹性模量相对于正常椎体骨组织过高；（2）PMMA的生物惰性使其无法与骨组织形成骨整合；（3）PMMA骨水泥存在固化温度高、易损伤骨水泥周围组织和神经等问题，且单体具有一定毒性
1）硬脂酸疏水改性后的镁锶掺杂羟基磷灰石晶须，SA通过羧基与羟基磷灰石（HA）表面的钙离子结合形成硬脂酸钙接枝在HA表面，提高疏水性，与PMMA更好地结合；镁离子的缓慢释放，赋予骨水泥更优异的生物相容性和生物活性；硬脂酸改性镁锶掺杂羟基磷灰石晶须中羟基磷灰石具有良好的生物学性能，锶、镁掺杂有助于缩短磷灰石的沉积期，提升生物相容性和生物活性；晶须形态具有较高的力学强度，硬脂酸的疏水改性抑制晶须团聚，提高晶须和PMMA的结合力。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of bone cement technology, and in particular to a modified magnesium-strontium doped hydroxyapatite whiskers and polymethyl methacrylate composite bone cement and its preparation method. Background Technology
[0002] Polymethyl methacrylate (PMMA) bone cement has been widely used in clinical practice due to its good biomechanical properties and rapid molding capabilities. However, PMMA bone cement has the following drawbacks: (1) the elastic modulus of the cured PMMA bone cement is too high compared to normal vertebral bone tissue; (2) the bioinertness of PMMA prevents it from forming osseointegration with bone tissue; and (3) PMMA bone cement has problems such as high curing temperature, easy damage to surrounding tissues and nerves, and the monomer has a certain degree of toxicity.
[0003] To improve the biological properties of PMMA bone cement, researchers have conducted extensive studies, with the most significant focus on adding bioactive components to bone cement powder. These include bioceramics, bioglass, collagen, chitosan, and hydroxyapatite (HA). HA shares similarities in chemical composition and crystal structure with the inorganic components of natural human bone, exhibiting excellent biocompatibility and osteogenic activity. To meet clinical application needs, elements are often added to synthetically produced HA to improve material properties, such as magnesium-doped hydroxyapatite. Mg directly affects the bone calcification process and is a major factor influencing mineral metabolism in the body. Mg ion depletion can lead to bone cessation, reduced osteoblast activity, and consequently, osteoporosis and bone fragility. Research results indicate that insufficient addition of biological components does not significantly improve the biological activity of modified PMMA bone cement; excessive addition leads to agglomeration, and while the bone cement possesses some biological activity, it directly results in a significant decrease in the mechanical properties of the PMMA bone cement, even rendering it unable to provide structural support, thus failing to meet clinical requirements.
[0004] Therefore, it is of great significance to provide a PMMA composite bone cement that can effectively inhibit hydroxyapatite agglomeration and improve mechanical properties, biocompatibility and osteogenic activity. Summary of the Invention
[0005] The purpose of this invention is to provide a modified magnesium-strontium doped hydroxyapatite whiskers and polymethyl methacrylate composite bone cement and its preparation method, addressing the shortcomings of existing technologies.
[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing modified magnesium strontium-doped hydroxyapatite whiskers, comprising the following steps: 1) Mix calcium salt, magnesium salt, strontium salt, phosphate powder and water to obtain a mixed solution; 2) After adjusting the pH value of the mixture, hydrothermal reaction and aging were carried out sequentially to obtain magnesium-strontium-doped hydroxyapatite; 3) Stearic acid and anhydrous ethanol were mixed, acetic acid was added dropwise to adjust the pH of the mixture, magnesium strontium-doped hydroxyapatite was added, and the mixture was calcined after reaction to obtain modified magnesium strontium-doped hydroxyapatite whiskers.
[0007] Preferably, the calcium salt in step 1) is calcium nitrate and / or calcium chloride, the magnesium salt is magnesium nitrate and / or magnesium chloride, the strontium salt is strontium nitrate, and the phosphate is diammonium hydrogen phosphate and / or ammonium hydrogen phosphate.
[0008] Preferably, in the mixture described in step 1), the molar ratio of calcium, magnesium and strontium is 10:0.4~0.8:0.3~0.6; the concentration of calcium salt in the mixture is 0.1~0.6 mol / L; and the concentration of phosphate in the mixture is 0.05~0.5 mol / L.
[0009] Preferably, the hydrothermal reaction temperature in step 2) is 170~200℃, the hydrothermal reaction time is 10~18h; the pH value of the mixture is adjusted to 8~10; and the aging time is 5~10h.
[0010] Preferably, in step 3), the mass ratio of stearic acid to magnesium strontium-doped hydroxyapatite is 2-6:100, the reaction temperature is 60-75℃, the reaction time is 10-14h, and the pH value is adjusted to 4-6; the calcination temperature is 800-900℃, and the calcination time is 1-2h.
[0011] The present invention also provides a method for preparing modified magnesium strontium-doped hydroxyapatite whiskers, and the modified magnesium strontium-doped hydroxyapatite whiskers obtained therefrom.
[0012] The present invention also provides a polymethyl methacrylate composite bone cement comprising the modified magnesium strontium doped hydroxyapatite whiskers, wherein the polymethyl methacrylate composite bone cement comprises bone cement powder and bone cement liquid; the mass-to-volume ratio of the bone cement powder to the bone cement liquid is 1.8~2.6g:1mL; The bone cement powder comprises the following components in parts by weight: 65-75 parts polymethyl methacrylate, 10-15 parts modified magnesium strontium doped hydroxyapatite, 10-15 parts contrast agent, and 0.5-1 part initiator; The bone cement liquid contains the following components in parts by weight: 96-98 parts of methyl methacrylate monomer, 0.00007-0.0001 parts of stabilizer, and 2-3 parts of accelerator.
[0013] Preferably, the polymethyl methacrylate has a weight-average molecular weight of 70,000 to 100,000, and the contrast agent contains one or more of barium sulfate, zirconium dioxide, and tantalum powder, with a particle size of 0.5 to 5 μm.
[0014] Preferably, the initiator is one or more of benzoyl peroxide, cyclohexanone peroxide, and methyl ethyl ketone peroxide; the stabilizer comprises hydroquinone and / or p-tert-butylcatechol; and the accelerator is N,N-dimethyl-p-toluidine.
[0015] The present invention also provides a method for preparing the polymethyl methacrylate composite bone cement, wherein bone cement powder and bone cement liquid are mixed and then cured to obtain polymethyl methacrylate composite bone cement.
[0016] The beneficial effects of this invention are: 1) Stearic acid-modified magnesium-strontium-doped hydroxyapatite whiskers: SA binds to calcium ions on the surface of hydroxyapatite (HA) through carboxyl groups to form calcium stearate grafts on the HA surface, improving hydrophobicity and better bonding with PMMA; the slow release of magnesium ions gives bone cement better biocompatibility and bioactivity; hydroxyapatite in stearic acid-modified magnesium-strontium-doped hydroxyapatite whiskers has good biological properties, and strontium and magnesium doping helps to shorten the deposition period of apatite, improving biocompatibility and bioactivity; the whisker morphology has high mechanical strength, and the hydrophobic modification of stearic acid inhibits whisker agglomeration and improves the bonding force between whiskers and PMMA.
[0017] 2) The polymethyl methacrylate composite bone cement of the present invention can improve osteogenic activity, reduce the side effects of PMMA bone cement, and has suitable mechanical strength, good bioactivity, biocompatibility and mechanical properties; it is suitable for filling cavities caused by various bone defects or bone injuries. Detailed Implementation
[0018] This invention provides a method for preparing modified magnesium strontium-doped hydroxyapatite whiskers, comprising the following steps: 1) Mix calcium salt, magnesium salt, strontium salt, phosphate powder and water to obtain a mixed solution; 2) After adjusting the pH value of the mixture, hydrothermal reaction and aging were carried out sequentially to obtain magnesium-strontium-doped hydroxyapatite; 3) Stearic acid (SA) is mixed with anhydrous ethanol, acetic acid is added dropwise to adjust the pH of the mixture, magnesium strontium-doped hydroxyapatite is added, and the mixture is calcined after reaction to obtain modified magnesium strontium-doped hydroxyapatite whiskers.
[0019] In this invention, the calcium salt in step 1) is preferably calcium nitrate and / or calcium chloride, the magnesium salt is preferably magnesium nitrate and / or magnesium chloride, the strontium salt is preferably strontium nitrate, and the phosphate is preferably diammonium hydrogen phosphate and / or ammonium hydrogen phosphate.
[0020] In this invention, in the mixture described in step 1), the molar ratio of calcium, magnesium, and strontium is preferably 10:0.4~0.8:0.3~0.6, more preferably 10:0.5~0.7:0.4~0.5, and even more preferably 10:0.6:0.45; the concentration of calcium salt in the mixture is preferably 0.1~0.6 mol / L, more preferably 0.2~0.5 mol / L, and even more preferably 0.3~0.4 mol / L; the concentration of phosphate in the mixture is preferably 0.05~0.5 mol / L, more preferably 0.1~0.4 mol / L, and even more preferably 0.2~0.3 mol / L.
[0021] In this invention, the temperature of the hydrothermal reaction in step 2) is preferably 170~200℃, more preferably 180~190℃, and the time of the hydrothermal reaction is preferably 10~18h, more preferably 12~16h, and more preferably 14h; the pH value of the mixture is preferably adjusted to 8~10, more preferably to 9; and the aging time is preferably 5~10h, more preferably 6~9h, and more preferably 7~8h.
[0022] In this invention, the mass ratio of stearic acid to magnesium strontium-doped hydroxyapatite in step 3) is preferably 2-6:100, more preferably 3-5:100, and even more preferably 4:100. The reaction temperature is preferably 60-75°C, more preferably 63-72°C, and even more preferably 65-70°C. The reaction time is preferably 10-14 h, more preferably 11-13 h, and even more preferably 12 h. The pH value is preferably adjusted to 4-6, and even more preferably to 5. The calcination temperature is preferably 800-900°C, more preferably 820-880°C, and even more preferably 850-860°C. The calcination time is preferably 1-2 h, and even more preferably 1.5 h.
[0023] In this invention, the composition and structure of the modified magnesium-strontium doped hydroxyapatite whiskers are closer to those of natural bone. Magnesium ions play an important role in the early stages of bone formation, regulating bone formation and remodeling through surface reactions in bone minerals. The continuous release of magnesium ions endows the material with certain osteogenic activity. Strontium ions can stimulate osteoblast proliferation and differentiation and inhibit osteoclast activity, significantly improving bone density and bone quality. Grafting the hydrophobic substance stearic acid onto the whisker surface improves the interfacial compatibility between hydroxyapatite and PMMA, reduces water absorption, thereby reducing the aggregation effect of hydroxyapatite whiskers and improving the bonding force between the modified magnesium-strontium doped hydroxyapatite whiskers and PMMA.
[0024] The present invention also provides a method for preparing modified magnesium strontium-doped hydroxyapatite whiskers, and the modified magnesium strontium-doped hydroxyapatite whiskers obtained therefrom.
[0025] The length of the modified magnesium-strontium doped hydroxyapatite whiskers prepared by the present invention is preferably 200-400 nm, more preferably 260-350 nm, and the diameter is preferably 10-20 nm, more preferably 12-15 nm.
[0026] The present invention also provides a polymethyl methacrylate composite bone cement comprising the modified magnesium strontium doped hydroxyapatite whiskers, wherein the polymethyl methacrylate composite bone cement comprises bone cement powder and bone cement liquid; the mass-to-volume ratio of the bone cement powder to the bone cement liquid is 1.8~2.6g:1mL; The bone cement powder comprises the following components in parts by weight: 65-75 parts polymethyl methacrylate, 10-15 parts modified magnesium strontium doped hydroxyapatite, 10-15 parts contrast agent, and 0.5-1 part initiator; The bone cement liquid contains the following components in parts by weight: 96-98 parts of methyl methacrylate monomer, 0.00007-0.0001 parts of stabilizer, and 2-3 parts of accelerator.
[0027] In this invention, the mass-to-volume ratio of bone cement powder to bone cement liquid is 1.8~2.6g:1mL, preferably 2~2.4g:1mL, and more preferably 2.2~2.3g:1mL; The bone cement powder comprises the following components in parts by weight: 65-75 parts of polymethyl methacrylate, preferably 67-72 parts, more preferably 70 parts; 10-15 parts of modified magnesium-strontium doped hydroxyapatite, preferably 11-14 parts, more preferably 12-13 parts; 10-15 parts of contrast agent, preferably 11-14 parts, more preferably 12-13 parts; and 0.5-1 part of initiator, preferably 0.6-0.9 parts, more preferably 0.7-0.8 parts. The bone cement liquid comprises the following components in parts by weight: 96-98 parts of methyl methacrylate monomer, preferably 97 parts; 0.00007-0.0001 parts of stabilizer, preferably 0.00008-0.00009 ppm; and 2-3 parts of accelerator, preferably 2.2-2.8 parts, more preferably 2.5-2.6 parts.
[0028] In this invention, the weight-average molecular weight of the polymethyl methacrylate is preferably 70,000 to 100,000, more preferably 80,000 to 90,000, and even more preferably 83,000 to 86,000. The contrast agent preferably contains one or more of barium sulfate, zirconium dioxide, and tantalum powder. The particle size of the contrast agent is preferably 0.5 to 5 μm, more preferably 1 to 4 μm, and even more preferably 1.5 to 3 μm.
[0029] In this invention, the initiator is preferably one or more of benzoyl peroxide, cyclohexanone peroxide, and methyl ethyl ketone peroxide; the stabilizer preferably contains hydroquinone and / or p-tert-butylcatechol; and the accelerator is preferably N,N-dimethyl-p-toluidine.
[0030] The present invention also provides a method for preparing the polymethyl methacrylate composite bone cement, wherein bone cement powder and bone cement liquid are mixed and then cured to obtain polymethyl methacrylate composite bone cement.
[0031] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0032] In the examples and comparative examples, the weight-average molecular weight of polymethyl methacrylate was 83,000 to 86,000, and the particle size of the contrast agent was 1.5 to 3 μm.
[0033] Example 1
[0034] Calcium nitrate, magnesium nitrate, and strontium nitrate were added to deionized water and mixed thoroughly. Diammonium hydrogen phosphate powder was then added and mixed thoroughly to obtain a mixed solution. The molar ratio of calcium, magnesium, and strontium in the mixed solution was 10:0.6:0.45, and the concentrations of both calcium and diammonium hydrogen phosphate in the mixed solution were 0.3 mol / L.
[0035] The pH of the mixture was adjusted to 9 using a 0.1 mol / L sodium hydroxide aqueous solution, and then hydrothermally reacted at 180 °C for 15 h, followed by aging at room temperature for 8 h to obtain magnesium-strontium-doped hydroxyapatite.
[0036] 1g of stearic acid was mixed with 100mL of anhydrous ethanol, and acetic acid was added dropwise to adjust the pH of the mixture to 5. Then, 25g of magnesium strontium-doped hydroxyapatite was added. After reacting at 70℃ for 12h, the mixture was calcined at 850℃ for 1.5h to obtain modified magnesium strontium-doped hydroxyapatite whiskers.
[0037] The bone cement powder consists of the following components in parts by weight: 70 parts polymethyl methacrylate, 13 parts modified magnesium strontium doped hydroxyapatite, 12 parts barium sulfate, and 0.7 parts benzoyl peroxide; the bone cement liquid consists of the following components in parts by weight: 97 parts methyl methacrylate monomer, 0.00008 parts p-tert-butylcatechol, and 2.5 parts N,N-dimethyl-p-toluidine; the bone cement powder and bone cement liquid are mixed evenly at a mass-volume ratio of 2.2 g: 1 mL and then cured to obtain polymethyl methacrylate composite bone cement.
[0038] Example 2
[0039] Calcium chloride, magnesium chloride, and strontium nitrate were added to deionized water and mixed thoroughly. Ammonium hydrogen phosphate powder was then added and mixed thoroughly to obtain a mixed solution. The molar ratio of calcium, magnesium, and strontium in the mixed solution was 10:0.4:0.3. The concentration of calcium salt in the mixed solution was 0.2 mol / L, and the concentration of ammonium hydrogen phosphate was 0.4 mol / L.
[0040] The pH of the mixture was adjusted to 8 using a 0.1 mol / L sodium hydroxide aqueous solution, and then hydrothermally reacted at 170 °C for 17 h, followed by aging at room temperature for 10 h to obtain magnesium-strontium-doped hydroxyapatite.
[0041] 1g of stearic acid was mixed with 100mL of anhydrous ethanol, and acetic acid was added dropwise to adjust the pH of the mixture to 6. Then, 32g of magnesium strontium-doped hydroxyapatite was added. After reacting at 65℃ for 14h, the mixture was calcined at 820℃ for 2h to obtain modified magnesium strontium-doped hydroxyapatite whiskers (length 220~320nm, diameter 10~13nm).
[0042] The bone cement powder consists of the following components in parts by weight: 67 parts polymethyl methacrylate, 15 parts modified magnesium strontium doped hydroxyapatite, 10 parts zirconium dioxide, and 0.5 parts cyclohexanone peroxide; the bone cement liquid consists of the following components in parts by weight: 96 parts methyl methacrylate monomer, 0.00007 parts hydroquinone, and 2 parts N,N-dimethyl-p-toluidine; the bone cement powder and bone cement liquid are mixed evenly at a mass-volume ratio of 2g:1mL and then cured to obtain polymethyl methacrylate composite bone cement.
[0043] Example 3
[0044] Calcium nitrate, magnesium nitrate, and strontium nitrate were added to deionized water and mixed thoroughly. Diammonium hydrogen phosphate powder was then added and mixed thoroughly to obtain a mixed solution. In the mixed solution, the molar ratio of calcium, magnesium, and strontium was 10:0.8:0.5, the concentration of calcium salt in the mixed solution was 0.5 mol / L, and the concentration of diammonium hydrogen phosphate in the mixed solution was 0.1 mol / L.
[0045] The pH of the mixture was adjusted to 10 using a 0.1 mol / L sodium hydroxide aqueous solution, and then hydrothermally reacted at 190 °C for 12 h, followed by aging at room temperature for 6 h to obtain magnesium-strontium-doped hydroxyapatite.
[0046] 1g of stearic acid was mixed with 100mL of anhydrous ethanol, and acetic acid was added dropwise to adjust the pH of the mixture to 4. Then, 20g of magnesium-strontium-doped hydroxyapatite was added. After reacting at 75℃ for 11h, the mixture was calcined at 880℃ for 1h to obtain modified magnesium-strontium-doped hydroxyapatite whiskers (300~400nm in length and 14~18nm in diameter).
[0047] The bone cement powder consists of the following components in parts by weight: 75 parts polymethyl methacrylate, 11 parts modified magnesium strontium doped hydroxyapatite, 14 parts barium sulfate, and 0.8 parts methyl ethyl ketone peroxide; the bone cement liquid consists of the following components in parts by weight: 98 parts methyl methacrylate monomer, 0.0001 parts p-tert-butylcatechol, and 3 parts N,N-dimethyl-p-toluidine; the bone cement powder and bone cement liquid are mixed evenly at a mass-volume ratio of 2.4 g: 1 mL and then cured to obtain polymethyl methacrylate composite bone cement.
[0048] Comparative Example 1
[0049] By omitting strontium nitrate from Example 1, magnesium-doped hydroxyapatite was obtained. The stearic acid modification step was omitted, and the magnesium-doped hydroxyapatite was directly added to the bone cement powder. Other process conditions were the same as in Example 1.
[0050] Comparative Example 2
[0051] Magnesium nitrate was omitted in Example 1. When preparing modified strontium-doped hydroxyapatite whiskers, the amount of strontium-doped hydroxyapatite was changed from 25g to 10g. The calcination step was omitted. The amount of modified strontium-doped hydroxyapatite in the bone cement powder was changed from 13g to 8g. Other process conditions were the same as in Example 1.
[0052] The performance of polymethyl methacrylate composite bone cements from Examples 1-3 and Comparative Examples 1-2 was tested.
[0053] (1) Mechanical property test: The compressive strength, flexural strength and flexural modulus of elasticity were tested in accordance with the provisions of the text and appendices A to F of the international standard ISO5833:2002(E). For the compressive test, the sample size was Φ6mm×12mm, the crosshead pressing displacement speed was 20mm / min, and the 2% offset strength or the upper yield point strength that first appeared on the strain-stress curve was taken as its compressive strength. For the flexural test, the four-point bending measurement method was adopted, the sample size was 75mm×10mm×3.3mm, the crosshead pressing displacement speed was set to 5mm / min, and the strength at which the sample broke was taken as its flexural strength.
[0054] (2) Curing performance test: According to ISO 5833 standard, molds were prepared using polytetrafluoroethylene (PTFE), and a data acquisition device (FLUKE HYDRA SERIES II) was connected using a 0.5mm K-type thermocouple. This device can convert the thermocouple output signal into temperature readings and continuously record the readings with an accuracy of ±0.1℃. The bone cement was mixed and filled into the mold, and the temperature was continuously measured until it began to drop. Each sample was repeated 3 times, and the average value was taken.
[0055] (3) Biocompatibility test: According to the national standard GB / T 16886.5-2003 "Biological evaluation of medical devices - Part 5: In vitro cytotoxicity test", the extract test was selected, and the effect of bone cement on cell proliferation was tested according to the MTT colorimetric method recommended in GB / T 14233.2-2005 for cytotoxicity test.
[0056] Table 1. Performance test results of bone cement in the examples and comparative examples.
[0057] As can be seen from the examples and Table 1, the present invention obtains modified magnesium-strontium-doped hydroxyapatite with improved biocompatibility and hydrophobicity and good bonding with PMMA by doping magnesium and strontium into hydroxyapatite and using stearic acid to hydrophobically modify hydroxyapatite. By reasonably controlling the amount of each component in the bone cement powder and bone cement liquid, polymethyl methacrylate composite bone cement with good mechanical properties, curing properties, biocompatibility and osteoinduction ability is obtained.
[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing modified magnesium strontium-doped hydroxyapatite whiskers, characterized in that, It includes the following steps: 1) Mix calcium salt, magnesium salt, strontium salt, phosphate powder and water to obtain a mixed solution; 2) After adjusting the pH value of the mixture, hydrothermal reaction and aging were carried out sequentially to obtain magnesium-strontium-doped hydroxyapatite; 3) Stearic acid and anhydrous ethanol were mixed, acetic acid was added dropwise to adjust the pH of the mixture, magnesium strontium-doped hydroxyapatite was added, and the mixture was calcined after reaction to obtain modified magnesium strontium-doped hydroxyapatite whiskers.
2. The method for preparing modified magnesium strontium-doped hydroxyapatite whiskers according to claim 1, characterized in that, Step 1) The calcium salt is calcium nitrate and / or calcium chloride, the magnesium salt is magnesium nitrate and / or magnesium chloride, the strontium salt is strontium nitrate, and the phosphate is diammonium hydrogen phosphate and / or ammonium hydrogen phosphate.
3. The method for preparing modified magnesium strontium-doped hydroxyapatite whiskers according to claim 1 or 2, characterized in that, In step 1), the molar ratio of calcium, magnesium and strontium in the mixture is 10:0.4~0.8:0.3~0.6; the concentration of calcium salt in the mixture is 0.1~0.6 mol / L; and the concentration of phosphate in the mixture is 0.05~0.5 mol / L.
4. The method for preparing modified magnesium strontium-doped hydroxyapatite whiskers according to claim 3, characterized in that, Step 2) The hydrothermal reaction temperature is 170~200℃, and the hydrothermal reaction time is 10~18h; the pH value of the mixture is adjusted to 8~10; the aging time is 5~10h.
5. The method for preparing modified magnesium strontium-doped hydroxyapatite whiskers according to claim 4, characterized in that, Step 3) The mass ratio of stearic acid to magnesium strontium-doped hydroxyapatite is 2~6:100, the reaction temperature is 60~75℃, the reaction time is 10~14h, and the pH value is adjusted to 4~6; the calcination temperature is 800~900℃, and the calcination time is 1~2h.
6. Modified magnesium strontium doped hydroxyapatite whiskers prepared by the method according to any one of claims 1 to 5.
7. A polymethyl methacrylate composite bone cement comprising the modified magnesium-strontium-doped hydroxyapatite whiskers as described in claim 6, characterized in that, The polymethyl methacrylate composite bone cement comprises bone cement powder and bone cement liquid; the mass-to-volume ratio of the bone cement powder to the bone cement liquid is 1.8~2.6g:1mL; The bone cement powder comprises the following components in parts by weight: 65-75 parts polymethyl methacrylate, 10-15 parts modified magnesium strontium doped hydroxyapatite whiskers, 10-15 parts contrast agent, and 0.5-1 part initiator. The bone cement liquid contains the following components in parts by weight: 96-98 parts of methyl methacrylate monomer, 0.00007-0.0001 parts of stabilizer, and 2-3 parts of accelerator.
8. The polymethyl methacrylate composite bone cement according to claim 7, characterized in that, The polymethyl methacrylate has a weight-average molecular weight of 70,000 to 100,000, and the contrast agent contains one or more of barium sulfate, zirconium dioxide, and tantalum powder, with a particle size of 0.5 to 5 μm.
9. The polymethyl methacrylate composite bone cement according to claim 7 or 8, characterized in that, The initiator is one or more of benzoyl peroxide, cyclohexanone peroxide, and methyl ethyl ketone peroxide; the stabilizer contains hydroquinone and / or p-tert-butylcatechol; and the accelerator is N,N-dimethyl-p-toluidine.
10. The method for preparing the polymethyl methacrylate composite bone cement according to any one of claims 7 to 9, characterized in that, Bone cement powder and bone cement liquid are mixed and then cured to obtain polymethyl methacrylate composite bone cement.