Method for modifying hydroxyapatite by using calcium bisphosphonate containing unsaturated quaternary ammonium cations

Abstract

The invention provides a method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations, and the hydroxyapatite modified with calcium bisphosphonate containing unsaturated quaternary ammonium cations can participate in polymerization reaction of methyl methacrylate to prepare functional polymethyl methacrylate micro powder. Therefore, the polymethyl methacrylate is endowed with antibacterial and bacteriostatic performance, medical efficacy of the bisphosphonate, water absorption performance in a medium and biocompatibility, and meanwhile, the binding force and dispersity of the hydroxyapatite and the polymethyl methacrylate can be improved; further, the tensile strength, the bending strength and the compressive strength of the polymethyl methacrylate-based bone cement are improved; the addition amount of hydroxyapatite in the polymethyl methacrylate-based bone cement is increased, so that the curing thermal effect and the curing shrinkage of the polymethyl methacrylate-based bone cement are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for preparing functional hydroxyapatite, in particular to a method for modifying hydroxyapatite with a calcium bisphosphonate having an unsaturated quaternary ammonium cation in its molecular structure to prepare unsaturated hydroxyapatite having the characteristics of participating in the polymerization of methyl methacrylate, and to the modification of polymethyl methacrylate-based bone cement, belonging to the field of biological inorganic materials. TECHNICAL BACKGROUND

[0002] Polymethyl methacrylate (PMMA for short) based bone cement is the main variety of bone adhesive used in bone transplantation or bone repair surgery. After decades of research and development, clinical application and effect observation, it is found that the major defect of PMMA based bone cement is its lack of osteogenesis, which does not fuse with autologous bone in the long term. In addition, there are also the following shortcomings: the mechanical strength (excessive elastic modulus, low bending strength, low compressive strength, etc.) of PMMA bone cement after polymerization and solidification does not match the autologous bone; the sustained antibacterial efficacy of PMMA based bone cement compounded with antibiotics is poor due to deep embedding or lack of sustained release characteristics; the heat release during the polymerization and solidification process of PMMA based bone cement causes the temperature of the surrounding human bone tissue or bone cells to be too high and necrotic; the monomer residue during the polymerization and solidification process of PMMA bone cement has biological toxicity; and the volume shrinkage of PMMA based bone cement before and after polymerization and solidification is obvious.

[0003] Hydroxyapatite, also known as hydroxyapatite, is the main inorganic component of human bone tissue. After being implanted into the body, calcium and phosphorus will be released from the surface of its particles and absorbed by the body tissue, and new bone tissue will grow. Studies have shown that the finer the grain of hydroxyapatite, the higher the biological activity. Therefore, the existing public technologies and methods are mostly to add nano-hydroxyapatite to PMMA powder to form a composite material, thereby improving the osteogenic activity of PMMA based bone cement. The composite material effectively combines the bone conduction, biodegradability, rigidity of hydroxyapatite, and the toughness of polymers, etc. However, the mechanical properties of the composite material are largely dependent on the dispersity and interfacial bonding force of the hydroxyapatite particles and the polymer, especially the nano-hydroxyapatite, which is prone to agglomeration during the mixing process with the polymer, and the interfacial bonding force between them is poor, which affects the mechanical properties of the composite material. Therefore, it is of great significance to introduce organic molecules to the surface of nano-hydroxyapatite through chemical modification. Currently, there are documents that report the surface modification of hydroxyapatite with small organic molecules such as amino silane coupling agent, isocyanate silane coupling agent, fatty acid, and organic phosphonic acid, which have achieved certain effects.

[0004] The professional people are familiar with PMMA-based bone cement including two components of powder and liquid. The content of PMMA micro powder in the PMMA-based bone cement powder component accounts for 52-89%, so the traditional modification idea of PMMA micro powder is to add functional ingredients, and to give PMMA micro powder functions by compounding. For example, the bone formation activity of PMMA-based bone cement is improved by compounding hydroxyapatite, or silver is plated on the surface of PMMA micro powder by silver mirror reaction, or mixed with antibacterial polymers, antibiotics, and nano-copper to make antibacterial PMMA composite micro powder. From the antibacterial effect, it is difficult to achieve the expected effect by adding inorganic nano-metal, antibacterial polymer or small molecule antibiotic. On the one hand, the added antibacterial agent may not be distributed on the surface of PMMA-based bone cement, and the antibacterial agent distributed in the PMMA-based bone cement cannot be released or released slowly, which cannot achieve the antibacterial purpose; secondly, the water-soluble antibacterial agent is dissolved and released quickly in the body fluid, which can only ensure the early antibacterial effect, and lacks the ability to resist the continuous growth of bacteria. There are also cellulose, carbon nanotubes, graphene oxide, nano-ZrO2, chitosan, sodium hyaluronate, polycaprolactone, polylactic acid and the like added in PMMA micro powder, which aims to improve the bending strength, compressive strength, reduce the elastic modulus, reduce the curing heat, reduce the shrinkage of the cured body, and improve the biocompatibility of PMMA-based bone cement, all of which show some one-sided significant modification effect.

[0005] The professional people are familiar with PMMA micro powder, which is a powdery polymer material prepared by emulsion polymerization, suspension polymerization, dispersion polymerization or precipitation polymerization of methyl methacrylate (abbreviated as MMA), so people naturally think of adding functional comonomers in the polymerization system of MMA to obtain copolymer PMMA micro powder and realize the optimization modification of PMMA-based bone cement. So far, the disclosed copolymer functional monomers include: acrylic acid, butyl methacrylate, hydroxyethyl methacrylate, vinyl pyrrolidone, methacryloyloxyethyl dimethyl benzyl ammonium chloride, 3,4-dichloro-5-hydroxy-5H-furan-2-ketone methacrylate, dimethylamino triclosan methacrylate, allyl isoniazid and the like. The purpose is to give copolymer PMMA persistent hydrophilic and antibacterial properties, change the condensed state appearance of PMMA bone cement after curing, improve the bending strength, compressive strength and biocompatibility of PMMA-based bone cement, reduce the elastic modulus, curing heat and shrinkage of the cured body.

[0006] In summary, the existing modification of PMMA by compounding or copolymerization etc. mostly obtains some performance improvement or improvement, or gives new functions, but there are few reports on overall consideration of various modification effects and more optimized application performance. Based on the performance, function and use requirement of PMMA micro powder material in PMMA based bone cement, the application optimizes the safety and stability of PMMA based bone cement, and uses a kind of calcium bisphosphonate modified hydroxyapatite containing unsaturated quaternary ammonium cation in the molecular structure to prepare an unsaturated hydroxyapatite which can participate in the polymerization of MMA. SUMMARY

[0007] The application provides a method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cation, characterized in that it is realized by the following process:

[0008] Step one, preparation of tertiary amine group hydroxyapatite

[0009] A calcium salt aqueous solution with a molar concentration of 0.10-1.00 mol / L is added to a reaction kettle, and a phosphonate solution prepared from an alcohol aqueous solvent, a dispersant, a phosphate and a tertiary amine group containing bisphosphonate salt as raw materials is slowly added to the reaction kettle under rapid stirring, and an appropriate amount of alkali aqueous solution is used to adjust the pH of the materials in the reaction kettle to 7.5-11.0, the temperature of the materials in the reaction kettle is controlled at 20-160℃, the stirring reaction is carried out for 2-6 hours, and the temperature is lowered for 2-24 hours for sedimentation, and then the tertiary amine group hydroxyapatite is prepared after separation, washing and drying.

[0010] The molar concentration of the phosphate in the phosphonate solution is 0.10-1.00 mol / L, and the amount of the phosphonate solution is 30-300% of the volume of the calcium salt aqueous solution;

[0011] The mass ratio of the phosphate / tertiary amine group containing bisphosphonate salt / dispersant / alcohol aqueous solvent is 100:5-100:0-30:200-2000;

[0012] The phosphate refers to one or two or more of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, or potassium dihydrogen phosphate.

[0013] The tertiary amine group containing bisphosphonate salt has the structure shown in general formula (I):

[0014]

[0015] In general formula (I), R1 and R1 are selected from C1-C 18 hydrocarbon group, M + NH4 + , Na + or K+ one of the following:

[0016] The preparation method of the bisphosphonate salt containing tertiary amine group of general formula (I) is as follows: according to the mass ratio of anhydrous ethanol or anhydrous methanol / 3-tertiary amine propylamine / diethyl vinylphosphonate or dimethyl vinylphosphonate 0-200:100:50-500, first put anhydrous ethanol or anhydrous methanol and 3-tertiary amine propylamine of general formula (II) into the reaction kettle, control the temperature of the material in the reaction kettle at 20-25℃, then slowly add diethyl vinylphosphonate or dimethyl vinylphosphonate, after the addition of diethyl vinylphosphonate or dimethyl vinylphosphonate is completed, increase the temperature of the material in the reaction kettle to 50-60℃, stir for 12 hours, after recovering ethanol or methanol and excess diethyl vinylphosphonate or dimethyl vinylphosphonate by rotary evaporation, add an appropriate amount of hydrochloric acid with a molar concentration of 5.5 mol / L to the reaction kettle until the residue in the reaction kettle is completely dissolved, control the temperature at 90-100℃, and stir for 24 hours to carry out the hydrolysis reaction, reduce the temperature of the hydrolysis reaction product to room temperature, use an appropriate amount of 30% sodium hydroxide aqueous solution to adjust the pH value of the material in the reaction kettle to 4.5-7.5, concentrate by rotary evaporation until solid substances are precipitated, reduce the temperature and stand still to precipitate the solid product, filter, recrystallize with 90-93% aqueous ethanol, control the temperature at 40-50℃, and vacuum dry until the weight is constant to obtain the bisphosphonate salt containing tertiary amine group of general formula (I) with the structure shown in general formula (I);

[0017] The 3-tertiary amine propylamine has the structure shown in general formula (II):

[0018]

[0019] In general formula (II), R1 and R1 are respectively selected from C1-C 18 hydrocarbon group.

[0020] The calcium salt refers to one of calcium nitrate, calcium chloride or calcium acetate.

[0021] The dispersing agent refers to one or two or more of polyvinylpyrrolidone K30, polyvinylpyrrolidone K60, polyvinyl alcohol-1788, polyvinyl alcohol-2488, polyethylene glycol-2000, polyethylene glycol-4000, polyethylene glycol-6000, Span-80, Tween-80, N-dodecyl-N,N,N-trimethyl ammonium bromide, N-tetradecyl-N,N,N-trimethyl ammonium bromide, N-hexadecyl-N,N,N-triethyl ammonium bromide, N-dodecyl-N,N,N-triethyl ammonium bromide, N-tetradecyl-N,N,N-triethyl ammonium bromide, N-hexadecyl-N,N,N-triethyl ammonium bromide.

[0022] The aqueous base solution refers to one of 10-30% ammonia water, aqueous ammonium bicarbonate solution, aqueous sodium bicarbonate solution, aqueous sodium hydroxide solution or aqueous potassium hydroxide solution in terms of mass percentage concentration.

[0023] The aqueous alcohol solvent refers to a mixture of methanol, ethanol or propanol and deionized water in a mass ratio of 1-99:99-1.

[0024] Step two, preparation of polymerizable hydroxyapatite

[0025] The solvent, the polymerization inhibitor and the tertiary amine-based hydroxyapatite prepared in step one are weighed in sequence and added into a reaction kettle, and after nitrogen deoxygenation, unsaturated halogenated hydrocarbon is added into the reaction kettle, the temperature of the material in the reaction kettle is increased to 40-120°C, and after stirring for 6-60 hours, the temperature of the material in the reaction kettle is reduced to room temperature, and after separation, washing and drying, the hydroxyapatite modified by calcium bisphosphonate containing unsaturated quaternary ammonium cations, also known as unsaturated hydroxyapatite with polymerization characteristics, polymerizable hydroxyapatite or unsaturated hydroxyapatite, is prepared.

[0026] The mass ratio of the tertiary amine-based hydroxyapatite / unsaturated halogenated hydrocarbon / polymerization inhibitor / solvent is 100:5-150:0.15-15:50-500.

[0027] The unsaturated halogenated hydrocarbon refers to one of 3-chloropropene, 3-bromopropene or p-chloromethylstyrene.

[0028] The polymerization inhibitor refers to one or two or more of hydroquinone, p-methoxyphenol, tert-butyl hydroquinone, 2,6-dibutyl hydroquinone, 2,6-di-tert-butyl-p-cresol or 2,4,6-tri-tert-butylphenol.

[0029] The solvent refers to one or two or more of tetrahydrofuran, 1,4-dioxane, cyclohexane, decaline, benzene, toluene, chlorobenzene, dichloromethane, chloroform, carbon tetrachloride, acetonitrile, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide or N,N-dimethylacetamide.

[0030] The tertiary amine group in the bisphosphonate salt molecule containing the tertiary amine group according to the present application can be a short chain or a long chain tertiary amine group, and the bisphosphonate salt containing the long chain tertiary amine group has very excellent surfactant function. In the preparation of modified hydroxyapatite by using a soluble calcium salt, a phosphate salt or a phosphonate salt as a raw material, the bisphosphonate salt containing the long chain tertiary amine group can produce an anionic surfactant effect, which is beneficial to the uniform dispersion of the modified hydroxyapatite in an aqueous solution and the control of the particle size of the modified hydroxyapatite. At the same time, the bisphosphonate salt containing the tertiary amine group can be precipitated with the hydroxyapatite, and is converted into a bisphosphonate calcium containing the tertiary amine group, which is co-precipitated with the hydroxyapatite or is adsorbed on the surface of the hydroxyapatite by Ca-O-P bond interaction and deposited, thereby forming a co-crystal substance of the modified hydroxyapatite containing the bisphosphonate calcium containing the tertiary amine group.

[0031] The modified hydroxyapatite containing the bisphosphonate calcium containing the tertiary amine group according to the present application has the characteristics of nucleophilic substitution reaction with unsaturated halogenated hydrocarbons, and therefore, the modified hydroxyapatite containing the bisphosphonate calcium containing the tertiary amine group can further react with a quaternary ammonium salt of unsaturated halogenated hydrocarbons in an organic solvent, thereby realizing the preparation of the modified hydroxyapatite containing the unsaturated quaternary ammonium cation according to the present application. It can be seen that the polymerizable hydroxyapatite according to the present application contains the structural units of the unsaturated quaternary ammonium cation, the bisphosphonate calcium and the hydroxyapatite, and each of these structural units shows diverse physical, chemical and biological properties. DETAILED DESCRIPTION

[0032] In order to further understand the present application, the present application will be described in detail by way of examples, and the purpose of the examples is to better understand the content of the present application, and therefore, the polymerizable hydroxyapatite and the preparation method thereof not listed in the examples should not be regarded as a limitation on the protection scope of the present application.

[0033] Example 1 Preparation of the bisphosphonate salt containing the tertiary amine group of formula (I-1)

[0034] The following reaction formula represents the preparation method and process of the bisphosphonate salt containing the tertiary amine group of formula (I-1):

[0035]

[0036] In a reaction kettle, put in 30 g of N,N-dimethyl-1,3-propanediamine and 80 g of anhydrous ethanol, control the temperature of the material in the reaction kettle at 20-25°C, slowly put in 56 g of diethyl vinylphosphonate, after the diethyl vinylphosphonate is completely put in, increase the temperature of the material in the reaction kettle to 50-60°C, and stir for 12 hours. After recovering the ethanol and excess diethyl vinylphosphonate by rotary evaporation, add 5.5 mol / L hydrochloric acid into the reaction kettle until the residual material in the reaction kettle is completely dissolved, control the temperature at 90-100°C, and stir for 24 hours. Reduce the temperature of the hydrolysis reaction product to room temperature, adjust the pH value of the material in the reaction kettle to 7.0-7.5 using a 30% sodium hydroxide aqueous solution, concentrate by rotary evaporation until the solid material precipitates, reduce the temperature and precipitate the solid product, filter, recrystallize with 93% aqueous ethanol, control the temperature at 40-50°C, and dry to constant weight in a vacuum to obtain 103.8 g of a white powdery product with a melting range of 133-136°C. The elemental analysis of the white powdery product (%): C 29.32, H 6.03, N 7.71, P 17.18, which is basically consistent with the calculated value of C9H 22 N2P2O6Na2: C 29.84, H 6.12, N 7.73, P 17.10; its IR (KBr pellet, cm -1 -1): 3433, 2927, 2872, 1445, 1360, 1262, 1108, 964, 926, which are respectively characteristic vibration absorption peaks of HO, CH3, CH2, C-N, P=O, P-O. 1 H-NMR (TMS as internal standard, D2O, δ): 1.43 (t, 4H), 1.59 (m, 2H), 2.24 (s, 6H), 2.37 (t, 4H), 2.48 (t, 4H). According to the results of elemental analysis, IR and 1 H-NMR spectrum analysis, it is confirmed that the white powdery product has the structural characteristics shown in formula (I-1).

[0037] Preparation of a bisphosphonate salt containing a tertiary amine group of formula (I-2)

[0038] According to the method and operation steps of Example 1, replace N,N-dimethyl-1,3-propanediamine in Example 1 with N-benzyl-N-dodecyl-1,3-propanediamine, and the white powdery product is prepared in the same way, with a melting range of 76-82°C. Using the analysis and characterization methods of Example 1, it is confirmed that the white powdery product has the structural characteristics shown in formula (I-2):

[0039]

[0040] Preparation of a bisphosphonate salt containing a tertiary amine group of formula (I-3)

[0041] The product was prepared in the same manner as in Example 1, except that N,N-dimethyl-1,3-propanediamine in Example 1 was replaced by N,N-dibenzyl-1,3-propanediamine, and 30% aqueous sodium hydroxide was replaced by concentrated aqueous ammonia. The product was a white powder with a melting range of 101-104°C. The white powder was identified as having the structural characteristics of Formula (I-3) by the analytical characterization methods of Example 1.

[0042]

[0043] Example 4 Preparation of tertiary amine group-containing hydroxyapatite (I-1-1)

[0044] A reaction kettle was first charged with 220 g of a 0.52 mol / L aqueous calcium nitrate solution, followed by 30 g of ethanol, 70 g of deionized water, 6 g of polyvinyl alcohol-1788, 5.3 g of ammonium dihydrogen phosphate, and 5.4 g of a bisphosphonate salt of Formula (I-1) containing a tertiary amine group to prepare a phosphate aqueous solution. The phosphate aqueous solution was slowly added to the reaction kettle under rapid stirring, and the pH of the contents of the reaction kettle was adjusted to be greater than or equal to 10.0 using an appropriate amount of a 15% mass concentration aqueous NaOH solution. The contents of the reaction kettle were controlled to have a temperature of 100-140°C, and the reaction was allowed to proceed for 6 hours. After the reaction, the stirring was stopped, and the contents were allowed to settle for 24 hours. The precipitate was then separated by centrifugation, washed several times with an ethanol aqueous solution having a volume ratio of 1:1, and then dried in a vacuum drying oven at a temperature of 50-60°C to obtain 13.63 g of a tertiary amine group-containing hydroxyapatite powder (I-1-1). The SEM of the tertiary amine group-containing hydroxyapatite powder (I-1-1) showed that the powder was irregular particles having a particle size of 43-250 nm. TGA analysis showed that the tertiary amine group-containing hydroxyapatite powder (I-1-1) had a thermal weight loss of about 5.21% at 20-200°C, which should be attributed to the loss of crystal water. The thermal weight loss of the tertiary amine group-containing hydroxyapatite powder (I-1-1) was about 15.66% at 200-450°C, which should be attributed to the thermal decomposition of the organic components. There was almost no thermal weight loss at 450-700°C. Compared with the pure hydroxyapatite, the IR (KBr pellet, cm -1 ) of the tertiary amine group-containing hydroxyapatite powder (I-1-1) showed new characteristic absorption peaks at 2937, 2872, and 1542, which should be attributed to methyl, methylene, and C-N, respectively, confirming that the tertiary amine group-containing hydroxyapatite powder was a co-precipitated powder of calcium bisphosphonate containing a tertiary amine group and hydroxyapatite.

[0045] Example 5 Preparation of tertiary amine group-containing hydroxyapatite (I-2-1)

[0046] Example 6 Preparation of the tertiary amine group-containing hydroxyapatite (I-3-1) -1 ) appeared new characteristic absorption peaks at 2938, 2873, 1643, 1538, 1446, which should be attributed to methyl, methylene, benzene ring, C-N, respectively, confirming that the tertiary amine group-containing hydroxyapatite powder (I-2-1) was the co-precipitation powder of calcium bisphosphonate containing tertiary amine group and hydroxyapatite.

[0047] Example 6 Preparation of the tertiary amine group-containing hydroxyapatite (I-3-1)

[0048] Example 4, the tertiary amine group-containing bisphosphonate salt of formula (I-1) in Example 4 was replaced by the tertiary amine group-containing bisphosphonate salt of formula (I-3), and the tertiary amine group-containing hydroxyapatite powder (I-3-1) was prepared in the same way. The SEM showed that the tertiary amine group-containing hydroxyapatite powder (I-3-1) was irregular particles with a particle size of 62-235 nm. TGA analysis showed that the tertiary amine group-containing hydroxyapatite powder (I-3-1) had a thermal weight loss of about 4.62% between 20-200°C, which should be attributed to the loss of crystal water; the thermal weight loss was about 16.78% between 200-450°C, which should be attributed to the thermal decomposition loss of the organic components in the tertiary amine group-containing hydroxyapatite powder (I-3-1); there was no thermal weight loss performance thereafter to 700°C. Relative to the pure hydroxyapatite, the IR (KBr pellet, cm -1 ) appeared new characteristic absorption peaks at 2938, 2873, 1643, 1538, 1446, which should be attributed to methyl, methylene, benzene ring, C-N, respectively, confirming that the tertiary amine group-containing hydroxyapatite powder (I-2-1) was the co-precipitation powder of calcium bisphosphonate containing tertiary amine group and hydroxyapatite.

[0049] Example 6 Preparation of the tertiary amine group-containing hydroxyapatite (I-3-1)

[0050] In a reaction kettle, 220 grams of a calcium nitrate aqueous solution having a molar concentration of 0.52 mol / L was first added, then 30 grams of ethanol, 70 grams of deionized water, 6 grams of polyvinyl alcohol-1788, and 5.3 grams of ammonium dihydrogen phosphate were weighed and prepared into a phosphate aqueous solution, which was slowly added into the reaction kettle under rapid stirring, then 30 grams of an aqueous solution containing 5.4 grams of a bisphosphonate salt of formula (I-1) having a tertiary amine group was also slowly added into the reaction kettle, an appropriate amount of a 15% mass percentage caustic aqueous solution was used to adjust the pH of the materials in the reaction kettle to be greater than or equal to 10.0, and the temperature of the materials in the reaction kettle was controlled to be 100-120°C, and the reaction was performed for 6 hours, after which the stirring was stopped, the temperature was lowered for sedimentation for 12 hours, then the precipitate was separated by centrifugation, washed several times with an ethanol aqueous solution having a volume ratio of 1:1, then sent into a vacuum drying oven, controlled to have a temperature of 50-60°C, and vacuum dried, to obtain 13.66 grams of surface-tertiary-amine-group-modified hydroxyapatite powder (I-1-2). SEM showed that the surface-tertiary-amine-group-modified hydroxyapatite powder (I-1-2) was rod-shaped particles having a particle size of 60-280 nm. TGA analysis showed that the surface-tertiary-amine-group-modified hydroxyapatite powder (I-1-2) had a thermal weight loss of about 5.68% between 20-200°C, which should be attributed to the loss of crystal water; a thermal weight loss of about 14.73% between 200-450°C, which should be attributed to the thermal decomposition loss of the organic components in the surface-tertiary-amine-group-modified hydroxyapatite powder (I-1-2); and no thermal weight loss performance up to 700°C. Compared with the pure hydroxyapatite, the surface-tertiary-amine-group-modified hydroxyapatite powder (I-1-2) had new characteristic absorption peaks at 2938, 2872, and 1448 in IR (KBr pressed tablet, cm -1 ) which should be respectively attributed to methyl, methylene, and C-N, confirming that the surface-tertiary-amine-group-modified hydroxyapatite powder was a composite powder of hydroxyapatite and calcium bisphosphonate having a tertiary amine group deposited on the surface of the hydroxyapatite.

[0051] Preparation of surface-tertiary-amine-group-modified hydroxyapatite (I-2-2) in Comparative Example 2

[0052] According to the preparation method and procedure of Comparative Example 1, the tertiary amine group-containing bisphosphonate salt of formula (I-1) of Example 4 was replaced by the tertiary amine group-containing bisphosphonate salt of formula (I-2), and surface-tertiary amine group-modified hydroxyapatite powder (I-2-2) was prepared in the same way. SEM showed that the surface-tertiary amine group-modified hydroxyapatite powder (I-2-2) was columnar particles with a particle size of 60-230 nm. TGA analysis showed that the surface-tertiary amine group-modified hydroxyapatite powder (I-2-2) had a thermal weight loss of about 6.03% between 20-200°C, which should be attributed to the loss of crystal water; a thermal weight loss of about 16.48% between 200-450°C, which should be attributed to the thermal decomposition loss of the organic components in the surface-tertiary amine group-modified hydroxyapatite powder (I-2-2); and no thermal weight loss after 700°C. Compared with pure hydroxyapatite, the surface-tertiary amine group-modified hydroxyapatite powder (I-2-2) had new characteristic absorption peaks at 2938, 2873, 1643, 1538, and 1446 cm"1 in IR (KBr pellet, cm"1), which should be attributed to methyl, methylene, benzene nucleus, C-N, respectively, confirming that the surface-tertiary amine group-modified hydroxyapatite powder (I-2-2) should be a composite powder of hydroxyapatite with calcium bisphosphonate containing a tertiary amine group deposited on the surface of the hydroxyapatite. -1 ) in IR (KBr pellet, cm"1) at 2938, 2873, 1643, 1538, and 1446 cm"1, which should be attributed to methyl, methylene, benzene nucleus, C-N, respectively, confirming that the surface-tertiary amine group-modified hydroxyapatite powder (I-2-2) should be a composite powder of hydroxyapatite with calcium bisphosphonate containing a tertiary amine group deposited on the surface of the hydroxyapatite.

[0053] Preparation of surface-tertiary amine group-modified hydroxyapatite (I-3-2) of Comparative Example 3

[0054] According to the preparation method and procedure of Comparative Example 1, the tertiary amine group-containing bisphosphonate salt of formula (I-1) of Example 4 was replaced by the tertiary amine group-containing bisphosphonate salt of formula (I-3), and surface-tertiary amine group-modified hydroxyapatite powder (I-3-2) was prepared in the same way. SEM showed that the surface-tertiary amine group-modified hydroxyapatite powder (I-3-2) was columnar particles with a particle size of 63-155 nm. TGA analysis showed that the surface-tertiary amine group-modified hydroxyapatite powder (I-3-2) had a thermal weight loss of about 5.76% between 20-200°C, which should be attributed to the loss of crystal water; a thermal weight loss of about 15.37% between 200-450°C, which should be attributed to the thermal decomposition loss of the organic components in the surface-tertiary amine group-modified hydroxyapatite powder (I-3-2); and no thermal weight loss after 700°C. Compared with pure hydroxyapatite, the surface-tertiary amine group-modified hydroxyapatite powder (I-3-2) had new characteristic absorption peaks at 2937, 2873, 1641, 1538, and 1446 cm"1 in IR (KBr pellet, cm"1), which should be attributed to methyl, methylene, benzene nucleus, C-N, respectively, confirming that the surface-tertiary amine group-modified hydroxyapatite powder (I-3-2) should be a composite powder of hydroxyapatite with calcium bisphosphonate containing a tertiary amine group deposited on the surface of the hydroxyapatite. -1 ) in IR (KBr pellet, cm"1) at 2938, 2873, 1643, 1538, and 1446 cm"1, which should be attributed to methyl, methylene, benzene nucleus, C-N, respectively, confirming that the surface-tertiary amine group-modified hydroxyapatite powder (I-2-2) should be a composite powder of hydroxyapatite with calcium bisphosphonate containing a tertiary amine group deposited on the surface of the hydroxyapatite.

[0055] Preparation of surface-tertiary amine group-modified hydroxyapatite (I-3-2) of Comparative Example 3

[0056] Example 7 Preparation of polymerizable hydroxyapatite (I-1-1-1)

[0057] The above results show that 1.13 g of 3-bromo propene reacted with the tertiary aminated hydroxyapatite powder (I-1-1), which is equivalent to 0.0942 mol of bromo propene to achieve quaternary ammonium salt reaction. The original tertiary aminated hydroxyapatite powder (I-1-1) has a tertiary amine group content of 0.0219 mol, so the quaternary ammonium salt reaction efficiency of 3-bromo propene with the tertiary aminated hydroxyapatite powder (I-1-1) is 0.00942 / 0.0219 = 43%. The results show that more tertiary amine groups embedded in the interior of the tertiary aminated hydroxyapatite powder (I-1-1) particles failed to achieve quaternary ammonium salt reaction. The SEM of the polymerizable hydroxyapatite powder (I-1-1-1) shows that it is irregular particles with a particle size of 55-300 nm, indicating that the particle size of the polymerizable hydroxyapatite powder after quaternary ammonium salt reaction has little change.

[0058] Example 8 Preparation of polymerizable hydroxyapatite (I-2-1-1)

[0059] Example 9 Preparation of polymerizable hydroxyapatite (I-2-1-2)

[0060] Example 9 Preparation of polymerizable hydroxyapatite (I-2-1-2)

[0061] Example 9 Preparation of polymerizable hydroxyapatite (I-2-1-2)

[0062] Example 10 Preparation of polymerizable hydroxyapatite (I-1-2-1)

[0063] Example 9 Preparation of polymerizable hydroxyapatite (I-2-1-2)

[0064] Preparation of polymerizable hydroxyapatite (I-2-2-2) of Example 11

[0065] According to the preparation method and steps of Example 7, the surface tertiary aminated hydroxyapatite powder (I-2-2) of Example 7 is replaced by the surface tertiary aminated hydroxyapatite powder (I-2-2), and 3-bromopropene is replaced by p-chloromethylstyrene, and polymerizable hydroxyapatite (I-2-2-2) is prepared in the same way. It is calculated by carrying out a blank test that the quaternary amination reaction efficiency of p-chloromethylstyrene with the surface of the tertiary aminated hydroxyapatite powder (I-2-2) containing calcium bisphosphonate is 88.37%. The results show that, compared with the surface tertiary aminated hydroxyapatite powder (I-2-2) of Example 10, the steric hindrance of the tertiary aminated hydroxyapatite powder (I-2-2) containing calcium bisphosphonate is increased, and the quaternary amination rate of the tertiary aminated hydroxyapatite powder (I-2-2) containing calcium bisphosphonate is reduced. The SEM shows that the polymerizable hydroxyapatite powder (I-2-2-2) is columnar particles with a particle size of 50-335 nm, indicating that the particle size of the polymerizable hydroxyapatite powder after quaternary amination reaction is not obviously changed.

[0066] Antibacterial properties of polymerizable hydroxyapatite of Example 12

[0067] According to the method and operation steps specified in GBT 21510-2008 "Nano-inorganic antibacterial material antibacterial performance detection method", 1.0000 grams of polymerizable hydroxyapatite powder in Examples 3-11 is weighed, 5.0 mL of 1 x 10 6 CFU / mL of S. aureus or E. coli bacterial suspension is added, and 95 mL of 0.1% Tween-80 containing phosphate buffer is added, and the mixture is cultured in a 37°C constant temperature incubator for 2, 12 or 24 hours. After that, the total number of remaining viable bacteria is counted, and the antibacterial performance of the polymerizable hydroxyapatite powder is quantitatively evaluated. The results are shown in Table 1.

[0068] Antibacterial properties of polymerizable hydroxyapatite powder

[0069]

[0070] Table 1 shows that the higher the density of quaternary ammonium cations on the surface of the polymerizable hydroxyapatite powder, the higher the antibacterial activity, and the hydrocarbon group of the quaternary ammonium cation is changed from C3 hydrocarbon group to C7 or C 12 hydrocarbon group, and the antibacterial activity is also significantly improved. Comparative experiments show that pure nano-hydroxyapatite has no antibacterial activity, but has adsorption performance.

Claims

1. A method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations, characterized in that: This is achieved through the following process: Step 1: Preparation of tertiary amine-modified hydroxyapatite A calcium salt aqueous solution with a molar concentration of 0.10~1.00 mol / L was added to a reaction vessel. Under rapid stirring, a phosphate salt solution prepared from alcohol-water solvent, dispersant, phosphate, and bisphosphonate containing tertiary amine groups was slowly added to the reaction vessel. An appropriate amount of alkaline aqueous solution was used to adjust the pH of the material in the reaction vessel to between 7.5 and 11.

0. The temperature of the material in the reaction vessel was controlled between 20 and 160°C and the reaction was stirred for 2 to 6 hours. The mixture was then cooled and precipitated for 2 to 24 hours. After separation, washing, and drying, tertiary amine-modified hydroxyapatite was obtained. The phosphate molar concentration in the phosphate solution is 0.10~1.00 mol / L, and the amount of phosphate solution used is 30~300% of the volume of the calcium salt aqueous solution. The mass ratio of the phosphate / bisphosphonate containing tertiary amine group / dispersant / alcohol-water solvent is 100:5~100:0~30:200~2000; Step 2: Preparation of polymerizable hydroxyapatite Solvent, polymerization inhibitor and the tertiary amino-modified hydroxyapatite obtained in step one are weighed in sequence and added to a reaction vessel. After nitrogen purging and deoxygenation, unsaturated haloalkanes are added to the reaction vessel. The temperature of the material in the reaction vessel is raised to 40~120℃. After stirring and reacting for 6~60 hours, the temperature of the material in the reaction vessel is lowered to room temperature. After separation, washing and drying, calcium bisphosphonate modified hydroxyapatite containing unsaturated quaternary ammonium cations is obtained, which is polymerizable hydroxyapatite. The mass ratio of the tertiary amino-modified hydroxyapatite / unsaturated haloalkanes / polymerization inhibitor / solvent is 100:5~150:0.15~15:50~500; The unsaturated halogenated hydrocarbon refers to one of 3-chloropropene, 3-bromopropene, or p-chloromethylstyrene.

2. The method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations according to claim 1, characterized in that... The phosphate refers to one or more of the following: diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, or potassium dihydrogen phosphate.

3. The method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations according to claim 1, characterized in that... The bisphosphonate containing a tertiary amine group has the structure shown in general formula (Ⅰ): ； In general formula (Ⅰ), R1 and R1 are selected from C1 to C1 respectively. 18 hydrocarbon group, M + Select NH4 + Na + or K + One of them; The preparation method of the bisphosphonate containing the tertiary amine group of general formula (I) is as follows: according to anhydrous ethanol or anhydrous methanol / 3- Tertiary aminopropylamine / The mass ratio of diethyl vinylphosphonate or dimethyl vinylphosphonate is 0~200:100:50~500. Anhydrous ethanol or anhydrous methanol is first added to the reaction vessel. 3-Tertiary aminopropylamine The temperature of the material in the reactor is controlled at 20-25℃. Diethyl vinylphosphonate or dimethyl vinylphosphonate is slowly added. After the addition of diethyl vinylphosphonate or dimethyl vinylphosphonate is completed, the temperature of the material in the reactor is raised to 50-60℃ and stirred for 12 hours. Ethanol or methanol and excess diethyl vinylphosphonate or dimethyl vinylphosphonate are recovered by rotary evaporation. Then, an appropriate amount of 5.5 mol / L hydrochloric acid is added to the reactor until the residue in the reactor is completely dissolved. The temperature is controlled at 90-100℃ and stirred for 24 hours for hydrolysis. The temperature of the hydrolysis product is lowered to room temperature. The pH of the material in the reactor is adjusted to 4.5-7.5 using an appropriate amount of 30% sodium hydroxide aqueous solution. The mixture is concentrated by rotary evaporation until solid substances precipitate. The solid product is cooled and allowed to stand to precipitate. After filtration, recrystallization with 90-93% aqueous ethanol, and vacuum drying at 40-50℃ to constant weight, the bisphosphonate containing tertiary amine group with the structure shown in general formula (I) is obtained. The above 3-Tertiary aminopropylamine has The structure shown in general formula (II): ； In general formula (II), R1 and R1 are selected from C1 to C1 respectively. 18 Hydrocarbon group.

4. The method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations according to claim 1, characterized in that... The calcium salt refers to one of calcium nitrate, calcium chloride, or calcium acetate.

5. A method for modifying hydroxyapatite with calcium bisphosphate containing unsaturated quaternary ammonium cations according to claim 1. Its features The dispersant refers to one or more of the following: polyvinylpyrrolidone K30, polyvinylpyrrolidone K60, polyvinyl alcohol-1788, polyvinyl alcohol-2488, polyethylene glycol-2000, polyethylene glycol-4000, polyethylene glycol-6000, Span-80, Tween-80, N-dodecyl-N,N,N-trimethylammonium bromide, N-tetradecyl-N,N,N-trimethylammonium bromide, N-hexadecyl-N,N,N-triethylammonium bromide, N-dodecyl-N,N,N-triethylammonium bromide, N-tetradecyl-N,N,N-triethylammonium bromide, and N-hexadecyl-N,N,N-triethylammonium bromide.

6. The method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations according to claim 1, characterized in that... The alkaline aqueous solution refers to one of the following: ammonia water, ammonium bicarbonate aqueous solution, sodium bicarbonate aqueous solution, sodium hydroxide aqueous solution, or potassium hydroxide aqueous solution with a mass percentage concentration of 10-30%.

7. The method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations according to claim 1, characterized in that... The alcohol-water solvent refers to an alcohol-water solvent prepared by mixing methanol, ethanol or propanol with deionized water in a mass ratio of 1~99:99~1.

8. The method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations according to claim 1, characterized in that... The polymerization inhibitor refers to one or more of hydroquinone, p-methoxyphenol, tert-butylhydroquinone, 2,6-dibutylhydroquinone, 2,6-di-tert-butyl-p-cresol, or 2,4,6-tri-tert-butylphenol.

9. A method for modifying hydroxyapatite with calcium bisphosphonate containing unsaturated quaternary ammonium cations according to claim 1, characterized in that... The solvent refers to one or more of the following: tetrahydrofuran, 1,4-dioxane, cyclohexane, decahydronaphthalene, benzene, toluene, chlorobenzene, dichloromethane, chloroform, carbon tetrachloride, acetonitrile, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, or N,N-dimethylacetamide.

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