Disclosure of Invention
In view of the above problems of the prior art, the present application aims to provide a bone cement composite material and a method for preparing the same.
The bone cement composite of the present application, comprising: support material, powder and curing liquid;
the support material is a porous support material prepared from hydrophilic or modified hydrophilic polymer materials; the porous structure is a through porous structure;
the powder is used for being compounded in the porous structure of the support material;
the curing liquid is used for curing the powder in the porous structure.
Preferably, the scaffold material is prepared from at least one of polylactic glycolic acid, chitosan, collagen, chondroitin sulfate, polylactic acid, gelatin and polyvinyl alcohol;
the powder comprises at least one of magnesium phosphate, calcium sulfate hemihydrate and beta-tricalcium phosphate;
the solidifying liquid is a hydrogen phosphate solution.
Preferably, the hydrogen phosphate solution is at least one of a dipotassium hydrogen phosphate solution, a potassium dihydrogen phosphate solution, a sodium dihydrogen phosphate solution, and a disodium hydrogen phosphate solution.
Preferably, the powder particle size of the powder is 2-20 microns.
Preferably, after being cured, the bone cement composite material has a compressive strength of 2.5-5MPa, a compressive strength of 0.09-0.15 GPa, a porosity of not less than 60% and a pore size distribution in the range of 10-250 microns.
Preferably, the powder particle size of the powder is 10 microns.
The preparation method of the bone cement composite material comprises the following steps:
selecting proper hydrophilic or modified hydrophilic raw materials according to the degradation time or the requirement of indications to prepare the scaffold material with the porous structure;
compounding powder in the support material to ensure that the powder is fully filled in the porous structure of the support material;
and injecting the curing liquid into the bracket material compounded with the powder to cure the powder in the bracket material.
Preferably, the scaffold material is prepared from at least one of polylactic glycolic acid, chitosan, collagen, chondroitin sulfate, polylactic acid, gelatin and polyvinyl alcohol;
the powder comprises at least one of magnesium phosphate, calcium sulfate hemihydrate and beta-tricalcium phosphate;
the solidifying liquid is a hydrogen phosphate solution.
Preferably, the scaffold material is prepared by a freeze-drying method, an electrostatic spinning method and three-dimensional printing by using hydrophilic or modified hydrophilic raw materials.
Preferably, the powder is compounded into the porous structure of the scaffold material by a rapid stirring method, a negative pressure adsorption method or an ultrasonic vibration method.
The compressive strength of the bone cement composite material is about 2.5-5MPa, the compressive strength is 0.09GPa-0.15GPa, and the material has more proper mechanical strength due to the lower compressive modulus than the existing bone cement (the compressive strength is 0.5GPa-1GPa), so that the requirement on the mechanical property in the bone reconstruction process is met. The material has a good through pore structure, the porosity is about 60% or more, the pore size distribution is more reasonable, and the material is not only beneficial to adsorbing bone-forming related protein micropores (10-20 micrometers), but also beneficial to growing new tissues into macropores (200 micrometers or more); and more new pores or larger pores can be generated along with the different rapid degradation of the macromolecules and the bone cement in vivo, so that an ideal pore channel is provided for the growth of new cells and blood vessels and the delivery of nutrient substances.
Detailed Description
The product composition of the bone cement composite material of the present application:
(1) hydrophilic or modified hydrophilic macromolecule interpenetrating porous scaffold materials, for example: the through porous scaffold material is prepared from one or two or more of polylactic glycolic acid, chitosan, collagen, chondroitin sulfate, polylactic acid, gelatin, polyvinyl alcohol and the like.
(2) Powder: one or two or more of magnesium phosphate, calcium sulfate hemihydrate and beta-tricalcium phosphate, and the particle size of the powder is about 2-20 microns, preferably 10 microns.
(3) Curing liquid: hydrogen phosphate solutions, for example: dipotassium hydrogen phosphate, potassium dihydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, and the like.
The preparation method of the bone cement composite material comprises the following steps:
step 1. preparation of scaffold Material
The scaffold material with porous structure can be prepared by freeze-drying, electrostatic spinning, and three-dimensional printing, by selecting one or two or more raw materials according to degradation time or indication requirement, such as polylactic glycolic acid, chitosan, collagen, chondroitin sulfate, polylactic acid, gelatin, polyvinyl alcohol, etc., and selecting at least one hydrophilic raw material, and is in sponge shape. In the case of lyophilization, the raw materials are dissolved in a suitable solvent, such as an organic solvent like dichloromethane, chloroform, 1, 4-dioxane, or an acetic acid solution, and the mixture is prepared by magnetic stirring or ultrasonic dispersion. After the mixture is fully mixed, the mixture is transferred into a mould and frozen for 24-36 hours. Then freeze-drying in a freeze-drying machine for at least 48 hours to prepare the porous scaffold material (the shape of the porous scaffold is determined by a mold). The scaffold material prepared by the method has a porosity of more than 75% (as shown in fig. 2), the pore size is about 5-280 microns, and the pore size can be adjusted by adjusting the concentration of the mixed solution, the freeze-drying parameters and the like.
Step 2, compounding the porous support material and the powder
And (2) compounding the scaffold material (which can be randomly cut into small blocks) with the porous structure in the step (1) with one or two or more of magnesium phosphate powder, semi-hydrated calcium sulfate powder or beta-tricalcium phosphate powder, so that the powder is fully filled in pores of the porous scaffold. In the step, the compounding efficiency can be improved by means of a rapid stirring method, a negative pressure adsorption method or an ultrasonic vibration method.
Step 3, curing liquid composite reaction
When in use, the bracket material compounded with the powder is selected with proper shape, size and quantity according to the bone defect part. The scaffold material which has good flexibility and can be arbitrarily crushed and compounded with the powder is delivered to the bone defect, then a certain amount of hydrogen phosphate curing liquid (the mass ratio of solid to liquid is about 1: 0.8-2) is injected at the bone defect, and then the scaffold material is compacted at the bone defect, and the curing time is about 20 min.
The prepared bone repair material has the compressive strength of about 2.5-5MPa and the compressive strength of 0.09GPa-0.15GPa, and has a lower compressive modulus than that of the existing bone cement (the compressive strength is 0.5GPa-1GPa), so that the material has more proper mechanical strength overall and meets the requirement of mechanical property in the bone reconstruction process. The material has a good through pore structure, the porosity is about 60% or more, the pore size distribution is more reasonable and is distributed in the range of 10-250 microns, and the material is not only beneficial to adsorbing bone-related protein micropores (10-20 microns) but also beneficial to growing new tissues into macropores (200 microns or more) (as shown in figure 1); and more new pores or larger pores can be generated along with the different rapid degradation of the macromolecules and the bone cement in vivo, so that an ideal pore channel is provided for the growth of new cells and blood vessels and the delivery of nutrient substances.
Example 1:
step (1) molecular weight is 104-105The L-polylactic acid (PLLA) with kDa is dissolved in an organic solvent, such as dichloromethane or chloroform or 1, 4-dioxane, or a mixture thereof, to prepare a solution with a certain solubility, with a concentration of 20g-100g/L, preferably 60 g/L. Then adding a certain amount of chitosan (the mass ratio of polylactic acid to chitosan is preferably 4: 1). Magnetically stirring for 2-4 hr at normal temperature and ultrasonic dispersing for 1-3 hr.
And respectively pouring the prepared mixed solution into polytetrafluoroethylene molds, placing the polytetrafluoroethylene molds in a refrigerator at the temperature of-20 ℃ for freezing for 24-36 hours, transferring the molds into a freeze dryer, carrying out freeze drying for at least 48 hours under negative pressure, and completely pumping out the organic solvent. Obtaining the bracket material with the spongy porous structure.
And (2) compounding the porous support material (which can be randomly cut into small blocks) in the step (1) with magnesium phosphate powder of a certain mass, so that the magnesium phosphate powder and the support material are fully mixed, and generally 0.5-3g of powder can be mixed in each gram of support material. In this step, the compounding efficiency can be improved by means of rapid stirring, negative pressure adsorption or ultrasonic vibration.
When the step (3) is used, the powder-compounded bracket material prepared in the step (2) can be selected according to requirements, the bracket material is conveyed to a bone defect part by adopting an apparatus, a certain amount of curing liquid is injected into the bone defect part, and the mass ratio of the solid to the liquid is about 1: 0.8-2. Then lightly pressing and mixing evenly for many times at the bone defect position. The in vivo curing can be completed within 20 min.
The preparation method of the curing liquid in the step (3) comprises the following steps: the curing liquid is a hydrogen phosphate solution, the concentration of the curing liquid is 2-5mol/L, and the hydrogen phosphate at least contains one potassium hydrogen phosphate salt, such as dipotassium hydrogen phosphate and potassium dihydrogen phosphate.
Example 2:
the difference between the embodiment 2 and the embodiment 1 lies in the selection of the raw material chitin fiber in the process of preparing the scaffold material in the step (1), as follows:
step (1) molecular weight is 104-105The L-polylactic acid (PLLA) with kDa is dissolved in an organic solvent, such as dichloromethane or chloroform or 1, 4-dioxane, or a mixture thereof, to prepare a solution with a certain solubility, with a concentration of 20g-100g/L, preferably 60 g/L. Then adding a certain amount of deacetylated Chitin Fiber (CF), wherein deacetylation is more than 85%, fiber length is 0.5mm-2mm, and the mass ratio of polylactic acid to chitin fiber is preferably 4: 1. Magnetically stirring for 2-4 hr at normal temperature and ultrasonic dispersing for 1-3 hr.
And respectively pouring the prepared mixed solution into polytetrafluoroethylene molds, placing the polytetrafluoroethylene molds in a refrigerator at the temperature of-20 ℃ for freezing for 24-36 hours, transferring the molds into a freeze dryer, carrying out freeze drying for at least 48 hours under negative pressure, and completely pumping out the organic solvent. Thus obtaining the scaffold material with porous structure.
Example 3:
example 3 differs from example 1 in the selection of the raw material polylactic glycolic acid during the preparation of the porous scaffold in step (1), as follows:
in the step (1), a certain mass of polylactic-co-glycolic acid (PLGA, relative molecular mass 104-105 kDa; glycolide ratio is preferably 50: 50, 75: 25) is dissolved in an organic solvent, such as dichloromethane or 1, 4-dioxane or other organic solvents or organic solvent mixed solution, to prepare a solution with a certain solubility, wherein the concentration is 50 g/L to 100g/L, preferably 60 g/L. Magnetic stirring for 2-4 hours at normal temperature and ultrasonic dispersion for 1-3 hours to fully mix the solution.
And respectively pouring the prepared mixed solution into polytetrafluoroethylene molds, placing the polytetrafluoroethylene molds in a refrigerator at the temperature of-20 ℃ for freezing for 24 to 36 hours, transferring the molds into a freeze dryer, carrying out freeze drying for at least 48 hours under negative pressure, and completely pumping out the organic solvent. Obtaining the spongy porous scaffold material (the shape of the scaffold material is determined according to the mould).
Example 4:
example 4 differs from example 1 in the selection of the powder material components in step (2) as follows:
dissolving the L-polylactic acid (PLLA) with the molecular weight of 104-105kDa in an organic solvent, such as dichloromethane or trichloromethane or 1, 4-dioxane and other organic solvents or a mixed solution of the organic solvents to prepare a solution with a certain solubility, wherein the concentration of the solution is 20-100 g/L, and 60g/L is preferred. Then adding a certain amount of chitosan (the mass ratio of polylactic acid to chitosan is preferably 4: 1). And (3) performing magnetic stirring for 2-4 hours at normal temperature and performing ultrasonic dispersion for 1-3 hours.
And respectively pouring the prepared mixed solution into polytetrafluoroethylene molds, placing the polytetrafluoroethylene molds in a refrigerator at the temperature of-20 ℃ for freezing for 24 to 36 hours, transferring the molds into a freeze dryer, carrying out freeze drying for at least 48 hours under negative pressure, and completely pumping out the organic solvent. And (4) obtaining the scaffold material with a porous structure (the shape of the scaffold material is determined according to the mould).
And (2) compounding the bracket material (which can be randomly cut into small blocks) in the step (1) with certain mass of magnesium phosphate and calcium sulfate hemihydrate composite powder (the mass ratio of the magnesium phosphate to the calcium sulfate hemihydrate powder is preferably 1: 1), so that the powder and the bracket material are fully mixed, and generally 0.5-3g of powder can be compounded per gram of the bracket material. In this step, the compounding efficiency can be improved by means of rapid stirring, negative pressure adsorption or ultrasonic vibration.
When the step (3) is used, the powder-compounded bracket material prepared in the step (2) can be selected according to requirements, the bracket material is conveyed to a bone defect part by adopting an apparatus, a certain amount of curing liquid is injected into the bone defect part, and the mass ratio of the solid to the liquid is about 1: 0.8-2. Then lightly pressing and mixing evenly for many times at the bone defect position. The in vivo curing can be completed within 20 min.
The preparation method of the curing liquid in the step (3) comprises the following steps: the curing liquid is a mixed solution of potassium hydrogen phosphate and sodium hydrogen phosphate solution (the mass ratio of potassium hydrogen phosphate to sodium hydrogen phosphate is preferably 1: 0.5), and the concentration is 2-5 mol/L. The potassium hydrogen phosphate salt can be dipotassium hydrogen phosphate or potassium dihydrogen phosphate. The sodium hydrogen phosphate salt can be selected from disodium hydrogen phosphate or sodium dihydrogen phosphate.
Example 5:
example 5 differs from example 1 in the selection of the powder material components in step (2) as follows:
step (1) molecular weight is 104-105The L-polylactic acid (PLLA) with kDa is dissolved in an organic solvent, such as dichloromethane or chloroform or 1, 4-dioxane, or a mixed solution of the organic solvents to prepare a solution with certain solubility, wherein the concentration of the solution is 20g to 100g/L, and 60g/L is preferred. Then adding a certain amount of chitosan (the mass ratio of polylactic acid to chitosan is preferably 4: 1). Magnetically stirring for 2-4 hr at normal temperature and ultrasonic dispersing for 1-3 hr.
And respectively pouring the prepared mixed solution into polytetrafluoroethylene molds, placing the polytetrafluoroethylene molds in a refrigerator at the temperature of-20 ℃ for freezing for 24-36 hours, transferring the molds into a freeze dryer, carrying out freeze drying for at least 48 hours under negative pressure, and completely pumping out the organic solvent. And (4) obtaining the scaffold material with a porous structure (the shape of the scaffold material is determined according to the mould).
And (2) compounding the support material (which can be arbitrarily cut into small pieces) in the step (1) with certain mass of magnesium phosphate and beta-tricalcium phosphate composite powder (the mass ratio of the magnesium phosphate to the beta-tricalcium phosphate powder is preferably 1: 1), so that the powder and the support material are fully mixed, and generally 0.5-3g of powder can be compounded per gram of the support material. In this step, the compounding efficiency can be improved by means of rapid stirring, negative pressure adsorption or ultrasonic vibration.
(3) When in use, the bracket material compounded with the powder prepared in the step (2) can be selected according to requirements, the bracket material is conveyed to a bone defect part by adopting an instrument, a certain amount of curing liquid is injected into the bone defect part, and the mass ratio of the solid to the liquid is about 1: 0.8-2. Then lightly pressing and mixing evenly for many times at the bone defect position. The in vivo curing can be completed within 20 min.
The preparation method of the curing liquid in the step (3) comprises the following steps: the curing liquid is a mixed solution of potassium hydrogen phosphate and sodium hydrogen phosphate solution (the mass ratio of potassium hydrogen phosphate to sodium hydrogen phosphate is preferably 1: 0.5), and the concentration is 2-5 mol/L. The potassium hydrogen phosphate salt can be dipotassium hydrogen phosphate or potassium dihydrogen phosphate. The sodium hydrogen phosphate salt can be selected from disodium hydrogen phosphate or sodium dihydrogen phosphate.
Example 5:
example 5 differs from example 1 in the step (1) preparation of the scaffold material as follows:
respectively dissolving I-type collagen powder and chondroitin sulfate powder in a dilute acetic acid solution with certain solubility to prepare a collagen solution (1g-10g/100mL) and a chondroitin sulfate solution (5g/100mL) with certain concentrations, wherein the concentration of the dilute acetic acid is 1g-3g/1000 mL. Slowly dripping the chondroitin sulfate solution into the collagen solution, wherein the liquid adding speed is preferably 10mL/min, stirring the mixed solution at a certain speed in the dripping process, and the stirring speed is preferably 600 r/min. And (3) preparing the collagen and chondroitin sulfate compound. And (3) centrifugally collecting the compound, transferring the compound into a mold, freezing the compound for 24-36 hours at the temperature of minus 20 ℃, and then freezing and drying the compound under the negative pressure to prepare the scaffold material with the porous structure, wherein the scaffold material with the porous structure can further improve the mechanical strength through a high-temperature crosslinking (50-70 ℃) treatment process.
Fig. 3-5 are schematic diagrams comparing the mechanical property test results of the bone cement composite material and the two existing bone cements.
The compressive strength of the bone cement composite material before the first damage is 2.8MPa, the strain is about 2.5 percent, and the compressive modulus is calculated to be about 0.112GPa and is in a proper range of human tibial cancellous bone.
The compressive strength of the bone cement in the figure 4 is 4.8MPa before the first failure, the strain is about 0.8 percent, and the compressive modulus is calculated to be 0.6 GPa; the compression modulus is too high, which is about 5 times of human tibial cancellous bone.
The compressive strength of the bone cement in the figure 5 is 4.5MPa before the first failure, the strain is about 0.5 percent, and the compressive modulus is calculated to be 0.9 GPa; the compression modulus is too high, which is about 8 times of that of human tibial cancellous bone.
Due to the fact that the composite material has a lower compression modulus than that of existing bone cement, the composite material has more appropriate mechanical strength, and the requirement of mechanical property in a bone reconstruction process is met. The material has a good through pore structure, the porosity is about 60% or more (the porosity can be adjusted by different mass ratios of the support material and the powder), the pore size distribution is more reasonable and is distributed in the range of 10-250 microns, and the material is not only beneficial to adsorbing bone-forming related protein micropores (10-20 microns) but also beneficial to growing new tissues into macropores (200 microns); and more new pores or larger pores can be generated along with the different rapid degradation of the macromolecules and the bone cement in vivo, so that an ideal pore channel is provided for the growth of new cells and blood vessels and the delivery of nutrient substances. Overcomes the problem of clinical effect caused by too large compression modulus and undesirable in-situ pore-forming effect of the existing bone repair material.
The application of the bone cement composite material is characterized in that on the basis of high porosity of the scaffold material prepared by a freeze-drying method, magnesium phosphate and potassium phosphate salt solution form high-strength hexahydrate magnesium potassium phosphate complex bone cement network connection between pores of a polymer scaffold material. The surface of the hydrophilic polymer scaffold material contains charged groups, and can form a non-covalent coupling effect with the surface of bone tissue to form an adhesion layer, so that the introduction of the polymer scaffold material is beneficial to improving the mechanical property of the material, improving the bonding tightness between the bone repair material and autologous bone, and solving the problem that the existing bone cement repair material is not firmly bonded with autologous bone due to strength, physiological environment and environmental factors.
The materials such as magnesium phosphate, calcium sulfate, beta-tricalcium phosphate, deacetylated chitin fiber, chitosan, collagen, chondroitin sulfate, polylactic acid, polylactic glycolic acid and the like have good biocompatibility and in vivo degradability, so that the bone repair material provided by the invention has the characteristics of safety, degradable absorption, good biocompatibility and the like. Meanwhile, the bone repair material provided by the invention also has ideal compressive strength and compressive modulus, material microstructure, tissue cohesiveness and proper curing time.
By adjusting the proportion of each component in the bone repair material provided by the invention, the formed material is expected to be applied to the fields of bone defect repair and plastic of different parts.
Unless defined otherwise, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples set forth in this application are illustrative only and not intended to be limiting.
Although the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the teachings of this application and yet remain within the scope of this application.