Preparation method of drug-loaded gelatin / PVA fiber modified PMMA bone cement as well as product and application of drug-loaded gelatin / PVA fiber modified PMMA bone cement

Abstract

The invention relates to a preparation method of drug-loaded glue / PVA (polyvinyl alcohol) fiber modified PMMA (polymethyl methacrylate) bone cement as well as a product and application thereof. The preparation method comprises the following steps: uniformly mixing the prepared gelatin and PVA aqueous solution in proportion, adding nano-hydroxyapatite, water-soluble drugs and other bioactive components, and dispersing to obtain an electrostatic spinning solution; carrying out electrostatic spinning, collecting the obtained drug-loaded gelatin / PVA fibers, and carrying out freeze drying on the collected drug-loaded gelatin / PVA fibers; and adding the dried drug-loaded gelatin / PVA fiber into PMMA solid phase powder to prepare the drug-loaded gelatin / PVA fiber modified PMMA bone cement. The gelatin / PVA flexible fiber modifies the mechanical property of PMMA, so that the compression modulus of PMMA is reduced, the mechanical property is better matched with that of natural bones, and AVF caused by stress shielding is avoided.

Description

Technical Field

[0001] The invention relates to a method in the technical field of biomedical materials, in particular to a preparation method of PMMA bone cement modified by drug-loaded gelatin PVA fibers, and a product and application thereof. Background Art

[0002] Osteoporosis (OP) is a common systemic bone metabolic disease characterized by low bone mass and bone microstructure damage, which can easily lead to non-traumatic fractures. Osteoporotic vertebral compression fractures (OVCFs) are the most common osteoporotic fractures, accounting for about 45% of osteoporotic fractures. Percutaneous vertebroplasty (PVP) is the most commonly used minimally invasive technique for the treatment of OVCFs. Currently, PMMA bone cement can meet the treatment needs of most patients with its stable chemical properties and superior biomechanical properties, and has always been the preferred filling material for vertebral augmentation. However, PMMA bone cement still faces some inherent defects, such as excessive mechanical strength, lack of osteogenic activity, and non-porous structure, which may lead to the occurrence of adjacent vertebral compression fractures (AVF) after surgery. Studies have shown that the incidence of AVF accounts for about 8% to 52% of OVCFs patients.

[0003] Some scholars focus on studying bone cement materials and methods for local improvement of osteoporosis after PVP surgery, such as mixing elemental strontium into calcium phosphate bone cement, using strontium to promote osteoblast proliferation and osteogenic activity, and locally improving vertebral osteoporosis after PVP / PKP surgery [Lode, Acta Biomaterialia, 2018]; such as mixing mineralized collagen materials into PMMA bone cement to construct a bioactive MC-PMMA bone cement with both high mechanical strength and osteogenic effect [Zhu, Theranostics, 2020]. However, the existing methods cannot form interconnected micropores inside the PMMA solid body, resulting in the inability to effectively release the bioactive components; at the same time, due to the polymerization exotherm during the curing process of PMMA bone cement, protein peptides that are not resistant to high temperatures are often difficult to apply to the modification of PMMA bone cement, limiting its further development and application in bone repair. Gelatin is a natural polymer material obtained by hydrolysis of collagen. It has the advantages of good biocompatibility, wide sources, and biodegradability. It is widely used in food, medicine and other fields.

[0004] Based on the above research background, the present invention uses electrospinning to prepare gelatin / PVA fibers loaded with nano-hydroxyapatite and bioactive drugs, which are mixed with PMMA powder as fillers to prepare PMMA bone cement modified with drug-loaded gelatin / PVA fibers after curing. The fibrous structure of gelatin and PVA during the degradation process helps to form interconnected pores inside PMMA, and continuously releases the loaded hydroxyapatite and bioactive substances, which is beneficial to osteogenesis and angiogenesis, improves the internal microenvironment of PMMA, and prepares PMMA bone cement with high bone-promoting bioactivity and matching mechanical properties. Summary of the invention

[0005] The invention aims to provide a method for preparing drug-loaded gelatin / PVA fiber-modified PMMA bone cement.

[0006] Another object of the present invention is to provide a drug-loaded gelatin / PVA fiber-modified PMMA bone cement product prepared by the above method.

[0007] Another object of the present invention is to provide an application of the above product.

[0008] The object of the present invention is achieved by the following scheme: A method for preparing drug-loaded gelatin / PVA fiber-modified PMMA bone cement, characterized in that it comprises the following steps: The prepared gelatin and PVA aqueous solutions are mixed evenly in proportion, and bioactive ingredients such as nano-hydroxyapatite and water-soluble drugs are added for dispersion to obtain an electrospinning solution; electrospinning is performed, and the obtained drug-loaded gelatin / PVA fibers are collected and freeze-dried; the dried drug-loaded gelatin / PVA fibers are added to PMMA solid phase powder to prepare PMMA bone cement modified with drug-loaded gelatin / PVA fibers.

[0009] (1) preparing a gelatin solution with a concentration of 1-5% (w / v) and a PVA solution with a concentration of 5-10% (w / v), mixing the gelatin solution and the PVA solution at a volume ratio of 1:4-1:9, stirring and mixing at room temperature, adding bioactive ingredients such as nano-hydroxyapatite and water-soluble drugs, stirring to fully disperse them, and obtaining an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 10-15 cm, and the electrospinning spray was performed in a dry environment at 40 ° C. The product was freeze-dried to obtain drug-loaded gelatin / PVA fibers; (3) Prepare PMMA bone cement solid phase powder and PMMA bone cement curing liquid loaded with drug-loaded gelatin / PVA fiber, mix the PMMA bone cement solid phase powder and the curing liquid at a solid-liquid ratio of 1-1.5 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

[0010] The gelatin solution in step (1) is prepared by heating and dissolving at 50°C, and the PVA solution is prepared by heating and dissolving at 90°C, assisted by magnetic stirring or mechanical stirring.

[0011] The amount of nano-hydroxyapatite added in step (1) is 1-5% (w / v), and the water-soluble drugs include osteogenic active drugs, fibrogenic active drugs, antibacterial drugs, and anti-tumor drugs.

[0012] The PMMA bone cement solid phase powder in step (3) comprises 50-90% polymethyl methacrylate prepolymer powder, 1-5% initiator benzoyl peroxide, 4-10% developer, and 5-45% drug-loaded gelatin / PVA fiber, where the above are mass fractions and the total is 100%.

[0013] The PMMA bone cement curing liquid in step (3) comprises 90-95% of methyl methacrylate monomer, 4.9%-9.9% of N,N-dimethyl-p-toluidine as a coagulant, and 0.1% of hydroquinone as a stabilizer, wherein the above are mass fractions, and the total is 100%.

[0014] The invention provides a drug-loaded gelatin / PVA fiber-modified PMMA bone cement, which is characterized in that it is prepared according to any of the above methods.

[0015] The invention provides an application of drug-loaded gelatin / PVA fiber-modified PMMA bone cement in preparing a high-activity mechanically controllable PMMA bone cement material.

[0016] The present invention comprises the following steps: 1. Dissolve gelatin in pure water to prepare a gelatin solution with a concentration of 1-5% (w / v) by heating at 50°C with the aid of magnetic or mechanical stirring.

[0017] 2. Dissolve PVA in pure water to prepare a 5-10% (w / v) PVA solution by heating at 90°C with the aid of magnetic or mechanical stirring.

[0018] 3. The gelatin solution and PVA solution are mixed in a volume ratio of 1:4-1:9, stirred at room temperature, and then bioactive ingredients such as nanohydroxyapatite and water-soluble drugs are added, stirred to fully disperse, and an electrospinning solution is obtained. The amount of nanohydroxyapatite added is 1-5% (w / v), and the water-soluble drugs include osteogenic active drugs, fibrogenic active drugs, antibacterial drugs, antitumor drugs, etc.

[0019] 4. The positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 10-15 cm, and electrospinning spraying was performed in a dry environment at 40 ° C. The collected drug-loaded gelatin / PVA fibers were freeze-dried.

[0020] 5. Prepare PMMA bone cement solid phase powder: including polymethyl methacrylate prepolymer powder 50-90%, initiator benzoyl peroxide 1-5%, developer 4-10%, drug-loaded gelatin / PVA fiber 5-45%, the above are mass fractions, the total is 100%.

[0021] 6. Prepare PMMA bone cement curing liquid: including methyl methacrylate monomer 90-95%, accelerator N,N-dimethyl-p-toluidine 4.9%-9.9%, stabilizer hydroquinone 0.1%, the above are mass fractions, the total is 100%.

[0022] 7. Mix the PMMA bone cement solid phase powder and the solidifying liquid at a solid-liquid ratio of 1-1.5 g / mL to obtain drug-loaded gelatin / PVA fiber modified PMMA bone cement.

[0023] The advantages of the present invention are: 1. Gelatin / PVA fibers loaded with hydroxyapatite and bioactive drugs were prepared by electrospinning, and then PMMA bone cement was modified. The fibers formed a connected structure in PMMA bone cement. During the degradation process, the bioactive components affected the osteogenesis process through various mechanisms, including directly promoting bone formation and indirectly affecting bone regeneration by regulating angiogenesis, which is beneficial to osteogenesis and angiogenesis.

[0024] 2. The mechanical properties of PMMA modified by gelatin / PVA flexible fibers reduce its compression modulus, making its mechanical properties more compatible with natural bone and avoiding the occurrence of AVF caused by stress shielding. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Attached Figure 1 This is the compressive strength mechanical curve of the drug-loaded gelatin / PVA fiber-modified PMMA bone cement prepared in Example 1, with a compressive strength of 85 MPa and a compression modulus of 717 MPa. DETAILED DESCRIPTION

[0026] The following examples are implemented based on the technical solutions of the invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

[0027] Example 1 A drug-loaded gelatin / PVA fiber-modified PMMA bone cement is prepared according to the following steps: (1) Preparation of electrospinning solution: prepare a 2% gelatin solution under heating and stirring at 50°C, prepare a 10% PVA solution under heating and stirring at 90°C, mix the gelatin solution and PVA solution at a volume ratio of 1:9, stir and mix at room temperature, add 5% (w / v) nanohydroxyapatite and 10 μg of BMP-2, stir to fully disperse, and obtain an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 15 cm, and the electrospinning spraying was performed in a dry environment at 40 ° C. The product was freeze-dried, and the obtained drug-loaded gelatin / PVA fibers were collected and freeze-dried; (3) The PMMA bone cement solid phase powder is composed of 50% polymethyl methacrylate prepolymer powder, 1% initiator benzoyl peroxide, 10% developer, and 39% drug-loaded gelatin / PVA fiber; the PMMA bone cement curing liquid is composed of 95% methyl methacrylate monomer, 4.9% accelerator N,N-dimethyl-p-toluidine, and 0.1% stabilizer hydroquinone; the PMMA bone cement solid phase powder and the curing liquid are mixed at a solid-liquid ratio of 1 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

[0028] The compressive strength mechanical curve of PMMA bone cement modified with drug-loaded gelatin / PVA fiber was 85MPa and the compression modulus was 717MPa. Figure 1 .

[0029] Example 2 A drug-loaded gelatin / PVA fiber-modified PMMA bone cement is prepared according to the following steps: (1) Preparation of electrospinning solution: prepare a 5% gelatin solution under heating and stirring at 50°C, prepare a 10% PVA solution under heating and stirring at 90°C, mix the gelatin solution and PVA solution in a volume ratio of 1:9, stir and mix at room temperature, add 5% (w / v) nanohydroxyapatite and 1 mg / mL vancomycin, stir to fully disperse, and obtain an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 10 cm, and the electrospinning spraying was performed in a dry environment at 40 °C. The drug-loaded gelatin / PVA fibers were collected and freeze-dried; (3) The PMMA bone cement solid phase powder is composed of 50% polymethyl methacrylate prepolymer powder, 1% initiator benzoyl peroxide, 10% developer, and 39% drug-loaded gelatin / PVA fiber; the PMMA bone cement curing liquid is composed of 95% methyl methacrylate monomer, 4.9% accelerator N,N-dimethyl-p-toluidine, and 0.1% stabilizer hydroquinone; the PMMA bone cement solid phase powder and the curing liquid are mixed at a solid-liquid ratio of 1 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

[0030] Example 3 A drug-loaded gelatin / PVA fiber-modified PMMA bone cement is prepared according to the following steps: (1) Preparation of electrospinning solution: prepare a 2% gelatin solution under heating and stirring at 50°C, prepare a 10% PVA solution under heating and stirring at 90°C, mix the gelatin solution and PVA solution in a volume ratio of 1:9, stir and mix at room temperature, add 5% (w / v) nanohydroxyapatite and 1 μg / mL bmp-2, stir to fully disperse, and obtain an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 15 cm, and the electrospinning spraying was performed in a dry environment at 40 °C. The drug-loaded gelatin / PVA fibers were collected and freeze-dried; The PMMA bone cement solid phase powder is composed of 90% polymethyl methacrylate prepolymer powder, 1% initiator benzoyl peroxide, 4% developer, and 5% drug-loaded gelatin / PVA fiber; the PMMA bone cement curing liquid is composed of 95% methyl methacrylate monomer, 4.9% accelerator N,N-dimethyl-p-toluidine, and 0.1% stabilizer hydroquinone; the PMMA bone cement solid phase powder and the curing liquid are mixed at a solid-liquid ratio of 1 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

Claims

1. A method for preparing drug-loaded gelatin / PVA fiber-modified PMMA bone cement, characterized in that: The following steps are involved: (1) preparing a gelatin solution with a concentration of 1-5% (w / v) and a PVA solution with a concentration of 5-10% (w / v), mixing the gelatin solution and the PVA solution at a volume ratio of 1:4-1:9, stirring and mixing at room temperature, adding bioactive ingredients such as nano-hydroxyapatite and water-soluble drugs, stirring to fully disperse them, and obtaining an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 10-15 cm, and the electrospinning spray was performed in a dry environment at 40 ° C. The product was freeze-dried to obtain drug-loaded gelatin / PVA fibers; (3) Prepare PMMA bone cement solid phase powder and PMMA bone cement curing liquid loaded with drug-loaded gelatin / PVA fiber, mix the PMMA bone cement solid phase powder and the curing liquid at a solid-liquid ratio of 1-1.5 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

2. The method for preparing the drug-loaded gelatin / PVA fiber-modified PMMA bone cement according to claim 1, characterized in that: The gelatin solution in step (1) is prepared by heating and dissolving at 50°C, and the PVA solution is prepared by heating and dissolving at 90°C, assisted by magnetic stirring or mechanical stirring.

3. The method for preparing the drug-loaded gelatin / PVA fiber-modified PMMA bone cement according to claim 1, characterized in that: The amount of nano-hydroxyapatite added in step (1) is 1-5% (w / v), and the water-soluble drugs include osteogenic active drugs, fibrogenic active drugs, antibacterial drugs, and anti-tumor drugs.

4. The method for preparing the drug-loaded gelatin / PVA fiber-modified PMMA bone cement according to claim 1, characterized in that: The PMMA bone cement solid phase powder in step (3) comprises, by mass fraction, 50-90% of polymethyl methacrylate prepolymer powder, 1-5% of initiator benzoyl peroxide, 4-10% of developer, and 5-45% of drug-loaded gelatin / PVA fiber, which is mixed to 100%.

5. The method for preparing the drug-loaded gelatin / PVA fiber-modified PMMA bone cement according to claim 1, characterized in that: The PMMA bone cement curing liquid in step (3) comprises 90-95% of methyl methacrylate monomer, 4.9%-9.9% of N,N-dimethyl-p-toluidine as a coagulant, and 0.1% of hydroquinone as a stabilizer, wherein the above are mass fractions, and the total is 100%.

6. The method for preparing the drug-loaded gelatin / PVA fiber-modified PMMA bone cement according to any one of claims 1 to 5, characterized in that: Prepare as follows: (1) Preparation of electrospinning solution: prepare a 2% gelatin solution under heating and stirring at 50°C, prepare a 10% PVA solution under heating and stirring at 90°C, mix the gelatin solution and PVA solution at a volume ratio of 1:9, stir and mix at room temperature, add 5% (w / v) nanohydroxyapatite and 10 μg of BMP-2, stir to fully disperse, and obtain an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 15 cm, and the electrospinning spraying was performed in a dry environment at 40 ° C. The product was freeze-dried, and the obtained drug-loaded gelatin / PVA fibers were collected and freeze-dried; (3) The PMMA bone cement solid phase powder is composed of 50% polymethyl methacrylate prepolymer powder, 1% initiator benzoyl peroxide, 10% developer, and 39% drug-loaded gelatin / PVA fiber; the PMMA bone cement curing liquid is composed of 95% methyl methacrylate monomer, 4.9% accelerator N,N-dimethyl-p-toluidine, and 0.1% stabilizer hydroquinone; the PMMA bone cement solid phase powder and the curing liquid are mixed at a solid-liquid ratio of 1 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

7. The method for preparing the drug-loaded gelatin / PVA fiber-modified PMMA bone cement according to any one of claims 1 to 5, characterized in that: Prepare as follows: (1) Preparation of electrospinning solution: prepare a 5% gelatin solution under heating and stirring at 50°C, prepare a 10% PVA solution under heating and stirring at 90°C, mix the gelatin solution and PVA solution in a volume ratio of 1:9, stir and mix at room temperature, add 5% (w / v) nanohydroxyapatite and 1 mg / mL vancomycin, stir to fully disperse, and obtain an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 10 cm, and the electrospinning spraying was performed in a dry environment at 40 °C. The drug-loaded gelatin / PVA fibers were collected and freeze-dried; (3) The PMMA bone cement solid phase powder is composed of 50% polymethyl methacrylate prepolymer powder, 1% initiator benzoyl peroxide, 10% developer, and 39% drug-loaded gelatin / PVA fiber; the PMMA bone cement curing liquid is composed of 95% methyl methacrylate monomer, 4.9% accelerator N,N-dimethyl-p-toluidine, and 0.1% stabilizer hydroquinone; the PMMA bone cement solid phase powder and the curing liquid are mixed at a solid-liquid ratio of 1 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

8. The method for preparing the drug-loaded gelatin / PVA fiber-modified PMMA bone cement according to any one of claims 1 to 5, characterized in that: Prepare as follows: (1) Preparation of electrospinning solution: prepare a 2% gelatin solution under heating and stirring at 50°C, prepare a 10% PVA solution under heating and stirring at 90°C, mix the gelatin solution and PVA solution in a volume ratio of 1:9, stir and mix at room temperature, add 5% (w / v) nanohydroxyapatite and 1 μg / mL bmp-2, stir to fully disperse, and obtain an electrospinning solution; (2) The electrospinning solution was loaded into a syringe, the positive voltage at the injection needle was set to 10 kV, the negative voltage at the receiving rod was set to -1 kV, the receiving distance was 15 cm, and the electrospinning spraying was performed in a dry environment at 40 °C. The drug-loaded gelatin / PVA fibers were collected and freeze-dried; (3) The PMMA bone cement solid phase powder is composed of 90% polymethyl methacrylate prepolymer powder, 1% initiator benzoyl peroxide, 4% developer, and 5% drug-loaded gelatin / PVA fiber; the PMMA bone cement curing liquid is composed of 95% methyl methacrylate monomer, 4.9% accelerator N,N-dimethyl-p-toluidine, and 0.1% stabilizer hydroquinone; the PMMA bone cement solid phase powder and the curing liquid are mixed at a solid-liquid ratio of 1 g / mL to obtain PMMA bone cement modified with drug-loaded gelatin / PVA fiber.

9. A PMMA bone cement modified with drug-loaded gelatin / PVA fiber, characterized in that Prepared according to any one of claims 1 to 8.

10. Use of the PMMA bone cement modified with drug-loaded gelatin / PVA fibers according to claim 9 in the preparation of a highly active and mechanically controllable PMMA bone cement material.

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