A low-modulus bone cement and its preparation method

Abstract

The application discloses a low-modulus bone cement and a preparation method thereof, and the solid-liquid ratio of powder and liquid is 2g-3g:1mL; the powder comprises the following raw materials in percentage by mass: 52%-89.5% of acrylic resin, 10%-40% of barium sulfate and 0.5%-8% of powdered phospholipid; and the liquid comprises the following raw materials: 0.5%-5% of N, N-dimethyl-p-toluidine, 0.05%-2% of hydroquinone and 93%-99.45% of methyl methacrylate. The powdered phospholipid is introduced into the bone cement powder to modify the bone cement, reduce the excessively high elastic modulus of the bone cement and prevent secondary injuries such as the fracture of adjacent vertebral bodies caused by the high elastic modulus of the bone cement after filling. Meanwhile, the powdered phospholipid is uniformly distributed in the bone cement, meets the requirement of the bone cement compression strength≥70MPa in the bone cement forced standard and guarantees the demand of human mechanical strength support.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials, and more particularly to a low-modulus bone cement and its preparation method. Background Technology

[0002] Acrylic resin bone cement (mainly polymethyl methacrylate, PMMA) is an injectable filler and adhesive material, initially used in prosthesis replacement surgery, and now widely used in orthopedic clinics, especially in vertebral body repair and arthroplasty. PMMA bone cement has some drawbacks, such as the potential for burns to human tissue due to excessively high curing temperatures, particularly its excessively high elastic modulus, which is 4 to 40 times that of vertebral cancellous bone. This excessively high elastic modulus leads to excessive hardness of the implanted vertebra, causing stress concentration and potentially resulting in compression fractures of adjacent vertebrae. The compressive elastic modulus of autologous bone is around 1200 MPa; therefore, reducing the excessively high elastic modulus of PMMA bone cement is a trend. A lower elastic modulus can reduce the incidence of some post-implantation complications, such as fractures of adjacent vertebrae.

[0003] Some studies have focused on adding pore-forming agents to bone cement to prepare porous bone cement, thereby reducing its elastic modulus. Porous materials can exhibit a lower Young's modulus and allow for some bone ingrowth. However, methods such as pore-forming agent leaching are not suitable for surgeries like vertebroplasty. Other studies have introduced other polymer molecules into bone cement for copolymerization or graft modification to reduce its elastic modulus, such as US201414783019A. This study adds linoleic acid and its derivatives (liquid oils) to the bone cement liquid or to the bone cement mixture during use to obtain bone cement with a low Young's modulus. However, the addition of linoleic acid and its derivatives (castor oil, methyl linoleate, etc.) can also lead to a decrease in the compressive strength of the bone cement, posing a certain risk of mechanical strength degradation. Summary of the Invention

[0004] To address the shortcomings of the aforementioned technologies, this invention provides a low-modulus bone cement and its preparation method.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a low modulus bone cement, comprising two parts, powder and liquid, wherein the solid-liquid ratio of the powder and liquid is 2g-3g:1mL;

[0006] By weight percentage, the powder contains the following raw materials: 52%-89.5% acrylic resin, 10%-40% barium sulfate, and 0.5%-8% powdered phospholipids;

[0007] The liquid contains the following raw materials: N,N-dimethyl-p-toluidine 0.5%-5%, hydroquinone 0.05%-2%, and methyl methacrylate 93%-99.45%.

[0008] Furthermore, the main chain structure of the powdered phospholipid is glycerol phosphate, which is one or a mixture of soybean lecithin, egg yolk lecithin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and phosphatidic acid.

[0009] Furthermore, when the powdered phospholipid is one of phosphatidylserine, egg yolk lecithin, phosphatidylethanolamine, or soybean lecithin, the mass percentage of the powdered phospholipid is 0.6%-7%.

[0010] Furthermore, when phosphatidylserine is used in powdered phospholipids, the mass percentage of powdered phospholipids is 1%-7%.

[0011] Furthermore, when phosphatidylethanolamine is used as the powdered phospholipid, the mass percentage of the powdered phospholipid is 0.8%-3%.

[0012] Furthermore, when using soybean lecithin as the powdered phospholipid, the mass percentage of the powdered phospholipid is 2%-5%.

[0013] Furthermore, the particle size distribution range of acrylic resin is 0.5-100μm, the particle size distribution range of powdered phospholipid is 0.5-74μm, and the particle size distribution range of barium sulfate is 0.5-50μm.

[0014] Furthermore, the particle size distribution range of the acrylic resin is preferably 0.5-80 μm, the particle size distribution range of the powdered phospholipid is 10-53 μm, and the particle size distribution range of the barium sulfate is 1-38 μm.

[0015] A method for preparing low-modulus bone cement includes the following steps:

[0016] Step 1: Mix acrylic resin, barium sulfate and powdered phospholipids evenly according to the mass percentage to obtain bone cement powder;

[0017] The powder composition, by mass percentage, is: 52%-89.5% acrylic resin, 10%-40% barium sulfate, and 0.5%-8% powdered phospholipids;

[0018] The particle size distribution of acrylic resin is 0.5–100 μm, the particle size distribution of powdered phospholipid is 0.5–74 μm, and the particle size distribution of barium sulfate is 0.5–50 μm.

[0019] Step 2: Mix N,N-dimethyl-p-toluidine, hydroquinone, and methyl methacrylate evenly according to their mass percentages to obtain bone cement liquid;

[0020] The liquid composition, by mass percentage, is as follows:

[0021] N,N-Dimethyl-p-toluidine 0.5%-5%,

[0022] Hydroquinone 0.05%-2%,

[0023] Methyl methacrylate 93%-99.45%;

[0024] Step 3: Add the bone cement powder obtained in Step 1 to the bone cement liquid obtained in Step 2 at a solid-liquid ratio of 2g-3g:1mL, mix for 30s-60s to form a paste with a workable time of 5-15min, and finally solidify and shape within 15-25min.

[0025] Furthermore, the particle size distribution range of the powdered phospholipids mentioned in step one is 10-53 μm.

[0026] This invention discloses a low-modulus bone cement and its preparation method. Powdered phospholipids are introduced into the bone cement powder to modify it, reducing its excessively high elastic modulus and preventing secondary injuries such as fractures of adjacent vertebrae caused by the high elastic modulus after the bone cement is filled. Unlike the conventional method of adding or mixing linoleic acid and its derivatives into a liquid, high-purity powdered phospholipids are selected and added directly to the bone cement powder along with existing bone cement raw materials in a specific ratio. Furthermore, the particle size distribution of the phospholipids is chosen to fall between that of barium sulfate contrast agent and acrylic resin, achieving a synergistic and uniform distribution of large, medium, and small particles, thus ensuring the uniformity of the bone cement powder.

[0027] When using this bone cement, the powder and liquid are mixed. The carbon-carbon double bonds of the glycerol-grafted unsaturated fatty acids in the phospholipid structure of the bone cement powder open under the action of oxidative free radicals generated during the initial reaction of the bone cement. This allows them to polymerize with the carbon-carbon double bonds of methyl methacrylate, slowing down the polymerization reaction and extending the working time of the bone cement, which is beneficial for clinical surgery. After polymerization, due to the copolymerization or grafting of phospholipids and methyl methacrylate, the elastic modulus of the methyl methacrylate polymer in the bone cement is reduced to near that of autologous bone, meeting the mandatory standard requirement for bone cement compressive strength ≥70 MPa, thus ensuring the necessary mechanical strength support for the human body. Simultaneously, the selected micron-sized powdered phospholipids have a particle size distribution range between that of the barium sulfate contrast agent in the bone cement and that of the acrylic resin powder. This ensures that the powdered phospholipids are uniformly distributed in the bone cement after curing, meeting the mandatory standard requirement for bone cement compressive strength ≥70 MPa and guaranteeing the necessary mechanical strength support for the human body. Attached Figure Description

[0028] Figure 1 The graph shows a comparison of the compressive strength of bone cement in Examples 1-6 and the control group.

[0029] Figure 2 This is a comparison chart of the compression modulus of bone cement in Examples 1-6 and the control group.

[0030] Figure 3 The compression test curve of the bone cement in Example 2 is shown.

[0031] Figure 4 The graph shows a comparison of the compression performance of Examples 7-9.

[0032] Figure 5 The chart shows a comparison of the compression performance of Examples 10-13. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0034] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder contains, by mass percentage: 52%-89.5% acrylic resin, 10%-40% barium sulfate, and 0.5%-8% powdered phospholipids. The liquid contains, by mass percentage: 0.5%-5% N,N-dimethyl-p-toluidine, 0.05%-2% hydroquinone, and 93%-99.45% methyl methacrylate. The solid-liquid ratio of the powder to the liquid is 2g-3g:1mL.

[0035] The main chain structure of the powdered phospholipid is glycerol phosphate ester. It is made from one or a mixture of soybean lecithin, egg yolk lecithin, phosphatidylcholine (lecithin), phosphatidylethanolamine (cephalin), phosphatidylinositol (inositol phospholipid), phosphatidylserine, and phosphatidic acid. The selected powdered phospholipid, with its glycerol phosphate ester main chain structure, readily carries unsaturated fatty acids. The carbon-carbon double bonds in these glycerol bonds can react with the carbon-carbon double bonds of methyl methacrylate during the bone cement polymerization process, slowing down the polymerization and extending the processing time. After polymerization, because the phospholipid participates in the bone cement polymerization reaction, through copolymerization or grafting into the acrylic resin molecular chain, it reduces the elastic modulus of the methyl methacrylate polymer in the bone cement to near the modulus of autologous bone, meeting the mandatory standard requirement of ≥70 MPa for bone cement compressive strength, thus ensuring the necessary mechanical strength support for the human body.

[0036] The powdered phospholipids are preferably one of phosphatidylserine, egg yolk lecithin, phosphatidylethanolamine (cephalin), or soybean lecithin, with an optimal content of 0.6%-7%. The compressive strength and compressive modulus of the bone cement were tested with reference to the bone cement industry standard YY0459. The optimal content of 0.6-7% of one of these four materials ensures that the compressive modulus of the bone cement is close to that of the human body, and the compressive strength meets the industry standard requirement of ≥70MPa. Furthermore, the purity and particle size of the four materials are easily controlled, meeting the requirements of industrialized production processes.

[0037] The powdered phospholipids are further preferably formulated with a phosphatidylserine content of 1%-7%;

[0038] Phosphatidylserine is composed of glycerol, two fatty acids, and one serine molecule. Its main structure is a glycerol backbone, which readily incorporates unsaturated fatty acids. Its carbon-carbon double bonds readily open under the influence of oxidative free radicals, allowing it to chemically react with the carbon-carbon double bonds in methyl methacrylate through grafting or copolymerization. This alters the molecular structure and chemical composition of acrylic resins, enhancing their toughness, reducing their modulus, and maintaining compressive strength without a sharp decline. Furthermore, phosphatidylserine possesses amphiphilic properties (both hydrophilic and lipophilic) and is the only phospholipid capable of regulating the functional state of key cell membrane proteins. After being implanted and released into the body, it is easily metabolized and absorbed, helping to relieve brain fatigue and repair brain cell damage.

[0039] Powdered phospholipids may also preferably contain phosphatidylethanolamine (phosphatidylcholine) at a content of 0.8%-3%;

[0040] Phosphatidylethanolamine is a phospholipid composed of glycerol, fatty acids, phosphoric acid, and ethanolamine. It has reducing properties and, after being implanted into the body, can act as an antioxidant to prevent oxidative aging.

[0041] Powdered phospholipids can preferably contain 2%-5% soybean lecithin;

[0042] Soy lecithin is a conventional soybean lecithin, containing 25-32% phosphatidylcholine (lecithin), 15-22% phosphatidylethanolamine (cephalin), approximately 15% phosphatidylinositol (phospholipid), approximately 16% phosphatidylglycerol (sphingomyelin), approximately 4% phosphatidic acid, and approximately 8% other phospholipids. Egg yolk lecithin also has a conventional composition, with phosphatidylcholine as its main component, accounting for over 70%. Some of the metabolic release from soybean lecithin can enhance the body's metabolism and self-healing abilities, facilitating tissue healing and repair.

[0043] The particle size distribution range of acrylic resin is 0.5-100μm, the particle size distribution range of powdered phospholipid is 0.5-74μm, and the particle size distribution range of barium sulfate is 0.5-50μm.

[0044] Preferably, the acrylic resin has a particle size distribution range of 0.5-80 μm, the powdered phospholipid has a particle size distribution range of 10-53 μm, and the barium sulfate has a particle size distribution range of 1-38 μm. To ensure the uniformity of mixing of various materials, this invention specifically selects three different materials with different particle size ranges, and achieves particle size selection gradation through the synergistic effect of large, medium, and small particle size distribution ranges, ensuring that the bone cement powder is easy to mix uniformly.

[0045] A method for preparing low-modulus bone cement:

[0046] Step 1: Mix a certain amount of acrylic resin, barium sulfate and powdered phospholipid evenly to obtain bone cement powder;

[0047] Step 2: Mix a certain amount of N,N-dimethyl-p-toluidine, hydroquinone, and methyl methacrylate evenly to obtain bone cement liquid;

[0048] Step 3: Add bone cement powder to the liquid at a solid-liquid ratio of 2g-3g:1mL, mix for 30s-60s, and after mixing evenly, it can be operated for 5-15 minutes, and the filling is completed in 15-25 minutes.

[0049] Example 1

[0050] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 62% acrylic resin, 30% barium sulfate, and 8% soybean lecithin. The liquid has the following mass percentages: 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate. The solid-liquid ratio of the powder and liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 0.5 to 74 μm for the soybean lecithin, and 0.5 to 50 μm for the barium sulfate.

[0051] A method for preparing low-modulus bone cement:

[0052] (1) Mix 62% acrylic resin, 30% barium sulfate and 8% soybean lecithin evenly to obtain bone cement powder;

[0053] (2) Mix 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate evenly to obtain bone cement liquid;

[0054] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 60s, and after mixing evenly, it can be operated for 13min and solidified for 22min to complete the filling.

[0055] Low-modulus bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the method described in industry standard YY0459. Figure 1 As shown, the compressive strength of the bone cement in Example 1 was 73.38 ± 2.70 MPa, while the control bone cement, a similar commercially available bone cement (composed of acrylic resin and barium sulfate), had a compressive strength of 115.93 ± 7.49 MPa. Figure 2 As shown, the compressive modulus of the bone cement in Example 1 was 1154.82 ± 115.58 MPa, while the compressive modulus of the control bone cement was 1832.05 ± 81.88 MPa. The compressive modulus of autologous bone was around 1200 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, and the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the biomechanical strength support required by the human body.

[0056] Example 2

[0057] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 65% acrylic resin, 30% barium sulfate, and 5% soybean lecithin. The liquid has the following mass percentages: 5% N,N-dimethyl-p-toluidine, 2% hydroquinone, and 93% methyl methacrylate. The solid-liquid ratio of the powder and liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 80 μm for the acrylic resin, 10 to 53 μm for the soybean lecithin, and 0.5 to 50 μm for the barium sulfate.

[0058] A method for preparing low-modulus bone cement:

[0059] (1) Mix 65% acrylic resin, 30% barium sulfate and 5% soybean lecithin evenly to obtain bone cement powder;

[0060] (2) Mix 5% N,N-dimethyl-p-toluidine, 2% hydroquinone, and 93% methyl methacrylate evenly to obtain bone cement liquid;

[0061] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 30s, and after mixing evenly, it can be operated for 5min and the filling is completed in 15min.

[0062] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 1 As shown, the compressive strength of the bone cement in Example 2 was 86.53 ± 1.37 MPa. Figure 2 As shown, the compressive elastic modulus of the bone cement in Example 2 was 1357.02 ± 41.74 MPa. Figure 3 The compression test curve for bone cement in Example 2 is shown. For the other examples, the compression test curves were obtained using the same testing method as industry standard YY0459, and the compressive strength and compressive modulus were analyzed. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, and the compressive strength met the mandatory standard requirement of ≥70MPa, ensuring the biomechanical strength support required by the human body.

[0063] Example 3

[0064] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder contains, by mass percentage: 75.6% acrylic resin, 20% barium sulfate, and 4.4% soybean lecithin. The liquid contains, by mass percentage: 0.5% N,N-dimethyl-p-toluidine, 0.05% hydroquinone, and 99.45% methyl methacrylate. The solid-liquid ratio of the powder to the liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 80 μm for the acrylic resin, 10 to 53 μm for the soybean lecithin, and 0.5 to 50 μm for the barium sulfate.

[0065] A method for preparing low-modulus bone cement:

[0066] (1) Mix 76% acrylic resin, 20% barium sulfate and 4% soybean lecithin evenly to obtain bone cement powder;

[0067] (2) Mix 0.5% N,N-dimethyl-p-toluidine, 0.05% hydroquinone, and 99.45% methyl methacrylate evenly to obtain bone cement liquid;

[0068] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 30s, and after mixing evenly, it can be operated for 15min and solidified for 25min to complete the filling.

[0069] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 1 As shown, the compressive strength of the bone cement in Example 3 was 81.24 ± 3.12 MPa. Figure 2 As shown, the compressive modulus of the bone cement in Example 3 was 1231.17 ± 117.97 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, and the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0070] Example 4

[0071] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 88% acrylic resin, 10% barium sulfate, and 2% soybean lecithin. The liquid has the following mass percentages: 2.2% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.3% methyl methacrylate. The solid-liquid ratio of the powder to the liquid is 2 g: 1 mL. The particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 10 to 53 μm for the soybean lecithin, and 0.5 to 50 μm for the barium sulfate.

[0072] A method for preparing low-modulus bone cement:

[0073] (1) Mix 88% acrylic resin, 10% barium sulfate and 2% soybean lecithin evenly to obtain bone cement powder;

[0074] (2) Mix 2.2% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.3% methyl methacrylate evenly to obtain bone cement liquid;

[0075] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2g:1mL, mix for 45s, and after mixing evenly, it can be operated for 12min and solidified for 20min to complete the filling.

[0076] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 1 As shown, the compressive strength of the bone cement in Example 4 was 97.23 ± 4.71 MPa. Figure 2 As shown, the compressive modulus of the bone cement in Example 4 was 1488.31 ± 70.24 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, and the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0077] Example 5

[0078] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 69% acrylic resin, 30% barium sulfate, and 1% soybean lecithin. The liquid has the following mass percentages: 2% N,N-dimethyl-p-toluidine, 0.8% hydroquinone, and 97.2% methyl methacrylate. The solid-liquid ratio of the powder and liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 0.5 to 74 μm for the soybean lecithin, and 0.5 to 50 μm for the barium sulfate.

[0079] A method for preparing low-modulus bone cement:

[0080] (1) Mix 69% acrylic resin, 30% barium sulfate and 1% soybean lecithin evenly to obtain bone cement powder;

[0081] (2) Mix 2% N,N-dimethyl-p-toluidine, 0.8% hydroquinone, and 97.2% methyl methacrylate evenly to obtain bone cement liquid;

[0082] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 45s, and after mixing evenly, it can be operated for 11min and solidified for 21min to complete the filling.

[0083] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 1 As shown, the compressive strength of the bone cement in Example 5 was 105.92 ± 4.05 MPa. Figure 2 As shown, the compressive modulus of the bone cement in Example 5 was 1579.00 ± 51.99 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, and the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the mechanical strength support required by the human body.

[0084] Example 6

[0085] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder contains, by mass percentage: 59.5% acrylic resin, 40% barium sulfate, and 0.5% soybean lecithin. The liquid contains, by mass percentage: 2.1% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.4% methyl methacrylate. The solid-liquid ratio of the powder to the liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 0.5 to 74 μm for the soybean lecithin, and 0.5 to 50 μm for the barium sulfate.

[0086] A method for preparing low-modulus bone cement:

[0087] (1) Mix 59.5% acrylic resin, 40% barium sulfate and 0.5% soybean lecithin evenly to obtain bone cement powder;

[0088] (2) Mix 2.1% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.4% methyl methacrylate evenly to obtain bone cement liquid;

[0089] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 3g:1mL, mix for 45s, and after mixing evenly, it can be operated for 11min and solidified for 20min to complete the filling.

[0090] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 1 As shown, the compressive strength of the bone cement in Example 6 was 95.95 ± 3.82 MPa. Figure 2 As shown, the compressive modulus of the bone cement in Example 6 was 1421.12 ± 65.57 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, and the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0091] Example 7

[0092] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 63% acrylic resin, 30% barium sulfate, and 7% phosphatidylserine. The liquid has the following mass percentages: 2.2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 96.8% methyl methacrylate. The solid-liquid ratio of the powder and liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 0.5 to 74 μm for the phosphatidylserine, and 0.5 to 40 μm for the barium sulfate.

[0093] A method for preparing low-modulus bone cement:

[0094] (1) Mix 63% acrylic resin, 30% barium sulfate and 7% phosphatidylserine evenly to obtain bone cement powder;

[0095] (2) Mix 2.1% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.4% methyl methacrylate evenly to obtain bone cement liquid;

[0096] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 45s, and after mixing evenly, it can be operated for 10min and solidified for 16min to complete the filling.

[0097] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 4 As shown, the compressive strength of the bone cement in Example 7 was 74.45 ± 2.46 MPa, and the compressive modulus of elasticity was 1281.97 ± 171.96 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, while the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0098] The bone cement of this embodiment was subjected to an in vitro cytotoxicity test according to the method of GB / T 16886.5. The cell survival rate of the sample extract was 95.27%, which is >70%, indicating no potential cytotoxicity.

[0099] Example 8

[0100] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 66% acrylic resin, 30% barium sulfate, and 4% phosphatidylserine. The liquid has the following mass percentages: 1.9% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.6% methyl methacrylate. The solid-liquid ratio of the powder to the liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 0.5 to 74 μm for the phosphatidylserine, and 10 to 50 μm for the barium sulfate.

[0101] A method for preparing low-modulus bone cement:

[0102] (1) Mix 66% acrylic resin, 30% barium sulfate and 4% phosphatidylserine evenly to obtain bone cement powder;

[0103] (2) Mix 1.9% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.6% methyl methacrylate evenly to obtain bone cement liquid;

[0104] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 45s, and after mixing evenly, it can be operated for 10min and the filling is completed in 18min.

[0105] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 4 As shown, the compressive strength of the bone cement in Example 8 was 75.48 ± 1.68 MPa, and the compressive modulus of elasticity was 1375.82 ± 106.37 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, while the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0106] Example 9

[0107] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 69% acrylic resin, 30% barium sulfate, and 1% phosphatidylserine. The liquid has the following mass percentages: 2% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.5% methyl methacrylate. The solid-liquid ratio of the powder and liquid is 2.5 g: 1 mL. The particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 0.5 to 74 μm for the phosphatidylserine, and 21 to 50 μm for the barium sulfate.

[0108] A method for preparing low-modulus bone cement:

[0109] (1) Mix 69% acrylic resin, 30% barium sulfate and 1% phosphatidylserine evenly to obtain bone cement powder;

[0110] (2) Mix 2% N,N-dimethyl-p-toluidine, 0.5% hydroquinone, and 97.5% methyl methacrylate evenly to obtain bone cement liquid;

[0111] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 45s, and after mixing evenly, it can be operated for 10min and the filling is completed in 18min.

[0112] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 4 As shown, the compressive strength of the bone cement in Example 9 was 79.90±1.50 MPa, and the compressive modulus of elasticity was 1368.69±75.31 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, while the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0113] Example 10

[0114] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder contains, by mass percentage: 69.2% acrylic resin, 30% barium sulfate, and 0.8% phosphatidylethanolamine (phosphatidylcholine); the liquid contains, by mass percentage: 2% N,N-dimethyl-p-toluidine, 1.1% hydroquinone, and 96.9% methyl methacrylate; the solid-liquid ratio of the powder and liquid is 2.5 g:1 mL; the particle size distribution ranges from 0.5 to 100 μm for the acrylic resin, 0.5 to 74 μm for the phosphatidylethanolamine (phosphatidylcholine), and 0.5 to 50 μm for the barium sulfate.

[0115] A method for preparing low-modulus bone cement:

[0116] (1) Mix 69.2% acrylic resin, 30% barium sulfate and 0.8% powdered phospholipid evenly to obtain bone cement powder;

[0117] (2) Mix 2% N,N-dimethyl-p-toluidine, 1.1% hydroquinone, and 96.9% methyl methacrylate evenly to obtain bone cement liquid;

[0118] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 30s, and after mixing evenly, it can be operated for 10min and the filling is completed in 19min.

[0119] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 5 As shown, the compressive strength of the bone cement in Example 10 was 103.05±1.47 MPa, and the compressive modulus of elasticity was 1590.00±4.98 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, while the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0120] Example 11

[0121] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder contains, by mass percentage: 73.5% acrylic resin, 25% barium sulfate, and 1.5% phosphatidylethanolamine (phosphatidylcholine); the liquid contains, by mass percentage: 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate; the solid-liquid ratio of the powder and liquid is 2.5 g: 1 mL; the particle size distribution ranges from 0.5 to 80 μm for the acrylic resin, 10 to 53 μm for the phosphatidylethanolamine (phosphatidylcholine), and 32 to 50 μm for the barium sulfate.

[0122] A method for preparing low-modulus bone cement:

[0123] (1) Mix 73.5% acrylic resin, 25% barium sulfate and 1.5% phosphatidylethanolamine (phosphatidylcholine) evenly to obtain bone cement powder;

[0124] (2) Mix 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate evenly to obtain bone cement liquid;

[0125] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 60s, and after mixing evenly, it can be operated for 10min and the filling is completed in 19min.

[0126] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 5 As shown, the compressive strength of the bone cement in Example 11 was 101.25 ± 7.64 MPa, and the compressive modulus of elasticity was 1530.65 ± 142.00 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, while the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0127] Example 12

[0128] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 67% acrylic resin, 30% barium sulfate, and 3% phosphatidylethanolamine (phosphatidylcholine); the liquid has the following mass percentages: 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate; the solid-liquid ratio of the powder and liquid is 2.5 g: 1 mL; the particle size distribution ranges from 0.5 to 80 μm for the acrylic resin, 10 to 53 μm for the phosphatidylethanolamine (phosphatidylcholine), and 40 to 50 μm for the barium sulfate.

[0129] A method for preparing low-modulus bone cement:

[0130] (1) Mix 67% acrylic resin, 30% barium sulfate and 3% phosphatidylethanolamine (phosphatidylcholine) evenly to obtain bone cement powder;

[0131] (2) Mix 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate evenly to obtain bone cement liquid;

[0132] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2.5g:1mL, mix for 60s, and after mixing evenly, it can be operated for 10min and solidified for 20min to complete the filling.

[0133] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 5 As shown, the compressive strength of the bone cement in Example 12 was 78.2 ± 5.19 MPa, and the compressive modulus of elasticity was 1228.67 ± 49.85 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, while the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the need for mechanical strength support in the human body.

[0134] The bone cement of this embodiment was subjected to an in vitro cytotoxicity test according to the method of GB / T 16886.5. The cell survival rate of the sample extract was 84.73%, which is >70%, indicating no potential cytotoxicity.

[0135] Example 13

[0136] A low-modulus bone cement comprises two parts: a powder and a liquid. The powder has the following mass percentages: 83% acrylic resin, 10% barium sulfate, and 7% egg yolk lecithin. The liquid has the following mass percentages: 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate. The solid-liquid ratio of the powder and liquid is 2g:1mL. The particle size distribution ranges from 0.5 to 80 μm for the acrylic resin, 10 to 53 μm for the egg yolk lecithin, and 0.5 to 50 μm for the barium sulfate.

[0137] A method for preparing low-modulus bone cement:

[0138] (1) Mix 83% acrylic resin, 10% barium sulfate and 7% egg yolk lecithin evenly to obtain bone cement powder;

[0139] (2) Mix 2% N,N-dimethyl-p-toluidine, 1% hydroquinone, and 97% methyl methacrylate evenly to obtain bone cement liquid;

[0140] (3) Add bone cement powder to the liquid at a solid-liquid ratio of 2g:1mL, mix for 30s, and after mixing evenly, it can be operated for 10min and solidified for 20min to complete the filling.

[0141] Bone cement was formed into cylindrical shapes with a diameter of 6mm × 12mm, and its compressive strength and compressive modulus were tested using a mechanical testing machine according to the methods described in industry standard YY0459. Figure 5 As shown, the compressive strength of the bone cement in Example 13 was 75.24 ± 6.28 MPa, and the compressive modulus of elasticity was 1242.49 ± 309.27 MPa. Compared with the control bone cement, the compressive modulus was reduced to be close to that of autologous bone, while the compressive strength met the mandatory standard requirement of ≥70 MPa, ensuring the biomechanical strength support required by the human body.

[0142] The above embodiments are not intended to limit the present invention. Unless otherwise expressly specified and limited, those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. The present invention is also not limited to the examples described above. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the technical solutions of the present invention are also within the protection scope of the present invention. Furthermore, the technical features involved in the different embodiments of this application described above can be combined with each other as long as they do not conflict with each other.

Claims

1. A low modulus bone cement comprising two parts, a powder and a liquid, characterised in that, The solid-liquid ratio of the powder and the liquid is 2g-3g:1mL; The powder has the following raw materials in percentage by mass: acrylic resin 52%-89.5%, barium sulfate 10%-40%, and powdered phospholipid 0.5%-8%; The liquid has the following raw materials: N,N-dimethyl-p-toluidine 0.5%-5%, hydroquinone 0.05%-2%, and methyl methacrylate 93%-99.45%; The powdered phospholipid has a main chain structure of glycerylphosphatidyl, and is one or a mixture of soybean lecithin, egg yolk lecithin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and phosphatidic acid.

2. The low modulus bone cement of claim 1 wherein: When the powdered phospholipid is one of phosphatidylserine, egg yolk lecithin, phosphatidylethanolamine, and soybean lecithin, the mass percentage of the powdered phospholipid is 0.6%-7%.

3. The low modulus bone cement of claim 1 wherein: When the powdered phospholipid is phosphatidylserine, the mass percentage of the powdered phospholipid is 1%-7%.

4. The low modulus bone cement of claim 1 wherein: When the powdered phospholipid is phosphatidylethanolamine, the mass percentage of the powdered phospholipid is 0.8%-3%.

5. The low modulus bone cement of claim 1 wherein: When the powdered phospholipid is soybean lecithin, the mass percentage of the powdered phospholipid is 2%-5%.

6. The low modulus bone cement according to any one of claims 2-5, wherein: The particle size distribution of the acrylic resin is 0.5-100μm, the particle size distribution of the powdered phospholipid is 0.5-74μm, and the particle size distribution of the barium sulfate is 0.5-50μm.

7. The low modulus bone cement according to any one of claims 2-5, characterized in that: The particle size distribution of the acrylic resin is 0.5-80μm, the particle size distribution of the powdered phospholipid is 10-53μm, and the particle size distribution of the barium sulfate is 1-38μm.

8. A method of preparing a low modulus bone cement, characterized by, The method comprises the following steps: Step one, uniformly mixing acrylic resin, barium sulfate, and powdered phospholipid according to mass percentage to obtain bone cement powder; The powder composition is as follows in percentage by mass: Acrylic resin 52%-89.5%, Barium sulfate 10%-40%, Powdered phospholipid 0.5%-8%; The particle size distribution of the acrylic resin is 0.5-100μm, the particle size distribution of the powdered phospholipid is 0.5-74μm, and the particle size distribution of the barium sulfate is 0.5-50μm; Step two, uniformly mixing N,N-dimethyl-p-toluidine, hydroquinone, and methyl methacrylate according to mass percentage to obtain bone cement liquid; The liquid composition is as follows in percentage by mass: N,N-dimethyl-p-toluidine 0.5%-5%, Hydroquinone 0.05%-2%, Methyl methacrylate 93%-99.45%; Step three, adding the bone cement powder obtained in step one into the bone cement liquid obtained in step two according to a solid-liquid ratio of 2g-3g:1mL, mixing for 30s-60s, forming a paste with an operable time of 5-15min, and finally solidifying and shaping within 15-25min.

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