CN114681669A

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Publication number: CN114681669A
Application number: CN202210231028.0A
Authority: CN
Inventors: 杨玮; 宫海波; 肖杰
Original assignee: Suzhou Zhuoqia Medical Technology Co ltd
Current assignee: Suzhou Zhuoqia Medical Technology Co ltd
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2022-07-01
Anticipated expiration: 2042-03-10
Also published as: CN114681669B

Abstract

The invention relates to modified PMMA bone cement and a preparation method thereof, wherein the modified PMMA bone cement comprises powder, magnesium phosphate ceramic fiber and liquid, the total mass of the magnesium phosphate ceramic fiber and the powder is 100%, the mass of the magnesium phosphate ceramic fiber accounts for 20-40%, the mass of the powder accounts for 60-80%, and the powder mainly comprises polymethyl methacrylate and benzoyl peroxide; the liquid agent mainly comprises methyl methacrylate. The preparation method of the modified PMMA bone cement mainly comprises the steps of preparing magnesium phosphate ceramic fiber by using an electrostatic spinning method, mixing polymethyl methacrylate, benzoyl peroxide, a developing agent, a dispersing agent and a surfactant into powder, mixing methyl methacrylate and dimethyl p-toluidine into liquid, and finally, uniformly mixing the magnesium phosphate ceramic fiber and the powder and adding the liquid to complete the preparation. The modified PMMA bone cement has the advantages of high toughness and high compressive strength, and has bioactivity.

Description

Modified PMMA bone cement and preparation method thereof

Technical Field

The invention relates to the technical field of biomedical materials, in particular to modified PMMA bone cement and a preparation method thereof.

Background

Polymethyl methacrylate bone cement (PMMA bone cement) is a bone filling and bonding material commonly applied in the current orthopedic clinical operation, has excellent plasticity, biological safety and mechanical strength, and is widely applied to vertebroplasty and joint replacement. However, PMMA bone cement is a biologically inert material, has no bioactivity and is not degradable, and further development of the PMMA bone cement is limited by overhigh exothermic temperature in the process of solidification polymerization and cytotoxicity of monomers. In order to increase the biological activity of PMMA bone cements, it is possible to add to PMMA active components, such as: the patent CN201410541808.0 discloses an akermanite/PMMA composite bone cement with an osteogenesis inducing function and a preparation method thereof, wherein high-content akermanite powder maintains good mechanical properties of the bone cement, reduces polymerization temperature, improves bioactivity and biocompatibility of the bone cement, and can actively induce osteogenesis due to the contained elements of magnesium and silicon. However, the addition of akermanite ceramic particles can cause the plasticity of the PMMA high polymer bone cement to be reduced and the brittleness to be increased, which is not favorable for the biomechanical properties of the PMMA bone cement.

The bioactive ceramic has good bioactivity and can be widely used for artificial bones, artificial joints, artificial dental implants and the like, and part of the bioactive ceramic has the characteristic of biodegradation and absorption and can induce the growth of new bones in organisms. However, the mechanical strength of the bioactive ceramics is poor, and the brittleness of the ceramics limits the application of the bioactive ceramics on the bearing part of the human body. For example: patent CN201910472814.8 discloses a method for manufacturing a magnesium phosphate bioceramic functional gradient bone regeneration scaffold, wherein a functional gradient scaffold material is prepared by taking magnesium phosphate (MgP) bioceramic as a scaffold through a 3D printing technology and is used for bone defect regeneration and repair, and a porous scaffold can play a role in promoting bone defect regeneration and repair. However, the brittleness of the magnesium phosphate bioceramic is incapable of being used in a load-bearing part, and the mechanical strength of the magnesium phosphate bioceramic is ineffective along with degradation, so that the biological function of the magnesium phosphate bioceramic is seriously influenced.

Therefore, a new modified PMMA bone cement is to be developed to overcome the disadvantages of the existing PMMA bone cement and the modified bone cement.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention aims to improve the brittleness and insufficient strength of the existing PMMA bone cement, thereby enhancing the toughness of the PMMA bone cement.

The invention provides modified PMMA bone cement, which comprises powder, magnesium phosphate ceramic fiber and liquid, wherein the total mass of the magnesium phosphate ceramic fiber and the powder is 100%, the mass of the magnesium phosphate ceramic fiber accounts for 20-40%, the mass of the powder accounts for 60-80%, and the powder mainly comprises polymethyl methacrylate and benzoyl peroxide; the liquid agent mainly comprises methyl methacrylate.

Preferably, the modified PMMA bone cement is prepared by mixing the magnesium phosphate ceramic fiber with the above-mentioned magnesium phosphate ceramic fiber, wherein the magnesium phosphate ceramic fiber is 30% or 40% by mass.

Preferably, the modified PMMA bone cement as described above, wherein the powder further comprises a developing agent, a dispersing agent and a surfactant, and the weight ratio of each component of the powder is: 65-75 wt% of polymethyl methacrylate, 5-15 wt% of benzoyl peroxide, 5-10 wt% of a developing agent, 3-5 wt% of a dispersing agent and 3-5 wt% of a surfactant; the liquid agent further comprises dimethyl-p-toluidine, and the liquid agent comprises the following components in parts by weight: 93-97 wt% of methyl methacrylate and 3-7 wt% of dimethyl p-toluidine.

Preferably, the modified PMMA bone cement is characterized in that the magnesium phosphate ceramic fiber has a porous surface, a fiber diameter of 50-300 nm and a fiber length of 1-3 μm.

Preferably, the modified PMMA bone cement is as described above, wherein the ratio of the total mass of the powder and the magnesium phosphate ceramic fiber to the mass of the liquid agent is 2: 1.

The invention also provides a preparation method for preparing the modified PMMA bone cement, which comprises the following steps:

s1: the preparation method of the magnesium phosphate ceramic fiber by an electrostatic spinning method comprises the following steps:

s11: preparing the following components into an electrostatic spinning solution according to mass percentage: 250 to 60 percent of magnesium nitrate (Mg (NO3), 5 to 10 percent of monopotassium phosphate, 5 to 10 percent of sodium dihydrogen phosphate, 5 to 10 percent of deionized water and 5 to 10 percent of polyvinylpyrrolidone;

s12: stirring the electrostatic spinning solution prepared in the step S11 for 60 minutes, wherein the stirring temperature is 60 ℃, the stirring speed is 100-800 r/min, and the pH value is controlled to be 8-10;

s13: spinning the electrostatic spinning solution prepared in the step S12, and collecting the spun solution to obtain the magnesium phosphate ceramic nanofiber, wherein the pH value of the electrostatic spinning solution is controlled to be 8-10;

s14: and (3) sintering the magnesium phosphate ceramic nanofiber obtained in the step S13 at a high temperature, wherein the sintering temperature is 600-1100 ℃, and the sintering time is 3-6 h.

S2: the powder is prepared according to the following powder components and weight ratio: 65-75 wt% of polymethyl methacrylate, 5-15 wt% of benzoyl peroxide, 5-10 wt% of a developing agent, 3-5 wt% of a dispersing agent and 3-5 wt% of a surfactant;

s3: the liquid agent is prepared according to the following components by weight: 93-97 wt% of methyl methacrylate and 3-7 wt% of dimethyl p-toluidine;

s4: and (3) uniformly mixing and stirring the magnesium phosphate ceramic fiber prepared in the step S1 and the powder prepared in the step S2, and then adding the liquid prepared in the step S3, wherein the stirring time is 5-15 minutes.

Preferably, the preparation method is as described above, wherein the developer is zirconia, the dispersant is sodium alginate, and the surfactant is sodium carboxymethylcellulose.

Preferably, the preparation method is as described above, wherein the purity of the magnesium nitrate, the potassium dihydrogen phosphate and the sodium dihydrogen phosphate is not less than 99%, the K value of the polyvinylpyrrolidone is 30, and the relative molecular mass of the polyvinylpyrrolidone is 40000.

The modified PMMA bone cement has the beneficial effects that the modified PMMA bone cement has excellent bioactivity and mechanical property, the added magnesium phosphate ceramic fiber has a porous structure and higher specific surface area and bioactivity, the toughening effect of the ceramic fiber can be fully exerted, and the defects of high brittleness and low strength of the PMMA bone cement are overcome.

Drawings

Fig. 1 is a graph illustrating the compressive strength test results of the conventional PMMA bone cement and the modified PMMA bone cement having different contents of magnesium phosphate ceramic nanofibers.

Detailed Description

The technical means adopted by the invention to achieve the preset purpose are further described in the following accompanying drawings and the preferred embodiment of the invention.

The invention relates to modified PMMA bone cement, and concretely relates to magnesium phosphate ceramic fiber modified PMMA bone cement and a preparation method thereof.

Examples

In this embodiment, the PMMA-modified bone cement includes powder, liquid and magnesium phosphate ceramic fiber uniformly mixed therein. Wherein the weight ratio of the total weight of the powder and the magnesium phosphate ceramic fiber to the weight of the liquid is 2: 1. And the total mass of the powder and the magnesium phosphate ceramic fiber is 100%, wherein the mass of the magnesium phosphate ceramic fiber accounts for 20-40%, and the mass of the PMMA bone cement accounts for 60-80%.

In this embodiment, the powder includes the following components in parts by weight: 65-75 wt% of polymethyl methacrylate, 5-15 wt% of benzoyl peroxide, 5-10 wt% of a developing agent, 3-5 wt% of a dispersing agent and 3-5 wt% of a surfactant. In the present embodiment, the developer is preferably zirconia, the dispersant is preferably sodium alginate, and the surfactant is preferably sodium carboxymethylcellulose, and specifically, the present invention is not limited thereto, and other developers, dispersants, or surfactants may be selected. The liquid comprises the following components in parts by weight: methyl methacrylate (MMA, 93-97 wt%) and dimethyl-p-toluidine (DMPT, 3-7 wt%).

The magnesium phosphate ceramic fiber is preferably a magnesium phosphate ceramic nanofiber, the fiber diameter of the magnesium phosphate ceramic fiber is 50-300 nm, the fiber length of the magnesium phosphate ceramic fiber is 1-3 mu m, and the surface of the magnesium phosphate ceramic fiber is porous. The magnesium phosphate ceramic nanofibers in this embodiment are preferably magnesium phosphate ceramic nanofibers prepared by an electrospinning method and sintered at a high temperature.

Preparation examples

The preparation method of the magnesium phosphate ceramic nanofiber modified PMMA bone cement in the examples is specifically described below.

Firstly, preparing magnesium phosphate ceramic nano-fiber, which comprises the following steps:

s1: preparing an electrostatic spinning solution of the magnesium phosphate ceramic nanofiber, wherein the electrostatic spinning solution comprises the following components in percentage by mass: magnesium nitrate (Mg (NO)₃)₂AR with purity not less than 99%) 50-60 wt%, and potassium dihydrogen phosphate (KH)₂PO₄AR with purity not less than 99 percent and sodium dihydrogen phosphate (NaH) with the mass ratio of 5-10 percent₂PO₄AR, the purity is more than or equal to 99 percent), 5 to 10 percent of deionized water and 5 to 10 percent of polyvinylpyrrolidone (PVP, the K value is 30, and the relative molecular mass is 40000);

s2: preparing an electrostatic spinning solution, namely mixing and stirring the reagents according to a ratio for 60min at a stirring temperature of 60 ℃, wherein the stirring speed is 100-800 r/min, and the pH value of the electrostatic spinning solution is controlled between 8-10;

(3) in the spinning process of the electrostatic spinning solution, electrostatic spinning equipment is used for spinning, the direct-current high-voltage electricity is set to be 15-20 kv, a stainless steel flat plate is used for receiving, the distance between a spinning needle and the stainless steel flat plate is 15-20 cm, the ambient temperature is 25-30 ℃, and the humidity is 20-25 degrees;

(4) in the electrostatic spinning process, the electrostatic spinning solution is filled into an injection device, a power supply is turned on to start the spinning process according to the parameter setting, and the magnesium phosphate ceramic nanofibers on the stainless steel flat plate are collected after the spinning process is finished;

(5) and (2) performing heat treatment on the magnesium phosphate ceramic nanofiber, growing the magnesium phosphate ceramic crystal through high-temperature sintering, and removing unreacted substances such as high polymer materials and the like remained in the ceramic fiber to obtain the porous magnesium phosphate ceramic nanofiber, wherein the sintering temperature is 600-1100 ℃, and the sintering time is 3-6 h. And reserving the sintered magnesium phosphate ceramic nanofiber for later use.

The preparation of the powder of the magnesium phosphate ceramic nanofiber modified PMMA bone cement of the present embodiment comprises the following components by weight: 65-75 wt% of polymethyl methacrylate, 5-15 wt% of benzoyl peroxide, 5-10 wt% of developing agent (zirconium oxide), 3-5 wt% of sodium alginate and 3-5 wt% of surfactant (sodium carboxymethylcellulose). Mixing the above components, and stirring. The liquid preparation is prepared by mixing the following components in parts by weight: methyl methacrylate (MMA, 93-97 wt%), dimethyl-p-toluidine (DMPT, 3-7 wt%).

When the PMMA bone cement powder is used specifically, the magnesium phosphate ceramic nanofibers are added into PMMA bone cement powder, mixed and stirred for standby, then the liquid is added, and the PMMA bone cement powder can be used after being mixed and stirred uniformly, wherein the stirring time is 5-15 min.

Referring to fig. 1, the compressive strength test results of the conventional PMMA bone cement and the modified PMMA bone cement having different contents of magnesium phosphate ceramic nanofibers are shown schematically. Wherein, the total mass of the powder and the magnesium phosphate ceramic fiber is 100%, A represents the traditional PMMA bone cement without the magnesium phosphate ceramic fiber, and B, C and D represent the PMMA bone cement modified by the magnesium phosphate ceramic fiber of the embodiment with the mass ratio of the magnesium phosphate ceramic fiber of 20%, 30% and 40%, respectively. It can be seen that the compressive strength of the PMMA bone cement modified by the magnesium phosphate ceramic fiber of the present embodiment is all better than that of the conventional PMMA bone cement, wherein C is most excellent at 30% by mass of the magnesium phosphate ceramic fiber, and exceeds 120MPa, and D is only slightly reduced, but the reduction is not obvious. The compressive strength of the traditional PMMA bone cement is only about 95MPa, which fully shows that the modified PMMA bone cement has remarkable compressive strength resistance.

In the embodiment, the magnesium phosphate ceramic nanofiber is prepared by an electrostatic spinning method, the nano size and the porous structure of the ceramic nanofiber endow the ceramic nanofiber with higher surface activity and rough surface and nanofiber toughening effect, and the problems that the ceramic fiber prepared by a common method is larger in diameter, smooth in surface, poor in binding force between the fiber and a matrix and prone to peeling and falling are solved. In addition, in order to uniformly disperse the magnesium phosphate ceramic nano-fibers in the PMMA bone cement, the surface hydrophilicity of the ceramic fibers is improved by adding a surfactant and a dispersing agent, so that the ceramic fibers are better suspended and dispersed in the PMMA bone cement.

The magnesium phosphate ceramic fiber modified PMMA bone cement prepared by the preparation method has good mechanical property, good bioactivity and partial degradability. Before degradation, the magnesium phosphate ceramic fiber has the nanofiber toughening effect. Mg released during degradation of magnesium phosphate ceramic fibers²⁺The PMMA bone cement has good biological activity and osteogenesis inducing capability, and has wider application prospect in bone repair materials.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The modified PMMA bone cement is characterized by comprising powder, magnesium phosphate ceramic fibers and liquor, wherein the magnesium phosphate ceramic fibers account for 20-40% by mass and the powder accounts for 60-80% by mass based on 100% of the total mass of the magnesium phosphate ceramic fibers and the powder, and the powder mainly comprises polymethyl methacrylate and benzoyl peroxide; the liquid agent mainly comprises methyl methacrylate.

2. The modified PMMA bone cement of claim 1, wherein the magnesium phosphate ceramic fiber is 30% or 40% by mass.

3. The modified PMMA bone cement of claim 1, wherein the powder further comprises a developer, a dispersant and a surfactant, and the weight ratio of the components of the powder is as follows: 65-75 wt% of polymethyl methacrylate, 5-15 wt% of benzoyl peroxide, 5-10 wt% of a developing agent, 3-5 wt% of a dispersing agent and 3-5 wt% of a surfactant; the liquid agent further comprises dimethyl-p-toluidine, and the liquid agent comprises the following components in parts by weight: 93-97 wt% of methyl methacrylate and 3-7 wt% of dimethyl p-toluidine.

4. The modified PMMA bone cement of claim 1, wherein the magnesium phosphate ceramic fiber is prepared by an electrospinning method, the surface of the magnesium phosphate ceramic fiber is porous, the diameter of the fiber is 50-300 nm, and the length of the fiber is 1-3 μm.

5. A modified PMMA bone cement according to claim 1, wherein the ratio of the total mass of the powder and the magnesium phosphate ceramic fibers to the mass of the liquid formulation is 2: 1.

6. A method for preparing a modified PMMA bone cement according to any one of claims 3 to 5, characterized in that it comprises the following steps:

s11: preparing the following components into an electrostatic spinning solution according to mass percentage: mirabiliteMagnesium (Mg (NO)₃)₂50-60 percent of potassium dihydrogen phosphate, 5-10 percent of sodium dihydrogen phosphate, 5-10 percent of deionized water and 5-10 percent of polyvinylpyrrolidone;

7. The method according to claim 6, wherein the developer is zirconia, the dispersant is sodium alginate, and the surfactant is sodium carboxymethylcellulose.

8. The method according to claim 6, wherein the purity of the magnesium nitrate, the purity of the potassium dihydrogen phosphate, and the purity of the sodium dihydrogen phosphate are all equal to or greater than 99%, the K value of the polyvinylpyrrolidone is 30, and the relative molecular mass thereof is 40000.