CN115364277A - Preparation method of composite material for interbody fusion cage - Google Patents

Abstract

The invention discloses a composite material for an interbody fusion cage and a preparation method thereof, and the composite material comprises a novel 3D printed graphene oxide/osteogenic polypeptide/sulfonated polyether ether ketone composite material prepared by taking 3D printed polyether ether ketone PEEK after sulfonation treatment as a base material, bonding osteogenic polypeptide by modifying graphene oxide and polydopamine, and performing double modification of graphene oxide and osteogenic polypeptide on the surface of 3D printed PEEK. The composite material has excellent wettability, good biocompatibility and osteogenesis performance, and can lay a foundation for adhesion and growth of cells and tissues on the surface of the material.

Description

Preparation method of composite material for interbody fusion cage

Technical Field

The invention belongs to the technical field of medical material manufacturing, and particularly relates to a composite material for an interbody fusion cage.

Background

Currently, an intervertebral fusion device (Cage) is used for completing the fusion of cervical vertebra and lumbar vertebra clinically. Materials for preparing the interbody fusion cage in the prior art can be divided into autogenous bones, allogeneic bones, metal materials, carbon fibers, PEEK materials and the like, the fusion of cervical vertebra and lumbar vertebra is based on bone fusion, and the fusion cage prepared from different materials has the following advantages and disadvantages:

1. the speed of intervertebral fusion can be accelerated by autologous bone transplantation, however, complications such as pain, blood loss, infection and the like can be generated in the bone extraction area, and the operation time is prolonged; 2. the use of allogeneic bone can reduce the pain of autologous bone transplantation of patients, but has immunogenicity and potential risk of disease transmission; 3. the metal materials are mainly titanium, titanium alloy and the like, the metal after operation is permanently remained in the human body, certain stress shielding is generated in the later period of bone repair, the strength of new bone is influenced, and meanwhile, the collapse rate of the vertebral body is increased to be higher and can reach 16-60%. At the same time, the stability and the elastic modulus of the intervertebral implant are of crucial importance: if the stability is poor, the vertebral bodies are not easy to fuse with each other; the elastic modulus is far larger than that of the vertebral body, so stress concentration is easily caused, and complications such as bone absorption, vertebral body collapse, intervertebral fusion device displacement and the like are caused. Although the PEEK material can meet the requirements of cervical and lumbar vertebra segments on mechanical property and biological property of Cage, the biological inertia exists on the surface of the Cage prepared from pure PEEK material, which limits the direct bonding capability with surrounding tissues, so that the Cage does not have bone integration capability and is not beneficial to the fusion between vertebral bodies, and the Cage prepared in this way can not completely meet the clinical requirements. At present, researches on PEEK-Cage tend to implant autologous bones or other bioactive substances into the PEEK-Cage, and the PEEK-Cage is combined with autologous bone transplantation or titanium Cage for application to achieve the aim of promoting vertebral body fusion and improve the curative effect. Designing and optimally preparing PEEK-Cage with bioactive substances, so that the PEEK-Cage has higher intervertebral fusion rate, reduces postoperative complications and provides better biological and mechanical properties, and is a problem to be solved urgently at present.

Disclosure of Invention

The invention aims to provide a composite material for an interbody fusion cage and a preparation method thereof, so as to solve the problems.

In order to achieve the above objects, the present invention also provides a method for preparing a composite material for an intervertebral cage, comprising:

the sulfonated 3D printed polyether-ether-ketone PEEK is used as a base material, the bone-forming polypeptide is bonded by modifying graphene oxide and polydopamine, and the graphene oxide and the bone-forming polypeptide are subjected to double modification on the 3D printed PEEK surface to prepare the novel 3D printed graphene oxide/bone-forming polypeptide/sulfonated polyether-ether-ketone composite material.

Optionally, the sulfonated 3D printed polyetheretherketone PEEK comprises:

3D printing the PEEK to obtain a PEEK cage;

sequentially ultrasonically cleaning the PEEK cage by using acetone, ethanol and distilled water;

taking out the sample at room temperature, immersing the sample in concentrated sulfuric acid, and performing sulfonation treatment by ultrasonic stirring.

Optionally, the sulfonated 3D printed polyetheretherketone PEEK further comprises:

and (3) sequentially immersing the sulfonated 3D printed polyetheretherketone PEEK into acetone, ethanol and distilled water, and carrying out ultrasonic cleaning and drying treatment to obtain SPEEK.

Optionally, the binding of osteogenic polypeptides by modified graphene oxide and polydopamine comprises:

soaking the 3D printed PEEK in a graphene oxide GO suspension until the surface of the PEEK is completely coated with the GO suspension to obtain 3D printed porous GO-SPEEK;

immersing the GO-SPEEK in a dopamine solution, oscillating overnight in a dark place at a constant temperature, deionizing, ultrasonically cleaning, and drying;

and immersing and drying the osteogenic polypeptide BFP solution to obtain a 3D printed porous GO-SPEEK, carrying out light-shielding constant-temperature oscillation overnight, deionizing, carrying out ultrasonic cleaning, and drying to obtain a 3D printed porous GO-BFP-SPEEK cage.

Optionally, the preparation of the GO suspension comprises: 20mg of graphene oxide GO is dispersed in 40ml of distilled water, and the GO suspension is formed by ultrasonic stirring for 4 h.

Optionally, the PEEK surface being completely coated with the GO suspension comprises:

soaking the sulfonated PEEK in GO suspension for 10 minutes, and drying at 100 ℃;

repeating the above steps at least 5 times.

The invention has the following technical effects: according to the preparation method, sulfonated 3D printed polyether-ether-ketone is used as a base material, the osteogenic polypeptide is bonded by modifying graphene oxide and polydopamine, and double modification of graphene oxide and osteogenic polypeptide is carried out on the surface of the 3D printed polyether-ether-ketone to prepare the novel 3D printed graphene oxide/osteogenic polypeptide/sulfonated polyether-ether-ketone (3D printed GO-BFP-SPEEK cage) composite material. The material was used in the experiments: general observations after the rabbit femoral condyle test, X-ray film, computer tomography, all confirmed that the material has good biocompatibility. The results of simulation three-dimensional reconstruction simulation, scanning electron microscope detection, methylene blue-acid fuchsin staining observation and calcein marking after computed tomography show the best osteogenesis performance, meanwhile, quantitative analysis of trabecular bone shows that the co-modified material accelerates the repair process of a bone defect area, and the result obtained by the experiment shows that the co-modified material is most tightly combined with surrounding tissues. In conclusion, the composite material has excellent wettability, good biocompatibility and good osteogenesis performance, and can lay a foundation for adhesion and growth of cells and tissues on the surface of the material.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

Fig. 1 is a flowchart illustrating a method for preparing a composite material for an intervertebral cage according to a second embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description thereof.

As shown in FIG. 1, the invention also discloses a preparation method of the composite material for the interbody fusion cage, which comprises the following steps:

s1, taking 3D printed polyether-ether-ketone peek after sulfonation treatment as a substrate material;

s2, binding the modified graphene oxide and the polydopamine to form bone polypeptide;

s3, carrying out double modification on graphene oxide and osteogenic polypeptide on the surface of the 3D printed PEEK to prepare the novel 3D printed graphene oxide/osteogenic polypeptide/sulfonated polyether ether ketone composite material.

Graphene Oxide (GO) is a compound composed of carbon, hydrogen, and oxygen elements with variable mass ratios, and various functional groups bound by the GO provide the possibility of generating various chemical interactions. Due to the chemical interaction of the functional groups and the solvent, the graphene oxide sheet with a monolayer structure can be well dissociated in the solvent, and the abundant hydroxyl groups and carboxyl groups provide a plurality of reaction sites for the chemical functionalization of the basal plane, can improve the interaction with the protein through electrostatic interaction, and can contribute to the potential enhancement of the differentiation of the diaphyseal cells. In addition, graphene oxide shows good antibacterial ability against gram-negative and gram-positive bacteria. In addition, materials with good biocompatibility, such as osteoblast factors or bioactive materials, are modified on the graphene oxide, so that the osteogenic performance of the graphene oxide can be enhanced.

The osteoblast polypeptide (BFP) is an ideal osteoblast factor that can be co-modified with graphene oxide. BFP is structurally stable, resistant to denaturation, and also has no immunogenicity problems. BFP as a biological active factor with strong activity can obviously enhance the osteogenesis performance of the modified material, and the fixation of osteogenic polypeptide can be realized by a simple method, such as dopamine combination, thereby obtaining the biological material for promoting osteogenesis

In some alternative embodiments, the sulfonated 3D printed polyetheretherketone PEEK comprises:

3D printing the PEEK to obtain a PEEK cage;

sequentially ultrasonically cleaning the PEEK cage by using acetone, ethanol and distilled water;

taking out the sample at room temperature, immersing the sample in concentrated sulfuric acid, and performing sulfonation treatment by ultrasonic stirring.

In this example, sulfuric acid of 98% was used as the concentrated sulfuric acid, and sulfonation was performed for 5 minutes by ultrasonic stirring to obtain a uniform porous structure.

In some alternative embodiments, the sulfonated 3D printed polyetheretherketone PEEK further comprises:

and (3) sequentially immersing the sulfonated 3D printed polyetheretherketone PEEK into acetone, ethanol and distilled water, and carrying out ultrasonic cleaning and drying treatment to obtain SPEEK. Specifically, ultrasonic cleaning was performed for 10 minutes to remove residues on the surface, and drying was performed in an oven at 60 ℃ to obtain SPEEK.

In some alternative embodiments, the polypeptide for binding to bone by modifying graphene oxide and polydopamine comprises:

soaking the 3D printed PEEK in a graphene oxide GO suspension until the surface of the PEEK is completely coated with the GO suspension to obtain 3D printed porous GO-SPEEK; further, 3D printed porous GO-SPEEK could be obtained by standing the completely coated GO suspension overnight at 100 ℃.

Immersing the GO-SPEEK in a dopamine solution, carrying out light-shielding constant-temperature oscillation overnight, carrying out deionization, carrying out ultrasonic cleaning, and carrying out drying treatment; specifically, the GO-SPEEK is placed in a culture dish, 2g/L dopamine solution is injected into the culture dish, the GO-SPEEK is immersed, and then the culture dish is placed in a constant temperature culture shaker and is kept at the temperature of 37 ℃ and the rotating speed of 60rpm/min in dark for constant temperature shaking overnight. And after 12h, immersing the 3D printed porous GO-SPEEK treated by the dopamine solution into deionized water, ultrasonically cleaning for 5-10 minutes, and airing in the air.

And immersing and drying the osteogenic polypeptide BFP solution to obtain a 3D printed porous GO-SPEEK, carrying out light-shielding constant-temperature oscillation overnight, deionizing, carrying out ultrasonic cleaning, and drying to obtain a 3D printed porous GO-BFP-SPEEK cage. Specifically, 1mmol/L osteogenic polypeptide BFP solution is injected into a culture dish, and the 3D printing porous GO-SPEEK which is washed and dried in the culture dish is immersed. The plate was then placed in a constant temperature shaker and shaken overnight at 37 ℃ in the dark at 60 rpm/min. And after 12h, taking out the 3D printing porous GO-SPEEK processed by the osteogenic polypeptide solution, soaking the 3D printing porous GO-SPEEK in deionized water, ultrasonically cleaning for three times, and airing in the air to obtain a 3D printing porous GO-BFP-SPEEK cage.

In some alternative embodiments, the preparation of the GO suspension comprises: dispersing 20mg of graphene oxide GO in 40ml of distilled water, and ultrasonically stirring for 4 hours to form GO suspension.

In some alternative embodiments, the PEEK surface is completely coated with the GO suspension includes:

soaking the sulfonated PEEK in GO suspension for 10 minutes, and drying at 100 ℃, wherein the drying time is further 10 minutes;

repeating the above steps at least 5 times.

Experiment of the invention

The prepared interbody fusion cage is implanted into a 3-4 intervertebral space of a goat neck, and the stability effect and the effect on cervical vertebra fusion of the interbody fusion cage, the goat autologous three-sided cortical bone interbody fusion cage and the goat autologous three-sided cortical bone interbody fusion cage are observed through comparative analysis.

S100, experimental animals and grouping:

9 adult female white goats, 2 years old, with body mass (30.27 + -1.42) kg. Randomly dividing 9 goats into three groups, wherein each group comprises 3 goats (1); (2) titanium alloy cervical cage group; (3) autologous iliac group.

S200, preparing a fusion cage and a three-side cortical bone:

titanium alloy cage is a high brand of Shandongwei. Preparing three-side cortical bone: the thickness of the autologous ilium collected from the experimental goat is 5mm, and the depth is 12mm. The fixing system selects Shandongwei high brand anterior cervical vertebra fixing steel plates, and the experimental device is an anterior cervical vertebra surgical device of Shandongwei high company.

S300, and operation method

Penicillin was given to 240 million U intramuscular injections 4 times per day before and during surgery in all animals 1d before surgery. Anaesthesia was induced intravenously with 10mg of imazamethabenz, 0.1mg of fentanyl and maintained with sodium pentobarbital. After anesthesia, longitudinally cutting the right front outer side of the neck of a goat, separating fascia, exposing the cervical longus, distracting the intervertebral space by using a Caspar distracter, removing 3-4 nucleuses of the neck, removing cartilage endplates, keeping subchondral bone, implanting 3D printed porous GO-BFP-SPEEK cage (3D printed porous GO-BFP-SPEEK-cage group), titanium alloy-cage (titanium alloy cage group), implanting autogenous bone and autogenous three-sided cortical bone into the cavity of the cage main body. After the intervertebral implantation, the anterior cervical titanium alloy steel plate is fixed on the upper and lower vertebral bodies by two screws. After the three groups of the implant are fixed, the tangent plane is washed by normal saline, the suture layer by layer is carried out, and finally, the aseptic dressing is adopted for bandaging. And (5) feeding in cages after operation.

S400, observing indexes

(1) General conditions such as development, body weight, wound healing, postoperative complications and the like.

(2) X-ray examination, taking X-ray oblique cervical vertebra tablets at 4, 8, and 12 weeks after surgery under conditions of 50kV,50mA,0.15s, and 100cm.

(3) And Micro-CT examination, namely performing living Micro-CT examination after anesthesia for 4, 8 and 12 weeks after fixation. And analyzing fracture healing indexes such as volume density, surface area density, average trabecular bone thickness, trabecular bone number, trabecular bone gap and the like according to observation and dynamic comparison of the Micro-CT tomogram.

(4) After 12 weeks of operation, the goats were sacrificed by potassium chloride injection under total anesthesia with sodium pentobarbital, the C3-4 segments were taken out, the surrounding muscle tissue was removed, and the ligaments were retained for testing. The biomechanical detection of the cervical vertebra adopts a biomechanical loading system, and the biomechanical of the specimen is measured by a nondestructive elastic method. The system simulates physiological movement of the neck, a pulley system is adopted for loading, the cervical vertebra specimen generates forward flexion, backward extension and left and right lateral flexion, and a torque sensor automatic device is adopted for loading left and right twisting movement of the specimen. The maximum moment is 4N m, and 3 times of maximum moment-zero cycle mode is adopted to pre-load the specimen prepared in advance, so that the viscoelasticity of the specimen is reduced. Each group is loaded step by 1, 2, 3 and 4 N.m, and the angular displacement change of C3 relative to C4 is detected when the maximum torque is detected. Calculating the cervical stiffness of a sample, wherein the cervical stiffness = moment variation (N · m)/angular displacement increment (°). In the moment change in the experiment, the difference value of the maximum load of 4 N.m and the minimum load of 1 N.m is used, and the moment change is 3 N.m; angular displacement increment =4N · m angular displacement-1N · m angular displacement. Calculate the range of motion of the cervical spine (ROM), ROM = displacement between zero load and neutral position of the vertebral body + displacement between maximum load of the vertebral body and zero load.

(5) And taking out a specimen after biomechanical detection, roughly observing the combination condition between the fusion device and the upper and lower vertebral bodies, carrying out histological observation on surface tissues of the two groups of cage, observing the effect of callus formation by HE (high intensity plasma) dyeing, and observing the surface changes of the 3D printed porous GO-BFP-SPEEK-cage and the titanium alloy-cage by using a scanning electron microscope.

S500, statistics

SPSS17.0 statistical software was used. The measurement data are expressed in x + -s, single-factor analysis of variance is adopted for multiple groups of comparison, and LSD-t test is adopted for further pairwise comparison. P < 0.05 is statistically significant.

The sulfonated polyether ether ketone composite bone repair material which is modified by osteogenic polypeptide and graphene oxide and prepared by a 3D printing technology has good biocompatibility and osteogenic performance, the 3D printing porous GO-BFP-SPEEK cage used at this time is a further improvement of a PEEK material which is one of main materials of an intervertebral fusion device at present, graphene oxide is introduced, and osteogenic growth factors are compounded, so that a theoretical basis is provided for the intervertebral fusion device to generate better bone induction and bone integration effects, and early basic experiments prove that healing between centrums is facilitated, complications such as cage displacement, sinking, nail plate loosening and the like are reduced, and the sulfonated polyether ether ketone composite bone repair material is a great improvement of the PEEK-cage at present.

The above-described embodiments are only intended to illustrate the preferred embodiments of the present invention, and not to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims (6)

1. A method of making a composite material for an interbody cage, comprising:

the sulfonated 3D printed polyether-ether-ketone PEEK is used as a base material, the graphene oxide and the polydopamine are modified to be bonded into osteogenic polypeptide, and the graphene oxide and osteogenic polypeptide are subjected to double modification on the surface of the 3D printed PEEK to prepare the novel 3D printed graphene oxide/osteogenic polypeptide/sulfonated polyether-ether-ketone composite material.

2. The method of preparing a composite material for an intersomatic cage according to claim 1, wherein the sulfonated 3D printed polyetheretherketone PEEK comprises:

3D printing the PEEK to obtain a PEEK cage;

sequentially ultrasonically cleaning the PEEK cage by using acetone, ethanol and distilled water;

taking out the sample at room temperature, immersing the sample in concentrated sulfuric acid, and performing sulfonation treatment by ultrasonic stirring.

3. The method of claim 1, wherein the sulfonated 3D printed PEEK further comprises:

and (3) sequentially immersing the sulfonated 3D printed polyetheretherketone PEEK into acetone, ethanol and distilled water, and carrying out ultrasonic cleaning and drying treatment to obtain SPEEK.

4. The method for preparing a composite material for an intersomatic cage according to claim 1, wherein the binding of the osteogenic polypeptide by the modified graphene oxide and polydopamine comprises:

soaking the 3D printed PEEK in a graphene oxide GO suspension until the surface of the PEEK is completely coated with the GO suspension to obtain a 3D printed porous GO-SPEEK;

immersing the GO-SPEEK in a dopamine solution, carrying out light-shielding constant-temperature oscillation overnight, carrying out deionization, carrying out ultrasonic cleaning, and carrying out drying treatment;

and immersing and drying the osteogenic polypeptide BFP solution to obtain a 3D printed porous GO-SPEEK, carrying out light-shielding constant-temperature oscillation overnight, deionizing, carrying out ultrasonic cleaning, and drying to obtain a 3D printed porous GO-BFP-SPEEK cage.

5. The method of preparing a composite material for an intersomatic cage according to claim 4, wherein the preparation of the GO suspension comprises: dispersing 20mg of graphene oxide GO in 40ml of distilled water, and ultrasonically stirring for 4 hours to form GO suspension.

6. The method of making a composite material for an intersomatic cage according to claim 1, wherein the PEEK surface is completely coated with the GO suspension comprises:

soaking the sulfonated PEEK in GO suspension for 10 minutes, and drying at 100 ℃;

repeating the above steps at least 5 times.

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