CN208243822U - A kind of 3D printing composite magnetic metallic support - Google Patents

Abstract

The utility model discloses a 3D printing composite magnetic metal support, which comprises a three-dimensional porous metal support, a polydopamine shell and composite magnetic nanoparticles. Coating on the surface of the three-dimensional porous metal support, the composite magnetic nanoparticles are evenly adhered to the surface of the three-dimensional porous metal support coated with polydopamine shell. The 3D printing composite magnetic metal scaffold of the utility model can be applied in the preparation of bone defect repair materials, which not only meets the needs of bone repair materials for mechanical strength, but also has better biocompatibility and hydrophilicity, which is beneficial to cell Adhesion, and the coated material has weak magnetic properties, which is beneficial to the differentiation of osteoblasts and can promote osteogenesis.

Description

A 3D printing composite magnetic metal bracket

technical field

The utility model relates to the technical field of biomedical materials, in particular to a 3D printing composite magnetic metal bracket.

Background technique

The treatment of bone defects has always been a clinical problem. In vivo experiments show that a bone defect of 6×6×10mm ³ needs to be repaired by bone grafting. It has been reported that delayed union or nonunion occurs in up to 13% of tibial fractures. In addition, plastic surgery, oral and maxillofacial surgery, and large bone defects caused by severe trauma, infection, bone tumors, and skeletal deformities all require Repaired by bone grafting.

Clinically, graft materials for bone defects include autologous bone and allogeneic bone. Autologous bone transplantation has always been the "gold standard" for the treatment of bone defects, but autologous bone is generally taken from the patient's ilium and fibula, not only the amount of bone taken is limited, but it will also cause trauma and even infection at the place where the bone was taken; allogeneic bone has immune rejection , the risk of spreading disease.

At present, biomaterials used in bone tissue engineering mainly include four categories: bioceramics, polymer materials, metal materials, and composite materials. Each material has its unique advantages, but also generally has its own shortcomings. The first category: bioceramics, including calcium sulfate, calcium phosphate, hydroxyapatite (hydroxyapatite), β-TCP (β-Tricalciumphosphate), bioglass, etc. Ceramic materials have many similarities in inorganic composition and crystal structure with natural human bone, and have excellent biocompatibility, so they are a good bone substitute material. Hydroxyapatite and tricalcium phosphate are used to fill and reconstruct bone defects and have been widely used in orthopedics and dentistry. Studies by Ambrosio et al. also found that ceramic materials can promote the proliferation and differentiation of stem cells into osteoblasts. Although bioceramics have many advantages including high elastic modulus, high mechanical strength and excellent wear resistance, they also have many disadvantages such as high brittleness, poor plasticity, and difficulty in processing, which lead to many constraints in their clinical application. . In addition, how to control the degradation rate of ceramic stents is also the difficulty of research. The second category: polymer materials, divided into natural polymer materials, including collagen, chitosan, alginate, etc.; and synthetic polymer materials, including polylactic acid (PLA), polylactic acid-glycolic acid copolymer (PLGA) ), polycaprolactone (PCL), etc. Natural polymer materials such as collagen, chitosan, and alginate have good biological activity, can promote cell adhesion and proliferation, and have good degradability at the same time, but the problem is that the processing and shaping performance is poor , and the mechanical strength of its preparations is often insufficient, which limits its clinical use. Synthetic polymer materials are a field that has developed rapidly in recent years. It has a single composition, controllable properties, and the preparation has a certain mechanical strength. It can also make various complex porous structures that meet the requirements by means of rapid prototyping technology. It has become a biological material. It is the main force of research in the field, but its problems are generally lack of biological activity, lack of sites for cell recognition, and its degradation metabolites often have a negative impact on local cells. Some scholars have found that materials such as poly-L-lactic acid and polyglycolic acid will produce acidic substances after degradation, which will reduce the pH value of the local environment and lead to cell and tissue necrosis. The third category: metal materials, including stainless steel, titanium alloys, cobalt-chromium-molybdenum alloys, tantalum metals, magnesium alloys, etc. Their advantages are that they can provide sufficient mechanical strength and good biocompatibility, but the disadvantage is that they have no biological activity And often cannot be degraded and absorbed. The fourth category: composite materials, as the name implies, is a composite tissue engineering scaffold constructed by combining two or more of the above materials. A single material has more or less shortcomings in one way or another, and the combined use of multiple materials can complement each other's strengths and complement each other's advantages, which is a new hotspot in biomaterials research. For example, combining bioceramics with polymer materials can not only obtain sufficient mechanical strength, but also obtain good biocompatibility and bioactivity.

Titanium and titanium alloys in metal materials have been used clinically for many years because of their good biocompatibility and corrosion resistance, and their excellent mechanical properties have also been fully confirmed. However, the elastic modulus of titanium alloys is about 103- The elastic modulus of normal cancellous bone is about 110GPa, while the elastic modulus of normal cancellous bone is about 0.5-3.5GPa. It can be seen that the elastic modulus of titanium alloy does not match the normal bone tissue of the human body seriously. The stress shielding effect occurs, which seriously affects the stability of titanium alloy implants and bone tissue. The emergence of 3D printing technology has made people recognize titanium alloys again. Using 3D printing technology, titanium alloys can be prepared into porous structures. These porous structures can not only simulate the porous structure of normal natural bone tissue, but also provide space for new bone growth. , the elastic modulus of the material is also reduced through the change of the porous structure, making the elastic modulus close to that of bone tissue, reducing the stress shielding of the implant on the bone, and significantly improving the stability of the combination of the implant and bone tissue. However, titanium alloy is an inert metal, which has no biological activity and no sites that cells can recognize. Therefore, how to modify titanium alloy implants with osteogenesis-promoting modification technology is the focus of current research. However, because the porous structure of titanium alloy scaffolds brings difficulties to the application of various modification technologies such as plasma spraying, surface active coatings, and loaded growth factors, how to comprehensively promote osteogenesis of porous metal scaffolds Modification is a research hotspot.

In recent years, with the continuous development of tissue engineering, some scholars have begun to try to use nano-magnetic particles as an osteogenic factor in tissue engineering to prepare bone biomaterial scaffolds. As we all know, nano-magnetic particles have been used in research for many years, mainly in the field of molecular biology, including nuclear magnetic resonance imaging, drug carriers, targeted therapy, cell screening and other fields. Inspired by the effect of electromagnetic stimulation, in recent years, some research teams at home and abroad have prepared a variety of composite scaffolds containing magnetic nanoparticles (MNPs), exploring the effect of magnetic nanoparticles on osteoblasts and their role in bone defect repair and improved implantation. Applications in body/bone interface integration. Rajendra K. Singh studied the physical, chemical, mechanical and biological properties of polycaprolactone (PCL) scaffolds containing magnetic nanoparticles and their effects on bone regeneration. The apatite formation ability of adding nano-magnetic particle scaffolds soaked in simulated body fluids was greatly improved, and the adhesion and proliferation of osteoblasts were significantly better than those of pure PCL scaffolds. In terms of biocompatibility, they found that PCL-MNPs fiber scaffolds implanted greatly The adverse reactions of mouse subcutaneous tissue were minimal, and a large number of new blood vessels could be induced. The better bone regeneration ability of PCL-MNPs fibrous scaffolds was also verified in animal experiments.

Numerous studies in recent years have shown that polydopamine (PDA) adheres well to wet surfaces of any material, even polytetrafluoroethylene (PTFE). These materials include not only organic materials such as polymers, but also inorganic materials such as metal and non-metal oxides and ceramics. Moreover, polydopamine has excellent biocompatibility, which attracted a lot of attention after it was reported in "Science" in 2007, and has been widely used in the surface modification of biomedical materials. Polydopamine can adhere to the wet surface of almost all organic and inorganic materials, and the phenolic hydroxyl group and N-containing group of polydopamine itself can trigger a secondary reaction, forming a metal layer on the surface of polydopamine through electrochemical or grafting reaction. or other macromolecules to obtain functionalized composites. Si et al. reported a method for preparing monodisperse magnetic nanoparticles, that is, depositing polydopamine on the wet surface of Fe ₃ O ₄ to prepare Fe ₃ O ₄ @PDA composite nanoparticles with a core-shell structure. The composite nanoparticles _The particles significantly reduced the cytotoxicity of bare _Fe3O4 . In addition, a large number of phenolic hydroxyl groups and amino groups on the molecular chain of polydopamine are hydrophilic, so the hydrophilicity and dispersibility of the material after deposition of polydopamine will be greatly improved. Zhu et al. used dopamine to modify the surface of carbon black, and successfully realized the transformation of carbon black from hydrophobic to hydrophilic.

Utility model content

In order to overcome the deficiencies of the prior art, the purpose of this utility model is to provide a 3D printed composite magnetic metal bracket with large pore size, high porosity, connected pores and proper elastic modulus.

The second purpose of the present utility model is to provide the application of the composite magnetic metal support in the preparation of bone defect repair materials.

In order to achieve the above purpose, the utility model provides a 3D printing composite magnetic metal support, the composite magnetic metal support includes a three-dimensional porous metal support, polydopamine shell and composite magnetic nanoparticles, the three-dimensional porous metal support is a three-dimensional through porous The polydopamine shell is coated on the surface of the three-dimensional porous metal support, and the composite magnetic nanoparticles are uniformly adhered to the surface of the three-dimensional porous metal support covered with the polydopamine shell.

Preferably, the three-dimensional porous metal support is a three-dimensional porous through-through support with interconnected pores that is printed according to a 3D digital model of a certain pore diameter and a pore column, with regular dodecahedron or rhombic dodecahedron as the basic unit.

Preferably, the pore diameter of the three-dimensional porous metal scaffold is 300-800 μm, and the pore column is 200-300 μm.

Preferably, the material of the three-dimensional porous metal stent is titanium alloy, pure titanium, cobalt alloy or stainless steel.

More preferably, the material of the three-dimensional porous metal scaffold is titanium alloy.

Preferably, the polydopamine shell has a thickness of 50-200 nm.

Preferably, the composite magnetic nanoparticles are Fe ₃ O ₄ modified by polydopamine, that is, Fe ₃ O ₄ @PDA; the composite magnetic nanoparticles have a core-shell structure, wherein Fe ₃ O ₄ is the core, and polydopamine is the shell .

Preferably, the polydopamine has a thickness of 50-200 nm.

Beneficial effect

1. The 3D printed composite magnetic metal stent of this utility model is a three-dimensional porous penetrating stent with large pore diameter, high porosity and appropriate elastic modulus, which can meet the mechanical strength requirements of bone repair materials while reducing the amount of metal used, realizing the metal Optimization of usage.

2. The surface of the 3D printed composite magnetic metal stent of the utility model is coated with a polydopamine coating, which not only increases the hydrophilicity of the stent, but also facilitates the adhesion of cells, and at the same time reduces the cytotoxicity of the metal stent, significantly increasing the biocompatibility.

3. The composite magnetic nanoparticles of the present invention can evenly adhere to the surface of the metal stent through polydopamine modification, increase the magnetic properties of the material, promote the adhesion and proliferation of osteoblasts, and greatly enhance the osteogenic ability of the stent.

4. The 3D printed composite magnetic metal stent designed by the utility model has a simple structure, is easy to produce, has better biocompatibility, and has a stronger ability to promote osteogenesis. It is an excellent bone repair material.

Description of drawings

Fig. 1 Three-dimensional porous titanium alloy scaffold prepared by 3D printing technology;

Figure 2 is a schematic diagram of a three-dimensional porous titanium alloy scaffold coated with a polydopamine shell;

Figure 3 is a schematic diagram of a three-dimensional porous titanium alloy scaffold adhered with composite magnetic nanoparticles;

The cross-sectional structure schematic diagram of Fig. 4 composite magnetic nanoparticle;

The reference signs in the figure are as follows:

Three-dimensional porous metal scaffold 1, polydopamine shell 2, composite magnetic nanoparticles 3, Fe ₃ O ₄ 31, polydopamine 32.

Detailed ways

The following examples are used to illustrate the utility model, but not to limit the scope of the utility model.

The term "Fe ₃ O ₄ @PDA" used in this utility model is a composite magnetic nano particle with a core-shell structure, that is, polydopamine is deposited on the surface of Fe ₃ O ₄ .

As shown in Figures 1-4, the utility model provides a 3D printing composite magnetic metal support, comprising a three-dimensional porous metal support 1, a polydopamine shell 2 and composite magnetic nanoparticles 3, the three-dimensional porous metal support 1 is three-dimensional A penetrating porous network structure, as shown in Figure 1; the polydopamine shell 2 is coated on the surface of the three-dimensional porous metal support 1, as shown in Figure 2; the composite magnetic nanoparticles 3 evenly adhere to the The surface of the three-dimensional porous metal stent 1 coated with the polydopamine shell 2 is shown in FIG. 3 .

The three-dimensional porous metal support 1 is a three-dimensional porous through-through support with pores connected by printing according to a certain pore diameter and a 3D digital model of a pore column, as shown in Figure 1. The three-dimensional porous metal support is a three-dimensional porous through-through support with rhombic dodecahedron as the basic unit.

The pore diameter of the three-dimensional porous metal support 1 is 300-800 μm, and the pore column is 200-300 μm.

In a preferred embodiment, the pore diameter of the three-dimensional porous metal scaffold is 300 μm, and the pore column is 200 μm.

In another preferred embodiment, the pore diameter of the three-dimensional porous metal scaffold is 600 μm, and the pore column is 300 μm.

In yet another preferred embodiment, the pore diameter of the three-dimensional porous metal scaffold is 800 μm, and the pore column is 300 μm.

The material of the three-dimensional porous metal stent 1 is titanium alloy, pure titanium, cobalt alloy stent or stainless steel.

In a preferred embodiment, the material of the three-dimensional porous metal stent 1 is titanium alloy.

The thickness of the polydopamine shell is 50-200nm.

The composite magnetic nanoparticle 3 is Fe ₃ O ₄ modified by polydopamine, that is, Fe ₃ O ₄ @PDA; the composite magnetic nanoparticle has a core-shell structure, wherein Fe ₃ O ₄ 31 is the core, and polydopamine 32 is the shell ,As shown in Figure 4. The thickness of the polydopamine is 50-200nm.

Although, the utility model has been described in detail with general description and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the utility model. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the utility model all belong to the protection scope of the utility model.

Claims (8)

1. a kind of 3D printing composite magnetic metallic support, which is characterized in that the composite magnetic metallic support includes three-dimensional porous Metallic support, poly-dopamine shell and composite magnetic nanoparticle, the three-dimensional porous metallic support are porous in three-dimensional perforation Reticular structure, the poly-dopamine shell are coated on the surface of the three-dimensional porous metallic support, the composite magnetic nanoparticle Sub- uniform adhesion is on the surface of the three-dimensional porous metallic support for being coated with poly-dopamine shell.

2. 3D printing composite magnetic metallic support as described in claim 1, which is characterized in that the three-dimensional porous metallic support It is basic unit by regular dodecahedron or granatohedron, according to having for the 3D mathematical model of certain pore size and hole post printing The three-dimensional porous perforation bracket of hole hole connection.

3. 3D printing composite magnetic metallic support as claimed in claim 2, which is characterized in that the three-dimensional porous metallic support Aperture be 300-800 μm, hole post is 200-300 μm.

4. 3D printing composite magnetic metallic support as claimed in any one of claims 1-3, which is characterized in that the three-dimensional is more The material of mesoporous metal bracket is titanium alloy, pure titanium, cobalt alloy or stainless steel.

5. 3D printing composite magnetic metallic support as claimed in claim 4, which is characterized in that the three-dimensional porous metallic support Material be titanium alloy.

6. 3D printing composite magnetic metallic support as described in claim 1, which is characterized in that the thickness of the poly-dopamine shell Degree is 50-200nm.

7. 3D printing composite magnetic metallic support as described in claim 1, which is characterized in that the composite magnetic nanoparticle For the Fe of poly-dopamine modification₃O₄, i.e. Fe₃O₄@PDA；The composite magnetic nanoparticle is core-shell structure, wherein Fe₃O₄It is interior Core, poly-dopamine are shell.

8. 3D printing composite magnetic metallic support as claimed in claim 7, which is characterized in that the poly-dopamine with a thickness of 50-200nm。