A composite material, a method of making the same and an implant

Abstract

This invention discloses a composite material, its preparation method, and an implant, belonging to the field of medical materials technology. The composite material is obtained by combining a piezoelectric material and a metal ion-releasing material; the metal ion-releasing material is selected from one or more of magnesium-based biodegradable alloys, iron and iron-based biodegradable alloys, and zinc and zinc-based biodegradable alloys. The composite material can adaptively generate microcurrents of varying magnitudes at different stages of patient recovery through the piezoelectric response of the piezoelectric material. These microcurrents promote intelligent degradation of the metal ion-releasing material that matches the patient's own recovery process. The resulting metal ions and the microcurrents jointly promote healing at the implantation site, which is of great significance for the development and application of implant materials.

Description

[0001] This application claims priority to Chinese Patent Application No. 202410689865.7, filed on May 30, 2024, entitled "A Composite Material and its Preparation Method and Implant", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of medical materials technology, and in particular to a composite material, its preparation method, and an implant. Background Technology

[0003] Fractures are one of the most common accidental injuries in daily life. If the injury is severe, resulting in a complete fracture, internal fixation surgery is necessary to fix and protect the fracture site using bone screws and plates. Currently, titanium alloy is still the primary material used for these bone implants in orthopedic clinics. While titanium alloy has good biocompatibility and corrosion resistance, its high stiffness can easily induce stress shielding effects, leading to secondary fractures after surgery. Furthermore, titanium alloy is a non-degradable material, requiring a second surgery to remove it after recovery for most patients, increasing surgical pain and the risk of postoperative infection. If not removed, the implant remains in the body long-term and may release harmful ions or metal particles due to wear or corrosion, causing inflammation, allergic reactions, and other adverse reactions.

[0004] Based on the above issues, researchers have focused on developing more suitable bone implant materials, and thus began research on magnesium alloys. Firstly, the elastic modulus and density of magnesium alloys are closer to those of human bone, effectively avoiding stress shielding effects. Secondly, magnesium alloys are biodegradable and bioactive; their degradation products can promote osteoogenesis and have antibacterial properties. While these inherent properties of magnesium alloys effectively avoid the shortcomings of titanium alloys in clinical applications, they also have a major problem: their degradation rate is too rapid and uncontrollable. This leads to a sudden drop in mechanical properties and hydrogen evolution during degradation, which is detrimental to bone tissue repair at fracture sites. This problem is precisely what limits its application in bone implants. Therefore, developing absorbable bone implants with suitable degradation rates is particularly important.

[0005] Patent CN110449579A discloses a controllable degradable zinc-magnesium gradient material, which is prepared by spark plasma sintering using magnesium powder and zinc powder as raw materials. In vitro immersion degradation experiments showed that the average degradation rate of this gradient material was only 1.188 mm / a in the early stage (3 months), but increased significantly to 62.101 mm / a in the later stage (6 months). Although this invention achieves a change in degradation rate through a gradient strategy, fulfilling the unique functional requirements of corrosion resistance of the outer layer material in the early stage of implantation, ensuring overall mechanical properties, and rapid degradation in the later stage, it cannot match the specific needs of patients with different conditions and age groups, and cannot adaptively degrade intelligently according to the recovery status of different patients.

[0006] Patent CN111334688A discloses a biodegradable Zn-RE zinc alloy material, with Zn as the main element and one of the non-radioactive rare earth elements (RE) as the alloying element. The RE content is 0-3% by mass, but not including 0%, with the balance being zinc. The non-radioactive rare earth element (RE) includes scandium (Sc), yttrium (Y), lanthanum (139La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (150Sm), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (175Lu), and is prepared by hot extrusion. Electrochemical experimental data show that the degradation rate of these alloys is in the range of 0.02-2.85 mm / a. Although the degradation performance can be controlled by changing the type of rare earth element added, the ideal implant should have a corresponding degradation rate at different recovery stages of the human body. The Zn-RE zinc alloy material in this invention cannot meet this unique functional requirement.

[0007] Amorphous alloys generally possess excellent corrosion resistance due to their homogeneous structure (absence of grain boundaries, dislocations, and precipitates). Among Mg-based amorphous alloys, the elastic modulus of Mg, Zn, and Ca closely matches that of human bone, they are biodegradable, and exhibit better corrosion resistance than traditional magnesium alloys. This was first reported in 2009. F. Researchers investigated the hydrogen evolution of MgZnCa amorphous stripes with different zinc contents. The results showed that Mg... 60 Zn 35 Ca5 exhibits the best corrosion resistance, showing no hydrogen evolution even after immersion in SBF solution for 70 hours. In contrast, pure magnesium shows a hydrogen evolution rate as high as 18 mL / cm³. 2 Similarly, in the in vivo hydrogen evolution experiment, Mg 60 Zn 35 No hydrogen gas was produced around the Ca5 band, while a large amount of hydrogen gas was produced around the WZ21 band. Subsequently... F. The research team also prepared Mg60 Zn 35 The degradation of Ca5 amorphous rods (1.6*3mm) in vivo was investigated. Results showed that Mg... 60 Zn 35 Ninety days after Ca5 was implanted into the tibia of mice, there was no hydrogen evolution or degradation, and the surrounding new bone tissue remained continuous and intact.

[0008] Piezoelectric crystals, a type of piezoelectric material, are materials with asymmetric crystal structures, such as barium titanate (BTO), zinc oxide (ZnO), and aluminum nitride (AlN). When deformed by external force, they exhibit internal polarization, resulting in opposite charges on their two opposing surfaces. When the external force is removed, they return to their uncharged state. This phenomenon of converting mechanical energy into electrical energy is called the direct piezoelectric effect.

[0009] Current biodegradable bone implants are neither ideal nor intelligent, failing to adapt to the specific needs of patients with different conditions and age groups. Ideally, absorbable bone implants should provide robust fixation in the initial postoperative period, offering a stable mechanical environment for the fracture site. As the implant degrades, its stiffness decreases, while bone tissue heals and gradually bears more load, promoting bone growth. Ultimately, the implant completely degrades and is replaced by new bone, eliminating the need for removal. Therefore, developing an intelligent biodegradable implant that degrades according to the patient's individual recovery process would have greater clinical value. Summary of the Invention

[0010] In view of this, the technical problem to be solved by the present invention is to provide a composite material, its preparation method, and an implant. The composite material can intelligently degrade metal ions through the piezoelectric response of the piezoelectric material.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] This invention provides a composite material obtained by combining a piezoelectric material and a metal ion releasing material.

[0013] The metal ion releasing material is selected from one or more of magnesium-based biodegradable alloys, iron and iron-based biodegradable alloys, and zinc and zinc-based biodegradable alloys.

[0014] The present invention does not have any particular limitation on the above-mentioned composite, and can be a common composite method such as doping or deposition.

[0015] In some specific embodiments of the present invention, preferably, composite is performed by doping or deposition.

[0016] The piezoelectric material in the aforementioned composite material generates an electric charge in response to pressure. This charge promotes the degradation of the metal ion-releasing material, releasing metal ions. The generation of this charge and the release of metal ions together promote healing at the implantation site.

[0017] Preferably, the piezoelectric material in the composite material comprises 1% to 15% by mass; more preferably, 5% to 10%. In some specific embodiments of the present invention, 8% is preferred.

[0018] Preferably, the piezoelectric material of the present invention is selected from tetragonal barium titanate (T-BTO), zinc oxide, and molybdenum sulfide; more preferably, it is tetragonal barium titanate.

[0019] Preferably, the magnesium-based biodegradable alloy of the present invention is selected from Mg. 60 Zn 35 One or more of the following: Ca5 amorphous alloy, MgZnCaSr amorphous alloy, MgZnYNd alloy, MgYReZr alloy, MgZnCa alloy, MgZnSr alloy, MgZnCaSr alloy, and MgZnCu alloy; more preferably Mg 60 Zn 35 Ca5 amorphous alloy.

[0020] Preferably, the iron-based biodegradable alloy is selected from FeZn series alloys and / or FeMn series alloys.

[0021] The FeZn series alloys include, but are not limited to, Fe-15Zn.

[0022] The FeMn series alloys include, but are not limited to, FeMnAg alloys, FeMnCu alloys, FeMnSi alloys, and FeMnSiCa alloys.

[0023] Preferably, the zinc-based biodegradable alloy is selected from one or more of the ZnMg series alloys, ZnCa series alloys, ZnCu series alloys, ZnMn series alloys, ZnLi series alloys, and ZnRe series alloys; more preferably, it is a ZnMg alloy.

[0024] The ZnCu series alloys include, but are not limited to, Zn-3Cu, Zn-3Cu-0.5Fe, and Zn-3Cu-0.5Mg.

[0025] The ZnMg series alloys include, but are not limited to, Zn-0.8Mg, Zn-3Mg, Zn-1Mg-1Sr, Zn-1Mg-0.1Mn, and Zn-1Mg-1Ca.

[0026] The ZnCa series alloys include, but are not limited to, Zn–1Ca–1Sr.

[0027] The ZnMn series alloys include, but are not limited to, Zn-0.1Mn.

[0028] The ZnLi series alloys include, but are not limited to, Zn-0.4Li, Zn-0.5Li, Zn-0.8Li, Zn-0.8Li-0.2Ag, etc.

[0029] The ZnRe series alloys include, but are not limited to, Zn-0.2La, Zn-0.2Y, Zn-0.2Ce, Zn-0.2Nd, Zn-0.2Ho, Zn-0.2Lu, etc.

[0030] The numerical values ​​preceding the metallic elements in the above series of alloys all represent the mass percentage of that element in the alloy.

[0031] Preferably, in this invention, the piezoelectric material is selected from tetragonal barium titanate, and the metal ion releasing material is selected from Mg. 60 Zn 35 One or more of the following: Ca5 amorphous alloy, iron, zinc, and zinc-based biodegradable alloy.

[0032] Preferably, the zinc-based biodegradable alloy is selected from Zn-Mg alloys, wherein the mass percentage of Mg is 0.1% to 0.8%; more preferably 0.8%.

[0033] When the metal ion releasing material is selected from Mg 60 Zn 35 When Ca5 is an amorphous alloy, the composite material is represented as T-BTO-Mg. 60 Zn 35 Ca5 composite material.

[0034] In some specific embodiments of the present invention, the T-BTO-Mg 60 Zn 35 The Ca5 composite material is prepared by laminating a metal ion-releasing material onto the surface of a piezoelectric material. The T-BTO-Mg... 60 Zn 35 The thickness of the piezoelectric T-BTO layer in the Ca5 composite material is 370 nm, and the metal ion releasing material Mg... 60 Zn 35 The Ca5 layer has a thickness of 4.03 μm.

[0035] When the metal ion releasing material is selected from iron, the composite material is referred to as a T-BTO-Fe composite material.

[0036] When the metal ion-releasing material is selected from zinc-based biodegradable alloys, the composite material is designated as a T-BTO-Zn-0.8Mg composite material. The zinc-based biodegradable alloy is selected from Zn-0.8Mg, with a Zn to Mg mass ratio of 99.2%:0.8%.

[0037] The present invention also provides a method for preparing the above-mentioned composite material, comprising the following steps:

[0038] The composite material is obtained by combining piezoelectric materials and metal ion-releasing materials through magnetron sputtering, melting, or 3D printing.

[0039] The composite material obtained by magnetron sputtering consists of a piezoelectric material layer and a metal ion release material layer.

[0040] Preferably, the magnetron sputtering method of the present invention includes preparing the composite material by uniformly sputtering a piezoelectric material onto the substrate surface through a first magnetron sputtering and then uniformly sputtering a metal ion releasing material onto the piezoelectric material surface through a second magnetron sputtering.

[0041] The first and second magnetron sputtering are preferably performed in an inert gas atmosphere.

[0042] Preferably, the inert gas includes, but is not limited to, argon, helium, neon, tritium, etc.

[0043] Preferably, the inert gas is selected from argon.

[0044] Preferably, the vacuum level of the vacuum environment is 3*10. -4 ~8*10 -3 Pa; more preferably 5*10 Pa; -4 ~9*10 - 4 Pa; more preferably 5*10 Pa; -4 Pa.

[0045] Preferably, the first magnetron sputtering and the second magnetron sputtering are performed using a DC power supply or a radio frequency power supply.

[0046] Preferably, the power of the DC power supply or radio frequency power supply is 50-150W; more preferably 90-120W; and even more preferably 100W.

[0047] Preferably, the pressure of the first or second magnetron sputtering is 0.5–1.8 Pa; more preferably 0.8–1.5 Pa; and even more preferably 0.8 Pa. In some specific embodiments of the present invention, the pressure of the first magnetron sputtering is preferably 1.5 Pa, and the pressure of the second magnetron sputtering is preferably 0.8 Pa.

[0048] Preferably, the duration of the first or second magnetron sputtering is 0.3 to 3 hours. More preferably, it is 0.5 to 2 hours; even more preferably, it is 0.5 hours. In some specific embodiments of the present invention, the duration of the first magnetron sputtering is preferably 2 hours, and the duration of the second magnetron sputtering is preferably 0.5 hours.

[0049] The magnetron sputtering process includes processes such as ion bombardment and deposition.

[0050] In this invention, the preferred method for preparing the magnetron sputtering method includes the following steps:

[0051] 1) Under the influence of the electric field, electrons are accelerated towards the substrate and collide with argon atoms, causing the argon atoms to ionize and produce a large number of argon ions and new electrons.

[0052] 2) The new electrons continue to fly toward the substrate, while the argon ions are accelerated and bombard the surface of the metal ion releasing material under the action of the electric field, so that the neutral atoms or molecules on the surface of the metal ion releasing material gain sufficient kinetic energy, detach from the material surface, and deposit onto the surface of the piezoelectric material to form a metal ion releasing material layer, thus preparing the composite material.

[0053] Preferably, the smelting method of the present invention includes mixing and smelting a metal ion releasing material and a piezoelectric material to obtain the composite material.

[0054] The 3D printing method involves uniformly mixing piezoelectric material powder and metal ion-releasing material powder, and then laser melting and molding the mixture using 3D printing to obtain the composite material.

[0055] The composite material obtained by the above melting method and 3D printing is a doped composite material.

[0056] The present invention also provides an implant comprising the above-described composite material or the composite material prepared by the above-described preparation method.

[0057] In the above-mentioned implant, the piezoelectric material in the composite material is preferably a material with stable physicochemical properties, excellent piezoelectric performance, and good biocompatibility.

[0058] In this invention, the piezoelectric material in the composite material is preferably tetragonal barium titanate, zinc oxide, or molybdenum sulfide. While tetragonal barium titanate (T-BTO) does not degrade, it is excreted from the body with minimal harm once the metal ion-releasing material in the composite material has degraded. Zinc oxide or molybdenum sulfide, when used as the piezoelectric material in the implant, both degrade, and the resulting metal ions pose minimal health risks.

[0059] The present invention also provides the application of the above-mentioned implants in biomedical biodegradable scaffolds, biomedical biodegradable suture materials, biodegradable orthopedic implants, biodegradable dental materials, biodegradable self-powered electronic bandages, and biodegradable electrodes.

[0060] The biodegradable biomedical stents include, but are not limited to, tracheal stents, esophageal stents, intestinal stents, vascular stents, biliary stents, or urethral stents.

[0061] The biodegradable suture materials mentioned include, but are not limited to, absorbable skin staples, absorbable sutures, or medical zippers.

[0062] The biodegradable orthopedic implants include, but are not limited to, bone plates, intramedullary nails, screws, bone pins, spinal fixation devices, ligatures, patellar consolidators, bone repair materials, and bone tissue repair scaffolds.

[0063] The biodegradable dental materials include, but are not limited to, dental implant materials or root canal files. When the composite material is used as a biodegradable orthopedic implant, the metal ion-releasing material in the composite material can intelligently degrade according to piezoelectric response, meeting the needs of patients at different stages of bone recovery.

[0064] In the initial postoperative period, the patient's limb cannot bear weight. At this time, the composite material described in this invention provides good fixation for the fracture site. As the patient recovers, the fractured limb begins to bear weight. The stress acts on the piezoelectric material, causing it to generate a microcurrent within the metal ion-releasing material. This microcurrent promotes the degradation of the metal ion-releasing material, releasing metal ions and thus promoting bone growth at the fracture site. Furthermore, the degradation rate of the metal ion-releasing material can adaptively change according to the magnitude of the force applied to the fractured limb, intelligently degrading while promoting fracture healing.

[0065] In this invention, when the composite material is selected from T-BTO-Zn-0.8Mg composite material, T-BTO-Zn-0.8Mg provides good fixation for the fracture site when the patient's limb cannot bear force. As the fractured limb begins to bear force, stress is applied to the piezoelectric material T-BTO, causing T-BTO to generate a microcurrent in the Zn-0.8Mg alloy. This microcurrent can promote the degradation of the Zn-0.8Mg alloy, releasing Mg. 2+ and Zn 2+ This promotes bone growth at the fracture site. Furthermore, Mg... 2+ and Zn 2+ The release amount is determined by the different forces exerted on the patient's limb, thus achieving adaptive and intelligent degradation for the patient.

[0066] Compared with existing technologies, the composite material provided by this invention is obtained by combining piezoelectric materials and metal ion-releasing materials; the metal ion-releasing materials are selected from one or more of magnesium-based biodegradable alloys, iron and iron-based biodegradable alloys, and zinc and zinc-based biodegradable alloys. The composite material can adaptively generate microcurrents of different magnitudes at different stages of patient recovery through the piezoelectric response of the piezoelectric material. These microcurrents promote intelligent degradation of the metal ion-releasing materials that matches the patient's own recovery. The degraded metal ions and the microcurrents jointly promote healing at the implantation site, which is of great significance for the development and application of implant materials. Attached Figure Description

[0067] Figure 1 The T-BTO-Mg prepared in Example 1 60 Zn 35 The structural characterization diagrams of the Ca5 composite material are shown in Figure a, where Figure a is the XRD pattern, Figure b is the TEM image, and Figure c is the EDS energy dispersive spectroscopy pattern.

[0068] Figure 2 Figures show the piezoelectric properties of the T-BTO coatings prepared in Example 1 under different stresses. Figure a is the piezoelectric response phase hysteresis loop diagram, Figure b is the amplitude butterfly loop diagram, Figures c, d, and e are the piezoelectric response diagrams under stresses of 0.1N, 0.2N, and 0.3N, respectively, and Figure f is a schematic diagram of the voltage test.

[0069] Figure 3 The graph shows the degradation performance test results of different composite materials under different stresses, where a represents BTO-Mg. 60 Zn 35 SEM images of Ca5 composite material degrading under cyclic dynamic loading (0.3 N, 1.25 Hz) for 10 minutes, b is BTO-Mg 60 Zn 35 A laboratory schematic diagram of Ca5 composite material under dynamic load, where c represents the weight loss rate of the composite material under different stresses;

[0070] Figure 4 The image shows the SEM image of the BTO-Zn composite material prepared in Example 2 after 1 hour of degradation under cyclic dynamic load (0.3 N, 1.25 Hz).

[0071] Figure 5 The graph shows the weight loss rate of the BTO-Zn composite material prepared in Example 2 under cyclic dynamic loading (0.3 N, 1.25 Hz).

[0072] Figure 6 The image shows the SEM image of the BTO-Fe composite material prepared in Example 3 after 5 hours of degradation under cyclic dynamic loading (0.3 N, 1.25 Hz).

[0073] Figure 7 The graph shows the weight loss rate of the BTO-Fe composite material prepared in Example 3 under cyclic dynamic loading (0.3 N, 1.25 Hz).

[0074] Figure 8 The structural characterization diagrams of the T-BTO-Zn-0.8Mg composite material prepared in Example 4 are shown in a. a is the XRD pattern and b is the distribution diagram of T-BTO in the alloy.

[0075] Figure 9 Figure 4 shows the piezoelectric characteristics of the T-BTO particles in Example 4. Figure 1a is the piezoelectric response phase hysteresis loop diagram, and Figure 2b is the amplitude butterfly loop diagram.

[0076] Figure 10 The following is a characterization diagram of the degradation performance of the T-BTO-Zn-0.8Mg composite material prepared in Example 4: a is a diagram of the testing device, and b is a diagram of the average weight loss rate. Detailed Implementation

[0077] To further illustrate the present invention, the following describes in detail the composite material, its preparation method, and the implant provided by the present invention with reference to embodiments.

[0078] The following Mg 60 Zn 35 In the attached diagram, Ca5 is abbreviated as MgZnCa.

[0079] (I) Preparation of composite materials

[0080] Example 1

[0081] (1) Preparation of amorphous BTO coating

[0082] Using 301 stainless steel (dimensions 36*6*0.15mm (length*width*thickness)) as a substrate, an amorphous BTO (A-BTO) layer was sputtered onto its surface using magnetron sputtering technology. The parameters for the magnetron sputtering technology are as follows: 100W RF power supply, vacuum degree 5*10 -4 Pa, sputtering atmosphere is argon atmosphere, pressure is 1.5 Pa, sputtering time is 2 h.

[0083] (2) Preparation of tetragonal BTO coating

[0084] The amorphous BTO (A-BTO) was annealed at 700℃ for 15 min to obtain tetragonal BTO (T-BTO).

[0085] (3) Preparation of composite materials

[0086] The tetragonal BTO (T-BTO) prepared in (2) was used as a substrate, and Mg was sputtered onto its surface. 60 Zn 35 Ca5, thus yielding T-BTO-Mg 60 Zn 35 Ca5 composite material, in which sputtered Mg 60 Zn 35 The parameters for Ca5 are as follows: a DC power supply with a power of 100W, a vacuum degree of 5*10-4Pa, an argon atmosphere for sputtering with a pressure of 0.8Pa, and a sputtering time of 0.5h.

[0087] Example 2

[0088] The preparation process of T-BTO-Zn composite material is as follows:

[0089] The prepared tetragonal BTO (T-BTO) was used as a substrate, and Zn was sputtered on its surface to obtain the T-BTO-Zn composite material. The sputtering parameters of Zn were as follows: a DC power supply with a power of 100W, a vacuum degree of 5*10-4Pa, an argon atmosphere with a pressure of 1.6Pa, and a sputtering time of 1h.

[0090] Example 3

[0091] The preparation process of T-BTO-Fe composite material is as follows:

[0092] The prepared tetragonal BTO (T-BTO) was used as a substrate, and Fe was sputtered on its surface to obtain the T-BTO-Fe composite material. The sputtering parameters of Fe were as follows: a DC power supply with a power of 100W, a vacuum degree of 5*10-4Pa, an argon atmosphere with a pressure of 0.6Pa, and a sputtering time of 1h.

[0093] Example 4

[0094] Raw material purchases: Zinc and magnesium granules (purity: 99.996%) were purchased from Hebei Qinbang New Material Technology Co., Ltd., and tetragonal barium titanate powder (particle size: 0.5-1μm) was purchased from Shanghai Buwei Applied Materials Technology Co., Ltd.

[0095] 1) Preparation of Zn-0.8Mg alloy: Zinc and magnesium particles were fed in a mass percentage ratio of 99.2%:0.8% and smelted in an induction melting furnace under a vacuum of 8*10. -3 Pa, the melting atmosphere is argon atmosphere, and the pressure is -0.05 MPa.

[0096] 2) Preparation of T-BTO-Zn-0.8Mg composite material: Weigh 200g of zinc and magnesium particles with a mass percentage of 99.2%:0.8%. Then, mix 3g of tetragonal barium titanate powder with the zinc and magnesium particles by vibration to ensure uniform adsorption of the tetragonal barium titanate powder on the surface of the zinc and magnesium particles. The mixture is then smelted in an induction melting furnace under a vacuum of 8*10⁻⁶. -3 Pa, the melting atmosphere is argon atmosphere, and the pressure is -0.05 MPa.

[0097] Comparative Example 1

[0098] The amorphous BTO (A-BTO) prepared in step (1) of Example 1 was used as a substrate, and Mg was sputtered onto its surface. 60 Zn 35 Ca5, thus yielding A-BTO-Mg 60 Zn 35 Ca5 composite material (abbreviated as A-BTO-MgZnCa), in which sputtered Mg 60 Zn 35 The parameters for Ca5 are as follows: a DC power supply with a power of 100W, a vacuum degree of 5*10-4Pa, an argon atmosphere for sputtering with a pressure of 0.8Pa, and a sputtering time of 0.5h.

[0099] Comparative Example 2

[0100] Similar to Example 2, except that amorphous BTO (A-BTO) was used as the substrate to obtain A-BTO-Zn composite material.

[0101] Comparative Example 3

[0102] Similar to Example 3, except that amorphous BTO (A-BTO) was used as the substrate to obtain A-BTO-Fe composite material.

[0103] (II) Performance Test Results

[0104] The T-BTO-Mg prepared in Example 1 60 Zn 35 The structural characterization of the Ca5 composite material (abbreviated as T-BTO-MgZnCa) was obtained. Figure 1 Figure a shows T-BTO-Mg. 60 Zn 35 The XRD pattern of the Ca5 composite material shows that the diffraction peaks of the composite material in the (100), (110), (111), (211), and (200) planes are consistent with the peaks of tetragonal T-BTO, and Mg deposited on the surface of the tetragonal T-BTO is also present. 60 Zn 35Ca5 exhibits a typical amorphous structure with a broadened peak between 30° and 45°, but no obvious crystal diffraction peaks. To observe T-BTO-Mg... 60 Zn 35 The thickness and microstructure of each layer in the Ca5 composite material were observed by TEM after FIB treatment, as shown in Figure b. 60 Zn 35 The Ca5 layer has a thickness of approximately 4.03 μm, and the BTO layer has a thickness of approximately 370 nm. Figure c shows the EDS energy dispersive spectroscopy (EDS) spectrum, indicating that Mg, Zn, Ca, Ba, Ti, and O elements are uniformly distributed. In summary, Example 1 successfully prepared T-BTO-Mg. 60 Zn 35 Ca5 composite material.

[0105] The piezoelectric properties of the tetragonal BTO coating prepared in Example 1 were tested using piezoelectric force microscopy (PFM). The results are as follows: Figure 2 As shown in the figure, Figure a is the piezoelectric response phase hysteresis loop diagram, which shows that the phase voltage signal of T-BTO exhibits a significant 180° phase shift; Figure b is the amplitude butterfly loop diagram, which shows that a butterfly-shaped hysteresis loop was obtained in the voltage range of -5V to 5V, indicating that the prepared T-BTO has a typical piezoelectric response; subsequently, the voltage response of the T-BTO film under different stresses was tested using an oscilloscope (YOKOGAWADL850). Under stresses of 0.1N (Figure c), 0.2N (Figure d), and 0.3N (Figure e), the T-BTO coating produced output voltages of approximately 0.5V, 1.0V, and 1.5V, respectively; Figure f is a schematic diagram of the voltage test, showing that under stress, T-BTO-Mg... 60 Zn 35 The T-BTO in Ca5 composite material exhibits polarization, resulting in opposite charges on its two opposing surfaces.

[0106] The T-BTO-Mg prepared above 60 Zn 35 Ca5 composite material (Example 1) and T-BTO-Mg 60 Zn 35 The Ca5 composite material (Comparative Example 1) was immersed in PBS buffer solution at 37℃, and a dynamic load (0.3N, 1.25Hz) was applied to it to test the degradation performance of the composite material under different stresses. Figure 3 As shown in Figure b, Figure b represents BTO-Mg 60 Zn 35 A schematic diagram of an experiment involving dynamic loading of Ca5 composite materials, including BTO-Mg. 60 Zn 35The Ca5 composite material is T-BTO-Mg. 60 Zn 35 Ca5 composite material or A-BTO-Mg 60 Zn 35 Ca5 composite material. After 10 minutes of treatment, the samples were removed and cleaned with a 5% chromic acid solution to remove corrosion products. The corrosion was then observed using SEM on different sample surfaces. The two selected sample groups were A-BTO-Mg, which does not exhibit piezoelectric effect. 60 Zn 35 Ca5, and T-BTO-Mg with piezoelectric effect 60 Zn 35 As shown in Figure a, Ca5 was identified by EDS energy dispersive spectroscopy. The results indicate that under the same stress, T-BTO-Mg... 60 Zn 35 The higher BTO exposure in the Ca5 coating indicates that the Mg on its surface... 60 Zn 35 The increased degradation of Ca5 demonstrates that the piezoelectric effect can indeed promote Mg degradation under stress. 60 Zn 35 The degradation of Ca5 was observed. Furthermore, the middle of the same sample showed greater degradation than the ends. This is because during the experiment, the middle of the sample was directly subjected to force, while the stress gradually decreased towards the ends. In addition, by applying different stresses (0.1N, 0.2N, or 0.3N) to the composite material and allowing it to degrade for 10 minutes, the corrosion products on the surface were washed away with a 5% chromic acid solution. The mass before and after degradation was measured using an analytical balance, and the weight loss rate of the coating under different stresses was calculated (weight loss rate = (mass before degradation - mass after degradation) / surface area of ​​the coating). The results are shown in Figure c. Under the three stresses, T-BTO-Mg... 60 Zn 35 Mg in Ca5 60 Zn 35 The degradation of Ca5 was faster than that of A-BTO-Mg. 60 Zn 35 The amount of Ca5 is greater, and the difference between the two increases with increasing stress. This is because as stress increases, T-BTO generates a larger current, which can further promote degradation.

[0107] In summary Figures 1-3 It can be seen that the present invention successfully prepared T-BTO-Mg 60 Zn 35 In Ca5 composite materials, different stresses will cause T-BTO to generate currents of corresponding magnitudes, thereby promoting the growth of Mg. 60 Zn 35 Ca5 undergoes varying degrees of degradation, which is known as stress-responsive smart degradation.

[0108] The degradation performance of BTO-Zn composite material under cyclic dynamic loading (0.3 N, 1.25 Hz) was tested to obtain the results. Figure 4 , Figure 4 SEM images of BTO-Zn composites under cyclic dynamic loading (0.3 N, 1.25 Hz) for 1 hour show the degradation of the composites. The BTO-Zn composites are T-BTO-Zn composites (Example 2) and A-BTO-Zn composites (Comparative Example 2). The results show that under the same stress, the T-BTO-Zn coating exposes more BTO, indicating greater Zn degradation on its surface. Specifically, under the same stress, the degree of Zn degradation in T-BTO-Zn is greater than that in A-BTO-Zn. This is because T-BTO exhibits a piezoelectric effect, and the current it generates better promotes Zn degradation on the composite surface.

[0109] Figure 5 The weight loss rate diagrams for BTO-Zn composites (T-BTO-Zn composite and A-BTO-Zn composite) at a stress of 0.3 N and 1.25 Hz show that under the same stress, more Zn is degraded in the T-BTO-Zn coating.

[0110] comprehensive Figure 4 , 5 It can be seen that under stress, the piezoelectric effect can also promote the degradation of Zn.

[0111] The degradation performance of BTO-Fe composite material under cyclic dynamic loading (0.3 N, 1.25 Hz) was tested to obtain the results. Figure 6 , Figure 6 The SEM images show the degradation of BTO-Fe composites (T-BTO-Fe composite (Example 3) and A-BTO-Fe composite (Comparative Example 3)) under cyclic dynamic loading (0.3 N, 1.25 Hz) for 5 hours. The results show that under the same stress, more BTO is exposed in the T-BTO-Fe composite, indicating that more Fe is degraded on its surface.

[0112] Figure 7 The graph shows the weight loss rate of the BTO-Fe composite material under cyclic dynamic loading (0.3 N, 1.25 Hz). The results indicate that under the same stress, the Fe in the T-BTO-Fe coating degrades more.

[0113] comprehensive Figure 6 , 7 It can be seen that under stress, the piezoelectric effect can also promote the degradation of Fe.

[0114] First, XRD tests were performed on the T-BTO particles used in Example 4 and the synthesized Zn-0.8Mg and T-BTO-Zn-0.8Mg composite materials, as shown below. Figure 8 As shown in Figure a, the T-BTO particles used are tetragonal barium titanate with piezoelectric effect, and the magnesium in Zn-0.8Mg is in the form of the intermetallic compound Mg2Zn. 11 The presence of T-BTO diffraction peaks in the T-BTO-Zn-0.8Mg composite material indicates that we successfully incorporated T-BTO into the Zn-0.8Mg alloy. We then further observed the distribution of BTO in the alloy using SEM, such as... Figure 8 As shown in b, the T-BTO particles have a size of 0.5–1 μm and are uniformly dispersed in the alloy without obvious agglomeration. These results demonstrate the successful synthesis of a T-BTO-Zn-0.8Mg composite material with uniform BTO distribution.

[0115] Furthermore, the piezoelectric properties of the T-BTO particles used were tested using piezoelectric force microscopy (PFM), and the results are as follows: Figure 9 As shown in the figure. Figure a is the phase hysteresis loop diagram of the piezoelectric response, which shows that the phase voltage signal of BTO exhibits a significant 180° phase shift; Figure b is the amplitude butterfly loop diagram, which shows that a butterfly-shaped hysteresis loop was obtained in the voltage range of -6V to 6V, indicating that the BTO particles we used have a typical piezoelectric response.

[0116] Furthermore, the prepared Zn-0.8Mg and T-BTO-Zn-0.8Mg composite materials were cut into 5*5*5mm samples, and then... Figure 10 The device shown in figure a was used to apply a dynamic load (20 MPa, 1 Hz) to the sample for 1 hour, and the weight loss rate of the sample was tested. Figure 10 As shown in b, the average weight loss of the Zn-0.8Mg alloy is approximately 2.04 mg / cm³. 2 The average weight loss of the T-BTO-Zn-0.8Mg composite material is approximately 3.73 mg / cm³. 2 The above results demonstrate that by uniformly distributing piezoelectric materials in the form of nanoparticles in a biodegradable alloy, intelligent degradation in a piezoelectric response can be achieved.

[0117] In summary, the composite material described in this invention promotes the intelligent release of metal ions in the metal ion releasing material through the piezoelectric response of the piezoelectric material.

[0118] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An implant comprising a composite material; The implant is used in biodegradable suture materials, biodegradable orthopedic implants, biodegradable dental materials, biodegradable self-powered electronic bandages, or biodegradable electrodes. The composite material is obtained by combining piezoelectric material and metal ion releasing material; the composite material adaptively generates microcurrents of different magnitudes at different stages of patient recovery through the piezoelectric response of the piezoelectric material. The microcurrent promotes the intelligent degradation of the metal ion releasing material that matches the patient's own recovery. The metal ions obtained from the degradation and the microcurrent together promote the healing of the implantation site. The piezoelectric material in the composite material accounts for 1% to 15% by mass. When the metal ion releasing material is selected from Mg 60 Zn 35 When Ca5 is an amorphous alloy, the composite material is represented as T-BTO-Mg. 60 Zn 35 Ca5 composite material; When the metal ion releasing material is selected from iron, the composite material is referred to as a T-BTO-Fe composite material; When the metal ion releasing material is selected from Zn-0.8Mg, the composite material is referred to as T-BTO-Zn-0.8Mg composite material; T-BTO is a tetragonal phase barium titanate.

2. The implant according to claim 1, characterized in that, The method for preparing the composite material includes the following steps: The composite material is obtained by combining piezoelectric materials and metal ion-releasing materials through magnetron sputtering, melting, or 3D printing.

3. The implant according to claim 2, characterized in that, The magnetron sputtering method includes uniformly sputtering a piezoelectric material onto the substrate surface through a first magnetron sputtering, and then uniformly sputtering a metal ion-releasing material onto the surface of the piezoelectric material through a second magnetron sputtering to prepare the composite material. The smelting method includes mixing and smelting a metal ion-releasing material and a piezoelectric material to obtain the composite material; The 3D printing method involves uniformly mixing piezoelectric material powder and metal ion-releasing material powder, and then laser melting and molding the mixture using 3D printing to obtain the composite material.

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