Completely degradable composite anchor with line
By combining biodegradable metals with polymer materials to form a composite wire anchor with a mechanically interlocking structure, the problems of insufficient biocompatibility and mechanical properties of existing anchor materials are solved, achieving complete degradation and improved mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU JINGJUN NEW MATERIAL TECH CO LTD
- Filing Date
- 2024-12-26
- Publication Date
- 2026-05-05
AI Technical Summary
Existing bone fixation devices have shortcomings in terms of biocompatibility, degradation performance, and mechanical properties, leading to pain during secondary surgeries and poor performance.
By combining biodegradable metal materials with polymer materials to form a mechanically interlocking structure, and combining this with surface treatment to improve the interfacial bonding strength, a fully degradable composite wire anchor is prepared.
It achieves complete degradation of the anchor, avoids the pain of secondary surgery, improves mechanical and degradation properties, and adapts to different mechanical requirements.
Smart Images
Figure CN224193558U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of bone fixation device technology, and in particular to a fully degradable composite suture anchor. Background Technology
[0002] Currently, the materials used in bone fixation techniques generally suffer from various defects, limiting their clinical application. Many traditional anchors lack biocompatibility and degradation properties, failing to meet patients' needs during the healing process. In particular, some metal anchors cannot completely degrade in vivo, requiring secondary surgery for removal, increasing patient suffering and financial burden. While biodegradable metal materials can degrade completely, the degradation cycle is uncontrollable, and the degradation process releases excessive metal ions, affecting local pH and triggering inflammatory responses. Biopolymer materials are currently mainly composed of collagen, chitosan, and polylactic acid and their composites, but their inherent drawbacks include insufficient mechanical properties to meet the strength requirements of the implantation site and a lack of functionalities such as bioactivity. Biocomposite materials offer comprehensive advantages in improving various properties, including biological characteristics, effectively compensating for the shortcomings of single materials in biological, physical, and chemical properties. However, current technologies cannot achieve effective combination and performance optimization of different materials, thus limiting improvements in the mechanical and biodegradability properties of anchors.
[0003] Therefore, it is of great significance to provide a novel, fully degradable composite strip anchor with good mechanical properties. Utility Model Content
[0004] In view of this, the present invention provides a fully degradable composite suture anchor, which aims to overcome the shortcomings of the prior art, achieve better mechanical properties and fully degradable characteristics, and thus meet the high standards of clinical bone fixation devices.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A fully biodegradable composite anchor with wire, the composite anchor with wire includes an anchor body and a wire hole, the anchor body includes a columnar core and a covering layer covering the columnar core; the covering layer covering the columnar core is provided with threads;
[0007] The columnar core is a biodegradable metal material, and the coating layer covering the columnar core is a biodegradable polymer material.
[0008] Preferably, the biodegradable metal material is a magnesium alloy or a zinc alloy.
[0009] Preferably, the biodegradable polymer material is polylactic acid, polycaprolactone, hydroxyapatite-doped polylactic acid, zinc oxide-doped polylactic acid, hydroxyapatite-doped polycaprolactone, or zinc oxide-doped polycaprolactone.
[0010] Preferably, in the composite strip anchor, a mechanical interlocking structure is formed between the columnar core and the covering layer that covers the columnar core.
[0011] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:
[0012] This invention provides a fully degradable composite anchor with wire, comprising an anchor body and a wire hole. The anchor body includes a columnar core and a covering layer encasing the columnar core; the covering layer encasing the columnar core has threads; the columnar core is a biodegradable metal material, and the covering layer encasing the columnar core is a biodegradable polymer material. The composite anchor uses a biodegradable polymer material as the matrix phase and a biodegradable metal material as the reinforcing phase, combining the advantages of both materials. It is fully degradable, and its mechanical and degradation properties are easily controlled. The biodegradable polymer material degrades to acidic conditions, while the biodegradable metal material degrades to alkaline conditions, avoiding the defects of single-material implantation causing local pH changes and hindering cell survival. Furthermore, this invention enhances the combination of the two materials through structural design and surface treatment, further improving degradation performance, mechanical strength, and especially pull-out resistance. The composite suture anchor prepared by this invention is completely biodegradable in the body, which can effectively avoid the great pain caused to patients by secondary surgery, and can be customized with different mechanical performance requirements according to needs. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the fully degradable composite anchor with wire in this utility model; Figure 1 In the diagram, 1 is the thread hole, 2 is the columnar core, 3 is the covering layer that covers the columnar core, 4 is the thread, and 5 is the circular through hole.
[0015] Figure 2 Stress-strain curves for different materials (stain—strain, stress—stress). Detailed Implementation
[0016] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0017] As a preferred embodiment of this utility model, this utility model provides a fully degradable composite anchor with wire, the composite anchor with wire includes an anchor body and a wire hole; the anchor body includes a columnar core and a covering layer covering the columnar core; the covering layer covering the columnar core is provided with threads; the columnar core is a biodegradable metal material, and the covering layer covering the columnar core is a biodegradable polymer material.
[0018] In a preferred embodiment of this utility model, the biodegradable metal material is a magnesium alloy or a zinc alloy.
[0019] In a preferred embodiment of this utility model, the magnesium alloy was purchased from Suzhou Jingjun New Materials Co., Ltd.; the zinc alloy was purchased from Suzhou Jingjun New Materials Co., Ltd.
[0020] In this invention, magnesium alloy or zinc alloy is used as the reinforcing phase of the composite strip anchor, thereby endowing the material with excellent mechanical properties.
[0021] As a preferred embodiment of this utility model, the biodegradable polymer material is polylactic acid, polycaprolactone, hydroxyapatite-doped polylactic acid, zinc oxide-doped polylactic acid, hydroxyapatite-doped polycaprolactone, or zinc oxide-doped polycaprolactone.
[0022] In a preferred embodiment of this utility model, polylactic acid was purchased from Nature Works, USA, model number 3051D, with a number average molecular weight of 80,000; polycaprolactone was purchased from Solvay, USA, with a number average molecular weight of 80,000; the hydroxyapatite-doped polylactic acid, zinc oxide-doped polylactic acid, hydroxyapatite-doped polycaprolactone, and zinc oxide-doped polycaprolactone were prepared by conventional techniques in the art.
[0023] In this invention, polylactic acid (PLA) or polycaprolactone (PCT) is used as the matrix phase of the composite wire anchor. The material is FDA certified, possesses biocompatibility, moderate mechanical properties, and is completely degradable in vivo. Nanoscale bioactive materials (hydroxyapatite or zinc oxide nanoparticles) are doped into PLA to obtain hydroxyapatite-doped PLA, zinc oxide-doped PLA, hydroxyapatite-doped PCT, or zinc oxide-doped PCT. Using these as the matrix phase can further enhance tissue compatibility and promote osseointegration.
[0024] In a preferred embodiment of this invention, before preparing the composite wire anchor, the biodegradable metal material is surface-treated. The purpose of the surface treatment is to reduce the corrosion and degradation rate of the biodegradable metal material and enhance the interfacial bonding between the biodegradable metal material (columnar core) and the biodegradable polymer material (coating layer covering the columnar core). The surface treatment methods include micro-arc oxidation or chemical modification. The reagents used in the chemical modification method include hydrofluoric acid, dopamine, or γ-aminopropyltriethoxysilane. The surface treatment is carried out using conventional techniques in the art.
[0025] In a preferred embodiment of this utility model, a mechanical interlocking structure is formed between the columnar core and the coating layer covering the columnar core in the composite anchor. Specifically, the biodegradable metal material (columnar core) is drilled, and the shape, size, and depth of the drilling are conventionally selected by those skilled in the art according to specific performance requirements. The purpose of the drilling is to form a mechanical interlocking structure between the biodegradable metal material (columnar core) and the biodegradable polymer material (coating layer covering the columnar core), thereby further improving the pull-out resistance of the composite anchor.
[0026] As a preferred embodiment of this utility model, such as Figure 1 As shown, this utility model provides a fully degradable composite anchor with wire, the composite anchor with wire includes an anchor body and a wire hole 1; the anchor body includes a columnar core 2 and a covering layer 3 covering the columnar core; the covering layer 3 covering the columnar core is provided with threads 4; a plurality of circular through holes 5 are evenly distributed on the columnar core 2.
[0027] As a preferred embodiment of this utility model, the composite anchor with wire strip is prepared by using conventional injection molding process in the art.
[0028] In this invention, after drilling, the surface of the columnar core of the metal material has circular holes. During the injection molding process, the polymer material is embedded in the holes of the columnar core and solidifies to form protrusions. These protrusions are then bonded together through the holes of the columnar core to form a single unit, achieving mechanical interlocking, i.e., a mechanical interlocking structure (the covering layer 3 covering the columnar core is embedded in the circular holes of the columnar core 2 to form a mechanical interlocking structure).
[0029] Example 1
[0030] A magnesium alloy rod with a length of 120 mm and a diameter of 4 mm was drilled along its radial central axis to obtain 24 parallel through holes with a diameter of 0.8 mm and a center distance of 5 mm. The drilled magnesium alloy rod was then subjected to surface treatment. Specifically, the magnesium alloy rod was immersed in a 40% hydrofluoric acid solution at a temperature of 25°C for 24 hours. After immersion, it was washed with water and then with anhydrous ethanol in sequence, and then air-dried for later use.
[0031] Zinc oxide, polylactic acid, and dichloromethane were mixed evenly to obtain 70 mL of polylactic acid solution. The total mass concentration of zinc oxide and polylactic acid in the polylactic acid solution was 0.125 g / mL, and the mass ratio of zinc oxide to polylactic acid was 3:97. The polylactic acid solution was poured into a tray with a length of 180 mm and a width of 130 mm and placed in a fume hood for evaporation for 24 h to obtain a zinc oxide-doped polylactic acid film with a thickness of 0.3 mm. The film was then cut into small pieces for later use.
[0032] The magnesium alloy rod to be used is fixed in the injection mold. 2.5g of zinc oxide-doped polylactic acid film cut into small pieces is added to the material tank and preheated at 180°C. After the zinc oxide-doped polylactic acid film is completely melted, injection molding is started. The injection temperature is set to 40°C, the injection pressure is 70MPa, and the pressure is held for 15s to obtain the anchor body including the columnar core and the coating layer covering the columnar core.
[0033] The purpose of preparing the "anchor body including a columnar core and a coating layer covering the columnar core" in this embodiment is to facilitate tensile testing. In actual preparation of the composite wire anchor, only conventional technical means in the field are needed, and the composite wire anchor including the threaded hole and thread can be obtained by changing the appropriate injection mold.
[0034] According to GB / T 228.1-2021 standard for tensile testing of metallic materials, the anchor body (marked as novel Mg-PLA) prepared in this embodiment was subjected to a tensile test. The novel Mg-PLA was tightly fixed in a fixture, and the test was conducted at a constant speed of 2 mm / min. The load-displacement curve and the maximum force applied when pulling a single filament from the PLA matrix were recorded. The gauge length was 60 mm. Using the same test method, single polylactic acid rods (marked as PLA) and Mg-PLA composite rods prepared by conventional methods were tested (keeping other conditions unchanged in Example 1, omitting the drilling and surface treatment of the magnesium alloy rods, and omitting the addition of zinc oxide to the polylactic acid solution, marked as Mg-PLA). The stress-strain curves of different materials were obtained, as shown in the figure. Figure 2 As shown. From Figure 2As can be seen, the Mg-PLA composite rods prepared by the traditional method have very limited effect on improving tensile mechanical properties due to the poor interfacial bonding performance between the Mg columnar core and the PLA coating layer covering the columnar core. The improvement is only 1.42 times that of pure PLA, increasing from 51 MPa to 72.56 MPa. The novel Mg-PLA prepared in this embodiment has good interfacial bonding and significantly improved mechanical properties, which are 3.05 times that of pure PLA, increasing to 156.21 MPa.
[0035] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.
Claims
1. A fully biodegradable composite anchor with wire, characterized in that, The composite anchor with wire includes an anchor body and a wire hole. The anchor body includes a columnar core and a covering layer that covers the columnar core. The covering layer that covers the columnar core is provided with threads. The columnar core is a biodegradable metal material, and the coating layer covering the columnar core is a biodegradable polymer material.
2. The fully degradable composite anchor with wire as described in claim 1, characterized in that, Biodegradable metallic materials are magnesium alloys or zinc alloys.
3. The fully degradable composite anchor with wire as described in claim 1, characterized in that, In composite strip anchors, a mechanical interlocking structure is formed between the columnar core and the covering layer that encapsulates the columnar core.