A method of manufacturing a medical metal implant having a 3D printed striation texture and a medical metal implant and uses thereof

Abstract

The application provides a manufacturing method of a medical metal implant with a 3D printing stripe texture, the medical metal implant and the use thereof. The manufacturing method comprises the following steps: S1, establishing a three-dimensional model of a customized bone implant according to the anatomical morphology of a patient bone defect position; S2, designing a metal composition and a structure of the customized bone implant, wherein the structure design comprises a surface stripe texture interval, and the surface stripe interval is 50-500 microns; S3, performing cross-section profiling on the three-dimensional model of the bone implant, and determining a laser scanning interval and an interlayer scanning rotation angle of a laser powder bed fusion printer based on the structure design of the bone implant, wherein the laser scanning interval is 100-400 microns, and the interlayer scanning rotation angle is 0 or 60 degrees; and S4, printing and forming by layer-by-layer powder feeding and laser scanning fusion based on printing data, so as to obtain an integrated medical metal implant with a 3D printing stripe texture.

Description

Technical Field

[0001] This invention belongs to the field of medical metal materials, specifically relating to a method for manufacturing a medical metal implant with a 3D printed striped texture, and the medical metal implant and its uses. Background Technology

[0002] Bone defects of critical size caused by trauma, tumor resection, and other factors cannot heal and reconstruct spontaneously by the body, making them difficult to treat in orthopedic clinics and requiring replacement repair with artificial bone implants. Ideally, implants should be made of biocompatible materials, providing sufficient mechanical support and ample interconnected pore space for tissue invasion, cellular nutrition, and oxygenation, especially during the early angiogenesis stage. Furthermore, the bone scaffold should function to stimulate and guide the bone tissue regeneration process; that is, the scaffold design should provide cues to stimulate cells to produce de novo bone tissue and guide this process in the correct direction to reshape the bone tissue into the original anatomical shape of the segmental defect.

[0003] L-PBF technology has increasingly become a key technology for manufacturing porous metal scaffolds. It employs a high-energy laser to selectively melt metal powder layer by layer with precise control, enabling the high-precision and efficient fabrication of digitally designed porous structures. However, limited by the laser spot size, it can only provide pore structures of a few hundred micrometers. Suitable pore sizes not only promote cell permeability but also ensure the effective delivery of nutrients and oxygen, while promptly removing metabolic waste, thereby improving cell viability and accelerating tissue regeneration. However, for biodegradable metals, surface and structural design also affect the degradation process. The low biodegradation rate and poor surface wettability of zinc alloys pose challenges to cell adhesion, proliferation, and subsequent osteogenic processes.

[0004] Currently, researchers are altering the wettability of bone scaffold surfaces through surface treatments such as acid etching to promote initial cell adhesion. Meanwhile, studies have shown that introducing striped structures with specific orientations and morphologies onto the scaffold surface is also an important strategy that can significantly influence cell behavior. These striped structures not only provide physical cues conducive to cell adhesion, migration, and orientation, but also mimic the topological features of the natural tissue microenvironment, enhancing the biomimetic properties of the scaffold.

[0005] Reference 1 discloses a dental implant and its fabrication method, in which a surface etching process is used to form micro-striped structures on the implant surface. This surface etching process includes laser etching or chemical etching. However, while traditional methods such as laser etching and chemical etching can construct striped structures on planar materials, their processes are often complex and subject to parameter control limitations, leading to problems such as limited processing accuracy and poor structural uniformity. These methods are difficult to adapt to the complex and curved three-dimensional surface processing requirements of 3D printed metal scaffolds, severely limiting their widespread application in personalized bone scaffold fabrication.

[0006] Therefore, providing a method to adapt to the complex and curved three-dimensional surface treatment requirements of 3D printed metal supports to introduce striped structures with specific orientation and morphology is an urgent problem to be solved.

[0007] References:

[0008] Reference 1: CN111728726A Summary of the Invention

[0009] The problem the invention aims to solve

[0010] To address the problem that existing technologies cannot form striped texture patterns on the surface of 3D-printed medical metal implants, this invention proposes to design a medical metal implant with 3D-printed striped texture by using a novel method to optimize the design of laser powder bed melting (L-PBF) process parameters, thereby improving the wettability and biocompatibility of the implant to achieve good bone regeneration.

[0011] Solution for solving the problem

[0012] This invention first provides a method for manufacturing a medical metal implant with a 3D-printed striped texture, which includes the following steps:

[0013] S1: Establish a three-dimensional model of a customized bone implant based on the anatomical morphology of the patient's bone defect location;

[0014] S2: Metal composition and structural design of customized bone implants, wherein the structural design includes surface stripe texture spacing of 50~500μm;

[0015] S3: The three-dimensional model of the bone implant is cross-sectionally segmented, and the laser scanning spacing and interlayer scanning rotation angle of the laser powder bed fusion printer are determined based on the structural design of the bone implant, wherein the laser scanning spacing is 100~400μm, and the interlayer scanning rotation angle is 0 or 60°.

[0016] S4: Based on the printing data, the medical metal implant with 3D printed stripe texture is obtained by printing through layer-by-layer powder feeding and laser scanning melting.

[0017] According to the manufacturing method of the present invention, the metal includes at least one selected from inert metals, magnesium alloys, pure zinc, and zinc alloys.

[0018] According to the manufacturing method of the present invention, the structural design further includes a pore structure, wherein the porosity of the metal implant is 50-90%, the pore unit size is 1-2 mm, and the pore diameter is 300-600 μm;

[0019] Preferably, the pore unit is a biomimetic structure, and more preferably a triple-period minimal surface structure.

[0020] According to the manufacturing method of the present invention, in step S4, the step of layer-by-layer powder feeding and laser scanning melting includes: pre-placing the nano-metal powder prepared by argon atomization in the powder chamber of the laser powder bed melting printer, pre-placing the scraper on the focal plane, filling the processing chamber with argon gas to maintain a purity of more than 99.99%, and keeping the oxygen content below 120ppm, and performing melting and forming according to the printing data.

[0021] According to the manufacturing method of the present invention, the laser scanning power of the laser powder bed fusion printer is 50-500W, the scanning speed is 200-2000mm / s, the layer thickness is 0.01-0.05mm, and the laser spot diameter is 0.05-0.07mm.

[0022] According to the manufacturing method of the present invention, the average particle size of the nano-metal powder is 15-50 nm.

[0023] According to the manufacturing method of the present invention, the manufacturing method further includes a post-processing step, the post-processing including: ultrasonic treatment of the metal implant.

[0024] According to the manufacturing method of the present invention, the ultrasound includes ultrasound in anhydrous ethanol for 10-30 minutes.

[0025] The present invention also provides a metal implant manufactured by the manufacturing method described in the present invention, wherein the metal implant includes a metal scaffold and a regular striped texture pattern distributed on the surface of the metal scaffold, and the stripe spacing of the striped texture is 50~500μm.

[0026] The present invention also provides the use of a metal implant manufactured by the manufacturing method described in the present invention for filling bone defects.

[0027] The effects of the invention

[0028] This invention provides a method for manufacturing medical metal implants with 3D-printed striped textures. By using a specific combination of laser scanning spacing and interlayer scanning rotation angle during L-PBF printing, a regular striped texture can be formed on the surface of the metal scaffold. The stripe spacing can be adjusted by regulating the scanning spacing. This enhances capillary action, improving the surface wettability and biocompatibility of the medical metal implant. Furthermore, by increasing material exchange efficiency and regulating cell adhesion and other behaviors to match the bone repair microenvironment, the bioreactivity of the implant interface with surrounding bone tissue is improved. This method has significant application potential for the rapid, accurate, and controllable performance enhancement of personalized bone repair implants in clinical settings. Attached Figure Description

[0029] Figure 1 A schematic diagram illustrating the manufacturing process of the medical metal implant with 3D-printed striped texture of the present invention is shown.

[0030] Figure 2 The μ-CT model of the striped texture of implants prepared by zinc alloy under different scanning interval parameters in Examples 1-3 and the surface morphology observed by SEM are shown.

[0031] Figure 3 The surface morphology of the striped texture of implants prepared by zinc alloy under different interlayer rotation angle parameters in Examples 2 and 4 is shown by SEM observation in the X and Y axes.

[0032] Figure 4 The surface morphology of the striped texture of implants prepared by titanium alloys in Examples 4-5 and Comparative Example 1 under different scanning spacing parameters is shown under SEM observation.

[0033] Figure 5 The bar graphs showing the specific surface area of ​​implants prepared by zinc alloy under different scanning interval parameters in Examples 1-3 are shown.

[0034] Figure 6 The following are scanning electron microscope images of cell adhesion of implants prepared by zinc alloy under different scanning interval parameters in Comparative Example 1 and Examples 1-3;

[0035] Figure 7 Line graphs showing the degradation mass loss of implants prepared by zinc alloy under different scanning interval parameters in Examples 1-3 are shown. Detailed Implementation

[0036] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0037] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0038] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0039] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0040] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0041] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0042] <First Aspect>

[0043] A first aspect of the present invention provides a method for manufacturing a medical metal implant with a 3D-printed striped texture, comprising the following steps:

[0044] S1: Establish a three-dimensional model of a customized bone implant based on the anatomical morphology of the patient's bone defect location;

[0045] S2: Metal composition and structural design of customized bone implants, wherein the structural design includes surface stripe texture spacing of 50~500μm;

[0046] S3: The three-dimensional model of the bone implant is cross-sectionally segmented, and the laser scanning spacing and interlayer scanning rotation angle of the laser powder bed fusion printer are determined based on the structural design of the bone implant, wherein the scanning spacing is 100~400μm, and the interlayer scanning rotation angle is 0 or 60°.

[0047] S4: Based on the printing data, the medical metal implant with 3D printed stripe texture is obtained by printing through layer-by-layer powder feeding and laser scanning melting.

[0048] The preparation method of this invention employs laser powder bed fusion (L-PBF) technology. By optimizing the scanning strategy, a periodic striped texture structure is formed on the surface of the metal scaffold, thereby improving the biocompatibility of the implant interface with the surrounding bone tissue. This method can directly obtain an integrated medical metal implant with a 3D-printed striped texture without additional post-processing steps to apply the striped texture to the metal scaffold surface, offering advantages such as high controllability, repeatability, and high process integration.

[0049] Specifically, the manufacturing method of the medical metal implant with 3D printed striped texture of the present invention can be found in [reference needed]. Figure 1 The following is a combination of... Figure 1 Each step is described in detail:

[0050] (Step S1)

[0051] In step S1 of the present invention, a three-dimensional model of a customized bone implant is established based on the anatomical morphology of the patient's bone defect location.

[0052] The present invention does not impose any particular limitation on the method of establishing the three-dimensional model. For example, the data of bone defects can be imported into a computer through CT scanning or other means to establish a three-dimensional model for implants used to repair bone defects.

[0053] (Step S2)

[0054] In step S2 of this invention, the metal composition and structural design of the customized bone implant are described. The structural design primarily includes the surface stripe pattern spacing, which is 50-500 μm, for example, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, etc. The presence of the stripe pattern enhances the wettability of the bone implant metal scaffold through capillary action, strengthens cell adhesion, and allows for rapid infiltration of body fluids and nutrients after implantation, providing high material exchange efficiency. This promotes the subsequent osteogenic process and facilitates good bone regeneration.

[0055] Regarding the metal composition, such as Figure 1As shown, the metal composition can be designed based on clinical needs such as the load-bearing characteristics, blood supply properties, and susceptibility to infection at the site of the bone defect. Taking the vertebral vertebra as an example, according to the physiological structure and functional requirements of the spine, a high load-bearing capacity is required. Therefore, the metal composition should be a metal with high load-bearing capacity to provide initial mechanical support for the bone defect. Preferably, the metal scaffold can gradually degrade in body fluids, eliminating the need for secondary surgical removal, and also possesses good biocompatibility.

[0056] In some specific embodiments, the metal may include at least one of inert metals, magnesium alloys, pure zinc, zinc alloys, and stainless steel. The inert metal may include pure titanium or titanium alloys. Preferably, the titanium alloy may include TC4 (Ti-6Al-4V) or other clinically approved titanium alloys. The magnesium alloy may include WE43 or other clinically approved magnesium alloys. The zinc alloy may include Zn-Li, Zn-Mg, or other clinically approved zinc alloys. The stainless steel may include 316L or other clinically approved stainless steel.

[0057] In some specific implementations, the structural design may further include a porous structure, wherein the porosity of the metal implant is 50-90%, for example, 55%, 60%, 65%, 70%, 75%, 80%, 85%, etc.; the pore unit size is 1-2 mm; and the pore diameter is 300-600 μm, for example, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, etc.

[0058] In some preferred embodiments, the pore unit can be a biomimetic structure, such as a triple periodic minimal surface (TPMS) structure.

[0059] In the process of manufacturing striped textures by adjusting the laser scanning spacing using the present invention, the design of metal composition and pore structure parameters can meet the needs of load-bearing and bone healing characteristics of bone defects in different locations. Zinc alloys have a slow degradation rate, and the problem of slow degradation rate and mismatch with bone healing cycle can be solved by using a higher scanning spacing to design striped textures with larger spacing to increase the specific surface area of ​​the scaffold.

[0060] (Step S3)

[0061] In step S3 of the present invention, the three-dimensional model of the bone implant is cross-sectionally segmented, and the laser scanning spacing and interlayer scanning rotation angle of the laser powder bed fusion printer are determined based on the structural design of the bone implant. Figure 1(Parameter optimization in the process), wherein the laser scanning spacing is 100~400μm, for example, it can be 150μm, 200μm, 250μm, 300μm, 350μm, etc., and the interlayer scanning rotation angle is 0 or 60°. Generally speaking, the default interlayer scanning rotation angle of the laser powder bed fusion printer is 67°. However, the inventors discovered that by adjusting the interlayer scanning rotation angle and scanning spacing to the above range, a regular stripe texture can be formed on the surface of the metal support through the combination of the two. The larger the laser scanning spacing, the larger the spacing of the stripe texture pattern formed, and the spacing of the stripe texture pattern is approximately equal to the scanning spacing.

[0062] In some specific implementation schemes, step S3 may also determine the laser power, scanning speed and other printing parameters of the laser powder bed fusion printer based on the material and structural characteristics of the implant, and input the interface contour parameter data into the printer.

[0063] (Step S4)

[0064] In step S4 of the present invention, the medical metal implant with 3D printed stripe texture is obtained by printing the material based on the printing data through layer-by-layer powder feeding and laser scanning melting.

[0065] In some specific implementation schemes, the steps of layer-by-layer powder feeding and laser scanning melting are as follows: Figure 1 The laser powder bed melting process, as shown in the diagram, specifically includes: pre-placing nano-metal powder prepared by argon atomization in the powder chamber of a laser powder bed melting printer; pre-positioning a scraper on the focal plane; filling the forming chamber with argon gas, maintaining a purity of over 99.99% and keeping the oxygen content below 120 ppm; and melting and forming according to the printing data to obtain a metal implant with a surface stripe texture, which can increase the specific surface area and enhance cell adhesion.

[0066] In some specific implementations, the laser scanning power used in the laser powder bed fusion printer can be 50–500W, for example, 100W, 150W, 200W, 250W, 300W, 350W, 400W, 450W, etc.; the scanning speed can be 200–2000mm / s, for example, 500mm / s, 800mm / s, 1000mm / s, 1200mm / s, 1500mm / s, etc.; the layer thickness can be 0.01–0.05mm, for example, 0.02mm, 0.03mm, 0.04mm, etc.; and the laser spot diameter can be 0.05–0.07mm, for example, 0.055mm, 0.06mm, 0.065mm, etc.

[0067] In some specific implementations, the average particle size of the nano-metal powder is 15-50 nm, for example, it can be 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, etc.

[0068] (Other steps)

[0069] The manufacturing method of the present invention may further include a post-processing step, wherein the post-processing includes: subjecting the metal implant to ultrasonic treatment.

[0070] In some specific implementations, the ultrasound includes sonication in anhydrous ethanol for 10 to 30 minutes, for example, 15 minutes, 20 minutes, 25 minutes, etc.

[0071] In some preferred embodiments, the post-processing includes: after the chamber temperature has cooled to room temperature, opening the chamber door, removing the printed implant and substrate, separating the part from the substrate using wire cutting, and sonicating in anhydrous ethanol to remove unmelted powder.

[0072] <Second aspect>

[0073] A second aspect of the present invention provides a metal implant manufactured according to the manufacturing method described in the first aspect, wherein the metal implant includes a metal scaffold and a regular striped texture pattern distributed on the surface of the metal scaffold. The stripe spacing of the stripe texture is 50~500μm, for example, it can be 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, etc. The stripe spacing should be approximately equal to the scanning spacing, and it is also related to the material properties. Depending on the material, the parameter range for the appearance of stripe morphology is different. For example, for stainless steel or titanium alloy, stripe morphology can generally be observed above 100μm, while for zinc alloy, a scanning spacing of 200μm is required to observe obvious stripe morphology.

[0074] <Third aspect>

[0075] A third aspect of the present invention provides the use of a metal implant manufactured according to the manufacturing method of the first aspect for filling bone defects.

[0076] Example

[0077] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0078] Example 1

[0079] (1) Perform CT scans on the vertebral vertebral bone defects of the patient and import the data into a computer to establish a three-dimensional model for implants to repair bone defects;

[0080] (2) Based on the physiological structure and functional requirements of the vertebral vertebrae, a high load-bearing capacity is required. Among the alloy compositions, Zn-0.8Li has a tensile strength of over 600 MPa, close to that of pure titanium, which can provide initial mechanical support for bone defects and gradually degrade in body fluids, eliminating the need for secondary surgical resection. At the same time, alloying with the bioactive element Li can improve the strength of pure Zn and enhance its biocompatibility. Therefore, Zn-0.8Li was chosen for preparation.

[0081] (3) The model of the support was designed according to the TPMS method. The structural parameters are: large pore diameter of 900 μm, porosity of 70%, and pore unit size of 1.55 mm.

[0082] (4) The pre-alloyed Zn-0.8Li cylindrical rods were converted into powder by inert gas atomization, resulting in an average particle size of 26.9 μm. The powder was then dried in a vacuum oven at 70°C for 4 h to remove moisture. Sample preparation was performed using an L-PBF system with a single-mode ytterbium fiber laser, a focal diameter of 70 μm, and a working wavelength of 1070 nm. During the processing, the chamber was filled with argon gas, maintaining a purity of over 99.99% during melting and keeping the oxygen content below 120 ppm. Pure Zn plates were used as the substrate, which were ground and cleaned with ethanol before each printing.

[0083] (5) The key parameters of the L-PBF process include laser power (P), scanning speed (Vs), scanning spacing (Hs), and layer thickness (Ds). By optimizing the processing parameters, Ds was set to 20 μm, P and Vs were set to 40 W and 800 mm / s, respectively, and Hs was selected as 100 μm. The internal scanning adopted a zigzag pattern, and the rotation angle of each layer was 60° to ensure the mechanical properties of the implant.

[0084] (6) After printing, wait for the temperature inside the printing chamber to cool to room temperature, open the chamber door and take out the printed parts and substrate. Separate the parts from the substrate using a cutting machine. Then soak the parts in alcohol and clean them for 20 minutes at a frequency of 25kHz to further remove the powder attached to the surface. Finally, dry the parts with a hair dryer to obtain an integrated medical metal implant with 3D printed striped texture.

[0085] Example 2

[0086] The difference from Example 1 is that Hs is replaced with 200μm in step (5).

[0087] Example 3

[0088] The difference from Example 1 is that Hs is replaced with 300μm in step (5).

[0089] Example 4

[0090] The difference from Example 2 is that the interlayer rotation angle is replaced with 0° in step (5).

[0091] Example 5

[0092] The difference from Example 1 is that in step (2), Zn-0.8Li is replaced with TC4 (Ti-6Al-4V).

[0093] Example 6

[0094] The difference from Example 2 is that Zn-0.8Li is replaced with TC4 (Ti-6Al-4V) in step (2).

[0095] Comparative Example 1

[0096] The difference from Example 4 is that in step (5), Hs is replaced with 70μm and each layer is rotated by 67°, under which there is no striped texture.

[0097] Performance testing

[0098] 1. Surface stripe structure test: The μ-CT models of the integrated medical metal implants with 3D-printed stripe texture obtained in Examples 1-5 and Comparative Example 1 were analyzed using a 3D X-ray microscope. The surface microstructure of the metal implants obtained in Examples 1-6 and Comparative Example 1 was observed using a scanning electron microscope. The test results for Examples 1-3 are as follows: Figure 2 As shown, the test results of Example 1 and Example 4 are as follows: Figure 3 As shown, the test results of Examples 5-6 and Comparative Example 1 are as follows: Figure 4 As shown.

[0099] Depend on Figure 2 It can be seen that the prepared zinc alloy implant samples exhibit obvious striped texture micropatterns when the scanning interval is greater than 200 μm. Specifically, the stripe spacing of the zinc alloy implant sample prepared in Example 2 is approximately 200 μm, and the stripe spacing of the zinc alloy implant sample prepared in Example 3 is approximately 300 μm, which is basically consistent with the scanning interval. Figure 4 It can be seen that the titanium alloy samples prepared in Examples 4 and 5 have obvious striped texture micropatterns above 100 μm, while Comparative Example 1 could not form a striped structure because the scanning spacing and rotation angle did not meet the conditions of this invention. This demonstrates that the stripe spacing of this preparation method can be adjusted by changing the scanning spacing, proving that this preparation method has advantages of high controllability, repeatability, and high process integration.

[0100] Depend on Figure 3 It can be seen that when the rotation angle is 0° (Example 4), a distinct striped texture can also be formed, but this will lead to mechanical anisotropy, making it impossible to form a striped texture in the Y-axis direction. However, when the rotation angle is 60° (Example 2), the anisotropy can be eliminated to a certain extent, and a distinct striped texture can be formed in both the X-axis and Y-axis directions.

[0101] 2. Specific surface area test: Nitrogen adsorption method was used for determination. The test was based on the BET theory proposed by Stephen Brunauer, Paul Hugh Emmett, and Edward Teller. Samples prepared in Examples 1-3 were placed in a specific surface area analyzer (SI-MP type, Konta). Before testing, the samples were degassed under vacuum at 100–200℃ for 4–12 h to remove surface adsorbates. Using high-purity nitrogen as the adsorbate, adsorption isotherms were measured at 77 K. BET linear fitting was performed within the relative pressure range of 0.05–0.30 to calculate the monolayer adsorption capacity and obtain the sample specific surface area (m² / g). The results are as follows: Figure 5 As shown.

[0102] Depend on Figure 5 It can be seen that the larger the stripe spacing of the striped texture, the larger the specific surface area of ​​the support, and the better it can provide material exchange.

[0103] 3. BMSCs Adhesion Assay: After sterilizing the 3D-printed metal scaffold with UV irradiation for 30–60 min, it was immersed in simulated body fluid for 48 h, and the solution was discarded. The sample was placed in a 24-well plate and co-cultured with BMSCs for 48 h. After the culture, the culture medium was discarded, and the sample was washed twice with PBS buffer to remove non-adhering cells. Subsequently, the sample was subjected to a gradient dehydration treatment with 50%, 60%, 70%, 80%, 90%, 95%, and 100% ethanol (volume fractions), each stage lasting 10–15 min, and dried overnight. After gold sputtering, the cell adhesion morphology on the scaffold surface was observed using scanning electron microscopy to evaluate the cell adhesion performance of the scaffold. The metal implants prepared in Examples 1–3 and Comparative Example 1 were tested according to the above method, and the test results are as follows: Figure 6 As shown, where, Figure 6 The blue part in the image represents the cell adhesion region.

[0104] Depend on Figure 6As can be seen, in Comparative Example 1, due to the lack of surface striations, the adhered cells were spherical with no obvious pseudopodia, resulting in poor spreading. Compared to Comparative Example 1 without striations, Examples 1-3 enhanced cell adhesion and viability through striations on the surface of the metal implants, and also provided better wettability. Therefore, the formation of surface striations can be precisely controlled through customized parameter design to achieve a suitable bone regeneration process. This invention provides a microstructure control strategy integrated into the 3D printing process, balancing manufacturing efficiency and functional improvement, and offering a new direction for the development of next-generation intelligent bone implant materials.

[0105] 4. Degradation Rate Test of Biodegradable Metals: The 3D-printed porous metal scaffold was immersed in Hank's solution (37°C, pH 7.4) according to ASTM G31-72. The solution volume to sample surface area ratio was maintained at 20 mL / cm², and the immersion was continued at 37°C for 28 days. After the experiment, the sample was removed, washed with deionized water, and corrosion products were removed using CrO3 solution. The sample mass was then measured using an electronic balance with an accuracy of ±0.1 mg. The metal implants prepared in Examples 1-3 were tested according to the above method, and the test results are as follows. Figure 7 As shown.

[0106] Depend on Figure 7 It can be seen that the mass loss of the zinc alloy porous scaffold follows the same trend as the specific surface area. The increase in porosity and the expansion of specific surface area brought about by the striped texture significantly accelerate the degradation rate of the sample.

[0107] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0108] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for manufacturing a medical metal implant with a 3D-printed striped texture, characterized in that, It includes the following steps: S1: Establish a three-dimensional model of a customized bone implant based on the anatomical morphology of the patient's bone defect location; S2: Metal composition and structural design of customized bone implants, wherein the structural design includes surface stripe texture spacing of 50~500μm; S3: The three-dimensional model of the bone implant is cross-sectionally segmented, and the laser scanning spacing and interlayer scanning rotation angle of the laser powder bed fusion printer are determined based on the structural design of the bone implant, wherein the laser scanning spacing is 100~400μm, and the interlayer scanning rotation angle is 0 or 60°. S4: Based on the printing data, the medical metal implant with 3D printed stripe texture is obtained by printing through layer-by-layer powder feeding and laser scanning melting.

2. The manufacturing method according to claim 1, characterized in that, The metal includes at least one of inert metals, magnesium alloys, pure zinc, and zinc alloys.

3. The manufacturing method according to claim 1 or 2, characterized in that, The structural design also includes a pore structure, wherein the porosity of the metal implant is 50-90%, the pore unit size is 1-2 mm, and the pore diameter is 300-600 μm; Preferably, the pore unit is a biomimetic structure, and more preferably a triple-period minimal surface structure.

4. The manufacturing method according to any one of claims 1 to 3, characterized in that, In step S4, the step of layer-by-layer powder feeding and laser scanning melting includes: pre-placing the nano-metal powder prepared by argon atomization in the powder chamber of the laser powder bed melting printer, pre-placing the scraper on the focal plane, filling the processing chamber with argon gas to maintain a purity of over 99.99%, and keeping the oxygen content below 120ppm, and melting and forming according to the printing data.

5. The manufacturing method according to claim 4, characterized in that, The laser powder bed fusion printer uses a laser scanning power of 50-500W, a scanning speed of 200-2000mm / s, a layer thickness of 0.01-0.05mm, and a laser spot diameter of 0.05-0.07mm.

6. The manufacturing method according to claim 4 or 5, characterized in that, The average particle size of the nano-metal powder is 15-50 nm.

7. The manufacturing method according to any one of claims 1 to 6, characterized in that, The manufacturing method further includes a post-processing step, which includes ultrasonic treatment of the metal implant.

8. The manufacturing method according to claim 7, characterized in that, The ultrasound consists of sonication in anhydrous ethanol for 10-30 minutes.

9. A metal implant manufactured by the manufacturing method according to any one of claims 1 to 8, characterized in that, The metal implant includes a metal scaffold and a regular striped pattern distributed on the surface of the metal scaffold, wherein the stripe spacing of the striped pattern is 50~500μm.

10. The use of a metal implant manufactured by the manufacturing method according to any one of claims 1 to 8 for filling bone defects.

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