Implanted prosthesis structure imitating lantern design and preparation method thereof

Abstract

The invention discloses an implanted prosthesis structure imitating lantern design and a preparation method thereof, and relates to the field of medical implants.The implanted prosthesis structure comprises an implant and a lantern-shaped bridging structure, a composite coating is deposited on the implant, and the composite coating comprises three layers including a homing layer, a response layer and a piezoelectric layer from inside to outside. Through cooperation of the homing layer and the response layer, endogenous repair cells can be actively collected, regulatory factors are intelligently and sequentially released according to the healing stage, accurate and active guidance of the angiogenesis and osteogenesis process is achieved, and the certainty and speed of osseointegration are greatly improved; biochemical signals and piezoelectric bioelectricity signals triggered by physiological loads are creatively fused, a chemical-physical dual synergistic stimulation mechanism is formed, daily functional activities are converted into effective treatment for promoting bone healing, and the bone regeneration efficiency is remarkably enhanced.

Description

Technical Field

[0001] This invention relates to the field of medical implants, and more specifically, to an implant prosthesis structure with a lantern-like design and its preparation method. Background Technology

[0002] Repairing large bone defects is one of the most challenging problems in orthopedics. Current mainstream treatment strategies fall into two main categories: one relies on transplantation using biomaterials, and the other uses artificial prostheses for reconstruction. Biomaterials, such as autologous bone, while possessing good biocompatibility and osteoinductive potential, face challenges including limited donor availability, donor site complications, and difficulties in shaping. Allogeneic bone, while eliminating the need for autologous bone harvesting, carries risks of immune rejection, disease transmission, slow creeping replacement leading to high refracture rates, and nonunion. Neither approach provides immediate mechanical stability for large defects, often requiring external fixation and prolonging the rehabilitation period. The second category, artificial prosthesis reconstruction, offers a more reliable option for restoring immediate limb structure and function; however, current technologies have significant limitations. Traditional custom-made solid metal prostheses, while possessing high mechanical strength, have smooth surfaces that prevent biointegration with the host bone. To promote bone ingrowth, porous metal implants have been developed. These materials provide physical space for bone tissue ingrowth through osteoconduction mechanisms. However, its osseointegration process is essentially a passive waiting for host repair cell migration, vascular invasion, and new bone deposition. This process is slow, and in cases of poor blood supply and weak osteogenic capacity in the patient, bone ingrowth is extremely unsatisfactory, often resulting in incomplete or absent ingrowth, leading to long-term fixation failure. This limits its function to providing skeletal support, lacking the ability to actively guide and accelerate healing.

[0003] However, whether it is a solid prosthesis or a porous prosthesis, the fixation method to the host bone relies on the traditional use of bone plates and screws to bridge and fix the prosthesis at both ends, or the use of long intramedullary nails to lock the prosthesis through. These traditional fixation methods are highly invasive, requiring extensive soft tissue and periosteal dissection of the limb, severely damaging the blood supply to the bone, increasing the risk of infection, and delaying healing.

[0004] In addition, existing technologies attempt to coat porous metal surfaces with hydroxyapatite (HA) or load them with a single growth factor (such as BMP-2). However, these methods generally have drawbacks: 1) Uncontrollable release behavior: They are mostly simple physical adsorption or mixing, resulting in a burst release of the factor in the early postoperative period, with low bioavailability and potential side effects (such as heterotopic ossification of BMP-2, local inflammatory edema); 2) Single function and lack of synergy: They fail to simulate the natural timing and coupling law of "angiogenesis first, osteogenic differentiation later" in the bone healing process; 3) Lack of environmental responsiveness: They cannot intelligently adjust their treatment strategy according to the specific microenvironment of the implantation site (such as infection, inflammation, hypoxia); 4) Neglecting the mobilization of endogenous repair forces: They rely too much on exogenous factors, fail to effectively design surfaces to actively recruit the patient's own endogenous stem cells and progenitor cells, and fail to fully utilize the body's self-repair potential. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an implant prosthesis structure with a lantern-like design and its preparation method. It not only possesses a mechanical structure that meets load-bearing requirements and stability for permanent service, but also actively intervenes in and intelligently regulates the entire bone regeneration process. By mimicking and enhancing the physiological healing pathway, it ensures rapid, sufficient, and reliable bone-implant fusion under different patients and conditions.

[0006] The first aspect of this invention provides a method for preparing an implant prosthesis structure with a lantern-like design, comprising the following steps: Step 1: Design and model the implant cell, mimicking the structure of a bow and arrow; Step 2: Array the implant cells to obtain the implant; Step 3: Print the implant using laser powder bed fusion additive manufacturing technology; Step four involves depositing a composite coating on the implant obtained in step three to complete the implant preparation. The composite coating deposition includes the preparation of a homing layer, a responsive layer, and a piezoelectric layer. Step 5: The implant after composite coating deposition is fixed using a lantern-shaped bridging structure to obtain the implant prosthesis structure. The preparation of the homing layer includes: activating the implant and immersing it in a dopamine solution to obtain an implant with a dopamine substrate film on its surface, activating the carboxyl groups on the surface of dopamine, and transferring the activated implant to a grafting solution to obtain an implant with a homing layer. The preparation of the response layer includes: dispersing MSNs in PBS buffer containing VEGF, collecting drug-loaded MSNs by centrifugation, adding MSNs to hydrogel precursor A solution and mixing them with hydrogel precursor B solution at a volume ratio of 1:1, and submerging the implant with the homing layer in the mixture to obtain an implant with both the homing layer and the response layer. The piezoelectric layer preparation includes: adding piezoelectric material into a dispersion medium, immersing an implant with a homing layer and a response layer into the medium, and obtaining an implant with a composite coating.

[0007] Preferably, the preparation of the homing layer specifically includes the following steps: The implant was cleaned, dried with nitrogen, and then placed in an oxygen plasma cleaner for activation. Preparation of dopamine solution: Dissolve dopamine hydrochloride in 10mM Tris-HCl buffer, adjust the pH to 8.0-9.0, and prepare a solution with a concentration of 2.0-3.0 mg / mL. Store in the dark. The activated implant was completely immersed in a dopamine solution and placed on a shaker at room temperature for the reaction. The reaction container should be protected from light. After the reaction was completed, the implant was removed and rinsed with deionized water until the rinsing solution was colorless to remove the physically adsorbed dopamine polymer. Then it was vacuum dried to obtain an implant with a dopamine substrate film on its surface. Prepare a solution containing 0.05-0.2M EDC and 0.025-0.1M NHS using 0.1M MES buffer, with the molar ratio of EDC to NHS controlled between 1:0.5 and 1:2. The implant with a dopamine base film on its surface is immersed in the above solution and shaken at 4-25°C for 15-60 minutes to activate the carboxyl groups on the surface of dopamine. The activated implant was transferred to a grafting solution, which was a PBS buffer containing 10-200 μg / mL cyclic RGD peptide and 10-200 μg / mL SDF-1α mimic peptide. The grafting reaction was carried out at 4-10°C for 12-48 hours. After the reaction is complete, the implant is removed and immersed in PBS buffer containing 0.1M glycine or 1M ethanolamine to block unreacted active sites for 1-2 hours at room temperature. After thorough cleaning, the implants are freeze-dried or vacuum-dried at low temperature to obtain implants with a homing layer (5).

[0008] Preferably, the preparation of the response layer specifically includes the following steps: Disperse 10-100 mg of MSNs with a concentration of 2-8 nm in 1-10 mL of PBS buffer containing the target factor VEGF (VEGF concentration of 10-100 μg / mL), shake and adsorb at 4 °C for 12-36 hours, collect the drug-loaded MSNs by centrifugation, wash and freeze-dry. Preparation of hydrogel precursor solution A: Dissolve 2-8 wt% gelatin and 1-4 wt% sodium alginate together in PBS buffer and heat to 37°C to aid dissolution; After cooling the hydrogel precursor solution A to room temperature, MSNs with loading factors were added so that the mass fraction of MSNs in the final gel was 0.5-5.0 wt%. Preparation of hydrogel precursor solution B: Dissolve 1-4 wt% HA-ADH in PBS buffer; Place the implant with the homing layer in a vacuum desiccator. Mix hydrogel precursor liquid A and hydrogel precursor liquid B at a volume ratio of 1:1 on ice until homogeneous. Quickly pour the mixture into a container to submerge the implant with the homing layer. Maintain negative pressure for 5-20 minutes to ensure that the precursor fully penetrates all pores. Remove the implant and place it in an environment of 37°C and >90% humidity for 30-120 minutes to allow it to complete thermo-gelation and Schiff base cross-linking, forming a stable hydrogel coating, thus obtaining an implant with a homing layer and a responsive layer.

[0009] Preferably, the preparation of the piezoelectric layer specifically includes the following steps: Dissolve 1-10 wt% polyvinyl alcohol or 0.5-3 wt% polyethylene oxide in deionized water or an ethanol / water mixture as a dispersion medium. The piezoelectric material was added to the above dispersion medium, so that its solid content in the suspension was 0.1-5.0 wt%. The suspension was intermittently sonicated for 10-30 minutes under ice bath conditions to obtain a uniform and stable suspension. The implant with homing and response layers is immersed in the suspension at a constant speed, left for 30-180 seconds, then pulled out at a uniform speed and dried for 1-4 hours. Repeat the above immersion and lifting process to control the final dry coating thickness at 1-20 μm, thus obtaining an implant with a composite coating.

[0010] Preferably, the piezoelectric material is barium titanate nanoparticles, lead zirconate titanate nanoparticles, or vinylidene fluoride-trifluoroethylene copolymer nanofibers.

[0011] Preferably, the method for constructing the implant cell in 3D modeling software is as follows: To construct sketch A, first draw four curve segments, as follows: Curve D: First, draw two auxiliary axes, namely the y1 axis and the y2 axis, which are parallel to the y-axis. The y1 axis passes through the origin o, and the y2 axis is located to the left of the y1 axis. Draw the arc using the method of center / start / end point. The distance between the center of the arc and the origin o is d, the start point is located on the x-axis and the distance between it and the y2 axis is a, and the distance between the end point and the x-axis is c. Curve C: Using the tangent arc command, draw an arc with the endpoint of curve D as the starting point, the origin o as the center, and e as the radius. The distance between the endpoint and the x-axis is m. Curve B: Using the tangent arc command, draw an arc with radius f starting from the endpoint of curve C, and the distance between the endpoint and the x-axis is n; Curve A: Using the tangent arc command, draw an arc with radius g, starting from the endpoint of curve B, and make its center on the y1 axis, with the endpoint tangent to the x-axis. Draw a horizontal line with length a, starting from the starting point of curve D and ending at the y2 axis. Connect the end point of the horizontal line to the end point of curve A with a straight line. After symmetrically distributing the obtained graph along the x-axis, draw a straight line of length b from the starting point of curve D along the x-axis; To create sketch B, distribute the obtained shapes symmetrically along the y2 axis. Stretch sketch B and select the thin-walled feature to obtain the implant cell.

[0012] Preferably, the lantern-shaped bridging structure includes bridging rods and a locking structure. The bridging rods include a left bridging rod and a right bridging rod. The locking structure includes multiple longitudinal connecting rods and multiple transverse locking pins. The implant is located between the left and right bridging rods. The transverse locking pins are driven into the left and right bridging rods. The longitudinal connecting rods are arc-shaped, with one end connected to the transverse locking pin driven into the left bridging rod and the other end connected to the transverse locking pin driven into the right bridging rod.

[0013] Preferably, TC4 alloy is used as a powder material in step three.

[0014] The second aspect of the present invention provides an implant prosthesis structure with a lantern-like design, which is prepared by the method for preparing an implant prosthesis structure with a lantern-like design as described in the first aspect. The implant prosthesis structure includes an implant and a lantern-shaped bridging structure. A composite coating is deposited on the implant. The composite coating includes three layers, which are a homing layer, a responsive layer and a piezoelectric layer from the inside to the outside.

[0015] The beneficial effects of this invention are as follows: Through the synergy of the homing layer and the response layer, endogenous repair cells can be actively recruited and regulatory factors can be released intelligently and sequentially according to the healing stage, thereby achieving precise and active guidance of angiogenesis and osteogenic processes, which greatly improves the certainty and speed of bone integration. It innovatively integrates biochemical signals (growth factors) with piezoelectric bioelectric signals triggered by physiological load, forming a dual synergistic stimulation mechanism of "chemical-physical", which transforms daily functional activities into effective treatments that promote bone healing and significantly enhances bone regeneration performance. The implant prosthesis structure in this invention adopts a lantern-shaped bridging structure, with the implant as the "wick". It forms a three-dimensional support system through multiple longitudinal connecting rods and transverse locking screws. Without crossing the infection foci, it can achieve stable fixation of both ends of the bone defect, which can significantly reduce the risk of bacterial colonization and infection recurrence. Attached Figure Description

[0016] Figure 1 This is a schematic sketch of the implantable cell unit of the present invention; Figure 2 This is a schematic diagram of the structure of the implant of the present invention; Figure 3 This is a schematic diagram of the implant prosthesis structure of the present invention.

[0017] The reference numerals in the accompanying drawings of this invention are: 1. Bow and arrow structure; 2. Sketch A; 21. Curve A; 22. Curve B; 23. Curve C, 24. Curve D; 3. Sketch B; 4. Implant cell; 5. Implant; 6. Bridging rod; 61. Left bridging rod; 62. Right bridging rod; 7. Locking structure. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] Example 1: This example discloses a method for preparing an implant prosthesis structure with a lantern-like design, including the following steps: Step 1: Inspired by the bow and arrow structure 1, design and model the implanted cell 4 in imitation of the bow and arrow structure 1.

[0020] Step 2: Based on the CT data of the patient's large bone defect, the implant cell 4 is arrayed to obtain the implant 5.

[0021] Step 3: Based on laser powder bed melting (LPBF) additive manufacturing technology, using TC4 alloy as the material, the implant 5 is printed using appropriate printing parameters.

[0022] Step four: Deposit a composite coating on the implant 5 obtained in step three to complete the preparation of implant 5.

[0023] Step 5: The implant 5, after the composite coating was deposited in Step 4, is fixed using a lantern-shaped bridging structure to obtain the implant prosthesis structure.

[0024] Please see Figure 1In step one, inspired by the good stability of the implanted cell 4 when shooting an arrow, a sketch A2 was designed using SolidWorks software. First, four curves were drawn, as follows: Curve D24: First, construct two auxiliary axes: y1 and y2, parallel to the y-axis. The y1 axis passes through the origin o, and the y2 axis is located to the left of the y1 axis. Draw an arc using the center / start / end point method. The distance between the center of the arc and the origin o is d. The starting point is located on the x-axis and a distance a from the y2 axis, and the distance between the end point and the x-axis is c. Where d = 1.5 mm, a = 3 mm, and c = 1.5 mm.

[0025] Curve C23: Using the tangent arc command, draw an arc with the endpoint of curve D24 as the starting point, the origin o as the center, and e as the radius. The distance between the endpoint and the x-axis is m. Where e = 2.5mm, m = 2.36mm.

[0026] Curve B22: Using the tangent arc command, draw an arc with radius f, starting from the endpoint of curve C23, and the distance between the endpoint and the x-axis is n. Where f = 1 mm and n = 2.84 mm.

[0027] Curve A21: Using the tangent arc command, draw an arc with radius g, starting from the endpoint of curve B22, and centering it on the y1 axis, with the endpoint tangent to the x-axis. Where g = 0.3 mm.

[0028] Draw a horizontal line with length a, starting from the starting point of curve D24 and ending at the y2 axis. Connect the end point of the horizontal line to the end point of curve A21 with a straight line.

[0029] After symmetrically distributing the obtained graphics along the x-axis, draw a straight line of length b (b=1mm) along the x-axis from the starting point of curve D24. This completes the construction of sketch A2.

[0030] Then, sketch B3 is constructed by symmetrically distributing the graphics of sketch A2 along the y2 axis.

[0031] Please see Figure 2 Stretch the sketch B3 and select the thin-wall feature. Stretch symmetrically on both sides with a thickness of 2 mm and a thin-wall size of 0.2 mm to obtain implant cell 4.

[0032] The TC4 alloy used in step three is a powder material with a particle size of 15-53 micrometers. The printing parameters are: laser power 250W, scanning speed 1200mm / s, scanning spacing 80 micrometers, layer thickness 30 micrometers, scanning strategy is strip scanning, and scanning angle is 67°.

[0033] In step four, the composite coating deposition includes the preparation of three coating layers: a homing layer, a responsive layer, and a piezoelectric layer.

[0034] The preparation of the first layer of the composite coating, the homing layer, specifically includes the following steps: Implant 5 was ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 15-30 minutes each, dried with nitrogen, and then placed in an oxygen plasma cleaner for 5-15 minutes to activate it under the conditions of 100-300W power and 20-50sccm oxygen flow rate. Preparation of dopamine solution: Dissolve dopamine hydrochloride in 10mM Tris-HCl buffer, adjust the pH to 8.0-9.0, and prepare a solution with a concentration of 2.0-3.0 mg / mL. The solution should be prepared fresh and stored away from light. The activated implant 5 was completely immersed in the above dopamine solution. At room temperature (20-25℃), it was placed on a shaker and slowly shaken at a speed of 30-60 rpm for 12-24 hours. The reaction container should be protected from light. After the reaction, the implant 5 was removed and rinsed with a large amount of deionized water until the rinsing solution was colorless to remove the physically adsorbed dopamine polymer. Then, it was vacuum dried at 40-60℃ for 4-12 hours to obtain the implant 5 with a dopamine substrate film on the surface. Prepare a solution containing 0.05-0.2M EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) and 0.025-0.1M NHS (N-hydroxysuccinimide) using 0.1M MES buffer, with the molar ratio of EDC to NHS controlled between 1:0.5 and 1:2. The implant 5, with a dopamine base film on its surface, was immersed in the above solution and reacted with gentle shaking at 4-25°C for 15-60 minutes to activate the carboxyl groups on the surface of dopamine. The activated implant 5 was transferred to a grafting solution, which was a PBS buffer (phosphate buffer, pH 7.2-7.6) containing 10-200 μg / mL cyclic RGD peptide and 10-200 μg / mL SDF-1α mimic peptide. The grafting reaction was carried out at 4-10°C for 12-48 hours. After the reaction was completed, implant 5 was removed and immersed in PBS buffer containing 0.1M glycine or 1M ethanolamine to block unreacted active sites for 1-2 hours at room temperature. Finally, the implants were thoroughly washed with PBS buffer and deionized water, then lyophilized or vacuum dried at low temperature to obtain implants with a homing layer.

[0035] The preparation of the second layer of the composite coating, the responsive layer, specifically includes the following steps: Disperse 10-100 mg of 2-8 nm MSNs (mesoporous silica nanoparticles) in 1-10 mL of PBS buffer containing the target factor VEGF (vascular endothelial growth factor) at a concentration of 10-100 μg / mL. Incubate at 4 °C with shaking for 12-36 hours. Collect the drug-loaded MSNs by centrifugation, wash gently once with PBS, and freeze-dry. The loading rate can be controlled at 5%-20% (w / w) by adjusting the initial factor concentration and the amount of MSNs used. Preparation of hydrogel precursor solution A: Dissolve 2-8 wt% gelatin and 1-4 wt% sodium oxidized alginate (oxidation degree 20%-60%) together in PBS buffer and heat to 37℃ to aid dissolution; After cooling the hydrogel precursor A solution to room temperature, MSNs with loading factors are added so that the mass fraction of MSNs in the final gel is 0.5-5.0 wt%, and the mixture is thoroughly mixed. Preparation of hydrogel precursor solution B: Dissolve 1-4 wt% adipicohydrazide-modified hyaluronic acid (HA-ADH) in PBS buffer; Place the implant 5 with the homing layer in a vacuum desiccator. Mix the hydrogel precursor liquid A and hydrogel precursor liquid B at a volume ratio of 1:1 on ice until homogeneous. Quickly pour the mixture into a container to submerge the implant 5 with the homing layer. Start the vacuum pump and maintain a negative pressure of -0.08 to -0.1 MPa for 5-20 minutes to ensure that the precursor fully penetrates all pores. Release the vacuum, remove the implant 5, and place it in an environment of 37°C and >90% humidity for 30-120 minutes to allow it to complete thermo-gelation and Schiff base cross-linking, forming a stable hydrogel coating, thus obtaining the implant 5 with a homing layer and a response layer.

[0036] The preparation of the third layer of the composite coating, the piezoelectric layer, specifically includes the following steps: Dissolve 1-10 wt% polyvinyl alcohol (PVA, degree of alcoholysis >99%) or 0.5-3 wt% polyethylene oxide (PEO) in deionized water or an ethanol / water mixture as a dispersion medium. The piezoelectric material is added to the above dispersion medium, so that its solid content in the suspension is 0.1-5.0 wt%. The suspension is obtained by intermittently sonicating for 10-30 minutes in an ice bath using an ultrasonic cell disruptor (power 200-400W, 2 seconds on / 2 seconds off). The piezoelectric material can be barium titanate nanoparticles, lead zirconate titanate nanoparticles, or vinylidene fluoride-trifluoroethylene copolymer (P(VDF-TrFE)) nanofibers with a particle size or fiber diameter range of 50-500 nm. The implant 5, which has a homing layer and a response layer, is immersed in the suspension at a constant speed. After staying for 30-180 seconds, it is pulled out at the same speed and placed horizontally in an oven at 40-80℃ for 1-4 hours to dry. The above immersion and lifting process can be repeated 1-5 times to increase the coating thickness and uniformity, so that the final dry coating thickness is controlled at 1-20μm, and an implant with a composite coating is obtained.

[0037] Please see Figure 3 In step five, the lantern-shaped bridging structure includes bridging rods 6 and locking structures 7. Bridging rods 6 include a left bridging rod 61 and a right bridging rod 62. Locking structure 7 includes multiple longitudinal connecting rods and multiple transverse locking screws. The implant 5 is located between the left bridging rod 61 and the right bridging rod 62. After the left bridging rod 61 and the right bridging rod 62 are fixedly connected with titanium alloy screws, they are placed at the bone defect site and connected to the undamaged bone using bone cement. The transverse locking screws pass through healthy bone tissue and are inserted into the left bridging rod 61 and the right bridging rod 62. The longitudinal connecting rods are curved outwards, with one end connected to the transverse locking screw inserted into the left bridging rod 61 and the other end connected to the transverse locking screw inserted into the right bridging rod 62. The transverse locking screws and the longitudinal connecting rods form a lantern shape. Using the implant 5 as the "wick," a three-dimensional support system is formed by multiple longitudinal connecting rods and transverse locking screws. This achieves stable fixation of both ends of the bone defect without crossing the infection foci, significantly reducing the risk of bacterial colonization and infection recurrence.

[0038] After implant 5 is inserted into the body, the coatings work in sequence and in concert: In the early stage (0-2 weeks): the homing layer efficiently recruits endogenous MSNs; the response layer begins to degrade under the influence of mitochondrial membrane potential, preferentially releasing vascular endothelial growth factor (VEGF) to promote the growth of new blood vessels into the prosthesis pores; the piezoelectric signals generated by micromotion begin to stimulate cell activity.

[0039] Mid-stage (2-8 weeks): Abundant blood supply provides nutrients and more cells for osteoblasts. The response layer continuously releases vascular endothelial growth factor (VEGF), inducing recruited MSNs to differentiate into osteoblasts. The piezoelectric signals generated by physiological activities and the biochemical signals of VEGF have a synergistic effect, significantly accelerating the formation and mineralization of osteoid tissue.

[0040] Later stage (after 8 weeks): The newly formed bone tissue continues to mature and remodel, forming a strong bony interweaving (biolocking) with the porous structure of the prosthesis. The coating material is gradually metabolized and absorbed, ultimately achieving permanent biointegration between the prosthesis and the host bone.

[0041] The principle of this invention is as follows: The first layer of the composite coating, the dopamine layer, provides a powerful secondary reaction platform. The cyclic RGD peptide strongly mediates the adhesion and spread of various cells (such as osteoblasts and mesenchymal stem cells). The SDF-1α mimic peptide specifically binds to and recruits endogenous mesenchymal stem cells (MSCs) expressing the CXCR4 receptor, efficiently anchoring repair "seed cells" from the circulatory system and bone marrow to the surface of the prosthesis and initiating the regeneration process.

[0042] The second composite coating was designed to distribute VEGF in the coating, with the enzymatic degradation process proceeding from the surface to the interior, thereby mimicking the physiological healing sequence. Early release of VEGF promotes vascularization and establishes a blood supply basis for subsequent osteogenic formation. Later, continuous release of VEGF strongly induces osteogenic formation based on the established vascular network.

[0043] The third layer of the composite coating, consisting of barium titanate nanoparticles, lead zirconate titanate nanoparticles, and vinylidene fluoride-trifluoroethylene copolymer, are all excellent piezoelectric materials. When patients perform functional activities (such as muscle contraction and controlled weight-bearing) during postoperative rehabilitation, the prosthetic skeleton undergoes minute elastic deformation. This deformation is transmitted to the piezoelectric materials, causing a change in their internal dipole moment, thereby generating a weak, pulsed surface potential locally. This endogenous bioelectric signal has been widely proven to directly activate voltage-gated calcium channels in osteoblasts, promoting cell proliferation, differentiation, and the expression and mineralization of extracellular matrix proteins.

[0044] Example 2: This example discloses an implant prosthesis structure with a lantern-like design, prepared using the method for preparing an implant prosthesis structure with a lantern-like design as described in Example 1. The implant prosthesis structure includes an implant 5 and a lantern-shaped bridging structure.

[0045] The implant 5 has a composite coating deposited on it. The composite coating consists of three layers, from the inside out: a homing layer, a response layer, and a piezoelectric layer.

[0046] The lantern-shaped bridging structure includes bridging rods 6 and locking structures 7. Bridging rods 6 include a left bridging rod 61 and a right bridging rod 62. Locking structure 7 includes multiple longitudinal connecting rods and multiple transverse locking screws. The implant 5 is located between the left bridging rod 61 and the right bridging rod 62. After the left bridging rod 61 and the right bridging rod 62 are fixed together with titanium alloy screws, they are placed at the bone defect site and connected to the undamaged bone using bone cement. The transverse locking screws are driven into the left bridging rod 61 and the right bridging rod 62. The longitudinal connecting rods are curved outwards, with one end connected to the transverse locking screw driven into the left bridging rod 61 and the other end connected to the transverse locking screw driven into the right bridging rod 62. The transverse locking screws and the longitudinal connecting rods form a lantern shape.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. The present invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing an implant prosthesis structure with a lantern-like design, characterized in that, Includes the following steps: Step 1: Design and model the implanted cell unit (4) by imitating the structure of a bow and arrow (1); Step 2: Array the implant cell (4) to obtain the implant (5); Step 3: Based on laser powder bed fusion additive manufacturing technology, print the implant (5); Step four, the implant (5) obtained in step three is subjected to composite coating deposition to complete the preparation of implant (5); the composite coating deposition includes the preparation of homing layer, responsive layer and piezoelectric layer; Step 5: The implant (5) after composite coating deposition is fixed by a lantern-shaped bridging structure to obtain the implant prosthesis structure; The preparation of the homing layer includes: activating the implant (5) and immersing it in a dopamine solution to obtain an implant (5) with a dopamine substrate film on its surface, activating the carboxyl groups on the surface of the dopamine, and transferring the activated implant (5) to a grafting solution to obtain an implant (5) with a homing layer. The preparation of the response layer includes: dispersing MSNs in PBS buffer containing VEGF, collecting drug-loaded MSNs by centrifugation, adding MSNs to hydrogel precursor A solution and mixing them with hydrogel precursor B solution at a volume ratio of 1:1, and submerging the implant with the homing layer (5) to obtain the implant with the homing layer and the response layer (5). The piezoelectric layer preparation includes: adding piezoelectric material into a dispersion medium, immersing an implant (5) with a homing layer and a response layer into it, and obtaining an implant (5) with a composite coating.

2. The method for preparing the lantern-inspired implant structure according to claim 1, characterized in that, The preparation of the homing layer specifically includes the following steps: The implant (5) was cleaned, dried with nitrogen, and then activated in an oxygen plasma cleaner. Preparation of dopamine solution: Dissolve dopamine hydrochloride in 10mM Tris-HCl buffer, adjust the pH to 8.0-9.0, and prepare a solution with a concentration of 2.0-3.0 mg / mL. Store in the dark. The activated implant (5) was completely immersed in the dopamine solution and placed on a shaker at room temperature for the reaction. The reaction container should be protected from light. After the reaction was completed, the implant (5) was removed and rinsed with deionized water until the rinsing solution was colorless to remove the physically adsorbed dopamine polymer. Then it was vacuum dried to obtain an implant (5) with a dopamine substrate film on its surface. Prepare a solution containing 0.05-0.2M EDC and 0.025-0.1M NHS using 0.1M MES buffer, with the molar ratio of EDC to NHS controlled between 1:0.5 and 1:

2. The implant (5) with a dopamine base film on its surface is immersed in the above solution and shaken at 4-25°C for 15-60 minutes to activate the carboxyl groups on the surface of dopamine. The activated implant (5) was transferred to a grafting solution, which was a PBS buffer containing 10-200 μg / mL cyclic RGD peptide and 10-200 μg / mL SDF-1α mimic peptide. The grafting reaction was carried out at 4-10°C for 12-48 hours. After the reaction was completed, the implant (5) was removed and immersed in PBS buffer containing 0.1M glycine or 1M ethanolamine, and the unreacted active sites were blocked at room temperature for 1-2 hours. After thorough cleaning, the implants are freeze-dried or vacuum-dried at low temperature to obtain implants with a homing layer (5).

3. The method for preparing the lantern-inspired implant structure according to claim 1, characterized in that, The preparation of the response layer specifically includes the following steps: Disperse 10-100 mg of MSNs with a concentration of 2-8 nm in 1-10 mL of PBS buffer containing the target factor VEGF (VEGF concentration of 10-100 μg / mL), shake and adsorb at 4 °C for 12-36 hours, collect the drug-loaded MSNs by centrifugation, wash and freeze-dry. Preparation of hydrogel precursor solution A: Dissolve 2-8 wt% gelatin and 1-4 wt% sodium alginate together in PBS buffer and heat to 37°C to aid dissolution; After cooling the hydrogel precursor solution A to room temperature, MSNs with loading factors were added so that the mass fraction of MSNs in the final gel was 0.5-5.0 wt%. Preparation of hydrogel precursor solution B: Dissolve 1-4 wt% HA-ADH in PBS buffer; Place the implant (5) with the homing layer in a vacuum desiccator, mix the hydrogel precursor A liquid and the hydrogel precursor B liquid at a volume ratio of 1:1 on ice, pour the mixture into a container to submerge the implant (5) with the homing layer, and maintain it under negative pressure for 5-20 minutes to ensure that the precursor fully penetrates all pores. Remove the implant (5) and place it in an environment of 37°C and >90% humidity for 30-120 minutes to allow it to complete thermo-gelation and Schiff base cross-linking, forming a stable hydrogel coating, thus obtaining an implant (5) with a homing layer and a response layer.

4. The method for preparing the lantern-inspired implant structure according to claim 1, characterized in that, The piezoelectric layer fabrication specifically includes the following steps: Dissolve 1-10 wt% polyvinyl alcohol or 0.5-3 wt% polyethylene oxide in deionized water or an ethanol / water mixture as a dispersion medium. The piezoelectric material was added to the above dispersion medium, so that its solid content in the suspension was 0.1-5.0 wt%. The suspension was intermittently sonicated for 10-30 minutes under ice bath conditions to obtain a uniform and stable suspension. The implant (5) with homing layer and response layer is immersed in the suspension at a constant speed, left for 30-180 seconds, then pulled out at a uniform speed and dried for 1-4 hours. Repeat the above immersion and lifting process to control the final dry coating thickness at 1-20 μm, and obtain an implant with a composite coating (5).

5. The method for preparing the lantern-inspired implant structure according to claim 1, characterized in that, The piezoelectric material is barium titanate nanoparticles, lead zirconate titanate nanoparticles, or vinylidene fluoride-trifluoroethylene copolymer nanofibers.

6. The method for preparing the lantern-inspired implant structure according to claim 1, characterized in that, The method for constructing the implant cell (4) in the 3D modeling software is as follows: To construct sketch A (2), first draw four curve segments, as follows: Curve D (24): First, draw two auxiliary axes, namely the y1 axis and the y2 axis, which are parallel to the y axis. The y1 axis passes through the origin o, and the y2 axis is located to the left of the y1 axis. Draw the arc using the method of center / start / end point. The distance between the center of the arc and the origin o is d. The starting point is located on the x axis and the distance between it and the y2 axis is a. The distance between the end point and the x axis is c. Curve C (23): Using the tangent arc command, draw an arc with the endpoint of curve D (24) as the starting point, the origin o as the center, and e as the radius. The distance between the endpoint and the x-axis is m. Curve B (22): Using the tangent arc command, draw an arc with the endpoint of curve C (23) as the starting point and radius f. The distance between the endpoint and the x-axis is n. Curve A (21): Using the tangent arc command, draw an arc with radius g starting from the end point of curve B (22) and make its center on the y1 axis, with the end point tangent to the x-axis. Draw a horizontal line with a length of a, starting from the starting point of curve D (24) and ending at the y2 axis. Connect the end point of the horizontal line to the end point of curve A (21) with a straight line. After symmetrically distributing the obtained graph along the x-axis, draw a straight line of length b from the starting point of curve D (24) along the x-axis; Constructing sketch B (3): The obtained graphic is symmetrically distributed along the y2 axis to obtain sketch B (3); Stretch the sketch B (3) and select the thin-walled feature to obtain the implant cell (4).

7. The method for preparing the lantern-inspired implant structure according to claim 1, characterized in that, The lantern-shaped bridging structure includes a bridging rod (6) and a locking structure (7). The bridging rod (6) includes a left bridging rod (61) and a right bridging rod (62). The locking structure (7) includes multiple longitudinal connecting rods and multiple transverse locking pins. The implant (5) is located between the left bridging rod (61) and the right bridging rod (62). The transverse locking pins are driven into the left bridging rod (61) and the right bridging rod (62). The longitudinal connecting rod is arc-shaped, with one end connected to the transverse locking pin driven into the left bridging rod (61) and the other end connected to the transverse locking pin driven into the right bridging rod (62).

8. The method for preparing the lantern-inspired implant structure according to claim 1, characterized in that, In step three, TC4 alloy is used as a powder material.

9. An implant prosthesis structure with a lantern-like design, characterized in that, The implant prosthesis structure is prepared using the method of preparing the lantern-shaped design as described in any one of claims 1-8. The implant prosthesis structure includes an implant (5) and a lantern-shaped bridging structure. A composite coating is deposited on the implant (5). The composite coating includes three layers, which are a homing layer, a response layer and a piezoelectric layer from the inside to the outside.

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