A child skull repairing material and a preparation method and application thereof

Abstract

This invention relates to the field of cranioplasty materials, and particularly to a pediatric cranioplasty material, its preparation method, and its application. A method for preparing a pediatric cranioplasty material includes: acquiring cranial model data of a pediatric patient; obtaining a dense layer using 3D printing based on the cranial model data; placing a titanium mesh on the dense layer; wherein the titanium mesh comprises multiple titanium strips, each titanium strip having its two ends movably connected to the endpoints of two other titanium strips to form a titanium mesh, and each titanium strip rotating in the same plane about the movably connected point as an axis to extend or contract the titanium mesh; obtaining a porous layer using 3D printing on the dense layer and the titanium mesh based on the cranial model data, the dense layer and the porous layer encapsulating the titanium mesh to obtain the pediatric cranioplasty material. This invention provides a pediatric cranioplasty material, its preparation method, and its application, providing a cranioplasty material with strong mechanical properties and deformation capacity.

Description

Technical Field

[0001] This invention relates to the field of cranial repair materials technology, and in particular to a pediatric cranial repair material, its preparation method, and its application. Background Technology

[0002] When a child patient has a large skull defect, skull repair materials are needed to repair the skull.

[0003] In related technologies, mineralized collagen is used as the material for skull repair. However, the skulls of pediatric patients continue to grow and deform. The mineralized collagen gradually degrades and regenerates simultaneously with the bone tissue, but due to deformation and poor mechanical strength of newly formed bone tissue, the mechanical properties and deformation capacity of mineralized collagen cannot meet the needs of the growing and deforming skulls of children.

[0004] Therefore, in order to address the above shortcomings, there is an urgent need for a pediatric skull repair material, its preparation method, and its application. Summary of the Invention

[0005] This invention provides a pediatric cranial repair material, its preparation method, and its application, which can provide a cranial repair material with strong mechanical properties and deformation capacity.

[0006] In a first aspect, embodiments of the present invention provide a method for preparing a pediatric cranial repair material, comprising:

[0007] Obtain skull model data of pediatric patients;

[0008] A dense layer was obtained by 3D printing based on the skull model data.

[0009] A titanium metal mesh is placed on the dense layer; wherein the titanium metal mesh comprises a plurality of titanium metal strips, and the two ends of each titanium metal strip are movably connected to the ends of two titanium metal strips respectively to form the titanium metal mesh, and each titanium metal strip rotates in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh;

[0010] Based on the skull model data, a porous layer is obtained by 3D printing on the dense layer and the titanium mesh. The dense layer and the porous layer encapsulate the titanium mesh to obtain a pediatric skull repair material.

[0011] In one possible design, obtaining the dense layer by 3D printing based on the skull model data includes:

[0012] The first dense layer was obtained by 3D printing based on the skull model data.

[0013] A second dense layer is prepared on the first dense layer by 3D printing based on the skull model data; wherein the density of the first dense layer is higher than that of the second dense layer, and the second dense layer is used to place the titanium metal mesh.

[0014] In one possible design, the process of obtaining a porous layer by 3D printing from the dense layer and the titanium mesh based on the skull model data includes:

[0015] Based on the skull model data, a first porous layer is obtained by 3D printing on the dense layer and the titanium mesh;

[0016] A second porous layer is prepared on the first porous layer by 3D printing based on the skull model data; wherein the density of the first porous layer is higher than that of the second porous layer.

[0017] In one possible design, obtaining the first dense layer by 3D printing based on the skull model data includes:

[0018] Based on the skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is (0.001-0.3):1, and the filling density of the 3D print is 80-90%;

[0019] The process of preparing a second dense layer on the first dense layer using 3D printing based on the skull model data includes:

[0020] Based on the skull model data, a second dense layer is prepared on the first dense layer using a second solution via 3D printing; wherein, the second solution is prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution is (0.301-0.5):1, and the infill density of the 3D print is 70-79.9%.

[0021] In one possible design, the first porous layer, obtained by 3D printing from the dense layer and the titanium mesh based on the skull model data, includes:

[0022] Based on the skull model data, a first porous layer is obtained by 3D printing on the dense layer and the titanium mesh using a third solution; wherein, the third solution is prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution is (0.501-1):1, and the filling density of the 3D print is 50-69.9%;

[0023] The process of preparing a second porous layer on the first porous layer using 3D printing based on the skull model data includes:

[0024] The second porous layer is prepared by 3D printing on the first porous layer using a fourth solution based on the skull model data; wherein the fourth solution is prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution is 1:(0.5-0.99), and the infill density of the 3D printing is 20-49.9%.

[0025] In one possible design, the 3D printing speed is 30-60 mm / s, the layer thickness is 0.1-0.3 mm, the extrusion ratio is 1-1.5, the infill extrusion width is 100-150%, the retraction distance is 1 mm, the retraction speed is 20 mm / s, the contour deceleration is 50%, and the infill and support deceleration is 50%-80%.

[0026] In one possible design, the movable connection is provided with two connectors, each of which is perpendicular to one side of the plane containing the titanium mesh.

[0027] In one possible design, the cross-section of the connector gradually increases in the direction away from the titanium mesh.

[0028] Secondly, embodiments of the present invention provide a pediatric cranial repair material, which is prepared using the preparation method described in any one of the first aspects.

[0029] Thirdly, the present invention also provides an application of the pediatric cranial repair material described in the second aspect, applied to pediatric cranial repair, wherein the porous layer faces the pediatric patient's intracranial cavity.

[0030] Compared with the prior art, the present invention has at least the following beneficial effects:

[0031] In this embodiment, skull model data of a pediatric patient is first obtained. Then, a dense layer is obtained by 3D printing based on the skull model data. A titanium mesh is placed on the dense layer, and a loose layer is printed on the titanium mesh and the dense layer, resulting in a pediatric skull repair material comprising the dense layer, the loose layer, and the titanium mesh. The dense layer has a dense structure, providing excellent sealing and mechanical properties. The loose layer has a loose structure, which can guide tissue ingrowth to accelerate the skull repair rate. The titanium mesh in the skull repair material acts as a framework, encased in the dense and loose layers. The titanium mesh provides excellent mechanical properties, and the low density of titanium does not add burden to the patient. The titanium mesh is formed by multiple titanium strips connected end-to-end. The titanium strips can rotate in the same plane around the connection point to allow the titanium mesh to expand or contract. The elasticity of the titanium mesh allows the skull repair material to adapt to the growth of the child's skull, meeting the needs of skull growth and deformation. Furthermore, the mechanical properties can be further matched by designing the width, number of connections, and degree of opening and closing of the titanium strips. In addition, titanium mesh can only contract and expand in a plane and cannot deform in the vertical direction, thus providing excellent mechanical properties in the vertical direction and improving the mechanical properties of cranioplasty materials in the vertical direction. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart of a method for preparing a pediatric skull repair material according to an embodiment of the present invention;

[0034] Figure 2 This is a flowchart of another method for preparing a pediatric skull repair material provided in an embodiment of the present invention;

[0035] Figure 3 This is a top view schematic diagram of a pediatric skull repair material provided in an embodiment of the present invention;

[0036] Figure 4 This is a bottom view structural diagram of a pediatric skull repair material provided in an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the structure of a pediatric cranial repair material provided in an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of a titanium metal mesh structure provided by the present invention.

[0039] In the picture:

[0040] 1-Dense layer;

[0041] 2- Loose layer;

[0042] 3-Titanium metal mesh;

[0043] 31-Connector. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but 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.

[0045] In the description of the embodiments of the present invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0046] In this specification, it should be understood that the directional terms such as "upper" and "lower" used in the description of the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should also be understood that when it is mentioned that one element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0047] like Figure 1 , 3 As shown in Figures 4, 5, and 6, embodiments of the present invention provide a method for preparing a pediatric cranial repair material, comprising:

[0048] S1: Obtain skull model data of pediatric patients;

[0049] S2: A dense layer is obtained by 3D printing based on skull model data;

[0050] S3: Place a titanium metal mesh on a dense layer; wherein the titanium metal mesh includes multiple titanium metal strips, each titanium metal strip having its two ends movably connected to the ends of two titanium metal strips respectively to form a titanium metal mesh, and each titanium metal strip rotating in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh.

[0051] S4: Based on the skull model data, a porous layer is obtained by 3D printing on a dense layer and a titanium mesh. The dense layer and the porous layer encapsulate the titanium mesh to obtain a pediatric skull repair material.

[0052] In this embodiment, skull model data of a pediatric patient is first obtained. Then, a dense layer is obtained by 3D printing based on the skull model data. A titanium mesh is placed on the dense layer, and a loose layer is printed on the titanium mesh and the dense layer, resulting in a pediatric skull repair material comprising the dense layer, the loose layer, and the titanium mesh. The dense layer has a dense structure, providing excellent sealing and mechanical properties. The loose layer has a loose structure, which can guide tissue ingrowth to accelerate the skull repair rate. The titanium mesh in the skull repair material acts as a framework, encased in the dense and loose layers. The titanium mesh provides excellent mechanical properties, and the low density of titanium does not add burden to the patient. The titanium mesh is formed by multiple titanium strips connected end-to-end. The titanium strips can rotate in the same plane around the connection point to allow the titanium mesh to expand or contract. The elasticity of the titanium mesh allows the skull repair material to adapt to the growth of the child's skull, meeting the needs of skull growth and deformation. Furthermore, the mechanical properties can be further matched by designing the width, number of connections, and degree of opening and closing of the titanium strips. In addition, titanium mesh can only contract and expand in a plane and cannot deform in the vertical direction, thus providing excellent mechanical properties in the vertical direction and improving the mechanical properties of cranioplasty materials in the vertical direction.

[0053] In this embodiment, obtaining skull model data of pediatric patients includes:

[0054] S1. Obtain the patient's skull imaging data.

[0055] This step involves acquiring the patient's skull imaging data using methods such as computed tomography (CT), magnetic resonance imaging (MRI), and X-rays. Specifically, firstly, complete skull imaging data, including the defect area, is acquired using computed tomography (CT). To ensure that the acquired data clearly reflects the shape characteristics of the defect area, the slice thickness of the acquired data is required to be between 0.5 and 1.0 mm. The resulting medical image is a standard DICOM file, and the data can be stored on computer-readable media such as optical discs.

[0056] S2. Import the obtained skull image data into medical reverse engineering software, set the upper and lower thresholds to select the skull and exclude the surrounding soft tissue, and use the region growing operation to exclude bone tissue that is not connected to the main skull to obtain a three-dimensional skull model.

[0057] The medical reverse engineering software used in this step can be Mimics or other similar software. First, the skull image data obtained in step S1 is imported into Mimics software. In the File menu, click the "New Project Wizard" option to open the folder containing the patient's CT data. After importing the data, three views of the patient's skull CT are obtained. Select the "Threshold" button and set the upper threshold to 2190–2196 and the lower threshold to 222–230. Preferably, the upper threshold is 2193 and the lower threshold is 226. The threshold in the software corresponds to the actual density of the material; the larger the threshold, the greater the actual density, and the smaller the threshold, the smaller the actual density. The threshold range selected in this invention can include the entire skull while excluding surrounding soft tissue. Then, select the "Region Growing" button and click any point on the main skull. This will select all continuous surfaces radiating from that point, thus excluding discontinuous parts, such as bone tissue not connected to the main skull, eliminating interference for subsequent three-dimensional reconstruction. Finally, select the "Calculate3D" button to use the powerful calculation and reconstruction function of the Mimics software to output the child's skull model data in STL format. After importing the child's skull model data into the 3D printer's system software, 3D printing can be performed.

[0058] In some embodiments of the present invention, a dense layer is obtained by 3D printing based on skull model data, including:

[0059] The first dense layer was obtained by 3D printing based on skull model data;

[0060] A second dense layer is prepared on the first dense layer by 3D printing based on skull model data; wherein the density of the first dense layer is higher than that of the second dense layer, and the second dense layer is used to place titanium metal mesh.

[0061] In this embodiment, the dense layer includes a first dense layer and a second dense layer with progressively decreasing density, wherein the second dense layer is used to place the titanium mesh. The progressively decreasing density of the first and second dense layers creates a density gradient throughout the dense layer, making the density transition of the pediatric cranial repair material smoother and preventing cracking of the cranial repair material due to excessive density differences.

[0062] In some embodiments of the present invention, a porous layer is obtained by 3D printing on a dense layer and a titanium mesh based on skull model data, including:

[0063] The first porous layer was obtained by 3D printing on a dense layer and a titanium mesh based on skull model data.

[0064] A second porous layer is prepared on a first porous layer by 3D printing based on skull model data; wherein the density of the first porous layer is higher than that of the second porous layer.

[0065] In this embodiment, the porous layer includes a first porous layer and a second porous layer with progressively decreasing density. The first porous layer is bonded to the dense layer and the titanium mesh. The progressively decreasing density of the first and second porous layers creates a density gradient throughout the porous layer, making the density transition of the pediatric cranial repair material smoother and preventing cracking of the cranial repair material due to excessive density differences.

[0066] In some embodiments of the present invention, a first dense layer is obtained by 3D printing based on skull model data, including:

[0067] Based on skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is (0.001-0.3):1, and the filling density of the 3D printing is 80-90%;

[0068] A second dense layer was fabricated on top of the first dense layer using 3D printing based on skull model data. This second dense layer includes:

[0069] Based on skull model data, a second dense layer was prepared on the first dense layer using a second solution via 3D printing. The second solution was prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution was (0.301-0.5):1, and the infill density of the 3D print was 70-79.9%.

[0070] In this embodiment, poly(ε-caprolactone) provides excellent mechanical properties, mineralized collagen promotes bone tissue growth, and the solvent for the poly(ε-caprolactone) solution is chloroform / methanol (CHCl3 / CH3OH) with a volume ratio of 5:1. The molecular weight of poly(ε-caprolactone) is Mw = 80,000. Higher infill density in 3D printing results in higher material density. Infill density values ​​range from 0 to 100, representing different infill densities; 100 represents a solid model, and 0 represents a hollow object. To achieve the highest density in the first dense layer, an infill density of 80-90% is chosen for 3D printing. To maximize the mechanical properties of the first dense layer, the mass ratio of mineralized collagen to poly(ε-caprolactone) is (0.001-0.3):1. The density of the second dense layer is lower than that of the first dense layer. Therefore, the fill density of the 3D printing is selected to be 70-79.9%. The mechanical properties of the second dense layer are lower than those of the first dense layer. Therefore, the mass ratio of mineralized collagen to poly(ε-caprolactone) is (0.301-0.5):1.

[0071] In some embodiments of the present invention, a first porous layer is obtained by 3D printing on a dense layer and a titanium mesh based on skull model data, including:

[0072] Based on skull model data, a first porous layer is obtained by 3D printing on a dense layer and a titanium mesh using a third solution. The third solution is prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution is (0.501-1):1, and the filling density of the 3D print is 50-69.9%.

[0073] Based on skull model data, a second porous layer was prepared by 3D printing on top of the first porous layer, including:

[0074] Based on skull model data, a second porous layer was prepared by 3D printing on the first porous layer using a fourth solution. The fourth solution was prepared by uniformly mixing 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution was 1:(0.5-0.99), and the infill density of the 3D printing was 20-49.9%.

[0075] In this embodiment, poly(ε-caprolactone) provides excellent mechanical properties, mineralized collagen promotes bone tissue growth, and the solvent for the poly(ε-caprolactone) solution is chloroform / methanol (CHCl3 / CH3OH) with a volume ratio of 5:1. The molecular weight of poly(ε-caprolactone) is Mw = 80,000. The first porous layer has a loose structure; therefore, the infill density of the 3D printing is selected to be 50–69.9%. While providing mechanical properties, the first porous layer also needs to guide bone tissue regeneration; therefore, the mass ratio of mineralized collagen to poly(ε-caprolactone) is (0.501–1):1. The density of the second porous layer is lower than that of the first porous layer, and its structure is the most porous. Therefore, the fill density of 3D printing is selected to be 20-49.9%. The second porous layer is in direct contact with intracranial tissue and requires more mineralized collagen to quickly repair the skull. The requirements for mechanical properties are not high. Therefore, the mass ratio of mineralized collagen to poly(ε-caprolactone) is 1:(0.5-0.99).

[0076] It should be noted that the poly(ε-caprolactone) solution and mineralized collagen can be mixed evenly by ultrasonic dispersion.

[0077] The mineralized collagen in this invention can be obtained in the following ways:

[0078] Step 1: Dissolve collagen in any one of hydrochloric acid, nitric acid or acetic acid to prepare an acidic solution of collagen, wherein the collagen concentration is 0.01-0.2 g / ml;

[0079] Step 2: Add calcium salt solution dropwise to the acidic solution of collagen, wherein the amount of calcium ions added is 0.1 to 2 mol per gram of collagen;

[0080] Step 3: Add phosphoric acid solution dropwise to the solution obtained in step 2, wherein the molar ratio of the amount of phosphate ions added to the amount of calcium ions added in step S1-2 is Ca / P = 1 / 1 to 2 / 1;

[0081] Step 4: Add NaOH solution dropwise to the solution obtained in step 3 to form a mixed solution, and adjust the pH value to 6-8;

[0082] Step 5: After the mixed solution obtained in step 4 has been allowed to stand for 4 to 12 hours, it is centrifuged at 3000 to 6000 r / min to remove the precipitate, and then dried in a forced-air dryer at 50-70℃ for 24 to 72 hours to obtain mineralized collagen particles.

[0083] Step 6: Place the mineralized collagen particles obtained in Step 5 into a crucible and grind them until there are no obvious particles, thus obtaining mineralized collagen powder.

[0084] During 3D printing, the first and second solutions are first loaded into two independent reservoirs in the printer. Each reservoir corresponds to a separate nozzle assembly. When one nozzle is working, the other can remain outside the printing area or print simultaneously. After the first solution is finished printing, the printer switches to the second solution, simultaneously cleaning the reservoir that previously held the first solution. Then, the third solution is loaded. After the second solution is finished printing, the printer switches to the third solution, cleaning the reservoir that previously held the second solution, and then loading the fourth solution. The nozzle diameter is 0.6mm, and the nozzle temperature is set to 40℃, while the printing chamber temperature is set to -20℃. This ensures smooth lines when the solution is extruded from the nozzle and freeze-solidifies upon deposition onto the printing surface. After printing for 1 hour in the reservoir containing the first solution, the printer switches to the reservoir containing the second solution. After 1 hour, the printer pauses, places a titanium mesh on the surface of the resulting second dense layer, and switches to the reservoir containing the third solution. After 2 hours, the printer switches to the reservoir containing the fourth solution and prints for another 4 hours to complete the process. The pediatric skull repair material obtained after printing is stored in a -20°C freezer for 24 hours and then dried in a vacuum freeze dryer to completely remove the solvent.

[0085] In some embodiments of the present invention, the 3D printing speed is 30-60 mm / s, the layer thickness is 0.1-0.3 mm, the extrusion ratio is 1-1.5, the infill extrusion width is 100-150%, the retraction distance is 1 mm, the retraction speed is 20 mm / s, the contour deceleration is 50%, and the infill and support deceleration is 50%-80%.

[0086] In this embodiment, the preferred printing speed is 55 mm / s for the X and Y axes and 30 mm / s for the Z axis, the preferred filling and extrusion width is 150%, and the preferred filling and support speed reduction is 80%.

[0087] In some embodiments of the present invention, the movable connection is provided with two connectors, which are respectively perpendicular to the two sides of the plane where the titanium metal mesh is located.

[0088] In this embodiment, the connector can enhance the bonding strength between the titanium mesh and the dense and loose layers above and below it.

[0089] In some embodiments of the present invention, the cross-section of the connector gradually increases away from the titanium mesh.

[0090] In this embodiment, the cross-section of the connector gradually increases in size away from the titanium mesh, forming a trumpet shape or an inverted cone shape. This arrangement can further strengthen the bonding strength between the titanium mesh and the dense and loose layers above and below it.

[0091] like Figure 2 As shown, this embodiment of the invention also provides another method for preparing a pediatric skull repair material, comprising:

[0092] S1: Obtain skull model data;

[0093] S2: Based on the skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is (0.001-0.3):1, and the filling density of the 3D print is 80-90%;

[0094] S3: Based on the skull model data, a second dense layer is prepared by 3D printing on the first dense layer using a second solution; the second solution is prepared by uniformly mixing 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution is (0.301-0.5):1, and the filling density of the 3D printing is 70-79.9%;

[0095] S4: Place the titanium metal mesh on the second dense layer; wherein the titanium metal mesh includes multiple titanium metal strips, each titanium metal strip having its two ends movably connected to the ends of two titanium metal strips respectively to form a titanium metal mesh, and each titanium metal strip rotating in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh.

[0096] S5: Based on the skull model data, the first porous layer is obtained by 3D printing on the dense layer and titanium mesh using a third solution; wherein, the third solution is prepared by uniformly mixing 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution is (0.501-1):1, and the filling density of the 3D printing is 50-69.9%;

[0097] S6: Based on the skull model data, a second porous layer is prepared on the first porous layer by 3D printing using a fourth solution; wherein, the fourth solution is prepared by uniformly mixing a 20w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution is 1:(0.5~0.99), the filling density of the 3D printing is 20~49.9%, and a pediatric skull repair material is obtained.

[0098] This invention provides a pediatric cranial repair material, prepared using any one of the preparation methods described above.

[0099] The pediatric cranial repair material provided in this embodiment of the invention is based on the same inventive concept as the preparation method of the aforementioned pediatric cranial repair material. Therefore, it can achieve the same beneficial effects, and its beneficial effects will not be elaborated here.

[0100] This invention also provides an application of the above-mentioned pediatric cranial repair material, which is used for pediatric cranial repair with the porous layer facing the pediatric patient's skull.

[0101] In this embodiment, when applying pediatric cranial repair materials, the porous layer is the layer facing the patient's intracranial cavity. The porous layer has high porosity and a high content of mineralized collagen, which can promote cranial repair. The dense layer is the side facing away from the intracranial cavity. The dense layer has high density, a high content of poly(ε-caprolactone), and strong mechanical properties, which can protect intracranial tissues.

[0102] To more clearly illustrate the technical solution and advantages of the present invention, the following detailed description of a method for preparing a cranial repair material is provided through several embodiments.

[0103] Example 1

[0104] Skull model data can be obtained through software simulation.

[0105] Based on skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing a 20w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is 0.001:1, and the filling density of the 3D print is 80%;

[0106] Based on skull model data, a second dense layer was prepared by 3D printing on the first dense layer using a second solution. The second solution was prepared by uniformly mixing a 20 w / v% poly(ε-caprolactone) solution and mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution was 0.301:1, and the filling density of the 3D printing was 70%.

[0107] A titanium metal mesh is placed on the second dense layer; wherein the titanium metal mesh comprises multiple titanium metal strips, each titanium metal strip having its two ends movably connected to the ends of two titanium metal strips respectively to form a titanium metal mesh, and each titanium metal strip rotating in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh.

[0108] Based on skull model data, a first porous layer was obtained by 3D printing on a dense layer and a titanium mesh using a third solution. The third solution was prepared by uniformly mixing a 20w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution was 0.501:1, and the infill density of the 3D print was 50%.

[0109] Based on skull model data, a second porous layer was prepared by 3D printing on the first porous layer using a fourth solution. The fourth solution was prepared by uniformly mixing a 20w / v% poly(ε-caprolactone) solution and mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution was 1:0.99, and the infill density of the 3D printing was 20%, thus obtaining a pediatric skull repair material.

[0110] Example 2

[0111] Skull model data can be obtained through software simulation.

[0112] Based on skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing a 25w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is 0.3:1, and the filling density of the 3D print is 80%;

[0113] Based on skull model data, a second dense layer was prepared by 3D printing on the first dense layer using a second solution. The second solution was prepared by uniformly mixing a 25 w / v% poly(ε-caprolactone) solution and mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution was 0.5:1, and the filling density of the 3D printing was 70%.

[0114] A titanium metal mesh is placed on the second dense layer; wherein the titanium metal mesh comprises multiple titanium metal strips, each titanium metal strip having its two ends movably connected to the ends of two titanium metal strips respectively to form a titanium metal mesh, and each titanium metal strip rotating in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh.

[0115] Based on skull model data, a first porous layer is obtained by 3D printing on a dense layer and a titanium mesh using a third solution. The third solution is prepared by uniformly mixing a 20-30 w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution is 1:1, and the filling density of the 3D print is 60%.

[0116] Based on skull model data, a second porous layer was prepared on the first porous layer using a fourth solution via 3D printing. The fourth solution was prepared by uniformly mixing 20-30 w / v% poly(ε-caprolactone) solution and mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution was 1:0.5, and the infill density of the 3D printing was 20%, thus obtaining a pediatric skull repair material.

[0117] Example 3

[0118] Skull model data can be obtained through software simulation.

[0119] Based on skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing a 20w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is 0.001:1, and the filling density of the 3D print is 80%;

[0120] Based on skull model data, a second dense layer was prepared by 3D printing on the first dense layer using a second solution. The second solution was prepared by uniformly mixing a 20 w / v% poly(ε-caprolactone) solution and mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution was 0.301:1, and the filling density of the 3D printing was 70%.

[0121] A titanium metal mesh is placed on the second dense layer; wherein the titanium metal mesh comprises multiple titanium metal strips, each titanium metal strip having its two ends movably connected to the ends of two titanium metal strips respectively to form a titanium metal mesh, and each titanium metal strip rotating in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh.

[0122] Based on skull model data, a first porous layer was obtained by 3D printing on a dense layer and a titanium mesh using a third solution. The third solution was prepared by uniformly mixing a 20w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution was 0.501:1, and the infill density of the 3D print was 69.9%.

[0123] Based on skull model data, a second porous layer was prepared by 3D printing on the first porous layer using a fourth solution. The fourth solution was prepared by uniformly mixing a 20w / v% poly(ε-caprolactone) solution and mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution was 1:0.99, and the infill density of the 3D printing was 20%, thus obtaining a pediatric skull repair material.

[0124] Example 4

[0125] Skull model data can be obtained through software simulation.

[0126] Based on skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is 0.2:1, and the filling density of the 3D print is 90%;

[0127] Based on skull model data, a second dense layer was prepared by 3D printing on the first dense layer using a second solution. The second solution was prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution was 0.4:1, and the filling density of the 3D printed layer was 79.9%.

[0128] A titanium metal mesh is placed on the second dense layer; wherein the titanium metal mesh comprises multiple titanium metal strips, each titanium metal strip having its two ends movably connected to the ends of two titanium metal strips respectively to form a titanium metal mesh, and each titanium metal strip rotating in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh.

[0129] Based on skull model data, a first porous layer was obtained by 3D printing on a dense layer and a titanium mesh using a third solution. The third solution was prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution was 0.8:1, and the filling density of the 3D print was 50%.

[0130] Based on skull model data, a second porous layer was prepared by 3D printing on the first porous layer using a fourth solution. The fourth solution was prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution was 1:0.75, and the infill density of the 3D printing was 30%, thus obtaining a pediatric skull repair material.

[0131] Example 5

[0132] Skull model data can be obtained through software simulation.

[0133] Based on skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is 0.2:1, and the filling density of the 3D print is 90%;

[0134] Based on skull model data, a second dense layer was prepared by 3D printing on the first dense layer using a second solution. The second solution was prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution was 0.4:1, and the filling density of the 3D printed layer was 79.9%.

[0135] A titanium metal mesh is placed on the second dense layer; wherein the titanium metal mesh comprises multiple titanium metal strips, each titanium metal strip having its two ends movably connected to the ends of two titanium metal strips respectively to form a titanium metal mesh, and each titanium metal strip rotating in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh.

[0136] Based on skull model data, a first porous layer was obtained by 3D printing on a dense layer and a titanium mesh using a third solution. The third solution was prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution was 0.8:1, and the infill density of the 3D print was 60%.

[0137] Based on skull model data, a second porous layer was prepared by 3D printing on the first porous layer using a fourth solution. The fourth solution was prepared by uniformly mixing a 30w / v% poly(ε-caprolactone) solution with mineralized collagen. The mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution was 1:0.75, and the filling density of the 3D printing was 49.9%, thus obtaining a pediatric skull repair material.

[0138] Porosity tests were performed on the pediatric cranial repair materials obtained in Examples 1-5:

[0139] Test method: Accurately weigh the dry weight W1 of the sample (accurate to 0.01g), and analyze the sample volume V (cm³) using 3D printing system software. 3 The dried sample was placed in a container filled with isopropanol solvent and soaked for 2 hours. Finally, it was gently lifted with tweezers, removed from the liquid surface, and left to stand for 1 minute. The sample was then weighed, and the mass was W2 (accurate to 0.01 g).

[0140] Calculate the porosity q of the sample using the following formula.

[0141] q = (W2 - W1) / (0.7855 × V), where 0.7855 is the density of isopropanol (g / cm³). 3 Three samples were measured in parallel, and the average porosity was taken.

[0142] The test results are as follows:

[0143] The porosity measured in Example 1 was 58.88±1.15%, in Example 2 it was 56.16±0.97%, in Example 3 it was 53.4±0.73%, in Example 4 it was 51.33±0.89%, and in Example 5 it was 38.88±1.26%.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a skull repair material for children, characterized by, include: Obtain skull model data of pediatric patients; A dense layer was obtained by 3D printing based on the skull model data. A titanium metal mesh is placed on the dense layer; wherein the titanium metal mesh comprises a plurality of titanium metal strips, and the two ends of each titanium metal strip are movably connected to the ends of two titanium metal strips respectively to form the titanium metal mesh, and each titanium metal strip rotates in the same plane about the movable connection point as an axis to extend or contract the titanium metal mesh; Based on the skull model data, a porous layer is obtained by 3D printing on the dense layer and the titanium mesh. The dense layer and the porous layer encapsulate the titanium mesh to obtain a pediatric skull repair material. The process of obtaining a dense layer through 3D printing based on the skull model data includes: The first dense layer was obtained by 3D printing based on the skull model data. A second dense layer is prepared on the first dense layer by 3D printing based on the skull model data; wherein the density of the first dense layer is higher than that of the second dense layer, and the second dense layer is used to place the titanium metal mesh; The process of obtaining a porous layer by 3D printing on the dense layer and the titanium mesh based on the skull model data includes: Based on the skull model data, a first porous layer is obtained by 3D printing on the dense layer and the titanium mesh; A second porous layer is prepared on the first porous layer by 3D printing based on the skull model data; wherein the density of the first porous layer is higher than that of the second porous layer. The process of obtaining the first dense layer by 3D printing based on the skull model data includes: Based on the skull model data, a first dense layer is obtained by 3D printing using a first solution; wherein, the first solution is prepared by uniformly mixing 20~30w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the first solution is (0.001~0.3):1, and the infill density of the 3D print is 80~90%; The process of preparing a second dense layer on the first dense layer using 3D printing based on the skull model data includes: Based on the skull model data, a second dense layer is prepared by 3D printing onto the first dense layer using a second solution; wherein, the second solution is prepared by uniformly mixing 20~30w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the second solution is (0.301~0.5):1, and the infill density of the 3D print is 70~79.9%; The first porous layer, obtained by 3D printing on the dense layer and the titanium mesh based on the skull model data, includes: Based on the skull model data, a first porous layer is obtained by 3D printing on the dense layer and the titanium mesh using a third solution; wherein, the third solution is prepared by uniformly mixing 20~30w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the third solution is (0.501~1):1, and the infill density of the 3D print is 50~69.9%; The process of preparing a second porous layer on the first porous layer using 3D printing based on the skull model data includes: The second porous layer is prepared by 3D printing on the first porous layer using a fourth solution based on the skull model data; wherein the fourth solution is prepared by uniformly mixing 20~30w / v% poly(ε-caprolactone) solution and mineralized collagen, the mass ratio of mineralized collagen to poly(ε-caprolactone) in the fourth solution is 1:(0.5~0.99), and the filling density of the 3D printing is 20~49.9%.

2. The production method according to claim 1, characterized by, The printing speed of 3D printing is 30~60mm / s, the layer thickness is 0.1~0.3mm, the extrusion ratio is 1~1.5, the infill extrusion width is 100~150%, the retraction distance is 1mm, the retraction speed is 20mm / s, the contour speed reduction is 50%, and the infill and support speed reduction is 50%~80%.

3. The production method according to claim 1, characterized by, The movable connection is provided with two connectors, which are perpendicular to the plane of the titanium mesh and located on both sides of the titanium mesh.

4. The preparation method according to claim 3, characterized in that, The cross-section of the connector gradually increases in the direction away from the titanium mesh.

5. A pediatric cranial repair material, characterized in that, It is prepared by any one of the preparation methods according to claims 1-4.

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