A method for preparing a personalized biphasic condylar scaffold

Abstract

The invention discloses a method for preparing a personalized biphasic condylar scaffold, which comprises the following steps: collecting data to separate a mandibular digital model; selecting data on the opposite side of a lesion area in the mandibular digital model, and mirror-symmetric mapping the data to the lesion area to obtain a condylar head and neck prosthesis model; designing and printing a bone phase scaffold according to the condylar tissue structure morphology; preparing a cartilage phase scaffold; spraying a dense layer on the surface of the bone phase scaffold head, connecting the cartilage phase scaffold with the dense layer by a "dissolution-adhesion" process to form a dense layer bone-cartilage composite scaffold, thereby constructing a condylar biphasic composite scaffold; and designing a retention handle on the condylar biphasic composite scaffold to construct a personalized biphasic bionic condylar scaffold, which not only solves the problem that autologous bone transplantation for temporomandibular joint reconstruction cannot restore the condylar morphology and there are complications in the bone donor area, but also solves the problem that the mechanical properties of the materials and the degradation cycle of the existing prosthesis do not meet clinical needs.

Description

Technical Field

[0001] The invention belongs to the technical field of artificial joint design and preparation methods, and specifically relates to a preparation method of a personalized biphasic condylar scaffold. Background Art

[0002] The occurrence of diseases such as ankylosis, trauma, and tumors often leads to morphological defects and functional loss of the temporomandibular joint. For patients with such bone lesions, surgical treatment is a necessary choice, but there is currently a lack of effective condylar implant or replacement materials in the clinic. Autologous bone transplantation or artificial material replacement is often used, but autologous bone transplantation for temporomandibular joint reconstruction cannot restore the condylar morphology and there are complications in the bone donor area. Existing artificial materials are difficult to achieve ideal results due to mechanical toughness requirements, degradation cycles, and postoperative infections. With the development of tissue engineering, the emergence of dual-phase composite materials has provided new ideas for people to find new condylar tissue materials. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a personalized biphasic condylar scaffold, which solves the problem that autologous bone transplantation for temporomandibular joint reconstruction cannot restore the condylar morphology and there are complications in the bone donor area.

[0004] The technical solution adopted by the present invention is a method for preparing a personalized biphasic condylar scaffold, which is specifically implemented according to the following steps:

[0005] Step 1: Collect data to separate the mandibular digital model;

[0006] Step 2: Select the data on the opposite side of the lesion area in the mandibular digital model, mirror-symmetric map it to the lesion area, obtain the condylar head and neck prosthesis model, and design and print the bone phase scaffold according to the condylar tissue structure morphology;

[0007] Step 3, preparing a cartilage phase scaffold;

[0008] Step 4: spray a dense layer on the surface of the head of the bone phase scaffold, and use the "dissolution-adhesion" process to connect the cartilage phase scaffold with the dense layer to form a dense layer bone-cartilage composite scaffold, thereby constructing a condylar biphasic composite scaffold. After designing a retention handle on the condylar biphasic composite scaffold, the result is obtained.

[0009] The present invention is also characterized in that:

[0010] Step 1 specifically includes: collecting the patient's head CBCT data in DICOM format and importing it into the medical image processing software Mimics to generate a full head 3D virtual model, and separating the mandibular model from the full head 3D virtual model.

[0011] Step 2 is as follows: by exporting to an STL format file and importing it into Geomagic software, the surgical process is simulated to perform osteotomy on the affected area, and then reverse reconstruction is performed. By utilizing the natural symmetry of the two sides of the mandible, the data on the opposite side of the affected area in the mandibular digital model are selected, and mirror-symmetric mapping is performed to the affected area to obtain the relevant data of the condylar head and neck prosthesis model. The mandibular digital model is imported into ANSYS 14.0 software for optimization design, thereby obtaining a three-dimensional mesh digital model of the defect area, and inputting the 3D printing design to produce a gradient three-dimensional mesh bone scaffold. The printed bone scaffold is cleaned and sterilized for use.

[0012] Step 3 specifically involves preparing a cartilage phase scaffold by utilizing a temperature gradient thermally induced phase separation technique. The cartilage phase scaffold adopts a directional microtubule structure, and the directional microtubule structure is derived from bovine knee joint cartilage matrix.

[0013] In step 4, the ratio of the height of the retaining stem to the height of the condylar head and neck prosthesis is (1-1.5):1; the ratio of the width of the retaining stem to the width of the condylar head and neck prosthesis is (1-1.5):1.

[0014] 3-5 titanium nail holes are reserved on the retention handle according to the stress conditions.

[0015] The retention handle is composed of two narrow retention bands, each of which is implanted with 2-3 titanium nail holes 5.

[0016] The bone phase scaffold is manufactured by 3D printing using EBM or SLM method.

[0017] The bone phase bracket is made of Ti-6Al-4v titanium alloy.

[0018] The dense layer adopts lactic acid-glycolic acid copolymer / β-tricalcium phosphate organic solution.

[0019] The beneficial effects of the present invention are as follows: the present invention adopts computer-aided design and three-dimensional printing technology to prepare a gradient three-dimensional mesh titanium alloy osteogenic and cartilaginous biphasic scaffold, construct a personalized biphasic bionic condyle scaffold, and by utilizing the principles of tissue engineering, construct a condyle whose appearance, internal structure, histological characteristics, and biomechanical properties are similar to the original temporomandibular joint condyle. In addition, it matches the patient's own mandibular morphology and fits the jaw more closely. During the operation, there is no need to grind off a large amount of bone tissue to adapt to the shape of the prosthesis, which effectively reduces the occurrence of intraoperative and postoperative complications, shortens the operation time, and can achieve optimal stress distribution after implantation, solving the problems of the mechanical properties of the materials and the degradation cycle of the existing prostheses not meeting clinical needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a rendering of the personalized biphasic condylar scaffold prepared by the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the personalized biphasic condylar scaffold prepared by the present invention.

[0022] In the figure, 1. cartilage phase scaffold, 2. dense layer, 3. bone phase scaffold, 4. retention stem, 5. titanium nail hole, 6. condylar main part. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The structure of a personalized biphasic bionic condylar scaffold of the present invention is as follows: Figure 1 and Figure 2 As shown, it includes a bone phase support 3 and a cartilage phase support 1. The bottom of the bone phase support 3 is connected to a retaining handle 4, and a titanium nail hole 5 is set on the retaining handle 4.

[0025] The bone phase scaffold 3 includes a condylar head and a condylar main body 6. A dense layer 2 is arranged on the surface of the condylar head. The thickness of the dense layer 2 is 380-420 μm. Meshes are arranged on the dense layer 2. The diameter of the mesh is not greater than 100 μm.

[0026] The outer surface of the condylar main body 6 is provided with diamond-shaped holes, the diameter of the diamond-shaped holes is 400-600 μm, the porosity of the diamond-shaped holes is 65-75%, and the condylar main body 6 is provided with a simulated bone trabecular structure.

[0027] The bone phase support 3 is connected to the cartilage phase support 1 through the dense layer 2 set on the surface of the condylar head. The bone phase support 3 is connected to the retaining stem 4 through the bottom of the condylar main body 6. The lower end of the retaining stem 4 is trimmed into a round and blunt shape; the thickness of the retaining stem 4 is 1.5 to 2 mm; 3-5 titanium nail holes 5 are reserved on the retaining stem 4.

[0028] The cartilage phase scaffold 1 adopts an oriented microtubule structure, and the oriented microtubule structure is derived from bovine knee joint cartilage matrix.

[0029] The bone phase bracket 3 is made of titanium alloy.

[0030] The diameter of the titanium nail hole 5 is 1.5 to 3 mm.

[0031] The present invention provides a method for preparing a personalized biphasic condylar scaffold, which is specifically implemented according to the following steps:

[0032] Step 1: Collect data to separate the mandibular digital model;

[0033] Step 1 specifically includes: collecting the patient's head CBCT data in DICOM format and importing it into the medical image processing software Mimics to generate a full head 3D virtual model, and separating the mandibular model from the full head 3D virtual model.

[0034] Step 2: Select the data on the opposite side of the lesion area in the mandibular digital model, mirror-symmetric map it to the lesion area, obtain the condylar head and neck prosthesis model, and design and print the bone phase scaffold 3 according to the condylar tissue structure morphology.

[0035] Step 2 is specifically as follows: by exporting to an STL format file and importing it into Geomagic software, the surgical process is simulated to perform osteotomy on the affected area, and then reverse reconstruction is performed. By utilizing the natural symmetry of the two sides of the mandible, the data on the opposite side of the affected area in the mandibular digital model is selected, and mirror-symmetric mapping is performed to the affected area to obtain relevant data of the condylar head and neck prosthesis model. The mandibular digital model is imported into ANSYS 14.0 software for optimization design, thereby obtaining a three-dimensional mesh digital model of the defect area, and inputting the 3D printing design to produce a gradient three-dimensional mesh bone phase scaffold 3, and the printed bone phase scaffold 3 is cleaned and sterilized for use.

[0036] The bone phase bracket 3 is manufactured by 3D printing using an EBM or SLM method, and the bone phase bracket 3 is made of Ti-6Al-4v titanium alloy.

[0037] Step 3, preparing a cartilage phase scaffold 1;

[0038] Step 3 specifically prepares the cartilage phase scaffold 1 by utilizing the temperature gradient thermal induced phase separation technology. The cartilage phase scaffold 1 adopts a directional microtubule structure, and the directional microtubule structure is derived from the bovine knee joint cartilage matrix.

[0039] Step 4: Spray the dense layer 2 on the head surface of the bone phase scaffold 3, and use the "dissolution-adhesion" process to connect the cartilage phase scaffold 1 with the dense layer 2 to form a dense layer bone-cartilage composite scaffold, thereby constructing a condylar biphasic composite scaffold. After designing a retention handle 4 on the condylar biphasic composite scaffold, it is obtained.

[0040] In step 4, the ratio of the height of the retaining stem 4 to the height of the condylar head and neck prosthesis is (1-1.5):1; the ratio of the width of the retaining stem 4 to the width of the condylar head and neck prosthesis is (1-1.5):1.

[0041] According to the stress conditions, 3-5 titanium nail holes 5 are reserved on the retaining handle 4 or the retaining handle 4 is formed into two narrow retaining bands, and 2-3 titanium nail holes 5 are implanted on each retaining band. The positions of the titanium nail holes 5 avoid the inferior alveolar nerve.

[0042] The dense layer 2 is made of lactic acid-glycolic acid copolymer / β-tricalcium phosphate organic solution.

[0043] The condyle of the temporomandibular joint is a complex of bone and cartilage tightly combined, consisting of a thin layer of fibrocartilage and the subchondral bone tightly combined below. Bionic condyle reconstruction includes the restoration of the anatomical tissue structure of the condyle and the restoration of the function of the temporomandibular joint. The restoration of the anatomical tissue structure is the premise and basis of functional reconstruction. Titanium or titanium alloy is made into a three-dimensional mesh structure that imitates the structure of trabecular bone, which is conducive to mechanical conduction and then guides bone regeneration. The three-dimensional mesh titanium alloy scaffold is implanted into the bone defect area, and new bone is formed inside the scaffold after a period of time; titanium alloy mesh scaffolds with different pore sizes and hole types can induce the growth of different tissues. The scaffolds with smaller pore sizes and square hole types are conducive to cartilage formation, and the scaffolds with larger pore sizes and diamond hole types are conducive to bone tissue formation. The present invention can construct a bionic condyle tissue with bone and cartilage tightly combined, which has internal structure and histological characteristics similar to the original condyle. The cartilage scaffold was prepared using the extracellular matrix material of bovine knee articular cartilage, and the three-dimensional mesh titanium alloy scaffold was the bone phase scaffold. The dense layer was prepared on the head of the three-dimensional mesh titanium alloy condyle scaffold using bioprinting technology, and the three-dimensional mesh titanium alloy bone phase scaffold and the cartilage phase scaffold were bonded using the "dissolution-adhesion" technology to achieve a dual-phase bionic condyle scaffold.

[0044] The present invention prepares a personalized biphasic condyle scaffold, which adopts the bionic condyle of the condyle scaffold based on the principle of tissue engineering, and constructs a condyle whose appearance, internal structure, histological characteristics, and biomechanical properties are all similar to the original condyle of the temporomandibular joint condyle. The appearance is consistent with the original condyle morphology of the patient, matches the mandibular morphology of the patient, and fits the jaw more closely. There is no need to grind off a large amount of bone tissue during the operation to adapt to the prosthesis shape, which effectively reduces the occurrence of intraoperative and postoperative complications, shortens the operation time, and can achieve optimal stress distribution after implantation.

Claims

1. A method for preparing a personalized biphasic condylar scaffold, characterized in that: Follow the steps below to implement it: Step 1: Collect data to separate the mandibular digital model; Step 2: Select the data on the opposite side of the lesion area in the mandibular digital model, mirror-symmetric map it to the lesion area, obtain the condylar head and neck prosthesis model, and design and print the bone phase scaffold according to the condylar tissue structure morphology (3); Step 3, preparing a cartilage-phase scaffold (1); Step 4, spraying a dense layer (2) on the head surface of the bone phase scaffold (3), connecting the cartilage phase scaffold (1) and the dense layer (2) by a dissolution-adhesion process to form a dense layer bone-cartilage composite scaffold, thereby constructing a condylar biphasic composite scaffold, and designing a retaining handle (4) on the condylar biphasic composite scaffold. The step 1 specifically includes: collecting the patient's head CBCT data in DICOM format and importing it into the medical image processing software Mimics to generate a full head 3D virtual model, and separating the mandibular model from the full head 3D virtual model; The step 2 specifically comprises: outputting the file in STL format and importing it into Geomagic software, simulating the surgical process to perform osteotomy on the lesion area, and then performing reverse reconstruction, taking advantage of the natural symmetry of the two sides of the mandible, selecting the data on the opposite side of the lesion area in the mandibular digital model, mirror-symmetric mapping it to the lesion area, obtaining relevant data of the condylar head and neck prosthesis model, importing the mandibular digital model into ANSYS 14.0 software for optimization design, thereby obtaining a three-dimensional mesh digital model of the defect area, inputting the 3D printing design to produce a gradient three-dimensional mesh bone phase scaffold (3), and cleaning and sterilizing the printed bone phase scaffold (3) for standby use; The step 3 specifically comprises preparing a cartilage phase scaffold (1) by using a temperature gradient heat-induced phase separation technique, wherein the cartilage phase scaffold (1) adopts an oriented microtubule structure, and the oriented microtubule structure is derived from bovine knee joint cartilage matrix; The bone phase scaffold (3) comprises a condylar head and a condylar main body (6), a dense layer (2) is arranged on the surface of the condylar head, the thickness of the dense layer (2) is 380-420 μm, and mesh holes are arranged on the dense layer (2), the diameter of the mesh holes is not greater than 100 μm; The outer surface of the condylar main body (6) is provided with diamond-shaped holes, the diameter of the diamond-shaped holes is 400-600 μm, the porosity of the diamond-shaped holes is 65-75%, and the condylar main body (6) is provided with a simulated trabecular structure; The bone phase support (3) is made of Ti-6Al-4V titanium alloy; The dense layer (2) is made of lactic acid-hydroxyacetic acid copolymer / β-tricalcium phosphate organic solution.

2. A method for preparing a personalized biphasic condylar scaffold as claimed in claim 1, characterized in that: In step 4, the ratio of the height of the retaining handle (4) to the height of the condylar head and neck prosthesis is (1-1.5):1; the ratio of the width of the retaining handle (4) to the width of the condylar head and neck prosthesis is (1-1.5):

1.

3. A method for preparing a personalized biphasic condylar scaffold as claimed in claim 2, characterized in that: 3-5 titanium nail holes (5) are reserved on the retaining handle (4).

4. A method for preparing a personalized biphasic condylar scaffold as claimed in claim 2, characterized in that: The retention handle (4) is two narrow retention bands, and each retention band is implanted with 2-3 titanium nail holes (5).

5. The method for preparing a personalized biphasic condylar scaffold according to claim 1, characterized in that: The bone phase scaffold (3) is manufactured by 3D printing using an EBM or SLM method.

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