Method for manufacturing degradable breast implant by using 3D printing technology

Abstract

The invention provides a method for manufacturing a degradable breast implant through a 3D printing technology. The method comprises the following steps that a heating cavity of a 3D printing nozzle is filled with a printing material; when the heating cavity is heated to the preset temperature, the 3D printing equipment starts printing work, specifically, a nozzle of a printing spray head extrudes a printing material and moves above a printing platform according to a preset program, and the temperature of the heating cavity is kept stable at the preset temperature; the preset program comprises the steps that a printing path takes the center of a preset graph as a starting point, printing is conducted layer by layer from inside to outside in the radial direction, and printing work is finished when the last layer of the preset graph is completed; and heating of the heating cavity is stopped. Through stable and continuous heating of the heating cavity, the molecular weight of the material is gradually reduced, and the 3D printing method is combined to print a preset pattern layer by layer from inside to outside, so that the molecular weight of the breast implant is reduced layer by layer from the center to the outer layer, and the problem that the degradation direction and the cell regeneration process of the breast implant manufactured by the existing means cannot dynamically cooperate is solved.

Description

Technical Field

[0001] The present application relates to the field of 3D printing technology, and in particular to a method for producing a degradable breast implant using 3D printing technology. Background Art

[0002] With the continuous development of medical technology, breast implants, as an important medical device, have been widely used in breast reconstruction and cosmetic surgery. 3D printing technology, due to its advantages such as precise control and personalized customization, has become an important technical support in the field of medical device manufacturing. However, implants prepared using layer-by-layer printing processes such as fused deposition modeling have a material molecular weight gradient distribution that decreases from bottom to top along the printing layer stacking direction. This results in a gradual degradation direction from top to bottom after implantation into the human body. Human cell regeneration follows a progressive growth pattern "from the periphery to the center," with new cells first adhering and colonizing on the outer surface of the implant and then gradually extending to the inner core area. Therefore, the degradation direction of breast implants after implantation into the human body cannot achieve dynamic coordination with the cell regeneration process, thereby affecting the structural stability and functional adaptability of the repair site. Summary of the Invention

[0003] The present application provides a method for producing a degradable breast implant using 3D printing technology to solve the problem that existing breast implants are difficult to achieve a degradation rate compatible with human cell regeneration after implantation into the human body.

[0004] To address the above technical issues, the present application provides a method for manufacturing a degradable breast implant using 3D printing technology. The degradable breast implant has a three-dimensional porous structure comprising a plurality of nested unit layers radiating from a central point to the periphery, with adjacent unit layers interconnected. The manufacturing method is based on setting the same preset pattern on the breast implant. The manufacturing method comprises the following steps: Fill the heating chamber of the 3D printing nozzle with printing material; heating the heating chamber until the temperature inside the heating chamber reaches a preset temperature; The 3D printing device starts a printing operation, wherein the printing operation includes the nozzle of the print head extruding the printing material, and the print head simultaneously moving above the printing platform according to a preset program to maintain the temperature in the heating chamber stable at the preset temperature; The preset program includes a printing path, wherein the printing path is to start from the center of the preset graphic and to expand the printing layer by layer from the inside to the outside in a radial direction, and the printing process ends when the last layer of the preset graphic is printed; Stop heating the heating chamber.

[0005] Wherein, before the step of starting the printing work of the 3D printing device, the step further includes: A support container is placed above the printing platform, and a support bath is poured into the support container; The 3D printing device starts a printing operation, which includes the nozzle of the printing head entering the support bath to extrude the printing material, and the printing head simultaneously moves in the support bath according to a preset program.

[0006] Wherein, the printing material is a single polymer material or a polymer composite material.

[0007] The preset temperature is a fixed value, and the range of the preset temperature is greater than or equal to 1.5 times the melting point of the printing material and less than or equal to 2.5 times the melting point of the printing material.

[0008] The preset program includes a total printing time, and the total printing time includes a sub-printing time of each unit layer, and the sub-printing time ranges from 2 minutes to 8 minutes.

[0009] The total printing time ranges from 6 hours to 30 hours.

[0010] The number of unit layers ranges from 200 to 400 layers.

[0011] The center of the preset graph is the origin, and the radial average distance between the unit layer and the origin is R n The larger the n value, the radial average distance R between the corresponding unit layer and the origin n The larger the value, the longer the printing time T of the nth layer (n≥1) n Meet T n >T n-1 .

[0012] The printing material is selected from polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polyglycolide (PGA), polybutylene succinate (PBS), polyvinyl alcohol (PVA), polylactic acid (PLA), and polylactic-glycolic acid copolymer (PLGA).

[0013] Different from the prior art, the embodiments of the present application have the following advantages: the present application provides a method for producing a degradable breast implant using 3D printing technology, wherein the degradable breast implant has a three-dimensional porous structure comprising a plurality of nested unit layers radiating from a center point to the periphery, with adjacent unit layers interconnected. The production method sets the same preset pattern based on the breast implant, and the production method comprises the following steps: pouring printing material into a heating chamber of a 3D printing nozzle; heating the heating chamber until the temperature within the heating chamber reaches a preset temperature; initiating a printing operation of the 3D printing device, wherein the printing operation includes extruding the printing material through a nozzle of the printing nozzle, and the printing nozzle simultaneously moving above a printing platform according to a preset program to maintain the temperature within the heating chamber at a stable preset temperature; the preset program includes a printing path, wherein the printing path starts from the center of the preset pattern and expands radially from the inside to the outside layer by layer, and the printing operation ends when the last layer of the preset pattern is printed; and heating of the heating chamber is stopped. By continuously heating the heating chamber to a preset temperature, the molecular weight of the material within the chamber gradually decreases as the heating time increases. Combined with a 3D printing method that expands layer by layer from the center of a preset pattern outward, the molecular weight of the printed biodegradable breast implant decreases layer by layer. The smaller the molecular weight, the faster it degrades in the human body. Therefore, after implantation, the breast implant gradually degrades from the periphery to the interior, aligning with the regenerative processes of human cells. This manufacturing method resolves the problem of existing biodegradable breast implants being unable to dynamically coordinate their degradation direction with the cell regeneration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work, including: Figure 1 A flowchart of an implementation method of the first manufacturing method provided in this application; Figure 2 for Figure 1 Schematic diagram of the printing process of the process shown; Figure 3 for Figure 1 Schematic diagram of the conceptual structure of the preset graphic of the breast implant; Figure 4 A flowchart of an implementation method of the second production method provided in this application; Figure 5 for Figure 4 Schematic diagram of the printing process of the process shown; Figure 6 for Figure 4 Schematic diagram of the conceptual structure of the preset graphic of the breast implant; Figure 7 A schematic structural diagram of a specific embodiment of a breast implant provided by the present application; Figure 8 for Figure 7 A schematic structural diagram of a state in a printing process of a breast implant is shown; Figure 9 for Figure 7 Schematic diagram of the structure of the breast implant in the completed printing state. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0016] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0017] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0018] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0019] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0020] With the continuous development of medical technology, breast implants, as an important medical device, have been widely used in breast reconstruction and cosmetic surgery. 3D printing technology, due to its advantages such as precise control and personalized customization, has become an important technical support in the field of medical device manufacturing. However, implants prepared using layer-by-layer printing processes such as fused deposition modeling have a material molecular weight gradient distribution that decreases from bottom to top along the printing layer stacking direction. This results in a gradual degradation direction from top to bottom after implantation into the human body. Human cell regeneration follows a progressive growth pattern "from the periphery to the center," with new cells first adhering and colonizing on the outer surface of the implant and then gradually extending to the inner core area. Therefore, the degradation direction of breast implants after implantation into the human body cannot achieve dynamic coordination with the cell regeneration process, thereby affecting the structural stability and functional adaptability of the repair site.

[0021] Therefore, in order to solve the above problems, the present application proposes a method for producing a degradable breast implant using 3D printing technology. The degradation direction of the degradable breast implant printed by this printing method is compatible with the regeneration law of human cells.

[0022] The biodegradable breast implant proposed in this application has a three-dimensional porous structure consisting of several nested unit layers radiating from a central point, with adjacent unit layers interconnected. The three-dimensional porous structure has abundant pores, providing anchoring points for surrounding tissues and pathways for cell migration, allowing tissue cells to migrate into the pores and proliferate.

[0023] Example 1 See also Figures 1 to 3 , which is a method proposed in this application for making a degradable breast implant 100 using 3D printing technology. The method sets the same preset pattern 110 according to the required breast implant 100. The preset pattern 110 includes a surface portion 112 and a filling portion 113. The surface portion 112 is a virtual boundary used to define the outer shape of the preset pattern 110, and the filling portion 113 is a solid structure filled in the surface portion 112. In this embodiment, the shape of the surface portion 112 is hemispherical, and the filling portion 113 is a multi-layer nested hemispherical unit layer 114 formed around the origin 111 with the center point as the origin 111. Because the actual number of unit layers is too large to be clearly reflected in the figure, Figure 2 、 Figure 3 Only some unit layers 114 of the filling portion 113 are shown schematically, and are only used to illustrate the printing process and the relationship between the unit layers 114. Figure 1 As shown, the specific steps of the method are as follows: Step S11: pouring printing material into the heating chamber of the 3D printing nozzle.

[0024] Before printing begins, the heating chamber of the 3D printing nozzle 200 is filled with printing material. The printing material can be a single polymer or a polymer composite. The single polymer is selected from one of polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polyglycolide (PGA), polybutylene succinate (PBS), polyvinyl alcohol (PVA), polylactic acid (PLA), and polylactic-co-glycolic acid (PLGA). The polymer composite is selected from two or more of the above materials. In this embodiment, polycaprolactone (PCL) is selected as the printing material. Polycaprolactone (PCL) has excellent biocompatibility and degradability, with a controllable degradation rate in the body. It also has soft and ductile mechanical properties, making it suitable for breast implants.

[0025] Step S12: Heat the heating chamber until the temperature inside the heating chamber reaches a preset temperature. In some embodiments, the printed material inside the heating chamber can be heated by wrapping the outer periphery of the heating chamber with a heating coil and energizing it, or by connecting the heating chamber to a semiconductor. A temperature sensor can be used to monitor the temperature inside the heating chamber. When the temperature sensor detects that the temperature inside the heating chamber has reached a preset temperature, it triggers and sends a signal to the processor. The processor receives the signal sent by the temperature sensor and transmits the signal to the control device. At the same time, the monitoring frequency of the temperature sensor is set. When the temperature sensor detects that the temperature inside the heating chamber is higher than the preset temperature, the temperature sensor sends a signal to the processor. The processor receives the signal and controls the heating coil to stop heating the heating chamber; when the temperature sensor detects that the temperature inside the heating chamber is lower than the preset temperature, the temperature sensor sends a signal to the processor. The processor receives the signal and controls the heating coil to start heating the heating chamber. An appropriate monitoring frequency is set to stabilize the temperature inside the heating chamber at the preset temperature.

[0026] Step S13: The 3D printing device starts printing, and the printing work includes the nozzle of the printing head extruding the printing material, and the printing head simultaneously moves above the printing platform according to a preset program to keep the temperature in the heating chamber stable at the preset temperature.

[0027] In some embodiments, the printing control device receives a signal sent by the processor and controls the 3D printing device to start printing. The printing operation includes the nozzle 201 of the print head 200 extruding the printing material, and the print head moves above the printing platform 300 according to a preset program. During this period, the temperature in the heating chamber is kept stable at a preset temperature to ensure that the printing material in the heating chamber is always stable at a preset temperature. This embodiment is a method in which the nozzle 201 of the print head 200 prints directly on the printing platform 300, such as Figure 2 shown.

[0028] Step S14: The preset program includes a printing path. The printing path starts from the center of the preset graphic and expands radially from the inside to the outside layer by layer. The printing work ends when the last layer of the preset graphic is printed.

[0029] The printing work is carried out according to the preset program, which includes a printing path. The printing path is to start from the center of the preset graphic 110, that is, from the origin 111, and to expand the printing layer by layer from the inside to the outside in a radial direction until the last layer of the preset graphic is printed. Figure 2As shown, A1 represents the state where the nozzle 201 of the print head 200 contacts the printing platform 300 to begin printing, A2 represents the state where the print head 200 has completed a portion of the printing path, A3 represents the state where the print head 200 has completed the printing path, and A4 represents the state where the print head 200 has left the breast implant 100 after the printing process is completed. In this embodiment, the preset printing process includes setting a coordinate system in three-dimensional space, with the center of the preset figure 110 being the origin 111. Multiple concentric unit layers 114 are planned around the origin 111, each layer being a non-enclosed hemispherical shape. Starting from the first layer closest to the origin, each layer is printed outward in sequence until the printing process is completed, forming a hemispherical three-dimensional porous structure as a whole. Figure 3 shown.

[0030] Specifically, a coordinate system is first established in three-dimensional space, with the printing starting point determined to be the origin of a preset pattern. The geometric parameters of each unit layer are preset, including the number of layers, the preset radius of each layer, and the porosity of each layer. Next, the structure is divided into layers 1 to n (n ≥ 2) based on their distance from the origin. The surface morphology, edge coordinates, and mesh coordinates of each layer are defined, generating path data for each unit layer. Printing is then performed layer by layer, starting from the first layer and ending at the nth layer. Each unit layer is formed by depositing material at the preset coordinate positions based on the surface morphology of the current layer being printed. This process continues until all the preset layers are printed, resulting in a three-dimensional porous structure formed by bonding together several non-enclosed hemispherical surfaces. In some embodiments, breast implants with identical hemispherical surfaces can be bonded together at a flat surface to form a spherical breast implant, suitable for applications requiring spherical breast implants.

[0031] Step S15: Stop heating the heating chamber.

[0032] In some embodiments, when the print head completes printing, the processor receives a signal indicating that printing is complete and sends a signal to the heating coil control device to control the heating coil to stop working.

[0033] By continuously heating the heating chamber to a preset temperature, the molecular weight of the printed material within the chamber gradually decreases as the heating time increases. Combined with a printing method that starts from the center of a preset pattern and expands layer by layer from the inside out, the molecular weight of the printed biodegradable breast implant decreases layer by layer from the center outward. The lower the molecular weight, the faster it degrades in the human body. Therefore, after implantation, the breast implant gradually degrades from the periphery to the interior, aligning with the regenerative processes of human cells. This manufacturing method solves the problem of existing biodegradable breast implants being unable to dynamically coordinate their degradation direction with the cell regeneration process.

[0034] Example 2 See also Figures 4 to 6, which is another method of making a degradable breast implant using 3D printing technology proposed in this application. This method sets the same preset pattern 110 according to the required breast implant 100. The preset pattern 110 includes a surface portion 112 and a filling portion 113. The surface portion 112 is a virtual boundary used to limit the outer shape of the preset pattern 110, and the filling portion 113 is a solid structure filled in the surface portion 112. In this embodiment, the shape of the surface portion 112 is a truncated cone, and the filling portion 113 is a multi-layer nested truncated cone unit layer 114 formed around the origin 111 with the center point as the origin 111. Because the actual number of unit layers is too large to be clearly reflected in the figure, Figure 5 、 Figure 6 Only some unit layers 114 of the filling part are illustrated, which is only used to illustrate the printing process and the relationship between the unit layers 114.

[0035] In some embodiments, a suspension medium material is used to provide support for suspension printing. Therefore, before step S11 or after step S11 or after step S12, step S111 is included: a support container is placed above the printing platform, and a support bath is poured into the support container.

[0036] Specifically, a support container 310 filled with a support bath 311 can be placed on the printing platform 300 first, and then the printing material can be poured into the heating chamber of the 3D printing nozzle 200; or after the printing material is poured into the heating chamber of the 3D printing nozzle 200, a support container 310 filled with a support bath 311 can be placed on the printing platform 300; or when the heating chamber is heated until the temperature inside the heating chamber reaches a preset temperature, a support container 310 filled with a support bath 311 can be placed on the printing platform.

[0037] Therefore, step S13 may be step S131: the 3D printing device starts printing, and the printing operation includes the nozzle of the printing head entering the support bath to extrude the printing material, and the printing head simultaneously moves in the support bath according to a preset program.

[0038] In some embodiments, the printing control device receives a signal sent by the processor and controls the 3D printing device to start printing, such as Figure 4 As shown, the printing operation includes the nozzle 201 of the print head 200 entering the support bath 311 to extrude the printing material, and the print head 200 moves in the support bath 311 according to a preset program, during which the temperature in the heating chamber is kept stable at a preset temperature to ensure that the printing material in the heating chamber is always stable at a preset temperature.

[0039] Step S14: The preset program includes a printing path. The printing path starts from the center of the preset graphic and expands radially from the inside to the outside layer by layer. The printing work ends when the last layer of the preset graphic is printed.

[0040] The printing work is performed according to the preset program, which includes a printing path. The printing path is to start from the center of the preset graphic 110, that is, from the origin 111, and to expand the printing layer by layer from the inside to the outside in a radial direction until the last layer of the preset graphic 110 is printed. Figure 5 As shown, B1 is the state where the print head 200 enters the support bath 311 and starts printing, B2 is the state where part of the printing path is completed, B3 is the state where the print head 200 completes the printing path, and B4 is the state where the print head 200 leaves the support bath 311 after completing the printing work. In this embodiment, the preset procedure for the printing work includes setting a coordinate system in three-dimensional space, the center of the preset graphic 110 is the origin 111, and multiple concentric unit layers 114 are planned with the origin 111 as the center, each layer being a closed truncated cone. Starting from the first layer closest to the origin, each layer is printed outward in sequence until the printing path is completed, forming a truncated cone-shaped three-dimensional porous structure as a whole, as shown in FIG. Figure 6 shown.

[0041] Specifically, first set the coordinate system in three-dimensional space, determine the printing starting point as the origin of the preset graphic, and preset the geometric parameters of each unit layer. The geometric parameters include the number of layers, the preset radius of each vertex position of each layer, and the porosity of each layer. Secondly, according to the distance from each unit layer to the origin from near to far, divide the structure into the 1st layer to the nth layer (n≥2), define the surface morphology, edge coordinates and mesh coordinates of each layer, and generate the path data of each unit layer. Print layer by layer from the 1st layer to the nth layer in sequence. According to the surface morphology of the current layer being printed, each unit layer is formed by depositing the material at the preset coordinate position until all the preset layers are printed, forming a three-dimensional porous structure as a whole formed by bonding several closed frustum surfaces.

[0042] This application proposes a specific embodiment of the shape of a breast implant, such as Figures 7 to 9 The figure shows an embodiment in which the three-dimensional porous structure is a three-dimensional reticular structure. However, other three-dimensional porous structures not shown, such as sponge structures and minimal surface structures, are also within the scope of protection of this application. The three-dimensional reticular structure can provide a scaffold for human tissue cells to attach and grow, allowing the implant to form a biological fusion with the surrounding tissue rather than a simple physical wrapping. This property can reduce the body's immune rejection response to the implant and reduce the incidence of capsular contracture. The pores of the reticular structure allow endothelial cells to migrate and form new blood vessels, promoting blood supply around the implant. Figure 7 Schematic diagram of the three-dimensional structure of the printed breast implant 100. Figure 8A structural schematic diagram of a state in the printing process of a breast implant 100, the left side is a front view, and the right side is a top view, the outside is a surface part 112 of a preset pattern 110, and the inside is a printed breast implant 100. Figure 9 A structural schematic diagram of a state in the printing process of a breast implant 100, the left side is a front view, and the right side is a top view, the outside is a surface part 112 of a preset pattern 110, and the inside is a printed breast implant 100.

[0043] In the specific implementation process, different preset temperatures are set according to different printing materials, and the preset temperature of any manufacturing process is a fixed value. It is verified through experiments that the range of the preset temperature is greater than or equal to 1.5 times the melting point of the printing material and less than or equal to 2.5 times the melting point of the printing material. Not only can the molecular weight degradation distribution of the degradable breast implant be effectively controlled, but also the mechanical properties of the breast implant can be ensured. The printing material will undergo thermal degradation during continuous heating. In this embodiment, polycaprolactone (PCL) is selected as the printing material, and the melting point temperature of polycaprolactone (PCL) is 60 degrees Celsius. Therefore, the range of the preset temperature is between 90 degrees Celsius and 110 degrees Celsius. At this temperature, the ester bond of PCL will break, resulting in a decrease in molecular weight. In this embodiment, the preset temperature is selected to be 120 degrees Celsius. This temperature setting ensures that the material can be fully melted and maintain good fluidity, while preventing thermal degradation of the material due to excessive temperature. In actual operation, the preset temperature can be determined according to the number of layers and the size of the preset pattern.

[0044] In some specific embodiments, the preset program includes a total printing time, and the total printing time includes a sub-printing time of each unit layer. The sub-printing time directly determines the residence time of the material in the heating cavity. The longer the time, the more significant the molecular weight degradation, and the faster the degradation rate of the corresponding layer. In order to better control the molecular weight distribution of each unit layer and form a controllable degradation rate, it is verified through experiments that when the sub-printing time is in the range of 2 min to 8 min, a stable gradient of adjacent molecular weight difference can be formed, avoiding insufficient molecular weight change or insufficient material melting due to too short time, and avoiding strength failure due to too long time. The printing time of the outer layer can be set to be close to 8 min to form a lower molecular weight and a faster degradation rate, which provides a growth space for new cells first. The printing time of the inner layer is shorter and close to 2 min to form a higher molecular weight and a slower degradation rate, which maintains the structural support until the cells in the inner layer are completely regenerated.

[0045] The molecular weight of the implant decreases gradually from the center to the outer layers, requiring a cumulative total printing time to maximize the molecular weight difference across the layers. If the total printing time is too short, less than 6 hours, the material layers remain in the heating chamber for insufficient time, resulting in a weak molecular weight gradient and minimal degradation rate differences. This prevents the dynamic coordination of periphery degradation followed by inner degradation. If the total printing time exceeds 30 hours, the outer layer is heated for an extended period in the heating chamber, causing a decrease in melt viscosity and deviation from the preset printing coordinates. Considering the overall size and complexity of the breast implant, a total printing time range of 6 to 30 hours can achieve a 30% to 50% molecular weight difference between the inner and outer layers, corresponding to a 2- to 3-fold difference in degradation rate, precisely matching the regenerative process of human cells from the periphery to the center. Furthermore, 6 to 30 hours corresponds to the effective degradation time window of the material at the printing temperature, avoiding both the insufficient molecular weight gradient caused by short-term heating and the mechanical property collapse caused by long-term heating. This ensures that the entire 3D network structure is printed completely and accurately.

[0046] To mimic the density gradient of breast tissue and achieve anisotropic mechanical properties, matching the elastic modulus with native tissue, the number of unit layers in the biodegradable breast implant was set between 200 and 400. This was coordinated with the sub-printing time and total printing time parameters to achieve a slower degradation rate for the inner layers (1st to 100th layers), maintaining core support, while the outer layers (300th to 400th layers) degrade more rapidly, guiding cell growth from the periphery inward. The number of layers controls the speed of the degradation front, precisely matching the regeneration rate of human tissue.

[0047] In this embodiment, the number of unit layers of a degradable breast implant is 300, taking into account material degradation kinetics, structural functional zoning, and biomedical needs. The sub-printing time for the first 120 layers is 3 minutes, the sub-printing time for layers 120-200 is 4 minutes, the sub-printing time for layers 200-250 is 5 minutes, and the sub-printing time for layers 250-300 is 6 minutes, for a total printing time of 1230 minutes. The innermost printed material has the shortest residence time in the heating chamber and suffers the least molecular weight degradation. It serves as the core support structure, resisting the weight of the breast and external pressure, preventing implant collapse. The molecular weight of the middle printed material degrades moderately, forming a transitional support layer with a lower elastic modulus than the inner layer, simulating the mechanical transition from mammary glandular tissue to adipose tissue and reducing interfacial stress concentration. The molecular weight of the printed material in the middle and outer layers decreases further, and the porosity increases, providing an initial channel for endothelial cell ingrowth while maintaining a certain level of structural rigidity. The outer layer of printed material stays in the heating chamber the longest and has the most molecular weight degradation, corresponding to a high degradation rate, which accelerates tissue adhesion and angiogenesis.

[0048] The specific operation process of this embodiment is described in detail below: First, prepare a 3D printing device, including a printing head 200 with a precise temperature control system and a heating chamber.

[0049] The prepared PCL material is loaded into the feed system of the 3D printing device, and the material is fed into the heating chamber of the print head 200 through the feed mechanism. The heating chamber uses a heating coil heating method and has a precise temperature control system that can stably control the temperature at a preset value of 120°C.

[0050] The 3D printer's heating system activates and heats the heating chamber. When the chamber temperature reaches a preset 120°C, the 3D printer begins printing. The temperature control system monitors the chamber temperature in real time and adjusts the heating power to ensure a stable temperature of 120°C, with fluctuations within ±5°C.

[0051] The printing process involves the nozzle 201 of the print head 200 extruding printing material. The print head 200 moves over the printing platform 300 according to a preset program. The preset program contains detailed information about the printing path. This printing path is designed to start from the origin 111 of the preset pattern 110 and expand radially outward layer by layer. The preset pattern 110 is a three-dimensional model of the breast implant 100, ensuring that the manufactured breast implant 100 has the ideal shape and mechanical properties.

[0052] The printing process starts from the first unit layer, which is closest to the origin and takes 3 minutes to print. The sub-printing time for the first 120 layers is 3 minutes, the sub-printing time for layers 120 to 200 is 4 minutes, the sub-printing time for layers 200 to 250 is 5 minutes, and the sub-printing time for layers 250 to 300 is 6 minutes.

[0053] Each printed layer follows the same shape design but varies in size, forming a three-dimensional mesh structure that radiates from the center to the periphery. This structural design ensures that the breast implant has good mechanical strength and biocompatibility, while maintaining appropriate porosity to facilitate tissue growth and vascularization.

[0054] The entire printing process ends when the final layer (300th layer) of the preset pattern is printed, with a total printing time of 20.5 hours. At this point, the heating chamber is stopped and the printed breast implant is allowed to cool naturally to room temperature.

[0055] After cooling, the printed breast implants are removed and post-processed. This includes removing the suspending medium, smoothing the surface, and sterilizing to ensure the implants meet medical device quality requirements.

[0056] The degradable breast implant produced by the above method has the following characteristics: The three-dimensional mesh structure design gives the implant good mechanical strength and elasticity, which can maintain the shape and touch of the breast; the unit layer design radiating from the center point to the periphery enables the implant to evenly distribute stress when subjected to force, reducing local stress concentration; the selection of polymer materials ensures that the implant has good biocompatibility and a controllable degradation rate. Over time, the implant will gradually be replaced by the body's own tissues; the application of 3D printing technology enables the implant to be customized and manufactured according to the individual differences of the patient, improving its clinical applicability.

[0057] Example 3 In this example, a composite material of polylactic acid (PLA) and polylactic-co-glycolic acid (PLGA) was selected as the printing material, mixed in a 1:1 mass ratio. Both materials have excellent biocompatibility and biodegradability, with a controllable degradation rate in the body, making them suitable for breast implants.

[0058] In this embodiment, the melting point of the PLA and PLGA composite material used is about 156°C, so the preset temperature is set between 234°C and 390°C, specifically 300°C.

[0059] In some embodiments, such as Figure 3 As shown, the radial average distance between the unit layer 114 and the origin 111 is R n The larger the n value, the larger the radial average distance R between the layer and the origin. n The larger the value, the longer the printing time T of the nth layer (n≥1) n Meet T n >T n-1 .exist Figure 7 In the embodiment shown, the number of unit layers of the degradable breast implant is 200. The printing time T1 of the first layer (n=1) is set to 3 minutes. As the value of n increases, the printing time of each layer gradually increases. The printing time T1 of the outermost layer (n=200) is set to 3 minutes. 200 The print time was set to 8 minutes, resulting in a total of 21 hours. This incremental print time design takes into account that as the average radial distance increases, the area and complexity of each layer also increase, requiring longer printing time. The resulting degradable breast implant has a molecular weight in the outermost layer reduced to 0.5 to 0.9 times the molecular weight at the origin.

[0060] This application only proposes two specific implementation methods of printing materials, but not all implementation methods. Other implementation methods that meet the requirements of this application are also within the scope of protection of this application.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

[0062] The present application provides a method for producing a degradable breast implant using 3D printing technology. The degradable breast implant comprises a three-dimensional porous structure comprising a plurality of nested unit layers radiating outward from a center point, with adjacent unit layers interconnected. The production method sets a predetermined pattern identical to the breast implant and comprises the following steps: injecting printing material into a heating chamber of a 3D printing nozzle; heating the heating chamber until the temperature within the heating chamber reaches a predetermined temperature; initiating a printing operation of the 3D printing device, wherein the printing operation comprises extruding the printing material through a nozzle of the printing nozzle, and the printing nozzle simultaneously moving over a printing platform according to a predetermined program to maintain the temperature within the heating chamber at the predetermined temperature; the predetermined program includes a printing path, wherein the printing path starts at the center of the predetermined pattern and radially expands layer by layer from the inside outward, with the printing operation ending when the last layer of the predetermined pattern is printed; and terminating heating of the heating chamber. By continuously heating the heating chamber to a preset temperature, the molecular weight of the material within the chamber gradually decreases as the heating time increases. Combined with a 3D printing method that prints layer by layer from the center of a preset pattern outward, the molecular weight of the printed biodegradable breast implant decreases layer by layer. The lower the molecular weight, the faster it degrades in the human body. Therefore, after implantation, the breast implant gradually degrades from the periphery to the interior, aligning with the regenerative processes of human cells. This manufacturing method solves the problem of existing biodegradable breast implants being unable to dynamically coordinate their degradation direction with the cell regeneration process.

[0063] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for producing a degradable breast implant using 3D printing technology, characterized in that: The degradable breast implant is a three-dimensional porous structure comprising a plurality of nested unit layers radiating from a central point to the periphery, with adjacent unit layers interconnected. The method is to set the same preset pattern based on the breast implant. The manufacturing method comprises the following steps: Fill the heating chamber of the 3D printing nozzle with printing material; heating the heating chamber until the temperature inside the heating chamber reaches a preset temperature; The 3D printing device starts a printing operation, wherein the printing operation includes the nozzle of the print head extruding the printing material, and the print head simultaneously moving above the printing platform according to a preset program to maintain the temperature in the heating chamber stable at the preset temperature; The preset program includes a printing path, wherein the printing path is to start from the center of the preset graphic and to expand the printing layer by layer from the inside to the outside in a radial direction, and the printing process ends when the last layer of the preset graphic is printed; The heating of the heating chamber is stopped.

2. The method for producing a degradable breast implant using 3D printing technology according to claim 1, wherein: The 3D printing device also includes the following steps before starting the printing process: A support container is placed above the printing platform, and a support bath is poured into the support container; The 3D printing device starts a printing operation, which includes the nozzle of the printing head entering the support bath to extrude the printing material, and the printing head simultaneously moves in the support bath according to a preset program.

3. The method for producing a degradable breast implant using 3D printing technology according to claim 1 or 2, wherein: The printing material is a single polymer material or a polymer composite material.

4. The method for producing a degradable breast implant using 3D printing technology according to claim 3, wherein: The preset temperature is a fixed value, and the range of the preset temperature is greater than or equal to 1.5 times and less than or equal to 2.5 times the melting point of the printing material.

5. The method for producing a degradable breast implant using 3D printing technology according to claim 4, wherein: The preset program includes a total printing time, and the total printing time includes a sub-printing time of each unit layer, and the sub-printing time ranges from 2 minutes to 8 minutes.

6. The method for producing a degradable breast implant using 3D printing technology according to claim 5, wherein: The total printing time ranges from 6 hours to 30 hours.

7. The method for producing a degradable breast implant using 3D printing technology according to claim 6, wherein: The number of unit layers ranges from 200 to 400 layers.

8. The method for producing a degradable breast implant using 3D printing technology according to claim 7, wherein: The center of the preset graph is the origin, and the radial average distance between the unit layer and the origin is R n The larger the n value, the radial average distance R between the corresponding unit layer and the origin n The larger the value, the longer the printing time T of the nth layer (n≥1) n Meet T n >T n-1 .

9. The method for producing a degradable breast implant using 3D printing technology according to claim 3, wherein: The printing material is selected from polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polyglycolide (PGA), polybutylene succinate (PBS), polyvinyl alcohol (PVA), polylactic acid (PLA), and polylactic-co-glycolic acid (PLGA).

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