Medical material 3D printer and use method thereof

Abstract

The invention provides a medical material 3D printer and a use method thereof. The medical material 3D printer comprises an extrusion device, a printing container, a printing nozzle and a printing platform, the printing container is used for containing a printing material, the printing nozzle is installed on the printing container and used for extruding the printing material onto the printing platform, and the extrusion device is installed on the side, opposite to the printing nozzle, of the printing container and used for extruding the printing material onto the printing platform. The medical material 3D printer comprises a printing container, a printing nozzle and a printing platform, the printing nozzle is used for extruding a printing material in the printing container out of the printing nozzle, the printing platform is used for bearing the printing material extruded out of the printing nozzle, and the medical material 3D printer further comprises a refrigeration component arranged in a mode of surrounding the printing container and used for cooling the printing material in the printing container; the first heating device is arranged on the periphery of the printing spray head and used for preheating the printing material just extruded out of the printing spray head; and the second heating device is arranged below or inside the printing platform and is used for formally heating the printing material extruded onto the printing platform.

Description

Technical Field

[0001] The invention relates to a medical material 3D printer and a use method thereof. Background Art

[0002] Currently, some implantable devices on the market are made of non-degradable metal materials. When these non-degradable metal devices are implanted in the human body, some metals may cause allergic reactions, leading to local inflammation and pain. At the same time, although most metals have good biocompatibility, in some rare cases the patient's body may produce an immune response and reject the implant.

[0003] Over time and after long-term use, these non-degradable metal implants may experience wear or metal fatigue, and regular medical follow-up is required during the implant period to ensure that the implant is functioning properly and there is no inflammation.

[0004] After a non-degradable metal device is implanted in the human body, the patient may go to certain extreme environments (for example, extremely cold or hot environments). Since metal has good thermal conductivity, it may cause local discomfort in the human body.

[0005] Bone powder and bone cement are materials used in the medical field and are often used in bone repair and reconstruction surgery. As a bone transplant material (bone filling material), it can be used to fill bone defects and promote the formation and integration of new bones. Bioactive bone powder can be used as a substitute for autologous bone (the patient's own bone) to treat fractures, bone defects and other bone-related diseases. Some specially treated bone powders are osteoinductive and can guide and promote bone formation, which is very useful for bone regeneration and repair. However, it is still a difficult problem in the industry to make bone powder and bone cement combined with patient injury implants to achieve a fine match, especially in the face of some complex and irregular implants. At the same time, hydrogels made of calcium phosphate polymer composites, silicate-based materials, silk protein-based materials, polymer composites, gelatin and sodium alginate-based mixtures are all biomaterials that can be used for bone regeneration and repair. These biomaterials can improve their mechanical properties and retain good biodegradability. They can be formed by various methods such as 3D printing. In addition, this material can maintain a good spatial structure and mechanical properties in the early stage of degradation, and has a good bone conduction effect, which can effectively repair bone defects.

[0006] Or allogeneic bone transplantation can be used, but allogeneic bone is a type of allogeneic transplantation, which is generally divided into two types: structural bone grafting and filling bone grafting. It can be used in the fields of repairing fractures and soft tissues. At the same time, its source is wide and its usage is not restricted. When doing structural bone grafting, it is necessary to find a structure similar to the patient's resected bone. After bone grafting, the patient may also experience rejection reactions, absorption of allogeneic bone and slower healing.

[0007] At the same time, the choice of prostheses in traditional plastic surgery is often limited, and it is difficult to fully meet the needs of patients. 3D printing technology can customize the prosthesis according to the patient's facial features and needs. Customized prostheses can not only improve the effect of the operation, but also reduce the rejection reaction after the operation. At the same time, for facial reconstruction, the operation is difficult and the effect is uncertain. 3D printing technology can accurately print the prosthesis required for reconstruction based on the three-dimensional data of the injured part and restore the patient's facial structure. Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] However, it is still a difficult problem in the industry to make bone powder and bone cement match the patient's injury implantation precisely, especially in the face of some complex and irregular implants. The present invention can solve the above problem through a new structure 3D printing solution.

[0010] Means for solving technical problems

[0011] The present invention is made in view of the above problems, and its purpose is to provide a medical material 3D printer, which can flexibly print out a model with specific characteristics according to personalized needs from medical materials (for example, a mixed slurry obtained by mixing bone powder, bone cement powder and bone cement liquid in a specific proportion, and various additives can be added to the mixed slurry as needed) and has high biocompatibility and good mechanical properties after implantation, and can also promote bone regeneration and repair, and can be widely used in the fields of bone repair and plastic surgery. The purpose of the present invention is also to provide a method for using the above-mentioned medical material 3D printer.

[0012] The first aspect of the present invention provides a medical material 3D printer, characterized in that it includes an extrusion device, a printing container, a printing nozzle and a printing platform, wherein the printing container is used to contain a printing material as a medical material, the printing nozzle is installed on the printing container, and is used to extrude the printing material onto the printing platform, the extrusion device is installed on the side of the printing container opposite to the printing nozzle, and is used to extrude the printing material in the printing container from the printing nozzle, and the printing platform is used to carry the printing material extruded from the printing nozzle, and the medical material 3D printer also includes: a refrigeration component, which is arranged in a manner of surrounding the printing container, and is used to cool the printing material in the printing container; a first heating device, which is arranged around the printing nozzle, and is used to preheat the printing material just extruded from the printing nozzle; and a second heating device, which is arranged below or inside the printing platform, and is used to formally heat the printing material that has been extruded onto the printing platform.

[0013] In some embodiments, the refrigeration component is a semiconductor refrigeration component.

[0014] In some embodiments, the refrigeration component is a dry ice container containing dry ice.

[0015] In some embodiments, the first heating device is a device that uses hot air for heating.

[0016] In some embodiments, the second heating device is a hot plate.

[0017] In some embodiments, a control device is further included, which is used to control the actions of various parts included in the medical material 3D printer.

[0018] In some embodiments, the extrusion device includes a push rod motor, a push rod, and a piston.

[0019] In some embodiments, the extrusion device includes a stepper motor, a plum coupling, and a screw.

[0020] In some implementations, the printing container is a container having a syringe structure.

[0021] In some implementations, a light-sensitive remaining amount sensor for detecting the remaining amount of the printing material in the printing container is disposed outside or inside the printing container.

[0022] In some embodiments, the printing container includes an inverted conical silo and a supply pipe connected to the cone top of the silo.

[0023] In some embodiments, a remaining amount detection system for detecting the remaining amount of the printing material in the silo is disposed above the silo.

[0024] In some implementations, the remaining amount detection system includes a remaining amount sensor that detects the remaining amount using laser or infrared rays.

[0025] In addition, the second aspect of the present invention provides a method for using a medical material 3D printer, which is a method for printing using the above-mentioned medical material 3D printer, characterized in that it includes: a printing container cooling step, using the refrigeration component to cool the printing material in the printing container; a printing material extrusion step, using the extrusion device to extrude the printing material in the printing container from the printing nozzle; a preheating step, using the first heating device to preheat the printing material just extruded from the printing nozzle; and a formal heating step, using the second heating device to formally heat the printing material that has been extruded onto the printing platform.

[0026] In some implementations, before the printing container cooling step, the method includes: a printing material injecting step of injecting the printing material maintained at -20°C to 0°C into the printing container.

[0027] In some implementations, in the printing container cooling step, the printing material in the printing container is cooled to -20°C to 20°C by using the refrigeration component.

[0028] In some embodiments, in the preheating step, the first heating device is used to blow hot air toward the front end of the print head.

[0029] In some embodiments, the angle formed by the blowing direction of the hot air and the central axis of the print head is 20° to 40°.

[0030] In some embodiments, in the formal heating step, the printing platform is heated to 30° C. to 120° C. using the second heating device.

[0031] In some embodiments, the printing material is a mixed slurry including bone powder and bone cement, wherein the bone cement includes a powder and a liquid.

[0032] Effects of the Invention

[0033] By using the medical material 3D printer and the method for using the same of the present invention, bone powder and bone cement (bone cement includes powder and liquid) are mixed in a specific ratio to obtain a mixed slurry. Various additives can be added to the mixed slurry as needed. Such a mixed slurry is used on a 3D printer, and a model with specific characteristics can be flexibly printed according to personalized needs. The model has high biocompatibility and good mechanical properties after implantation, and can also promote bone regeneration and repair. It can be widely used in the fields of bone repair and plastic surgery.

[0034] Moreover, the printing material such as the mixed slurry of bone powder and bone cement will react faster in a high temperature environment. During the printing process, the temperature of the printing platform (hot bed) is much higher than the storage temperature of the printing material, and the printing nozzle is very close to the printing platform (hot bed), which will cause the printing platform (hot bed) to cause strong heat radiation to the printing material in the printing container, causing the temperature of the printing material to rise and accelerate the speed of its chemical reaction, thereby causing the printing material to solidify in large quantities before being extruded from the printing nozzle and blocking the printing nozzle. In the present invention, by arranging a refrigeration component in a manner surrounding the printing container, the printing material in the printing container is cooled by the refrigeration component, which can slow down the problem that the printing material (for example, the mixed slurry of bone powder and bone cement) in the printing container is affected by the ambient temperature or other factors during the extrusion process, causing the temperature of the printing material to rise and accelerate its solidification. Thus, it can ensure that the printing material maintains appropriate fluidity and extrudability during the extrusion process, and can accurately adjust the extrusion amount and extrusion speed of the printing material, thereby improving the accuracy of printing and the quality of the printed model.

[0035] In addition, after the above-mentioned printing material is extruded from the printing nozzle, it is necessary to speed up the chemical reaction rate of the printing material to speed up its curing process. In the present invention, a first heating device is arranged around the printing nozzle, and the first heating device is used to preheat the printing material just extruded from the printing nozzle, and a second heating device is arranged below or inside the printing platform, and the second heating device is used to formally heat the printing material that has been extruded onto the printing platform. In this way, the chemical reaction rate of the printing material can be appropriately accelerated to speed up its curing process. Moreover, by using the first heating device for preheating before using the second heating device for formal heating, the temperature rise process of the printing material can be smoother, and the curing of the printing material can be carried out more evenly, thereby improving the quality of the printed model. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall assembly of the medical material 3D printer of the present invention.

[0037] Figure 2 This is a partially enlarged view of the printing component of the medical material 3D printer of Example 1 of the present invention.

[0038] Figure 3 is a schematic diagram showing a three-dimensional model of a bone reconstructed from a CT scan.

[0039] Figure 4 This is a partially enlarged view of the printing component of the medical material 3D printer according to Example 2 of the present invention.

[0040] Figure 5It is a partial schematic diagram showing the printing components of the medical material 3D printer of Example 2 when viewed from the upper side.

[0041] It should be understood that, for the sake of simplicity and / or clarity of illustration, the elements shown in the drawings are not necessarily drawn to scale. For example, for the sake of clarity, the sizes of some elements may be exaggerated relative to other elements. In addition, in order to make the concept of the present invention easier to understand, elements known in the art are sometimes omitted in the drawings. The sizes of the drawings do not represent the exact sizes and / or size ratios of the various elements in this specification.

[0042] Description of Reference Numerals

[0043] 100: medical material 3D printer, 1: printer frame, 2: printing component, 3: printing platform, 4: hot plate (second heating device), 10: extrusion device, 20: syringe (printing container), 30: printing nozzle, 11: semiconductor refrigeration component (refrigeration component), 12: push rod motor bracket, 13: bracket, 14: hot air blowing device (first heating device), AX: central axis of the printing nozzle, θ: angle formed by the blowing direction of the hot air and the central axis of the printing nozzle, 101: push rod motor, 102: push rod, 103: piston, 40: extrusion device, 41, 42: dry ice holding part (refrigeration component), 401: stepping motor, 402: plum blossom coupling, 403: screw, 50: printing container, 501: silo, 502: supply pipeline. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the implementation methods of the present application clearer, the technical solutions in the implementation methods of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described implementation methods are part of the implementation methods of the present application, rather than all the implementation methods. Based on the implementation methods in the present application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application; the terms "including" and "having" in the specification of this application and any variations thereof are intended to cover non-exclusive inclusions.

[0046] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] It should be understood that in this specification, ordinal numbers such as "first", "second", "third", etc. may be used to refer to elements. Unless explicitly stated, this is only used to distinguish different elements and does not imply that the mentioned elements must be in a given order in time, space, or other aspects.

[0048] Example 1

[0049] First, refer to Figure 1 , Figure 2 The medical material 3D printer 100 according to the first embodiment of the present invention will be described.

[0050] like Figure 1 and Figure 2 As shown, the medical material 3D printer 100 of Example 1 includes a printer frame 1, a printing assembly 2, a printing platform 3, and a hot plate (second heating device) 4 arranged below (or inside) the printing platform 3. The printing platform 3 is detachably mounted inside the printer frame 1, and is used to carry the printing material extruded from the printing nozzle to form a model. The printing assembly 2 includes an extrusion device 10, a syringe 20 (printing container), and a printing nozzle 30. The syringe 20 is used to accommodate the printing material as a medical material (for example, a mixed slurry including bone powder and bone cement). The printing nozzle 30 is mounted on the syringe 20, specifically, at the front end of the syringe 20, for extruding the printing material onto the printing platform 3. The extrusion device 10 is mounted on the side of the syringe 20 opposite to the printing nozzle 30, and is used to extrude the printing material in the syringe 20 from the printing nozzle 30. The printing platform 3 is used to carry the printing material extruded from the printing nozzle 30. The medical material 3D printer 100 also includes: a semiconductor refrigeration component 11 (refrigeration component), which is arranged in a manner of surrounding the syringe 20, and is used to cool the printing material in the syringe 20; a hot air blowing device 14 (first heating device), which is arranged around the printing nozzle 30, and is used to preheat the printing material just extruded from the printing nozzle 30; and a hot plate 4 (second heating device), which is arranged below (or inside) the printing platform 3, and is used to formally heat the printing material that has been extruded onto the printing platform 3.

[0051] In addition, if Figure 2As shown, the extrusion device 10 includes a push rod motor 101, a push rod 102 and a piston 103. The push rod motor 101 is fixed on the push rod motor bracket 12. The push rod motor 101 can drive the push rod 102 to extend to push the piston 103 in the syringe 20 so that the mixed slurry in the syringe 20 is extruded from the print head 30. The printing assembly 2 can be supported on a track extending in the horizontal direction via the bracket 13 to achieve horizontal movement.

[0052] exist Figure 2 In the figure, the refrigeration component 11 is a semiconductor refrigeration component. Using a semiconductor refrigeration component to cool the printing container (such as a syringe) 20 can alleviate the problem that the mixed slurry in the printing container is affected by the ambient temperature or other factors during the extrusion process, causing the material temperature to rise, thereby accelerating its solidification. The semiconductor refrigeration component has the advantages of no vibration, small size, and light weight. By using the semiconductor refrigeration component, the mixed slurry in the syringe 20 can be properly cooled without affecting the accuracy and quality of printing. In addition, the refrigeration component 11 is not limited to a semiconductor refrigeration component as long as it can properly cool the mixed slurry in the syringe 20. For example, it can also be a component using a cooling method such as air cooling or water cooling.

[0053] exist Figure 2 In the figure, the first heating device 14 is a hot air blowing device, and the direction of the arrow indicates the blowing direction of the hot air. By using the hot air blowing device 14 to blow hot air, the mixed slurry just extruded from the print head 30 can be preheated quickly and conveniently. When using the hot air blowing device 14, the angle θ formed by the blowing direction of the hot air and the central axis AX of the print head 30 can be 20° to 40°, preferably 30°. In addition, the first heating device 14 is not limited to a hot air blowing device as long as it can quickly and conveniently preheat the mixed slurry just extruded from the print head 30. For example, it can also be a device that uses infrared rays or the like for heating.

[0054] In addition, the medical material 3D printer 100 also includes a control device (not shown), which is used to control the actions of various parts included in the medical material 3D printer 100. For example, the control device can control the reading of 3D printing data, the extrusion amount and extrusion speed of the printing material, the drive of the push rod motor 101, the cooling temperature of the refrigeration component 11, the heating temperature of the first heating device 14 and the second heating device 4, etc.

[0055] In Example 1, the printing material is, for example, a mixed slurry including bone powder and bone cement. Bone powder is a powder made from processed autologous or animal bones. Bone cement, also known as polymethyl methacrylate (PMMA) bone cement, usually consists of two parts: a powder part, which is a fine powder of polymethyl methacrylate (PMMA) polymer, and may also include some inorganic components such as barium sulfate (BaSO4) or zirconium oxide (ZrO2) for enhancing image visibility; and a bone cement liquid, which is the liquid part of the bone cement, mainly composed of liquid monomer methyl methacrylate (MMA). The mixed slurry may also include an additive, which may be polylactic acid (PLA), which is a biodegradable plastic polymerized from lactic acid in renewable resources (such as corn starch or sugarcane) and has excellent biocompatibility and biodegradability.

[0056] Furthermore, the additive may also include degradable polyesters, and the degradable polyesters include one or more of polyurethane, polycaprolactone, polyglycolide, polyanhydride, polyphosphate, polycarbonate, polyhydroxybutyrate, polydioxanone, and polyglycolic acid.

[0057] Furthermore, the additive may also include a solubilizer, such as polyvinyl pyrrolidone (PVP). PVP is a synthetic polymer material obtained by polymerizing vinyl pyrrolidone and has good solubility and biocompatibility.

[0058] Furthermore, the additive may also include artificial bone powder, also known as artificial bone powder, which is a biomaterial used for bone defect repair and bone transplantation. It is usually used to replace or assist natural bone tissue to help bone healing and regeneration.

[0059] The main components of artificial bone powder are: hydroxyapatite (HA), a biocompatible calcium phosphate mineral with a chemical composition similar to that of natural bone mineral, commonly used as bone filling material; tricalcium phosphate (TCP), a readily degradable calcium salt that promotes new bone formation; calcium phosphate composite materials, different artificial bone powders may contain a mixture of different types of calcium phosphates to optimize their degradation and mechanical properties; bioglass, a glass material containing silicon, calcium, phosphorus and other elements, with good biocompatibility and osteoconductivity; collagen; polymers, in some cases polylactic acid-glycolic acid copolymer (PLGA) can be added to increase the mechanical properties of the material or control the degradation rate.

[0060] Since bone cement is composed of bone cement powder (powder part: including polymethyl methacrylate (PMMA)) and bone cement liquid (liquid part: including liquid monomer methyl methacrylate (MMA)), the powder part is sometimes referred to as bone cement powder or powder, and the liquid part is sometimes referred to as bone cement liquid or liquid.

[0061] As mentioned above, the mixed slurry used as the printing material is a material including bone powder, bone cement powder and bone cement liquid, wherein bone powder: bone cement powder: bone cement liquid are mixed in a specific ratio. Bone powder is natural bone powder such as autologous bone powder, animal bone powder (such as cattle bone), which can improve the adaptability after implantation. Before printing, the printing material needs to be stored in a freezing environment of -20°C to 0°C (preferably -18°C to -12°C, more preferably -15°C) to slow down the curing speed of the printing material and ensure the stability of the material properties during the printing process. The freezing treatment helps to improve the extrudability and fluidity of the printing material, making it smoother for the printing material to be extruded through the syringe.

[0062] Furthermore, various additives may be added to the mixed slurry as the printing material as needed. The additives may be, for example, the polylactic acid (PLA), solubilizer, artificial bone powder, etc. as described above. The addition ratio (mass percentage) of the additives in the mixed slurry is 0% to 5%.

[0063] Furthermore, the inventors studied the mixing ratio of bone powder, bone cement powder and bone cement liquid, and confirmed that by making the mixing ratio (mass ratio) of bone powder, bone cement powder and bone cement liquid an appropriate value, the overall optimal 3D printing molding effect can be achieved, which is convenient for subsequent implantation.

[0064] After the mixing ratio is determined, the bone powder, bone cement powder and bone cement liquid are mixed in the determined ratio, and various additives are added as needed to prepare a mixed slurry. The prepared mixed slurry is stored in a storage device set at a temperature of -20°C to 0°C (preferably -18°C to -12°C, more preferably -15°C).

[0065] In addition, as a preferred example, the printing materials used in the present invention include, for example, biological bone powder and bone cement with biological activity, wherein the biological bone powder is made of one or more of autologous bone, allogeneic bone or animal bone, and the bone cement includes powder and liquid, and the mass ratio of biological bone powder and bone cement (biological bone powder: bone cement) is 1:1 to 1:12, and the mass ratio of bone cement powder and bone cement liquid (bone cement powder: bone cement liquid) is 0.5:1 to 1.5:1.

[0066] The 3D bone-printed prosthesis is a porous scaffold structure constructed by powder and liquid of bone cement, and biological bone powder with biological activity is present in the porous structure, thereby forming a biologically active structure. The present invention uses biological bone powder with biological activity as a raw material, has good biocompatibility with biological tissues, and retains biologically active cells, can induce the growth of osteocytes, and is more likely to achieve good bone ingrowth and bone integration with surrounding bone tissues, promote secondary growth of bones, improve the biocompatibility of 3D bone printing materials, and is conducive to reducing the biological inertness between bone cement materials and bone tissues.

[0067] By adjusting the solid-liquid ratio of bone cement powder and liquid, the extrusion performance and porosity of the material can be adjusted. And the content of biological bone powder in the material can be adjusted according to the load-bearing characteristics and bone density requirements of the printed bone structure.

[0068] In some preferred embodiments, the mass ratio of bone cement powder to bone cement liquid is 0.8:1 to 1.2:1. By controlling the solid-liquid ratio of bone cement powder and liquid, it is possible to ensure that bone cement has good bonding properties and flow properties, and has good extrusion properties. The printed material can be suitable for 3D printing equipment. At the same time, by adjusting the ratio of the two, the porosity of the printed material support structure can be regulated, thereby adjusting the density of the printed material, and the curing time as a binder can also be adjusted, which is more conducive to the control of the printing process. In some preferred embodiments, the mass ratio of biological bone powder to bone cement is 1:3 to 1:10. Due to the different functions of bones in different positions, the load-bearing capacity, strength and bone density required by bones are also different. In addition to being regulated by a porous support structure, it can also be regulated by the bone powder content present in the porous structure. Changes in bone powder content also affect the fluidity, extrudability and formability of bone printing materials, thereby affecting the stability of the formed bone structure.

[0069] In some preferred embodiments, the mass ratio of bone cement powder and bone cement liquid is 0.9:1 to 1.1:1. When the solid-liquid ratio of bone cement is too high, the material is too viscous and cannot be smoothly formed. On the other hand, when the solid-liquid ratio of bone cement is too low, the mixed slurry formed is too thin and difficult to form. In some preferred embodiments, the mass ratio of biological bone powder and bone cement is 1:4 to 1:10. When the bone powder content is too low, the bone density is low and the biological inertness of the bone cement material cannot be effectively reduced. On the other hand, when the bone powder content is too high, the material formed is not stable enough due to the influence of the bonding properties of bone cement.

[0070] In some preferred embodiments, the biological bone powder is preferably made of autologous bone. When autologous bone is used as the raw material, compared with bone powder raw materials from other sources, the patient is less likely to have an immune rejection reaction, making the transplantation process safer and having a higher success rate. The autologous bone selected is generally a bone in the human body that only has a decorative effect and does not affect the normal function of the human body.

[0071] In some embodiments, biological bone powder is obtained by removing the periosteum from fresh bones after in vitro pulverization. The bone powder used in the commonly used 3D bone printing often needs to be subjected to various complex treatments, including but not limited to defatting and deproteinization under high temperature, high pressure and various chemical reagents. These treatment processes are not only complicated, but also make the obtained bone powder lose its biological activity. Utilizing the material of the present invention, biological bone powder with biological activity is obtained only by simple operations of simple periosteum removal and crushing, and the cell activity of bone powder can be maintained to the greatest extent. The use of these biological bone powders with biological activity does not require the additional cultivation of active bone marrow cells and the increase of corresponding nutrients. Only simple treatment is required to activate the biological activity of bones, promote secondary growth of bones, and form a more stable bone structure. The operation is simple, safe and fast. The simple and fast processing method improves the efficiency of 3D bone printing and wins precious treatment time for rescuing patients with acute bone injuries.

[0072] In some embodiments, the particle size of the biological bone powder is controlled to be 50 to 200 μm. Considering the uniformity of the mixture of bone powder and bone cement, the particle size of the bone powder needs to be reasonably selected. If the particle sizes of the two do not match, the mixing uniformity may decrease, thereby causing a decrease in mechanical properties.

[0073] In some embodiments, the bone cement powder may include polymethyl methacrylate, and the bone cement liquid may include methyl methacrylate monomer. The present invention uses PMMA bone cement as a binder. It is known that PMMA bone cement is a traditional acrylic bone cement, which can achieve rapid coagulation at room temperature through polymerization reaction between powder and liquid.

[0074] In some embodiments, the 3D bone printing material may further include additives, which may include one or more of a developer, polylactic acid, degradable polyester, a solubilizer, and artificial bone powder. Thus, by selectively adding, the imaging performance, solubility, degradability, and biocompatibility of the material may be improved, and the mechanical properties of the material may be increased.

[0075] In some preferred embodiments, the developer may include barium sulfate or zirconium oxide to enhance the imaging visibility of the bone prosthesis formed after 3D printing. In some preferred embodiments, polylactic acid is polymerized from lactic acid in renewable resources (such as corn starch or sugarcane) and has excellent biocompatibility and biodegradability. In some preferred embodiments, the degradable polyester may include one or more of polyurethane, polycaprolactone, polyglycolide, polyanhydride, polyphosphate, polycarbonate, polyhydroxybutyrate, polydioxanone, and polyglycolic acid, which has a good Young's modulus, so that the mechanical properties of 3D bone printing materials are more matched with native bones, and the stress shielding effect can also be effectively reduced to prevent bone loss. In some preferred embodiments, the solubilizer may include polyvinyl pyrrolidone (PVP), which is soluble in water and most organic solvents, has excellent physiological inertness, does not participate in human metabolism, and has excellent biocompatibility. In some preferred embodiments, artificial bone powder includes hydroxyapatite, tricalcium phosphate, calcium phosphate composite material, bioglass, collagen, and lactic acid-glycolic acid copolymer. It can improve the regenerative ability of biological bone powder, which is beneficial to the growth of new bone. At the same time, it forms a good synergistic effect with biological bone powder and bone cement, improves the mechanical properties and processing properties of the material, and improves the stability of the bone prosthesis formed after printing.

[0076] In some preferred embodiments, the mass percentage of the additive can be 0-5%. The type and amount of the additive can be selected according to the specific location of the bone prosthesis to be printed and the type of prosthesis, so as to selectively improve the imaging performance, solubility, degradability, biocompatibility and mechanical properties of the prosthesis material formed after printing.

[0077] Next, the printing process using the medical material 3D printer 100 of Example 1 is described.

[0078] First, the patient is subjected to MRI magnetic resonance imaging or CT scanning to generate detailed internal body images. At the same time, the Dicom format images generated by MRI can be read with the help of common medical image file format conversion software including 3D Slicer, ITK-SNAP, OsiriX, etc. Doctors can manually edit and mark images according to personalized needs, use rigid and non-rigid algorithms to fuse and co-register data, and segment images to view the complete three-dimensional view. Then, with the help of three-dimensional visualization tools such as MIMICS, Amira, Avizo, ORS Visual, etc., specific information (such as bones) can be extracted and a three-dimensional mesh is generated, which is finally saved as STL format. Figure 3It is a schematic diagram of a three-dimensional model of a bone reconstructed through CT scanning. STL format files can be read by slicing software for slicing. The slicing software will also generate the printing path and motion instructions for each layer based on the slicing data. Finally, the signal is read by the control device in the 3D printer, and the control device controls the drive motor to move the printed model.

[0079] Before printing, the mixed slurry maintained at -20°C to 0°C in the storage device is injected into the syringe 20 of the medical material 3D printer 100 .

[0080] The control device in the 3D printer 100 can accurately control the push rod motor 101 so that the extrusion amount and extrusion speed of the mixed slurry can be adjusted as needed. At this time, the push rod motor 101 can make the push rod 102 extend to push the piston 103 in the syringe 20 so that the mixed slurry in the syringe 20 is extruded from the print nozzle 30. During the printing process, the temperature of the printing platform 3 (hot bed) is much higher than the storage temperature of the mixed slurry, and the print nozzle 30 is very close to the printing platform 3 (hot bed), which will cause the printing platform 3 (hot bed) to cause heat radiation to the syringe 20, causing the temperature of the mixed slurry in the syringe 20 to increase and thus accelerate the speed of its chemical reaction, causing the mixed slurry to solidify in large quantities before being extruded from the print nozzle 30 and blocking the print nozzle 30. Therefore, in this embodiment, a refrigeration component 11 is provided around the syringe 20 in a manner of surrounding the syringe 20. The refrigeration component 11 is preferably a semiconductor refrigeration component, but it can also be a component using refrigeration methods such as air cooling and water cooling. The mixed slurry in the syringe 20 is cooled by the refrigeration component 11, and the temperature of the mixed slurry is controlled at -20°C to 20°C, preferably 10°C, to alleviate the problem of accelerated chemical reaction caused by the ambient temperature. At this time, the mixed slurry can be smoothly squeezed out from the print head 30 by the piston 103 in the printing container (such as the syringe) 20.

[0081] After the mixed slurry is extruded from the print head 30, it is necessary to accelerate the chemical reaction speed of the mixed slurry to accelerate its curing process. Therefore, a hot air blowing device 14 disposed around the print head 30 is used to blow hot air toward the front end of the print head 30 to preheat the mixed slurry just extruded from the print head 30. At this time, the angle θ formed by the blowing direction of the hot air and the central axis AX of the print head 30 is, for example, 30°.

[0082] At this time, the mixed slurry falling from the print head 30 to the printing platform 3 (hot bed) is still in a fluid state with a certain fluidity, so it is necessary to accelerate the chemical reaction of the mixed slurry to speed up its curing process. At this time, the hot plate 4 (second heating device) arranged below (or inside) the printing platform 3 is used to formally heat the mixed slurry that has been extruded onto the printing platform 3, for example, the printing platform 3 is heated to 30°C to 120°C, preferably 60°C to 80°C, and more preferably 70°C, to accelerate the chemical reaction of the materials in the mixed slurry, thereby accelerating the curing speed and finally accumulating to form a model.

[0083] Furthermore, a light-sensing remaining amount sensor (not shown) is provided outside or inside the syringe 20 for detecting the remaining amount of the mixed slurry in the syringe 20. When the amount of the mixed slurry in the syringe 20 is lower than a preset value, a remote communication prompt or a light and a buzzer will be used to prompt that the remaining amount of the mixed slurry is low, reminding the user to add printing materials in time to avoid affecting the continuous printing of the model.

[0084] In addition, the printed model needs to be implanted in the human body, so the syringe 20 and the printing nozzle 30 used to contain the mixed slurry are preferably disposable syringes and matching printing nozzles, but syringes and printing nozzles that can be reused after disinfection can also be used.

[0085] Furthermore, when the patient's own bone mass is insufficient, the model can be printed directly on the allogeneic bone using allogeneic bone of similar structure in conjunction with a 3D printer, or the allogeneic bone or the patient's own bone (such as patella, fibula, rib) can be ground into bone powder and mixed in the above-mentioned proportions of bone powder, bone cement powder, and bone cement liquid to print the model.

[0086] Example 2

[0087] Figure 4 This is a partially enlarged view of the printing component of the medical material 3D printer according to Example 2 of the present invention. Figure 5 It is a partial schematic diagram showing the printing components of the medical material 3D printer of Example 2 when viewed from the upper side.

[0088] like Figure 4 and Figure 5 As shown, the difference between this embodiment and embodiment 1 is that: the printing container 50 includes an inverted cone-shaped silo 501 and a supply pipe 502 connected to the cone top of the silo 501, the extrusion device 40 includes a stepper motor 401, a plum blossom coupling 402 and a screw 403, and the refrigeration component is a dry ice container 41, 42 containing dry ice.

[0089] Specifically, dry ice containing parts 41 and 42 containing dry ice are arranged around or at the bottom of the inverted cone-shaped silo 501 and the supply pipe 502. The dry ice sublimates and absorbs heat to reduce the internal temperature of the silo 501 and the supply pipe 502 to slow down the reaction speed of the mixed slurry. At the same time, a stepper motor 401 is arranged above the silo 501. The stepper motor 401 is connected to the screw 403 through the coupling 402 to drive the screw 403 to rotate. The mixed slurry mixed in proportion is poured into the inverted cone-shaped silo 501, and is driven to rotate by the stepper motor 401 through the screw 403. The mixed slurry in the silo 501 is continuously transported to the supply pipe 502 by the screw 403, and finally extruded from the print nozzle 30 and carried by the printing platform 3 for solidification.

[0090] Furthermore, a residual amount detection system (not shown) for detecting the residual amount of the mixed slurry in the silo 501 is provided above the silo 501. The residual amount detection system may include a residual amount sensor that uses laser or infrared rays to detect the residual amount of the mixed slurry in the silo 501. When the mixed slurry in the silo 501 is about to be exhausted or the residual amount is lower than a preset value (for example, when the residual amount reaches 30% of the total amount), an alarm is issued to prompt the user to replenish the mixed slurry in the silo 501 to avoid affecting the continuity of 3D printing.

[0091] The beneficial effects of the present invention are as follows.

[0092] By using the medical material 3D printer and the method for using the same of the present invention, bone powder and bone cement (bone cement includes powder and liquid) are mixed in a specific ratio to obtain a mixed slurry. Various additives can be added to the mixed slurry as needed. Such a mixed slurry is used on a 3D printer, and a model with specific characteristics can be flexibly printed according to personalized needs. The model has high biocompatibility and good mechanical properties after implantation, and can also promote bone regeneration and repair. It can be widely used in the fields of bone repair and plastic surgery.

[0093] Furthermore, by arranging a refrigeration component in a manner of surrounding the printing container and using the refrigeration component to cool the printing material in the printing container, the problem that the printing material (for example, a mixed slurry including bone powder and bone cement) in the printing container is affected by the ambient temperature or other factors during the extrusion process, resulting in an increase in the temperature of the printing material and accelerating its solidification, can be alleviated. Thus, it is possible to ensure that the printing material maintains appropriate fluidity and extrudability during the extrusion process, and the extrusion amount and extrusion speed of the printing material can be accurately adjusted, thereby improving the accuracy of printing and the quality of the printed model.

[0094] In addition, by using the first heating device disposed around the print head to preheat the printing material just extruded from the print head, and using the second heating device disposed under or inside the printing platform to formally heat the printing material that has been extruded onto the printing platform, the chemical reaction rate of the printing material can be appropriately accelerated to accelerate its curing process. Moreover, by using the first heating device to preheat before using the second heating device to formally heat, the temperature rise process of the printing material can be smoother, and the curing of the printing material can be performed more evenly, thereby improving the quality of the printed model.

[0095] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above implementation modes, those skilled in the art should understand that they can still modify the technical solutions described in the above implementation modes, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the implementation modes of the present application.

Claims

1. A 3D printer for medical materials, characterized in that: It includes an extruder, a printing container, a printing nozzle and a printing platform. The printing container is used to contain printing material as a medical material. The printing nozzle is installed on the printing container and is used to extrude the printing material onto the printing platform. The extrusion device is installed on the side of the printing container opposite to the printing nozzle, and is used to extrude the printing material in the printing container from the printing nozzle. The printing platform is used to carry the printing material extruded from the printing nozzle. The medical material 3D printer also includes: a refrigeration component, which is arranged in a manner of surrounding the printing container and is used to cool the printing material in the printing container; A first heating device, which is arranged around the printing nozzle and is used to preheat the printing material just extruded from the printing nozzle; and The second heating device is arranged below or inside the printing platform and is used to formally heat the printing material that has been extruded onto the printing platform.

2. The medical material 3D printer according to claim 1, characterized in that: The refrigeration component is a semiconductor refrigeration component.

3. The medical material 3D printer according to claim 1, characterized in that: The refrigeration component is a dry ice storage part containing dry ice.

4. The medical material 3D printer according to claim 1, characterized in that: The first heating device is a device that uses hot air for heating.

5. The medical material 3D printer according to claim 1, characterized in that: The second heating device is a hot plate.

6. The medical material 3D printer according to claim 1, characterized in that: It also includes a control device for controlling the actions of various parts included in the medical material 3D printer.

7. The medical material 3D printer according to claim 1, characterized in that: The extrusion device comprises a push rod motor, a push rod and a piston.

8. The medical material 3D printer according to claim 1, characterized in that: The extrusion device comprises a stepping motor, a plum blossom coupling and a screw.

9. The medical material 3D printer according to claim 7, characterized in that: The printing container is a container with a syringe structure.

10. The medical material 3D printer according to claim 9, characterized in that: An optical remaining amount sensor for detecting the remaining amount of the printing material in the printing container is arranged outside or inside the printing container.

11. The medical material 3D printer according to claim 8, characterized in that: The printing container includes an inverted cone-shaped material bin and a supply pipeline connected to the cone top of the material bin.

12. The medical material 3D printer according to claim 11, characterized in that: A remaining amount detection system for detecting the remaining amount of the printing material in the silo is arranged above the silo.

13. The medical material 3D printer according to claim 12, characterized in that: The remaining amount detection system includes a remaining amount sensor for detecting the remaining amount using laser or infrared rays.

14. A method for using a medical material 3D printer, which is a method for printing using the medical material 3D printer according to any one of claims 1 to 13, characterized in that: include: a printing container cooling step, using the refrigeration component to cool the printing material in the printing container; a printing material extrusion step, using the extrusion device to extrude the printing material in the printing container from the printing nozzle; a preheating step, using the first heating device to preheat the printing material just extruded from the printing nozzle; and The formal heating step is to use the second heating device to formally heat the printing material that has been extruded onto the printing platform.

15. The method for using the medical material 3D printer according to claim 14, characterized in that: Before the printing container cooling step, the method comprises: The printing material injecting step injects the printing material maintained at -20°C to 0°C into the printing container.

16. The method for using the medical material 3D printer according to claim 14, characterized in that: In the printing container cooling step, the printing material in the printing container is cooled to -20°C to 20°C by using the refrigeration component.

17. The method for using the medical material 3D printer according to claim 14, characterized in that: In the preheating step, the first heating device is used to blow hot air toward the front end of the print head.

18. The method for using the medical material 3D printer according to claim 17, characterized in that: The angle formed by the blowing direction of the hot air and the central axis of the printing nozzle is 20° to 40°.

19. The method for using the medical material 3D printer according to claim 14, characterized in that: In the formal heating step, the printing platform is heated to 30° C. to 120° C. by using the second heating device.

20. The method for using the medical material 3D printer according to any one of claims 14 to 19, characterized in that: The printing material is a mixed slurry including bone powder and bone cement, wherein the bone cement includes powder and liquid.

Images