Hydrogel construct comprising magnetic structure and method for manufacturing same

Abstract

The present invention relates to a hydrogel construct comprising a magnetic structure and a method for manufacturing same, the method comprising: manufacturing a magnetic scaffold having a predetermined shape by curing an ink composition including magnetic particles; coating the manufactured magnetic scaffold with a hydrogel to manufacture a construct; and applying a magnetic field to the manufactured construct to deform the magnetic scaffold, thereby enabling the manufacture of a desired three-dimensional construct in various shapes.

Description

Hydrogel structure including a magnetic structure and method for manufacturing the same

[0001] The present invention relates to a hydrogel structure, and in particular to a tissue structure mimicking structure for mimicking various human organ tissues, and more specifically to a hydrogel structure comprising a magnetic structure and a method for manufacturing the same.

[0002] There are many efforts to replace damaged tissues or organs. Artificial substitutes, animal-derived non-living tissues, or organ transplants have been typically used for patient treatment. However, due to their heterogeneous composition compared to the original tissue or organ, these cannot serve as a fundamental solution. Therefore, tissue engineering has recently emerged as an alternative to traditional surgical procedures.

[0003] Among them, aligning cells within a hydrogel in a three-dimensional (3D) state can effectively mimic various types of tissues.

[0004] In particular, cell alignment is an important characteristic in tissues such as skeletal tissue, muscular tissue, and cardiac tissue.

[0005] Among these, cardiac tissue is representative, featuring a chamber-like structure and a unique configuration in which the alignment of cells varies with depth. This cell alignment structure plays a crucial role in the efficient performance of cardiac functions.

[0006] However, there is currently no effective method to fabricate complex and hierarchical in vitro tissue models.

[0007] [Prior Art Literature]

[0008] [Patent Literature]

[0009] Republic of Korea Published Patent No. 10-2019-0114294 (Published on Oct. 10, 2019)

[0010] The present invention aims to solve the aforementioned problems and to manufacture a desired three-dimensional structure in various shapes based on a hydrogel.

[0011] In addition, the present invention aims to align cells contained within a hydrogel in a desired direction in a three-dimensional structure.

[0012] By doing so, the present invention aims to more accurately simulate artificial tissue models where cell alignment is important, such as skeletal tissue, muscular tissue, and cardiac tissue.

[0013] In addition, the present invention aims to further promote or alter cell maturation, tissue formation, or alignment within a manufactured three-dimensional hydrogel structure.

[0014] One embodiment of the present invention for achieving the above-mentioned purpose is a method for manufacturing a hydrogel structure comprising a magnetic support, comprising: a step of manufacturing a magnetic support having a predetermined shape by curing an ink composition containing magnetic particles; a step of manufacturing a structure by coating a hydrogel on the manufactured magnetic support; and a step of deforming the magnetic support by applying a magnetic field to the manufactured structure.

[0015] As an example of the present invention, the step of manufacturing the magnetic support may include: a step of applying a magnetic field to an ink composition containing magnetic particles to impart magnetic anisotropy to the magnetic particles; and a step of curing the ink composition imparting magnetic anisotropy.

[0016] As an example of the present invention, the step of manufacturing the magnetic support may include: applying a magnetic field to an ink composition containing magnetic particles to impart magnetic anisotropy to the magnetic particles; passing the ink composition imparting magnetic anisotropy through a printer nozzle in which a nozzle magnet is created to print so that the magnetic particles are aligned; and curing the printed support.

[0017] As an example of the present invention, the printer nozzle may further include a magnetic shield layer provided in the direction in which the ink composition is discharged from the nozzle magnet.

[0018] As an example of the present invention, curing the ink composition may be done by curing the ink composition at 40 to 80°C for 5 to 30 hours.

[0019] As an example of the present invention, the structure can be manufactured by coating a hydrogel containing cells to surround all or part of the magnetic support manufactured above.

[0020] As an example of the present invention, the structure may be manufactured by coating a hydrogel containing cells and an extracellular matrix (ECM) to surround all or part of the magnetic support manufactured above.

[0021] As an example of the present invention, the structure can be manufactured by plasma treating all or part of the surface of the magnetic support manufactured above, and coating all or part of the plasma-treated surface with a hydrogel containing cells and decellularized extracellular matrix (dECM).

[0022] As an example of the present invention, deforming the magnetic support may involve applying a magnetic field to the manufactured structure to deform the shape of the structure including the magnetic support.

[0023] As an example of the present invention, deforming the magnetic support may be done by applying a magnetic field after incubating the manufactured structure to deform the magnetic support, or by applying a magnetic field to the manufactured structure to deform the magnetic support and then incubating.

[0024] As an example of the present invention, deforming the magnetic support may involve applying a magnetic field to the manufactured structure to deform the magnetic support, and then incubating it.

[0025] As an example of the present invention, the incubation can be performed by culturing in an incubator for 1 to 7 days.

[0026] Another embodiment of the present invention is a hydrogel structure manufactured by the above-described manufacturing method and containing a magnetic support that is deformable by an external magnetic field.

[0027] Another embodiment of the present invention is a hydrogel structure comprising a magnetic support having a predetermined shape, wherein an ink composition containing magnetic particles is cured; and a hydrogel coated on the magnetic support, wherein the magnetic support is deformable by an external magnetic field.

[0028] As an example of the present invention, the magnetic support may be deformed by an external magnetic field, and the hydrogel may be incubated.

[0029] As an example of the present invention, the magnetic support may comprise magnetic particles to which magnetic anisotropy is imparted by applying a magnetic field to an ink composition containing magnetic particles.

[0030] As an example of the present invention, the magnetic particles endowed with magnetic anisotropy can be aligned in one direction.

[0031] As an example of the present invention, the hydrogel may be coated to surround all or part of the magnetic support and may comprise one or more of cells and decellularized extracellular matrix (dECM).

[0032] As an example of the present invention, the magnetic support may have all or part of its surface plasma-treated, and the hydrogel may be coated on all or part of the surface of the plasma-treated magnetic support.

[0033] Another embodiment of the present invention is a composite hydrogel structure in which two or more of the above-described hydrogel structures are stacked or assembled together.

[0034] As an example of the present invention, the two or more hydrogel structures may have different shapes as the magnetic support is deformed by an external magnetic field.

[0035] Another embodiment of the present invention is a composite hydrogel structure comprising two or more of the above-described hydrogel structures, wherein the two or more hydrogel structures comprise hydrogels in which one or more of a cell and a decellularized extracellular matrix (dECM) are aligned in different directions.

[0036] As an example of the present invention, a hydrogel structure comprising a magnetic support according to the present invention described above may be used for mimicking artificial tissue.

[0037] As an example of the present invention, the artificial tissue may be skeletal tissue, muscular tissue, or cardiac tissue.

[0038] Another embodiment of the present invention is an artificial tissue mimicry model manufactured using the hydrogel structure described above.

[0039] Specific details of other embodiments are included in the detailed description and drawings.

[0040] The present invention has the effect of being able to manufacture a desired three-dimensional structure in various shapes by fabricating a hydrogel framework with a magnetic support, coating the hydrogel around it, and then applying deformation to the framework with a magnetic field.

[0041] In addition, the present invention makes it possible to align the cells contained within the hydrogel in a desired direction in a three-dimensional structure state by controlling the magnetic field applied to the hydrogel containing the cells and the incubation conditions.

[0042] Through this, the present invention can more accurately simulate artificial tissue models where cell alignment is important, such as skeletal tissue, muscular tissue, and cardiac tissue.

[0043] In addition, if an external magnetic field or incubation is additionally applied to the three-dimensional hydrogel structure prepared according to the present invention under various conditions, it is also possible to further promote or change cell maturation, tissue formation, or alignment within the hydrogel.

[0044] FIG. 1 is a schematic diagram illustrating an example of the entire process of a method for manufacturing a hydrogel structure according to the present invention, and

[0045] FIG. 2 is a schematic diagram showing an example of a process for manufacturing a magnetic support according to the present invention, and

[0046] FIG. 3 is a schematic diagram illustrating an example of a process for forming an assembly structure by assembling a hydrogel structure according to the present invention, and

[0047] FIG. 4 is a CT image showing the shape in which magnetic particles are distributed inside a magnetic support according to one embodiment of the present invention, and

[0048] FIG. 5 is a graph showing the results of a hysteresis analysis for a magnetic support according to one embodiment of the present invention, and

[0049] FIG. 6 is a photograph showing an example in which a magnetic support according to one embodiment of the present invention is deformed into different shapes, and

[0050] FIG. 7 is a photograph showing examples of a radial array magnetic support and a spiral array magnetic support according to one embodiment of the present invention, and

[0051] FIG. 8 is a photograph showing the manufacturing process of a radial hydrogel structure and a helical hydrogel structure according to one embodiment of the present invention, and

[0052] Figure 9 shows the results of tissue formation simulations in the case including deformation caused by a magnetic field (w / Deformation) and the case not including it (w / o Deformation) according to one embodiment of the present invention.

[0053] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0054] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0055] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0056] Throughout this specification, "%" used to indicate the concentration of a particular substance is (weight / weight) % for solid / solid, (weight / volume) % for solid / liquid, and (volume / volume) % for liquid / liquid, unless otherwise noted.

[0057] The present invention relates to a hydrogel structure, and in particular to a tissue structure mimicking structure for mimicking various human organ tissues, and more specifically to a hydrogel structure comprising a magnetic structure and a method for manufacturing the same.

[0058] These tissue-mimicking structures can be produced by printing bio-ink using a 3D bioprinting method. Tissue-mimicking structures must be capable of reproducing specific functions of tissues and spatially organizing in a form similar to actual tissues, and can be utilized in the production of bio-models for tissue and organ regeneration and new drug development.

[0059] The inventors have invented a method utilizing magnetic printing technology as an effective means for fabricating more complex and hierarchical in vitro tissue models. This method involves fabricating a magnetic scaffold that can be programmed to deform as desired using magnetic printing technology, and then incorporating a cell-containing hydrogel around it using 3D bioprinting technology. Through this, it was possible to fabricate tissue layers in which cells are aligned in a specific direction. These structures can be used independently, as well as assembled into hierarchical structures using bioprinting-assisted tissue assembly technology. Additionally, cell maturation and alignment can be promoted by applying an external magnetic field to the three-dimensional structure under various conditions.

[0060] I. Method for manufacturing a hydrogel structure

[0061] One embodiment of the present invention for this purpose is a method for manufacturing a hydrogel structure including a magnetic support, comprising: a step of manufacturing a magnetic support having a predetermined shape by curing an ink composition including magnetic particles (S100); a step of manufacturing a structure by coating a hydrogel on the manufactured magnetic support (S200); and a step of deforming the magnetic support by applying a magnetic field to the manufactured structure (S300).

[0062] FIG. 1 is a schematic diagram illustrating an example of the entire process of a method for manufacturing a hydrogel structure according to the present invention.

[0063] Below, each step of the manufacturing method according to the present invention is described in detail.

[0064] 1. Manufacture of magnetic support (S100)

[0065] FIG. 2 is a schematic diagram showing an example of a process for manufacturing a magnetic support according to the present invention.

[0066] A method for manufacturing a hydrogel structure including a magnetic support according to the present invention first includes the step (S100) of curing an ink composition including magnetic particles to manufacture a magnetic support having a predetermined shape. This is a process for manufacturing a central internal structure or framework of the hydrogel structure according to the present invention.

[0067] The magnetic particles mentioned above are not particularly limited, and any particles that exhibit magnetism can be used. Among these, hard magnetic particles such as NdFeB and CoFe2O4 can be used. These magnetic particles can be mixed with a polymer or an elastomer to form an ink composition. If the ink composition further includes a catalyst for curing, it is easy to cure. Furthermore, it is possible to print this ink composition to form a predetermined shape and to cure it to manufacture a magnetic support according to the present invention.

[0068] A magnetic ink composition can be prepared by uniformly mixing magnetic particles with an elastomer primarily composed of silicone rubber, such as PDMS, using a vacuum mixer. For example, NdFeB neodymium powder can be used as the ferromagnetic particles, and SE-1700 material can be used as the elastomer; a catalyst for curing can be further mixed in. The mixing ratio can be NdFeB : SE-1700 : catalyst in a weight ratio of 5 to 10:1 to 5:0.1 to 1, and it is preferable to mix in a ratio of 7:3:0.3.

[0069] As an example of the present invention, the step of manufacturing the magnetic support may include: a step of applying a magnetic field to an ink composition containing magnetic particles to impart magnetic anisotropy to the magnetic particles; and a step of curing the ink composition imparting magnetic anisotropy.

[0070] In other words, ferromagnetic particles such as NdFeB and CoFe2O4 have the property of becoming magnetized and exhibiting magnetic anisotropy when a strong magnetic field exceeding saturation magnetization is applied. Therefore, a strong magnetic field exceeding saturation magnetization is applied to the magnetic ink composition to induce the magnetic particles to exhibit magnetic anisotropy. This has the effect of inducing the magnetic particles to align in a specific direction with respect to an external magnetic field.

[0071] The process of applying such a strong magnetic field is called magnetization. As an example, a magnetization yoke in the form of an air-core coil can be used for magnetization, which can generate a strong magnetic field by applying a very high current of 1000A or more to a wire coil. When a sample to be subjected to a magnetic field (the ink composition according to the present invention) is placed inside the coil and operated, the magnetic particles within the ink composition can be magnetized to acquire magnetic anisotropy.

[0072] As an example of the present invention, the step of manufacturing the magnetic support may include: applying a magnetic field to an ink composition containing magnetic particles to impart magnetic anisotropy to the magnetic particles; passing the ink composition imparting magnetic anisotropy through a printer nozzle in which a nozzle magnet is created to print so that the magnetic particles are aligned; and curing the printed support.

[0073] When undergoing the magnetization process described above, the magnetic particles within the magnetic ink possess magnetic anisotropy but are not aligned. Therefore, by attaching a nozzle magnet to the printer nozzle and applying a magnetic field to the magnetic ink passing through the nozzle, the magnetic particles within the ink composition become aligned in one direction as they pass through the nozzle during printing. In other words, by first imparting magnetic anisotropy to the magnetic particles using an external magnetic field, the particles exhibit a precise response (attraction and repulsion), and secondarily, by passing them through the nozzle magnet, they can be aligned in a single direction. This makes it possible to control the polarity direction of the magnetic support according to the printing path. However, if the particles are passed through the nozzle magnet without imparting magnetic anisotropy, the magnetic particles will only generate attraction, much like iron filings pulled by a magnet, which has the disadvantage of making it difficult to align them in a desired direction within the support or to realize specific magnetic properties. In other words, the present invention is characterized by imparting magnetic anisotropy to magnetic particles through a magnetization process and then passing the magnetic particles through a nozzle magnet to align them in one direction.

[0074] When magnetic particles are aligned in one direction as described above, the entire magnetic support exhibits specific magnetic anisotropy. If the magnetic particles are not aligned, they are randomly distributed within the support, and consequently, the support cannot exhibit clear magnetic polarity and has the disadvantage of acting simply like iron filings attracted to a magnet. Therefore, in order for the support to respond precisely in a desired direction to an external magnetic field, it is necessary to align the magnetic particles. By controlling the magnetic properties of the support to match the intended design, it is possible to realize complex magnetic functionality.

[0075] As an example of the present invention, the printer nozzle may further include a magnetic shield layer provided in the direction in which the ink composition is discharged from the nozzle magnet.

[0076] That is, it is possible to shield the magnetic field by placing a magnetic shielding layer under the nozzle magnet so that the already printed support is not affected by the nozzle magnet. The magnetic shielding layer is not particularly limited as long as it can block or block the magnetic field. For example, the magnetic shielding layer may be a steel material that adheres to a magnet, and it is sufficient if it shields the magnetic field so that the printed support is not affected by the magnetic field. In the absence of a magnetic shielding layer, magnetic particles inside the printed support may be affected by the nozzle magnet, causing a change in the already induced alignment, and it may become difficult to deform into a desired shape.

[0077] As an example of the present invention, curing the ink composition may be performed by curing the ink composition at 40 to 80°C for 5 to 30 hours. Although the temperature and time for curing are not particularly limited, it is preferable to cure the printed support at 50 to 70°C for 10 to 20 hours. Through this curing process, the positions of the magnetic particles within the support are fixed, and when an external magnetic field is applied, the entire support can move together rather than just the particles moving.

[0078] The reason it is desirable to cure the support at 40 to 80°C for 5 to 30 hours is that it is the optimal condition considering all the characteristics of the NdFeB magnetic particles mixed with SE-1700 thermosetting silicone. SE-1700 material, which is a thermosetting silicone used to fabricate the support as an elastomer, is recommended to be cured at 150°C for 30 minutes in the product description, and complete curing is possible even at temperatures of 50 to 70°C if sufficient time is provided. However, the Curie temperature (the temperature at which magnetic particles lose their magnetism) of the NdFeB magnetic particle powder mixed with SE-1700 is 70 to 80°C, and if curing is performed at a temperature above this, demagnetization (a phenomenon in which magnetism decreases) may occur. Therefore, it is desirable to proceed with curing for a sufficient time (about 16 hours) at a temperature below the Curie temperature of about 60°C. This has the effect of ensuring that the support is thoroughly cured while preventing loss of magnetism.

[0079] 2. Preparation of hydrogel structure (S200)

[0080] Then, the present invention includes the step (S200) of manufacturing a structure by coating a hydrogel onto the magnetic support manufactured above.

[0081] As described above, it was possible to fabricate a magnetic-responsive elastomer that deforms into a desired shape in response to an external magnetic field, and subsequently, a hydrogel structure is manufactured by coating a hydrogel around the cured magnetic elastomer using 3D bioprinting technology. The magnetic elastomer acts as a framework for the hydrogel and can function as an actuator to move the hydrogel.

[0082] In the present invention, the hydrogel is not particularly limited and various materials known in the art, such as collagen, gelatin, dECM, etc., may be used. For example, the hydrogel of the present invention may further comprise one or more of cells or cell culture media. Additionally, it is possible to further comprise factors capable of proliferating cells, promoting cell differentiation, or promoting the secretion of extracellular matrix. Additionally, it may further comprise biocompatible polymer compounds.

[0083] As an example of the present invention, the structure can be manufactured by coating a hydrogel containing cells to surround all or part of the magnetic support manufactured above.

[0084] As an example of the present invention, the structure may be manufactured by coating a hydrogel containing cells and an extracellular matrix (ECM) to surround all or part of the magnetic support manufactured above.

[0085] For example, in an embodiment of the present invention, a heart dECM bioink containing human cardiac fibroblasts as cells was used with the goal of producing a heart model. The type or content of the cells and hydrogel is not particularly limited. Depending on the target tissue to be manufactured, one or more different types of cells may be included. A hydrogel containing cells can be printed on a magnetic support using 3D bioprinting technology.

[0086] As an example of the present invention, the structure can be manufactured by plasma treating all or part of the surface of the manufactured magnetic support and coating all or part of the plasma-treated surface with a hydrogel containing cells and decellularized extracellular matrix (dECM). If the material (SE-1700) constituting the magnetic support is hydrophobic, it may not easily integrate with the hydrogel and may separate. To solve this, the present invention makes it possible to perform a surface treatment that converts the surface of SE-1700 to hydrophilic through plasma coating. For example, O2 plasma coating can be performed at 70W for 1 minute. Coating conditions, such as plasma coating intensity, time, or hydrophilic treatment techniques used (e.g., UV ozone treatment, chemical surface modification), may vary depending on the properties of the hydrogel used.

[0087] 3. Deformation of magnetic support (S300)

[0088] Next, the present invention includes the step (S300) of applying a magnetic field to the manufactured structure to deform the magnetic support.

[0089] As an example of the present invention, deforming the magnetic support may involve applying a magnetic field to the manufactured structure to deform the shape of the structure including the magnetic support.

[0090] Since the hydrogel structure manufactured as described above contains a magnetic support, when an external magnetic field is applied to the hydrogel structure, the shape of the magnetic support can be deformed in a desired direction. The strength and period of the external magnetic field applied to the magnetic hydrogel structure can also be controlled by using an electromagnet platform that applies an external magnetic field.

[0091] The method or device for applying an external magnetic field is not particularly limited. For example, an electromagnet platform can be used that can provide a magnetic field of up to 250 mT in a parallel and vertical direction at a circular position of 100 pi. As an example, the magnetic field can be applied in various ways, such as by increasing the magnetic field from 0 to 250 mT and maintaining it at 250 mT, by oscillating it periodically from 0 to 250 mT, or by applying the magnetic field in a pulse form that intermittently alternates between 0 mT and 250 mT.

[0092] In addition, when cells are contained within a hydrogel, the cells are aligned in the direction of stress by an external magnetic field, so cell alignment within the hydrogel can be programmed. Also, since the direction and magnitude of the stress can be predicted through simulation, cell alignment can be predicted in advance.

[0093] Cell alignment is a crucial factor in mimicking the specific functional characteristics of tissues. For example, when aiming to fabricate cardiac muscle tissue, the orientation of muscle fibers in the heart optimizes cell-to-cell interactions, enabling the tissue to pump blood more effectively. Similarly, examples of tissues where cell alignment is important include tendons and bones; in tendon and bone tissues, collagen fibers and osteocytes, respectively, are aligned in a specific direction to ensure high tensile strength. In other words, cell alignment plays a role in enhancing the mechanical strength and physiological performance of tissues.

[0094] The magnetic field does not directly affect the cell itself; rather, when the magnetic scaffold responding to the magnetic field deforms, stress is applied to the surrounding tissue. Essentially, fibroblasts reconstruct and align the ECM in the direction of external stress. The magnetic scaffold provides mechanical stress to the cell and ECM merely by its presence within the hydrogel, and when deformed by the external magnetic field, it generates additional stress in a different direction. As a result, the ECM fibers are pulled and contract, causing the fibroblasts to contract and align along the direction of the stress, thereby reconstructing the ECM.

[0095] As an example of the present invention, deforming the magnetic support can be done by applying a magnetic field after incubating the manufactured structure, or by applying a magnetic field to the manufactured structure to deform the magnetic support and then incubating. That is, in the present invention, shear stress of various directions and magnitudes can be applied to the cells through stimuli such as incubating before deforming the magnetic support, incubating after deforming, or applying periodic deformation during the incubation process.

[0096] In the present invention, incubation refers to the process of allowing a hydrogel structure to mature by leaving it naturally, exposing it to a high-temperature environment, or culturing it. For example, the incubation can be performed by culturing it in an incubator for 1 to 7 days. For example, as mentioned above, fibroblasts possess a unique mechanism for reconstructing and reinforcing the extracellular matrix (ECM). When a hydrogel structure is fabricated and cultured in an incubator, the tissue contracts towards the center over time due to the ECM remodeling characteristics. During this process, the scaffold within the tissue generates tension in a direction opposite to the direction of contraction, and the cells align along the direction of this generated stress. This phenomenon can be understood as the 'maturation' or 'tissue formation' of the hydrogel structure. Through this incubation process, it is possible to align the cells in a desired direction.

[0097] As an example of the present invention, deforming the magnetic support may involve applying a magnetic field to the manufactured structure to deform the magnetic support, and then incubating it. As can be seen from the simulation results described below, it was confirmed that for hydrogels fabricated using radial and helical structures, stress is applied in a more uniform direction when incubation is performed after deformation by a magnetic field compared to when incubation is performed without deformation.

[0098] II. Hydrogel Structures and Models for Mimicking Artificial Tissues

[0099] Another embodiment of the present invention is a hydrogel structure manufactured by the above-described manufacturing method and containing a magnetic support that is deformable by an external magnetic field.

[0100] Through this, the present invention makes it possible to produce a structure capable of mimicking various types of tissues.

[0101] Another embodiment of the present invention is a hydrogel structure comprising a magnetic support having a predetermined shape, wherein an ink composition containing magnetic particles is cured; and a hydrogel coated on the magnetic support, wherein the magnetic support is deformable by an external magnetic field.

[0102] The present invention has the effect of being able to manufacture a desired three-dimensional structure in various shapes by fabricating a hydrogel framework with a magnetic support, coating the hydrogel around it, and then applying deformation to the framework with a magnetic field.

[0103] As an example of the present invention, the magnetic support may be deformed by an external magnetic field, and the hydrogel may be incubated.

[0104] The present invention makes it possible to align the cells contained within the hydrogel in a desired direction in a three-dimensional structure state by controlling the magnetic field applied to the hydrogel containing the cells and the incubation conditions.

[0105] As an example of the present invention, the magnetic support may comprise magnetic particles to which magnetic anisotropy is imparted by applying a magnetic field to an ink composition containing magnetic particles.

[0106] Magnetic particles endowed with such magnetic anisotropy have the effect of inducing them to align in a specific direction when an external magnetic field is applied.

[0107] As an example of the present invention, the magnetic particles endowed with magnetic anisotropy can be aligned in one direction.

[0108] When magnetic particles are aligned in one direction in this way, the magnetic support containing them possesses a specific magnetic anisotropy and has the effect of having a distinct magnetic polarity.

[0109] As an example of the present invention, the hydrogel may be coated to surround all or part of the magnetic support and may comprise one or more of cells and decellularized extracellular matrix (dECM).

[0110] The type or content of cells and / or extracellular matrix can be varied depending on the target tissue to be manufactured. This invention can more accurately simulate artificial tissue models where cell alignment is important, such as skeletal tissue, muscular tissue, and cardiac tissue.

[0111] As an example of the present invention, the magnetic support may have all or part of its surface plasma-treated, and the hydrogel may be coated on all or part of the surface of the plasma-treated magnetic support.

[0112] Through this plasma treatment, the bonding strength between the magnetic support and the hydrogel can be further enhanced.

[0113] FIG. 3 is a schematic diagram showing an example of a process for forming an assembly structure by assembling a hydrogel structure according to the present invention.

[0114] Another embodiment of the present invention is a composite hydrogel structure in which two or more of the above-described hydrogel structures are stacked or assembled together.

[0115] As an example of the present invention, the two or more hydrogel structures may have different shapes as the magnetic support is deformed by an external magnetic field.

[0116] A hydrogel structure according to the present invention can be used as a tissue mimic, and furthermore, two or more structures can be assembled to form an assembly with a more complex structure. By using this, a hierarchical hydrogel can be made in which cells are aligned in different directions in each layer.

[0117] Another embodiment of the present invention is a composite hydrogel structure comprising two or more of the above-described hydrogel structures, wherein the two or more hydrogel structures comprise hydrogels in which one or more of a cell and a decellularized extracellular matrix (dECM) are aligned in different directions.

[0118] In other words, the hydrogel structure according to the present invention can be used independently as well as applied in various ways, such as by assembling it into a hierarchical structure through bioprinting-assisted tissue assembly technology. The assembly method is not particularly limited, and various methods known in this field can be used. It is possible to fabricate tissue modules corresponding to each layer and join the modules together to induce natural interlayer linkage through cellular interactions between modules (self-assembly assisted crosslinking). Fibroblasts can also strengthen physical connections between modules by reconstructing the ECM.

[0119] As shown in Fig. 3, the unique structural characteristics of the heart can be simulated by configuring the middle layer in a radial array and assembling a helical array structure on both sides. The actual heart exhibits complex mechanical movements, such as left ventricular torsion, which are caused by the heart's inherent complex structure, such as orientational differences depending on the depth of the cardiac muscle fibers. Since structure and function are closely related, reproducing such a complex structure has the effect of effectively simulating the actual function of the heart.

[0120] As an example of the present invention, a hydrogel structure comprising a magnetic support according to the present invention described above may be used for mimicking artificial tissue.

[0121] In the present invention, the tissue may be intestinal tissue, skin tissue, liver tissue, heart tissue, cartilage tissue, bone tissue, adipose tissue, muscle tissue, mucosal epithelial tissue, amniotic membrane tissue, or corneal tissue, but is not limited thereto.

[0122] As an example of the present invention, the artificial tissue may be skeletal tissue, muscular tissue, or cardiac tissue.

[0123] Another embodiment of the present invention is an artificial tissue mimicry model manufactured using the hydrogel structure described above.

[0124] The present invention may be better understood by the following examples, which are for illustrative purposes only and are not intended to limit the scope of protection defined by the appended claims.

[0125] Example 1: Preparation of a magnetic support

[0126] First, a magnetic support having a predetermined shape was manufactured by curing an ink composition containing magnetic particles.

[0127] Specifically, NdFeB neodymium powder was used as a ferromagnetic particle and mixed with SE-1700, a silicone elastomer, and a catalyst for curing was further mixed. The mixing ratio was approximately 7:3:0.3 by weight for NdFeB : SE-1700 : SE-1700 catalyst, and the mixture was uniformly mixed using a vacuum mixer to prepare magnetic ink.

[0128] Then, a magnetization process was carried out to apply a strong magnetic field to the prepared magnetic ink composition. That is, a strong magnetic field was generated by applying a very high current of 1000A or more to a wire coil using a magnetization yoke. The magnetization yoke has the form of an air-core coil, and a sample to be subjected to the magnetic field (the prepared magnetic ink composition) was placed inside the air-core coil and operated so that the ferromagnetic particles (magnet powder) in the magnetic ink composition were magnetized, thereby imparting magnetic anisotropy.

[0129] Next, the magnetic ink composition imparted with magnetic anisotropy as described above was passed through a printer nozzle equipped with a nozzle magnet to print the magnetic particles so that they were aligned in one direction. Here, the printer nozzle utilized a magnetic shield layer disposed beneath the nozzle magnet to shield the magnetic field, thereby ensuring that the already printed support was not affected by the nozzle magnet (see FIG. 2).

[0130] Subsequently, the printed support was cured at approximately 60°C for about 16 hours. Through this process, the positions of the magnetic particles within the support were fixed, and the entire support was manufactured to move together with the particles when an external magnetic field was applied.

[0131] Figure 4 is a CT image showing the distribution of magnetic particles inside a magnetic support according to one embodiment of the present invention. As shown here, when hard magnetic particles, specifically NdFeB particles, were mixed with silicone elastomer SE1700, the particles were uniformly distributed within the ink without clumping.

[0132] FIG. 5 is a graph showing the results of hysteresis analysis for a magnetic support according to one embodiment of the present invention. As shown in the figure, it was confirmed that a magnetic support prepared with the magnetic ink composition according to the present invention is a ferromagnetic material having strong coercivity and remanent magnetization, has high stability against an external magnetic field, and can maintain a constant magnetization state for a long time.

[0133] FIG. 6 is a photograph showing an example of a magnetic support being deformed into different shapes according to an embodiment of the present invention, and FIG. 7 is a photograph showing an example of a radial array magnetic support and a spiral array magnetic support according to an embodiment of the present invention. As illustrated herein, by applying an external magnetic field to the magnetic support according to the present invention, it was possible to fabricate various magnetic supports that are deformed into different shapes by controlling the magnetic direction. Through this, it was confirmed that a structure that is customized and deformed according to the shape of the hydrogel can be programmed for the purpose.

[0134] Example 2: Preparation of a hydrogel structure

[0135] A structure was manufactured by coating a hydrogel onto a magnetic support prepared according to Example 1 above.

[0136] Prior to this, the magnetic support prepared above had the potential to separate and not easily integrate with the hydrogel because the SE-1700 material is hydrophobic. To prevent this, a surface treatment was performed to convert the surface of SE-1700 to hydrophilic through O2 plasma coating. The O2 plasma coating was performed at 70W for 1 minute.

[0137] And, a hydrogel containing 10 M / mL of human cardiac fibroblast as cells and 500 µL of 1% heart dECM bioink was used.

[0138] Next, a hydrogel containing the cell was printed on the surface-treated magnetic support using 3D bioprinting technology (see FIG. 8). FIG. 8 is a photograph showing the manufacturing process of a radial hydrogel structure and a helical hydrogel structure according to one embodiment of the present invention.

[0139] Gelation of the magnetic support was performed for 1 hour using a circular PEVA mold around the magnetic support.

[0140] Example 3: Deformation of magnetic support

[0141] A magnetic field was applied to the structure manufactured according to Example 2 above to deform the magnetic support.

[0142] Prior to this, the structure prepared above was stabilized by incubation. In this embodiment, the structure prepared above was placed in an incubator and cultured. This process is a process of 'maturation' or 'tissue formation' of the structure prepared above (or hydrogel, cell, ECM), and in fact, after 4 days of culture in the incubator, the cells aligned in the direction of stress caused by the shrinkage of the hydrogel (see Fig. 8).

[0143] Then, a magnetic field was applied to the structure incubated as described above using an electromagnet platform. Using an electromagnet platform capable of providing a magnetic field of up to 250 mT in a parallel vertical direction at a circular position of 100 pi, a magnetic field was applied to the incubated structure by increasing the magnetic field from 0 to 250 mT and maintaining it at 250 mT.

[0144] As a result of applying a magnetic field to deform the structure in this way, it was confirmed that the magnetic support and the hydrogel were not separated and were deformed to the desired extent (see Fig. 8).

[0145] Example 4: Simulation Test

[0146] Additionally, FIG. 9 is a tissue formation simulation result with and without deformation caused by a magnetic field according to one embodiment of the present invention.

[0147] In order to produce a cardiac tissue chamber with aligned cells according to the method described in Examples 1 to 3 above, a radial array magnetic support designed to have arms deformed vertically and a spiral array magnetic support designed to have arms deformed at an oblique angle were produced.

[0148] Simulation results showed that for hydrogels fabricated using radial and helical structures, stress was applied in a more uniform direction when incubated after deformation by a magnetic field compared to when incubated without deformation. Accordingly, it was concluded that the cells would be aligned more uniformly.

[0149] Although the present invention has been illustrated and described above in relation to specific preferred embodiments, it is obvious to those skilled in the art that the present invention may be modified and varied without departing from the technical features or scope of the invention as defined by the following claims.

Claims

1. A step of manufacturing a magnetic support having a predetermined shape by curing an ink composition containing magnetic particles; A step of manufacturing a structure by coating a hydrogel onto the magnetic support manufactured above; and A step comprising applying a magnetic field to the above-manufactured structure to deform the magnetic support; Method for manufacturing a hydrogel structure including a magnetic support.

2. In Paragraph 1, The step of manufacturing the above magnetic support is, A step of applying a magnetic field to an ink composition containing magnetic particles to impart magnetic anisotropy to the magnetic particles; and A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by including the step of curing the ink composition imparting magnetic anisotropy.

3. In Paragraph 1, The step of manufacturing the above magnetic support is, A step of applying a magnetic field to an ink composition containing magnetic particles to impart magnetic anisotropy to the magnetic particles; A step of printing by passing the ink composition imparting magnetic anisotropy through a printer nozzle in which a nozzle magnet is created so that the magnetic particles are aligned; and A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by including the step of curing the printed support.

4. In Paragraph 3, A method for manufacturing a hydrogel structure comprising a magnetic support, characterized in that the printer nozzle further comprises a magnetic shield layer provided in the direction in which an ink composition is discharged from the nozzle magnet.

5. In Paragraph 1, Curing the above ink composition is, A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by curing the above ink composition at 40 to 80°C for 5 to 30 hours.

6. In Paragraph 1, Manufacturing the above structure is, A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by manufacturing the structure by coating a hydrogel containing cells to surround all or part of the magnetic support manufactured above.

7. In Paragraph 1, Manufacturing the above structure is, A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by manufacturing the structure by coating a hydrogel comprising cells and an extracellular matrix (ECM) to surround all or part of the magnetic support manufactured above.

8. In Paragraph 1, Manufacturing the above structure is, A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by plasma treating all or part of the surface of the magnetic support manufactured above, and coating all or part of the plasma-treated surface with a hydrogel comprising cells and decellularized extracellular matrix (dECM) to manufacture the structure.

9. In Paragraph 1, Deforming the above magnetic support is, A method for manufacturing a hydrogel structure including a magnetic support, characterized by applying a magnetic field to the above-manufactured structure to deform the shape of the structure including the magnetic support.

10. In Paragraph 1, Deforming the above magnetic support is, After incubating the above-manufactured structure, a magnetic field is applied to deform the magnetic support, or A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by applying a magnetic field to the above-manufactured structure to deform the magnetic support and then incubating.

11. In Paragraph 1, Deforming the above magnetic support is, A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by applying a magnetic field to the above-manufactured structure to deform the magnetic support and then incubating.

12. In Paragraph 10, The above-mentioned incubation is, A method for manufacturing a hydrogel structure comprising a magnetic support, characterized by culturing in an incubator for 1 to 7 days.

13. Manufactured by a manufacturing method according to any one of paragraphs 1 to 12, A hydrogel structure containing a magnetic support that is deformable by an external magnetic field.

14. A magnetic support having a predetermined shape formed by curing an ink composition containing magnetic particles; and A hydrogel coated on the magnetic support; comprising The above magnetic support is deformable by an external magnetic field, Hydrogel structure including a magnetic support.

15. In Paragraph 14, The above magnetic support is deformed by an external magnetic field, and A hydrogel structure comprising a magnetic support, characterized in that the above hydrogel is incubated.

16. In Paragraph 14, The above magnetic support is, A hydrogel structure comprising a magnetic support, characterized by including magnetic particles in which magnetic anisotropy is imparted to the magnetic particles by applying a magnetic field to an ink composition containing magnetic particles.

17. In Paragraph 16, A hydrogel structure comprising a magnetic support, characterized in that the magnetic particles endowed with magnetic anisotropy are aligned in one direction.

18. In Paragraph 14, The above hydrogel is, A hydrogel structure comprising a magnetic support, characterized by being coated to surround all or part of the magnetic support and comprising one or more of a cell and a decellularized extracellular matrix (dECM).

19. In Paragraph 14, The above magnetic support has all or part of its surface plasma treated, and A hydrogel structure comprising a magnetic support, characterized in that the hydrogel is coated on all or part of the surface of the plasma-treated magnetic support.

20. A composite hydrogel structure in which two or more hydrogel structures according to any one of claims 14 to 19 are stacked or assembled together.

21. In Paragraph 20, The above two or more hydrogel structures are, A composite hydrogel structure characterized by the magnetic support having different shapes when deformed by an external magnetic field.

22. Comprising two or more hydrogel structures according to paragraph 18, The above two or more hydrogel structures are a composite hydrogel structure characterized by comprising a hydrogel in which one or more of the cells and the decellularized extracellular matrix (dECM) are aligned in different directions.

23. In any one of paragraphs 14 through 19, A hydrogel structure comprising a magnetic support, characterized by being used for mimicking artificial tissue.

24. In Paragraph 23, A hydrogel structure comprising a magnetic support, characterized in that the artificial tissue is skeletal tissue, muscular tissue, or cardiac tissue.

25. An artificial tissue mimicry model manufactured using a hydrogel structure according to paragraph 23.

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