KR20230161257A - Micro structures with a gyroid shape of structure of triple periodic minimum curved surface - Google Patents

Abstract

The present invention relates to a microstructure with a Gyroid shape applied among Triple Periodic Minimal Surfaces (TPMS) using the Two-Photon Polymerization (TPP) method and a driving method thereof. Using the invention, it is possible to provide and operate a microstructure with increased drug loading and targeting efficiency.

Description

Among the triple periodic minimum curved structures, a micro structure with a gyroid shape applied {MICRO STRUCTURES WITH A GYROID SHAPE OF STRUCTURE OF TRIPLE PERIODIC MINIMUM CURVED SURFACE}

The present invention relates to a microstructure with a Gyroid shape applied among Triply Periodic Minimal Surfaces (TPMS) using the Two-Photon Polymerization (TPP) method and a method of driving the same.

In order to effectively treat cancer, which is the second leading cause of death in the world, drugs need to be delivered selectively to the diseased area. However, with existing artificial surgical methods, it is not only difficult to reach deep within the body, but also unnecessary treatment areas are exposed, so secondary damage during the procedure inevitably occurs or side effects after the procedure cannot be overlooked. Accordingly, it is difficult to accurately target and inject drugs into narrow spaces such as the eyes and capillaries, and there is a risk of causing physical pain to the patient and psychological trauma while recovering from the wound.

To solve this problem, various drug delivery methods have been developed, and recently, many drug-loaded robots capable of micro-scale remote control have been developed. It has been reported that using these micro-scale robots, drugs can be efficiently delivered to the target disease area regardless of the diameter of narrow blood vessels. However, due to limitations in the manufacturing process, many existing drug-carrying microrobots have been manufactured in the form of spheres, porous thin films, and porous spheres. However, these types of microstructures cannot carry drugs due to limitations in surface area. There is a limit to quantity.

In addition, microrobots can be used for knee cartilage treatment by carrying not only molecular-sized drugs but also regenerative cells. However, in order to manufacture such cell-carrying microrobots, a complex manufacturing process and an optimization process that overcomes numerous limitations are essential. To overcome these problems, research has been conducted on loading drugs and cells into microrobots using the Two-Photon Polymerization (TPP) method to solve the morphological limitations of microrobots. This is a method of manufacturing a microrobot of the desired shape by designing it in micro or nano size on a software program and laser hardening it. Two-photon polymerization is attracting attention because it can be produced by mixing not only commercially available photoresins but also biocompatible or biodegradable polymer materials with a photoinitiator.

Accordingly, there is an urgent need to develop a microrobot structure with increased targeting efficiency while increasing the amount of drug carried in the microrobot, and to develop a manufacturing method that can simply and uniformly manufacture such a structure.

The present inventor tried to develop a microstructure with a new structure and a method for driving it in order to overcome the low drug loading efficiency and low targeting efficiency for cancer cells, etc., of conventional microrobots.

As a result, the microstructure with the Gyroid shape of Triply Periodic Minimal Surfaces (TPMS) using the Two-Photon Polymerization (TPP) method has a higher drug loading efficiency compared to the conventional technology. It was confirmed that the targeting efficiency and accuracy for cancer tissues and cancer cells can be improved by increasing and additionally coating with magnetic nanoparticles.

Accordingly, the purpose of the present invention is to provide a microstructure for drug delivery with increased drug loading and targeting efficiency.

Another object of the present invention is to provide a method for manufacturing a microstructure for drug delivery with increased drug loading and targeting efficiency.

Another object of the present invention is to provide a method of driving a microstructure for drug delivery with increased drug loading and targeting efficiency.

The present invention relates to a microstructure for drug delivery in which a Gyroid shape is applied among Triply Periodic Minimal Surfaces (TPMS) using a Two-Photon Polymerization (TPP) method, a manufacturing method thereof, and an actuation thereof. Regarding the method, using the present invention, it is possible to provide and operate a microstructure with increased drug loading and targeting efficiency.

Hereinafter, the present invention will be described in more detail.

An example of the present invention is a microstructure for drug delivery comprising pores of a gyroid structure in which pitch and grooves are alternately arranged,

The microstructure includes a coating layer coated with polydopamine on the surface of the microstructure; A magnetic nanoparticle layer to which magnetic nanoparticles are attached to surround the coating layer; and a pharmaceutical material layer to which the pharmaceutical material is attached so as to surround the magnetic nanoparticle layer.

In the present invention, the microstructure for drug delivery may include pores of a gyroid structure in which pitch and grooves are alternately arranged, but is not limited thereto.

In the present invention, the microstructure for drug delivery may include gyroid-structured pores on the surface of the structure and in the direction infiltrated from the surface, but is not limited thereto.

In the present invention, the microstructure for drug delivery may include gyroid-shaped pores on the surface, but is not limited thereto.

In the present invention, among the triple periodic minimum curved structures, the gyroid structure is cube-shaped and has the characteristic that all surfaces are uniformly connected to the interior as a single surface, and has the advantage of maximizing the surface area under the same volume. This can provide great efficiency in carrying materials.

In the present invention, pitch and groove may refer to ridges and valleys of micro structures arranged alternately in the gyroid structure.

In the present invention, the spacing between pitches is 1 to 50 um, 1 to 45 um, 1 to 40 um, 1 to 30 um, 1 to 20 um, 1 to 10 um, 3 to 50 um, 3 to 45 um, 3 to 40 um, 3 to 30 um, 3 to 20 um, 3 to 10 um, 5 to 50 um, 5 to 45 um, 5 to 40 um, 5 to 35 um, 5 to 30 um, 5 to 25 um, 5 It may be from 20 um, 5 to 15 um, or 5 to 10 um, for example, from 5 to 10 um, but is not limited thereto.

In the present invention, the shape of the microstructure is cube, helical, sphere, ovoid, oval, cylinder, cone, and polyhedron. It may be one type selected from the group consisting of

In one embodiment of the present invention, the shape of the microstructure may be a cube.

In one embodiment of the present invention, the shape of the microstructure may be helical.

In the present invention, the microstructure includes a coating layer coated with polydopamine (PDA) on the surface of the microstructure, a magnetic nanoparticle layer with magnetic nanoparticles attached to surround the coating layer, and a medicine layer surrounding the magnetic nanoparticle layer. It may include a pharmaceutical material layer to which the material is attached.

In the present invention, the coating layer may be polydopamine coated on the surface of the microstructure, but is not limited thereto.

Polydopamine may be the final oxidation product of dopamine or other catecholamines. Polydopamine is known to be able to coat the surface of almost any material to a thickness of several nm to about 100 nm, and can be used in various fields such as polymer synthesis, catalysis, production of supercapacity, or heavy metal extraction. .

In the present invention, the magnetic nanoparticle layer may have magnetic nanoparticles attached to surround the coating layer, but is not limited thereto.

In the present invention, the components of the magnetic nanoparticles are Fe, Co, Mn, Ni, Gd, Mo, MM' ₂ O ₄ and M _x O _y (M and M' are each independently Fe, Co, Ni, Mn, Zn , Gd or Cr, x is an integer from 1 to 3, and y is an integer from 1 to 5. For example, it may be magnetite (Fe ₃ O ₄ ). However, it is not limited to this.

In the present invention, the pharmaceutical material layer may be a pharmaceutical material attached to surround the magnetic nanoparticle layer, but is not limited thereto.

In the present invention, the medicinal substances include Doxorubicin, Methotrexate, 5-Fluorouracil, Gemcitabine, Arabinosylcytosine, Hydroxy urea, Mercaptopurine, Thioguanine, Nitrogen mustad, Cyclosporamide, Anthracycline, Daunorubicin, Epirubicin, Idarubicin Idarubicin, Pixantrone, Sabarubicin, Valrubicin, Actinomycin D, Vincristine, Taxol, Combretastatin A4 ( Combretastatin A4), Fumagillin, Herbimycin A, 2-Methoxyestradiol, OGT 2115, TNP 470, Tranilast, XRP44X, Thalidomide, Endostatin (Endostatin), Salmosin, Angiostatin, Plasminogen, Kringle domain of Apolipoprotein, Oxaliplatin, Carboplatin ), Cisplatin, Bortezomib, and radionuclides. For example, it may be doxorubicin, but is not limited thereto.

In the present invention, the microstructure contains 0.002 to 0.050% by weight, 0.002 to 0.045% by weight, 0.002 to 0.040% by weight, 0.002 to 0.035% by weight, 0.002 to 0.030% by weight, 0.002 to 0.025% by weight, based on the total weight of the microstructure. Weight %, 0.002 to 0.023 weight %, 0.004 to 0.050 weight %, 0.004 to 0.045 weight %, 0.004 to 0.040 weight %, 0.004 to 0.035 weight %, 0.004 to 0.030 weight %, 0.004 to 0.025 weight %, 0.004 to 0.023% by weight , 0.006 to 0.050% by weight, 0.006 to 0.045% by weight, 0.006 to 0.040% by weight, 0.006 to 0.035% by weight, 0.006 to 0.030% by weight, 0.006 to 0.025% by weight, 0.006 to 0.023% by weight, 0.008 to 0.050% by weight, 0.008 to 0.045% by weight, 0.008 to 0.040% by weight, 0.008 to 0.035% by weight, 0.008 to 0.030% by weight, 0.008 to 0.025% by weight, 0.008 to 0.023% by weight, 0.010 to 0.050% by weight, 0.010 to 0.045% by weight, 0.010 to 0.040 It may include weight%, 0.010 to 0.035% by weight, 0.010 to 0.030% by weight, 0.010 to 0.025% by weight, or 0.010 to 0.023% by weight, for example, it may include 0.010 to 0.023% by weight, but is limited thereto. no.

In one embodiment of the present invention, the microstructure includes a first coating layer coated with polydopamine on the surface of the microstructure; A magnetic nanoparticle layer to which magnetic nanoparticles are attached to surround the coating layer; A second coating layer coated with polydopamine to surround the magnetic nanoparticle layer; and a pharmaceutical material layer to which the pharmaceutical material is attached so as to surround the second coating layer.

In one embodiment of the present invention, the first coating layer may be polydopamine coated on the surface of the microstructure.

In one embodiment of the present invention, the second coating layer may be coated with polydopamine to surround the magnetic nanoparticle layer.

In one embodiment of the present invention, the pharmaceutical material layer may be one to which the pharmaceutical material is attached so as to surround the second coating layer.

Another example of the present invention includes a preparation step of preparing a microstructure including pores of a gyroid structure in which pitch and grooves are alternately arranged; A polydopamine layer coating step of coating polydopamine on the surface of the microstructure to form a polydopamine layer; A magnetic nanoparticle attachment step of attaching magnetic nanoparticles to surround the polydopamine layer to form a magnetic nanoparticle layer; and a drug substance attachment step of attaching the drug substance to surround the magnetic nanoparticle layer.

In the present invention, the preparation step may be preparing a microstructure containing pores of a gyroid structure in which pitches and grooves are alternately arranged.

In the present invention, the microstructure may be a mixture of photocurable monomer, photocurable oligomer, photoinitiator, and crosslinking agent printed through 3D printing, but is not limited thereto.

In the present invention, the polydopamine layer coating step may be coating polydopamine on the surface of the microstructure to form a polydopamine layer, but is not limited to this.

In the present invention, the polydopamine layer coating step may be performed by mixing the microstructure and dopamine hydrochloride, but is not limited to this.

In the present invention, dopamine hydrochloride may be dissolved in Tris buffer, but is not limited thereto.

In the present invention, the polydopamine layer coating step may be performed for 1 to 5 hours, 1 to 4 hours, 2 to 5 hours, 2 to 4 hours, or 3 hours, for example, may be performed for 3 hours. However, it is not limited to this.

In the present invention, the polydopamine layer coating step may be performed by shaking under conditions of 100 to 140 rpm, 100 to 130 rpm, 110 to 140 rpm, 110 to 130 rpm, 120 to 140 rpm, or 120 to 130 rpm, For example, the reaction may be performed by shaking under conditions of 120 to 130 rpm, but is not limited thereto.

In the present invention, the polydopamine layer coating step may be performed at a temperature of 30 to 50 ℃, 30 to 45 ℃, 35 to 50 ℃, or 35 to 45 ℃, for example, 35 to 45 ℃ It may be performed in, but is not limited to this.

In the present invention, the polydopamine layer coating step may be performed using a shaking incubator, but is not limited thereto.

In the present invention, the magnetic nanoparticle attachment step may be to attach magnetic nanoparticles to surround the polydopamine layer to form a magnetic nanoparticle layer, but is not limited to this.

In the present invention, the diameter of the magnetic nanoparticles may be 100 to 200 nm, but is not limited thereto.

In the present invention, the magnetic nanoparticles may be dissolved in Tris buffer, but are not limited thereto.

In the present invention, the magnetic nanoparticle attachment step is performed for 1 hour or more, 2 hours or more, 3 hours or more, 4 hours or more, 5 hours or more, 6 hours or more, 7 hours or more, 8 hours or more, 9 hours or more, 10 hours or more, It may be performed for more than 11 hours or more than 12 hours, for example, it may be performed for more than 12 hours, but is not limited thereto.

In the present invention, the magnetic nanoparticle attachment step may be performed by shaking reaction under conditions of 100 to 140 rpm, 100 to 130 rpm, 110 to 140 rpm, 110 to 130 rpm, 120 to 140 rpm, or 120 to 130 rpm, For example, the reaction may be performed by shaking under conditions of 120 to 130 rpm, but is not limited thereto.

In the present invention, the magnetic nanoparticle attachment step may be performed under temperature conditions of 30 to 50 ℃, 30 to 45 ℃, 35 to 50 ℃, or 35 to 45 ℃, for example, 35 to 45 ℃. It may be performed in, but is not limited to this.

In the present invention, the step of attaching a drug substance may be attaching the drug substance to surround the magnetic nanoparticle layer, but is not limited to this.

In the present invention, the medicinal substance may be dissolved in tertiary distilled water, but is not limited thereto.

In the present invention, the drug attachment step is 12 to 36 hours, 12 to 32 hours, 12 to 28 hours, 12 to 24 hours, 16 to 36 hours, 16 to 32 hours, 16 to 28 hours, 16 to 24 hours, 20 hours. It may be performed for 36 hours, 20 to 32 hours, 20 to 28 hours, or 20 to 24 hours, for example, 20 to 24 hours, but is not limited thereto.

In the present invention, the drug attachment step may be performed at a temperature of 30 to 50 ℃, 30 to 45 ℃, 35 to 50 ℃, or 35 to 45 ℃, for example, at a temperature of 35 to 45 ℃. It may be performed, but is not limited to this.

In one embodiment of the present invention, the method of manufacturing a microstructure for drug delivery includes a preparation step of preparing a microstructure including pores of a gyroid structure in which pitches and grooves are alternately arranged; A first polydopamine layer coating step of coating polydopamine on the surface of the microstructure to form a first polydopamine layer; A magnetic nanoparticle attachment step of attaching magnetic nanoparticles to surround the polydopamine layer to form a magnetic nanoparticle layer; A second polydopamine layer coating step of coating polydopamine to surround the magnetic nanoparticle layer to form a second polydopamine layer; And it may include a drug substance attachment step of attaching the drug substance to surround the second polydopamine layer.

In one embodiment of the present invention, the first polydopamine layer coating step may be to form a first polydopamine layer by coating polydopamine on the surface of the microstructure.

In the present invention, the first polydopamine layer coating step may be performed by mixing the microstructure and dopamine hydrochloride, but is not limited to this.

In the present invention, the first polydopamine layer coating step may be performed for 1 to 5 hours, 1 to 4 hours, 2 to 5 hours, 2 to 4 hours, or 3 hours, for example, performed for 3 hours. It may be, but is not limited to this.

In the present invention, the first polydopamine layer coating step may be performed by shaking reaction at 100 to 140 rpm, 100 to 130 rpm, 110 to 140 rpm, 110 to 130 rpm, 120 to 140 rpm, or 120 to 130 rpm. For example, the reaction may be performed by shaking under conditions of 120 to 130 rpm, but the reaction is not limited thereto.

In the present invention, the first polydopamine layer coating step may be performed under temperature conditions of 30 to 50 ℃, 30 to 45 ℃, 35 to 50 ℃, or 35 to 45 ℃, for example, 35 to 45 ℃ It may be performed under temperature conditions, but is not limited thereto.

In the present invention, the first polydopamine layer coating step may be performed using a shaking incubator, but is not limited thereto.

In the present invention, the magnetic nanoparticle attachment step may be to attach magnetic nanoparticles to surround the polydopamine layer to form a magnetic nanoparticle layer, but is not limited to this.

In one embodiment of the present invention, the step of attaching magnetic nanoparticles may be forming a magnetic nanoparticle layer by attaching magnetic nanoparticles to surround the first polydopamine layer, but is not limited to this.

In one embodiment of the present invention, the second polydopamine layer coating step may be to form a second polydopamine layer by coating polydopamine to surround the magnetic nanoparticle layer.

In the present invention, the second polydopamine layer coating step may be performed by mixing the microstructure and dopamine hydrochloride, but is not limited to this.

In the present invention, the second polydopamine layer coating step may be performed for 1 to 5 hours, 1 to 4 hours, 2 to 5 hours, 2 to 4 hours, or 3 hours, for example, performed for 3 hours. It may be, but is not limited to this.

In the present invention, the second polydopamine layer coating step may be performed by shaking reaction at 100 to 140 rpm, 100 to 130 rpm, 110 to 140 rpm, 110 to 130 rpm, 120 to 140 rpm, or 120 to 130 rpm. For example, the reaction may be performed by shaking under conditions of 120 to 130 rpm, but the reaction is not limited thereto.

In the present invention, the second polydopamine layer coating step may be performed under temperature conditions of 30 to 50 ℃, 30 to 45 ℃, 35 to 50 ℃, or 35 to 45 ℃, for example, 35 to 45 ℃ It may be performed under temperature conditions, but is not limited thereto.

In the present invention, the second polydopamine layer coating step may be performed using a shaking incubator, but is not limited thereto.

In one embodiment of the present invention, the step of attaching the drug substance may be attaching the drug substance to surround the second polydopamine layer.

Another example of the present invention relates to a method of driving a drug delivery microstructure including a magnetic field application step of applying a rotating magnetic field to the drug delivery microstructure.

In the present invention, the microstructure for drug delivery includes a coating layer coated with polydopamine on the surface, a magnetic nanoparticle layer with magnetic nanoparticles attached to surround the coating layer, and a pharmaceutical substance surrounding the magnetic nanoparticle layer. It may include a layer of attached medicinal material and pores with a gyroid structure in which pitch and grooves are alternately arranged.

In the present invention, the magnetic field application step may be applying a rotating magnetic field to the drug delivery microstructure, but is not limited thereto.

In the present invention, the microstructure for drug delivery may be rotationally driven by receiving a rotating magnetic field, but is not limited thereto.

In one embodiment of the present invention, when the shape of the drug delivery microstructure is helical, rotational driving about the long axis may be possible when a rotating magnetic field is applied.

In the present invention, a rotating magnetic field may refer to a magnetic field in which the direction of the magnetic field changes with time and appears as if it is rotating, but is not limited thereto.

In the present invention, the rotating magnetic field may refer to a circular magnetic field formed at the center when a symmetrical n-phase current flows through a separate coil arranged to have a spatial angle of 2π/n (where n is a natural number). , but is not limited to this.

In the present invention, the rotation rate of the rotating magnetic field is 5.0 to 13.0 Hz, 5.0 to 12.5 Hz, 5.0 to 12.0 Hz, 5.0 to 11.5 Hz, 6.0 to 13.0 Hz, 6.0 to 12.5 Hz, 6.0 to 12.0 Hz, 6.0 to 11.5 Hz. Hz, 7.0 to 13.0 Hz, 7.0 to 12.5 Hz, 7.0 to 12.0 Hz, 7.0 to 11.5 Hz, 8.0 to 13.0 Hz, 8.0 to 12.5 Hz, 8.0 to 12.0 Hz, 8.0 to 11.5 Hz, 9.0 to 13.0 Hz, 9 .0 to 12.5 Hz, 9.0 to 12.0 Hz, 9.0 to 11.5 Hz, 10.0 to 13.0 Hz, 10.0 to 12.5 Hz, 10.0 to 12.0 Hz, 10.0 to 11.5 Hz, 10.5 to 13.0 Hz, 10.5 to 12.5 Hz, 10.5 to 12 .0 Hz or 10.5 to 11.5 It may be Hz, for example, 10.5 to 11.5 Hz, but is not limited thereto.

In the present invention, the rotating magnetic field may be generated by a separately provided coil system, but is not limited thereto.

In the present invention, the coil system may include at least one electromagnet that receives electric current and generates a magnetic field.

In the present invention, the electromagnet may be one or more types of coils selected from the group consisting of solenoid coils, circular coils, square coils, and saddle coils, but is not limited thereto.

In this specification, the term "solenoid coil" can be interpreted as a device made by tightly rolling a conductor into a cylindrical shape, and a solenoid can create a magnetic field when electricity passes through it, so it can be used as an electromagnet.

In this specification, the term "circular coil" can be interpreted as a circular electromagnet, and a circular electromagnet can mean a ring-shaped magnet, that is, an endless magnet that is not affected by the demagnetizing force at the tip. .

The present invention relates to a microstructure with a Gyroid shape applied among Triple Periodic Minimal Surfaces (TPMS) using the Two-Photon Polymerization (TPP) method and a driving method thereof. Using the microstructure of the invention, it is possible to overcome the low drug loading efficiency of conventional microstructures and increase targeting efficiency for targets such as tumor cells, thereby providing a drug delivery system that efficiently delivers drugs. .

Figure 1 shows the results of analyzing the structure of a microcube to which a gyroid surface is applied and manufactured according to a manufacturing example of the present invention.
Figure 2 is a photograph of fluorescence images taken before and after drug loading of a microcube with a gyroid surface applied according to a manufacturing example of the present invention.
Figure 3 shows the results of analyzing the drug loading efficiency of a microcube with a gyroid surface applied according to an experimental example of the present invention.
Figure 4 shows the results of analyzing the structure of a micro helical to which a gyroid surface is applied, manufactured according to a manufacturing example of the present invention.
Figure 5 is a graph showing the diameter of magnetic nanoparticles coated on a helical-type micro structure and the magnetization value of the micro structure according to an experimental example of the present invention.
Figure 6 shows a helical-type microstructure to which a gyroid surface is applied within a blood vessel simulating channel being driven by an external magnetic field according to an experimental example of the present invention.
Figure 7 is a graph showing the moving speed within a blood vessel-mimetic channel of a helical-type microstructure driven according to an experimental example of the present invention.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention in more detail, and it will be obvious to those skilled in the art that the scope of the present invention is not limited by these examples according to the gist of the present invention. will be.

Manufacturing example. Fabrication of microstructures containing magnetic nanoparticles

1) Preparation of microstructure with gyroid surface applied

Using a Two-Photon Polymerization (TPP) system (NanoScribe GmbH, Germany), set an appropriate amount of IP-S photoresin (NanoScribe GmbH, Germany) on a glass substrate (thickness: 170 um, diameter: 30 mm). Then, laser hardening was performed by applying a cube-type or helical-type microstructure file with a gyroid surface designed through Rhino 3D (3D drawing design software) to the TPP system.

Photoresins include not only IP series such as IP-S, IP-Dip, and IP-visio, but also polyethylene glycol diacrylate (PEGDA) and poly lactic-co-gylcolic acid (PLGA). ), D,L-Lactic acid (PDLLA), etc. are used as the backbone, Irgacure-369, Irgacure-819, etc. are used as photoinitiators, and pentaerythritol tetraacrylic is used for cross-linking with the polymer chain. Acrylic resins such as Pentaerythritol tetraacrylate and Trimethylolpropane ethoxylate triacrylate dissolved in a solvent at a certain ratio can also be used.

After completing the photocuring process, the entire substrate is soaked in propylene glycol monomethyl ether acetate (PGMEA) and isopropyl alcohol (IPA) for 20 minutes each to remove uncured photoresin on the glass substrate. The work was carried out. When a glass substrate is naturally dried at room temperature, microstructures remain on the substrate.

2) Coating of magnetic nanoparticles on microstructures

The prepared microstructure was coated with magnetic nanoparticles (MNP) with a diameter of 50 to 100 nm to enable control by an external electromagnetic field.

First, polydopamine (PDA) coating work was performed before coating the magnetic nanoparticles. Dopamine hydrochloride was dissolved in Tris buffer (10 mM, pH 8.5) at a concentration of 5 mg/mL, and 3 mL was placed in a 30 mm Petri dish on which a glass substrate with microstructures was placed. After addition, reaction was performed in a shaking incubator at 40°C and 120 rpm for 3 hours. After the reaction was completed, the substrate was washed twice with distilled water.

Next, magnetic nanoparticles (MNP; Fe ₃ O ₄ (magnetite)) with a diameter of 100 to 200 nm were taken in Tris buffer (10 mM, pH 8.5) at a concentration of 50 mg/mL and then sonicated for 30 minutes. A magnetic nanoparticle solution was prepared by adding and dispersing.

The polydopamine coated microstructure was placed in a 30 mm Petri dish, about 3 mL of magnetic nanoparticle solution was added, and the mixture was reacted for more than 12 hours in a shaking incubator at 40°C and 120 rpm. After the reaction was completed, the microstructure was washed twice with distilled water. At this time, it is not impossible to add the magnetic nanoparticle solution in advance during the photocuring of the microstructure to proceed with the photocuring of the microstructure, but there is a concern that the magnetic nanoparticles may not disperse smoothly and aggregate due to the viscosity of IP-S photoresin. In addition, a problem may occur in which the gyroid structure of the microstructure is not precisely implemented.

3) Support of doxorubicin on microstructure coated with magnetic nanoparticles

After coating the magnetic nanoparticles, doxorubicin (Dox), an anticancer drug, was loaded on the surface of the microstructure to give the microstructure a cancer cell killing effect.

In order to carry a large number of drugs, polydopamine (PDA) coating on the magnetic nanoparticle-coated microstructure was performed once more in the same manner as Preparation Example 2). Afterwards, doxorubicin (Dox), used as an anticancer drug, was dissolved in distilled water at a concentration of 10 mg/mL to prepare a doxorubicin solution, which was then loaded onto the microstructure using the following method:

i) Take 100 uL of the doxorubicin solution prepared in the center of the confocal dish.

ii) Place the glass substrate on the confocal dish so that the surface of the glass substrate with the microstructure is in contact with the prepared doxorubicin solution.

iii) After sealing the confocal dish on which the glass substrate was placed, the reaction was performed in an incubator environment at 40°C for 24 hours, and the drug on the reacted substrate was washed with physiological saline (phosphate buffer saline; PBS).

Experimental Example 1. Analysis of cube-shaped microstructure

1-1. Surface area by pitch interval

To analyze the surface area, first, a cube-shaped microstructure with a gyroid structure was designed and manufactured with four pitch sizes of 40 um, 20 um, 10 um, and 5 um, and the surface is shown in Figure 1.

Figure 1 (a) is a photograph taken with an electron microscope of a cube-shaped micro structure manufactured for each pitch. Here, (i) the pitch-to-pitch spacing of the microstructure is 40 um, (ii) is 20 um, (iii) is 10 um, and (iv) is 5 um.

The results of analyzing the surface area of the microstructure to which four types of gyroid surfaces were applied are shown in Figure 1 (b) and Table 1.

Example 1 Example 2 Example 3 Example 4 Spacing between pitches (um) 40 20 10 5 Surface area (um ² ) 77992.86 159506.68 319546.90 638553.41

As can be seen in Figure 1 (b) and Table 1, the surface area of Example 1 is 77,992.86 um ² , the surface area of Example 2 is 159,506.68 um ² , the surface area of Example 3 is 319,546.90 um ² , and the surface area of Example 4 is was measured to be 638,553.41 um ² , and as the pitch size decreased, the surface area of the microstructure gradually increased.

1-2. Drug loading amount

Fluorescent images before and after doxorubicin was loaded were taken using a fluorescence microscope and are shown in Figure 2. Since doxorubicin is fluorescent, it is possible to check whether doxorubicin is contained using a fluorescence microscope.

In Figure 2, (i) is a microstructure with a smooth surface without a gyroid structure, (ii) is a microstructure to which a gyroid structure with a pitch spacing of 40 um in Example 1 () is applied, and (iii) is a pitch spacing. Example 2, which is 20 um, and (iv) are those in which doxorubicin is supported on the microstructure of Example 3, where the pitch spacing is 10 um.

Microstructure with a smooth surface without gyroid structure (interpitch spacing: 0 um), microstructure of Example 1 (interpitch spacing: 40 um), microstructure of Example 2 (interpitch spacing: 20 um), And the amount of doxorubicin supported on the microstructure (interpitch spacing: 10 um) of Example 3 is shown in Figure 3 and Table 2. Here, the unit weight of the microstructure when measuring the drug loading amount was 236 ug for Comparative Example, 65.31 ug for Example 1, 136 ug for Example 2, and 152 ug for Example 3. This unit weight is also the weight of one micro structure.

Comparative example Example 1 Example 2 Example 3 Spacing between pitches (um) 0 40 20 10 Drug loading (ng) 4.54 13.98 18.10 27.52

As can be seen in Figure 3 and Table 2, as the pitch size decreases, the amount of drug carried on the microstructure gradually increases. The amount of drug supported per unit weight was 0.00192% by weight in Comparative Example, 0.0214% by weight in Example 1, 0.0133% by weight in Example 2, and 0.0181% by weight in Example 3.

In particular, one microstructure of Example 3 with a pitch size of 10 um can carry about 6.06 times more doxorubicin compared to the amount of doxorubicin carried by one microstructure of the comparative example with a smooth surface without a gyroid structure. can confirm.

Experimental Example 2. Analysis of helical microstructure

In fact, in order to propel a microstructure within a blood vessel, it is advantageous to have a helical shape rather than a cube shape due to the low Reynolds number and to propel the microstructure while rotating, as this can reduce fluid resistance. This is similar to the principle of a bacteria's tail propelling itself forward while rotating. Therefore, in this Experimental Example 2, a helical-shaped microstructure was designed, manufactured, and applied.

Figure 4 (a) shows an electron micrograph of a helical-type microstructure to which a pitch of 10 um was applied. Figure 4 (b) shows the confirmation of whether magnetic particles are well attached to the surface using energy dispersive X-ray spectroscopy (EDS). Since there is a signal of iron atoms (Fe), it can be seen that the magnetic particles are well coated on the helical-type microstructure.

Figure 5 (a) is a graph showing the diameter of coated magnetic nanoparticles. The average diameter of the magnetic nanoparticles used was about 190.1 nm. Figure 5(b) is a graph showing the magnetization value of a helical-type microstructure measured using a vibrating sample magnetometer (VSM), and the measurement results show a magnetization value of up to about 30 emu/g. can be seen.

Experimental Example 3. Analysis of driving characteristics of helical microstructure

An experiment was conducted to drive a helical-type microstructure with a gyroid structure using external rotating magnetic field control.

Figure 6 (a) shows a schematic diagram of the external electromagnetic field driving system used in the experiment. The external electromagnetic field driving system consists of a pair of circular Helmholtz coils and two pairs of rectangular Helmholtz coils, and the size and direction of the magnetic field can be controlled depending on the degree of current applied to each coil, through which magnetic nanoparticles are coated. The movement of the helical microstructure can be controlled with five degrees of freedom (5 DOF). A 3D printer-produced blood vessel simulating channel was placed within the area of interest of the external electromagnetic field drive system, and a 50% glycerol solution simulating the human body environment was filled into the blood vessel simulating channel. The driving experiment was conducted through real-time feedback control of a magnifying glass placed in the center of an external electromagnetic driving system.

Figure 6(b) shows the propulsion of the helical-type microstructure in a blood vessel-simulating channel by electronic driving, and the movement of the helical-type microstructure was observed from (i) to (iv) over time. The electromagnetic field strength was fixed at 20 mT and the rotation rate of the external electromagnetic field was increased from 6 Hz to 1 Hz, while the movement speed of the helical microstructure in the blood vessel simulating channel was measured, and the results are shown in Figure 7 and Table 3. .

Turnover rate (Hz) 6 7 8 9 10 11 12 Speed (um/s) 11.89 11.25 10.98 13.04 18.52 22.50 8.90

As can be seen in Figure 7 and Table 3, when the rotation rate of the external electromagnetic field was about 11 Hz, the microstructure showed a maximum speed of 22.50 um/s, and at 12 Hz, the movement speed significantly decreased to 8.90 um/s. This means that the rotation of the helical microstructure can no longer keep up with the rotation speed of the external electromagnetic field, and the rotation rate of 11 Hz can be seen as the step-out rotation rate of the helical microstructure of the present invention.

Claims (11)

In the drug delivery microstructure containing pores of a gyroid structure in which pitch and grooves are alternately arranged,
The micro structure is,
A coating layer coated with polydopamine on the surface of the microstructure;
A magnetic nanoparticle layer to which magnetic nanoparticles are attached to surround the coating layer; and
A microstructure for drug delivery comprising: a pharmaceutical material layer to which the pharmaceutical material is attached so as to surround the magnetic nanoparticle layer. The microstructure for drug delivery according to claim 1, wherein the spacing between pitches of the microstructure is 1 to 60 um. The method of claim 1, wherein the shape of the microstructure is cube, helical, sphere, ovoid, oval, cylinder, cone, and polyhedron ( A microstructure for drug delivery, which is one type selected from the group consisting of polyhedron. The method of claim 1, wherein the magnetic nanoparticles are Fe, Co, Mn, Ni, Gd, Mo, MM' ₂ O ₄ and M _x O _y (M and M' are each independently Fe, Co, Ni, Mn, Zn, Gd, or Cr, x is an integer from 1 to 3, and y is an integer from 1 to 5). The method of claim 1, wherein the medicinal substance is Doxorubicin, Methotrexate, 5-Fluorouracil, Gemcitabine, Arabinosylcytosine, and Hydroxy urea. ), Mercaptopurine, Thioguanine, Nitrogen mustad, Cyclosporamide, Anthracycline, Daunorubicin, Epirubicin , Idarubicin, Pixantrone, Sabarubicin, Valrubicin, Actinomycin D, Vincristine, Taxol, Combreta Combretastatin A4, Fumagillin, Herbimycin A, 2-Methoxyestradiol, OGT 2115, TNP 470, Tranilast, XRP44X, Thalidomide ), Endostatin, Salmosin, Angiostatin, Plasminogen, Kringle domain of Apolipoprotein, Oxaliplatin, Carbottle A microstructure for drug delivery, which is at least one selected from the group consisting of Carboplatin, Cisplatin, Bortezomib, and Radionuclides. The microstructure for drug delivery according to claim 1, wherein the microstructure contains 0.002 to 0.050% by weight of the drug substance based on the total weight of the microstructure. In the drug delivery microstructure containing pores of a gyroid structure in which pitch and grooves are alternately arranged,
The micro structure is,
A first coating layer coated with polydopamine on the surface of the microstructure;
A magnetic nanoparticle layer to which magnetic nanoparticles are attached to surround the coating layer;
A second coating layer coated with polydopamine to surround the magnetic nanoparticle layer; and
A microstructure for drug delivery comprising a pharmaceutical material layer to which the pharmaceutical material is attached so as to surround the second coating layer. Method for manufacturing microstructures for drug delivery comprising the following steps:
A preparation step of preparing a microstructure containing pores of a gyroid structure in which pitch and grooves are alternately arranged;
A polydopamine layer coating step of coating polydopamine on the surface of the microstructure to form a polydopamine layer;
A magnetic nanoparticle attachment step of attaching magnetic nanoparticles to surround the polydopamine layer to form a magnetic nanoparticle layer; and
A drug substance attachment step of attaching the drug substance to surround the magnetic nanoparticle layer. Method for manufacturing microstructures for drug delivery comprising the following steps:
A preparation step of preparing a microstructure containing pores of a gyroid structure in which pitch and grooves are alternately arranged;
A first polydopamine layer coating step of coating polydopamine on the surface of the microstructure to form a first polydopamine layer;
A magnetic nanoparticle attachment step of attaching magnetic nanoparticles to surround the polydopamine layer to form a magnetic nanoparticle layer;
A second polydopamine layer coating step of coating polydopamine to surround the magnetic nanoparticle layer to form a second polydopamine layer; and
A drug substance attachment step of attaching the drug substance to surround the second polydopamine layer. In the method of driving a drug delivery microstructure comprising a magnetic field application step of applying a rotating magnetic field to the drug delivery microstructure,
The microstructure includes a coating layer coated with polydopamine on the surface, a magnetic nanoparticle layer with magnetic nanoparticles attached to surround the coating layer, and a pharmaceutical material layer with a pharmaceutical substance attached to surround the magnetic nanoparticle layer. Contains,
A method of driving a microstructure for drug delivery, comprising pores of a gyroid structure in which pitch and grooves are alternately arranged. The method of claim 10, wherein the rotation rate of the rotating magnetic field is 5.0 to 13.0 Hz.