Micro-needle array and patch

Abstract

To provide a microneedle and a patch that can generate an efficient electroosmotic flow and transport a molecule or particle having a relatively large size.SOLUTION: A microneedle array has a flow channel modified with polymer and has stationary charges. A patch includes the microneedle array and a plurality of electrodes installed while coming into contact with the microneedle array.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a microneedle array and a patch. [Background technology]

[0002] Flow control through the epithelial layers of skin and organs is widely important in the medical and health and beauty fields, and microneedles have attracted attention as a tool for such flow control.

[0003] Microneedles made of hydrogel can insert the dried hydrogel into the surface of biological tissue such as the skin, and as the hydrogel swells and dissolves, it is possible to deliver a substance contained within the hydrogel to the insertion site. In addition, microneedles made of porous materials are capable of transporting liquid to the insertion site and can deliver a large amount of liquid, making them superior to microneedles made of hydrogels.

[0004] Injection of drug solutions and collection of interstitial fluid are generally performed using mechanical pumps such as syringes, but electrical fluid delivery technology is advantageous for improving controllability, miniaturization, and automation.

[0005] For example, in Patent Document 1, a microneedle made of a porous material is filled with or surface-modified with a charged material (such as hydrogel), creating a field for generating electroosmotic flow, enabling the transport of water and other substances by electricity. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2020 / 179850 Summary of the Invention [Problem to be solved by the invention]

[0007] However, conventional charged microneedles leave room for improvement in terms of water and substance transport speed. Therefore, an object of the present invention is to provide a microneedle and a patch that are capable of generating a highly efficient electroosmotic flow and transporting molecules and particles of a relatively large size. [Means for solving the problem]

[0008] The gist of the present invention is as follows. The microneedle array of the present invention is characterized in that the flow channel is modified with a polymer and has a fixed charge. The microneedle array of the present invention preferably includes a porous body, and voids in the porous body form the flow paths. In the microneedle array of the present invention, the amount of the fixed charge in the porous body per unit surface area of ​​the porous body is on average 1×10 -6 C / cm 2 ~1×10 -1 C / cm 2 It is preferable that: In the microneedle array of the present invention, it is preferable that the polymer has the fixed charge. Here, in the microneedle array of the present invention, it is preferable that the polymer is modified on the surface of the porous body via a silane coupling agent. In the microneedle array of the present invention, the polymer preferably contains a monomer unit containing a functional group having a fixed charge. In the microneedle array of the present invention, it is preferable that the functional group includes at least one selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphate group, and an amino group. In the microneedle array of the present invention, the polymer preferably has a degree of polymerization of 5 to 50,000. In the microneedle array of the present invention, the polymer preferably has a weight average molecular weight (Mw) of 2,000 to 5,000,000. In the microneedle array of the present invention, the amount of the functional group in the porous body per unit surface area of ​​the porous body is on average 1×10 -12 moles / cm 2 More preferably, it is equal to or greater than this. In the microneedle array of the present invention, it is preferable that the porous body contains a material other than a hydrogel material. In the microneedle array of the present invention, a plurality of microneedles are preferably provided upright on a substrate. Here, in the microneedle array of the present invention, the microneedles preferably include a columnar body equipped with small microneedles. Moreover, the microneedle array of the present invention preferably comprises one or more small microneedles and a plurality of the pillars. The microneedle array of the present invention is preferably used for transporting at least one selected from the group consisting of large molecules with a molecular weight of 1 kDa to 100 kDa and particles with a particle diameter of 2 nm to 200 nm. The patch of the present invention is characterized by including the microneedle array of the present invention and a plurality of electrodes provided in contact with the microneedle array. Effect of the Invention

[0009] According to the present invention, it is possible to provide a microneedle and a patch that are capable of generating a highly efficient electroosmotic flow and transporting molecules and particles of a relatively large size. [Brief description of the drawings]

[0010] [Figure 1]1 is a diagram showing an example of a microneedle used in the microneedle array of this embodiment. (A) is a cross-sectional view of a cone-shaped microneedle (MN) composed of a porous body made of polyglycidyl methacrylate (PGMA) surface-modified with poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS), cut along a plane along the axis of the MN cone. (B) is an enlarged view of the part enclosed by the dashed square frame in (A). [Diagram 2] FIG. 2 is a photograph showing an example of the microneedle array of this embodiment. [Diagram 3] 3 is a diagram for explaining an outline of a method for introducing poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) onto the surface of a cone-shaped microneedle (MN) composed of a porous body made of polyglycidyl methacrylate (PGMA) in this embodiment. (A) is a diagram showing a schematic diagram of a porous body made of unmodified polyglycidyl methacrylate (PGMA), (B) is a diagram showing a schematic diagram of the state after the porous body shown in (A) is subjected to a surface treatment with 3-(trimethoxysilyl)propyl methacrylate, and (C) is a diagram showing a schematic diagram of the state after 2-acrylamido-2-methylpropanesulfonic acid is polymerized using the acrylic structure introduced by the surface treatment shown in (B) as a polymerization initiation point. [Figure 4] FIG. 4 is a diagram showing an outline of a test in this embodiment in which a flat plate-like member (thickness: 1 mm, diameter: 18 mm) composed of a porous body made of polyglycidyl methacrylate (PGMA) surface-modified with poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) is used, and the dynamics of the fluorescent dye is observed when a current is applied with or without dripping a fluorescent dye-tagged large molecule or particle into one cell of a Franz cell, thereby confirming the generation of an electroosmotic flow and the movement of large molecules or particles due to the application of current in the flat plate-like member. [Diagram 5] FIG. 5 shows the results of the test shown in FIG. 4, in which the generation of electroosmotic flow due to the passage of current in a flat member was confirmed by observing the movement of water from one side of a closed Franz cell to the other side. [Figure 6] Figure 6 shows the results of confirming the movement of dextran-FITC in a flat member by observing the dynamics of the fluorescent dye dextran-FITC (10 kDa) from one side to the other side of a sealed Franz cell in the test shown in Figure 4. In Figure 6, black circles represent the results of Example 1, white triangles represent the results of Comparative Example 1, and black triangles represent the results of Comparative Example 2. In Figure 6, bars represent standard deviation (N=3). [Figure 7] Fig. 7 shows the results of confirming the movement of albumin-FITC in a flat plate-like member by observing the dynamics of the fluorescent dye albumin-FITC (66 kDa) from one side to the other side of a sealed Franz cell in the test shown in Fig. 4. In Fig. 7, the black circles represent the results of Example 1. In Fig. 7, the bars represent the standard deviation (N=3). [Figure 8] Fig. 8 is a diagram showing the results of confirming the movement of gold nanoparticles (15 nm) in a flat plate-like member by observing the dynamics of the absorbance of gold nanoparticles (15 nm) from one side to the other side of a closed Franz cell in the test shown in Fig. 4. In Fig. 8, the black circles represent the results of Example 1. [Figure 9] Fig. 9 is a diagram showing the results of confirming the movement of gold nanoparticles (50 nm) in a flat plate-like member by observing the dynamics of the absorbance of gold nanoparticles (50 nm) from one side to the other side of a closed Franz cell in the test shown in Fig. 4. In Fig. 9, black circles represent the results of Example 1. [Figure 10] Fig. 10 is a diagram showing the results of confirming the movement of fluorescent silica nanoparticles (100 nm) in a flat plate-like member by observing the dynamics of the fluorescent dye of the fluorescent silica nanoparticles (100 nm) from one side to the other side of a closed Franz cell in the test shown in Fig. 4. In Fig. 10, the black circles represent the results of Example 1. In Fig. 10, the bars represent the standard deviation (N=3). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the microneedle array and patch of the present invention will be described in detail with reference to the drawings. In the following description, the microneedle array will also be referred to as "MNA" and the microneedle as "MN."

[0012] (Microneedle Array) The microneedle array of this embodiment is characterized in that the flow channels are modified with a polymer and have a fixed charge.

[0013] In this embodiment, the flow paths present in the MNA may be through-holes provided in the MN or MNA, or may be void portions communicating inside the MN or MNA made of a porous body.

[0014] The manner of modification of the flow path is not particularly limited as long as it is placed on the surface of the MN, and more specifically, the polymer may be modified by attachment, adhesion, adsorption, support, etc. through interactions such as hydrogen bonds and intermolecular forces, or may be modified by covalent bonds via coupling agents, etc. In this embodiment, the polymer is preferably modified by a covalent bond from the viewpoint of maintaining the content of the modified polymer (described in detail below).

[0015] The polymer used to modify the flow path is not particularly limited, and may be a polymer containing a monomer unit having a fixed charge, or a polymer containing a monomer unit having no fixed charge (described in detail below).

[0016] Furthermore, the fixed charge in this embodiment refers to a charge that is fixed and exists within the region of the flow channel, and does not include a charge that a substance that flows into or flows out of the flow channel has.

[0017] In the microneedle array of this embodiment, since the flow path has a fixed charge, it is possible to generate a highly efficient electroosmotic flow, and since the flow path is modified with a polymer, it has the effect of promoting the movement of relatively large molecules and particles, making it possible to efficiently transport such molecules and particles.

[0018] 1 is a diagram showing an example of a microneedle used in the microneedle array of this embodiment. (A) is a cross-sectional view of a cone-shaped microneedle (MN) composed of a porous body made of polyglycidyl methacrylate (PGMA) surface-modified with poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS), cut along a plane along the axis of the MN cone. (B) is an enlarged view of the part enclosed by the dashed square frame in (A).

[0019] As shown in FIG. 1, one example of the microneedle array of the present invention preferably includes a porous body, and is preferably made of a porous body.

[0020] The porous body in this embodiment has voids therein. In this case, the voids in the porous body may form a flow path. The voids may be closed cells or open cells, but open cells are preferred from the viewpoint of obtaining good electroosmotic flow and transport paths.

[0021] The porosity of the porous body of this embodiment is preferably 10 to 80%, and more preferably 20 to 60%. The porosity can be adjusted by changing the method or conditions usually used in the preparation of the porous body. For example, when the porous body is made of a resin, the porosity can be adjusted by changing the monomer concentration or the porogen concentration during the polymerization of the resin. The porosity can be measured by a method commonly used in the art, such as the use of a submersion method, the use of a pycnometer, etc. In the present embodiment, the porosity of the porous body after polymer modification may be determined based on the solid and void portions of the porous body before polymer modification, and may be calculated as the porosity of the porous body before polymer modification.

[0022] Furthermore, in this embodiment, the diameter and length of the flow channels of the MNA can be adjusted according to the purpose and application by changing the techniques and conditions normally used in the preparation of the porous body.

[0023] The porous body in this embodiment may contain a material other than the hydrogel material. In such a case, a flow path is formed in the voids of the porous body. Note that the hydrogel material refers to a material that forms a hydrogel by dispersing in water (dispersion medium).

[0024] Materials other than the hydrogel material of this embodiment include resins, oxides, metals, and the like.

[0025] Examples of the resin include polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, phenol resin, acrylic resin, methacrylic resin (polyglycidyl methacrylate resin, etc.), etc. Examples of the oxide include inorganic oxides and derivatives thereof, and examples of the inorganic oxide include silicon oxide, tin oxide, zirconia oxide, titanium oxide, niobium oxide, tantalum oxide, aluminum oxide, tungsten oxide, hafnium oxide, zinc oxide, etc. Examples of the metal include nickel, iron, and alloys thereof. These may be used alone or in combination of two or more.

[0026] In this embodiment, the fixed charge may be present in the polymer that modifies the surface of the flow path of the porous body, or the fixed charge may be present on the surface of the flow path of the porous body rather than in the polymer that modifies.

[0027] In one example of the microneedle array of the present invention, from the viewpoint of efficiently obtaining the molecular or particle transfer effect of the present invention, the amount of fixed charge in the porous body per unit surface area of ​​the porous body is set to be 1×10 on average. -6 C / cm 2 ~1×10 -1 C / cm 2 It is preferable that: The amount of the fixed charge per unit surface area can be measured by a zeta potential measuring device or the like. Here, the lower limit is 5×10 -5 C / cm 2 That's it, 1×10 -5 C / cm 2 or more, with the upper limit being 5×10 -2 C / cm 2 Below, 1×10 -2 C / cm 2 It may be the following. Although each fixed charge may be a mixture of anions and cations, the amount of the fixed charges per unit surface area refers to the total amount of the fixed charges, and refers to the absolute value of the charge of the anions or cations.

[0028] In one example of the microneedle array of the present invention shown in FIG. 1, the surface of the porous body is modified with a polymer having a fixed charge.

[0029] In this embodiment, as described above, from the viewpoint of maintaining the content of the modifying polymer, it is preferable that the polymer having a fixed charge be modified on the surface of the flow path of the porous body by a covalent bond. The manner of modification by covalent bonding is not particularly limited, and the polymer may be modified via functional groups introduced onto the surface of the porous body by surface treatments such as silane coupling agents and phosphonic acid derivatives, oxygen plasma treatment, gamma ray irradiation, acid / alkali treatment, and electroless plating. These may be used alone or in combination of two or more.

[0030] The silane coupling agent that can be used in the present embodiment is not particularly limited, but is preferably one having a structure that can serve as a polymerization initiation point. The structure that can be a polymerization initiation point is not particularly limited, but examples thereof include an acrylic structure, a methacrylic structure, a styryl structure, a vinyl structure, and a halogen structure. Examples of the silane coupling agent that can be used include 3-(trimethoxysilyl)propyl acrylate and 3-(trimethoxysilyl)propyl methacrylate. These may be used alone or in combination of two or more.

[0031] Here, the polymer having a fixed charge used for modification preferably contains a monomer unit containing a functional group having a fixed charge. Here, the content of the monomer unit containing a functional group having a fixed charge in the polymer having a fixed charge used for modification is preferably 0.1% by mass or more from the viewpoint of obtaining a good electroosmotic flow, more preferably 1% by mass or more, and further preferably 10% by mass or more. The content may be 100% by mass. The upper limit of the content is not particularly limited as long as a good electroosmotic flow is obtained, and may be 90% by mass or less, 60% by mass or less, or 30% by mass or less.

[0032] Specifically, the polymer having a fixed charge used for modification preferably contains a monomer unit containing a functional group having a fixed charge. The functional group is not particularly limited, but examples thereof include a sulfonic acid group, a carboxyl group, a phosphoric acid group, an amino group, etc. Among these, a sulfonic acid group, which has an ionization degree close to neutral, is more preferable. These may be used alone or in combination of two or more.

[0033] More specifically, examples of monomers containing functional groups having a fixed charge include polyacrylic acid, sodium polyacrylate, polymethacrylic acid, sodium polymethacrylate, poly(2-hydroxyethyl methacrylic acid), poly(2-acrylamido-2-methylpropanesulfonic acid), etc. Among these, poly(2-acrylamido-2-methylpropanesulfonic acid) having a sulfonic acid group with a degree of ionization near neutral is preferred. These may be used alone or in combination of two or more.

[0034] In this embodiment, from the viewpoint of efficiently obtaining the effect of transferring molecules or particles of the present invention, the amount of functional groups in the porous body per unit surface area of ​​the porous body is set to be 1×10 on average. -12 moles / cm 2 More preferably, it is equal to or greater than this. Such a content is more preferably 1×10 -11 moles / cm 2 More preferably, it is 1×10 -10 moles / cm 2 The content is preferably 5×10 -8 moles / cm 2 The following is the result.

[0035] In one example of the microneedle array of the present invention, from the viewpoint of efficiently obtaining the migration effect of the molecules or particles of the present invention, the degree of polymerization of the polymer used for modification is preferably 5 to 50000. The lower limit may be 10 or more, 20 or more, 50 or more, or 100 or more, and the upper limit may be 20000 or less, 10000 or less, 5000 or less, or 2000 or less. From the viewpoint of efficiently obtaining the mobility effect of the molecules or particles of the present invention, the weight-average molecular weight (Mw) of the polymer used for modification is preferably 2000 to 5000000. The lower limit may be 5000 or more, 10000 or more, or 20000 or more, and the upper limit may be 200000 or less, 100000 or less, or 50000 or less. The degree of polymerization and the weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC). In detail, a calibration curve is prepared from the elution time and Mw using a standard PLGA with a known degree of polymerization and weight average molecular weight (Mw) and an analytical gel column, and the degree of polymerization and the weight average molecular weight (Mw) of the sample PLGA can be obtained using the obtained calibration curve.

[0036] Furthermore, even when a polymer having the same fixed charge is used, the MNA of this embodiment, in which the polymer is covalently bonded to the flow path of a porous body, is more likely to promote the movement of relatively large molecules and particles due to the presence of pores of sufficient size in the MNA, compared to an MNA in which the polymer is filled into the flow path of a porous body. Furthermore, even when a substance having a similar fixed charge is used, the MNA of this embodiment, in which a polymer having a fixed charge is covalently bonded to the flow path of a porous body, can be modified with a larger amount of charge compared to an MNA in which a small molecule having a fixed charge is covalently bonded to the flow path of a porous body, and as a result, highly efficient transport of substances is possible, making it easier to obtain the effect of promoting the movement of relatively large molecules and particles.

[0037] A preferred shape of the MN in the MNA will be described below.

[0038] In the microneedle array of this embodiment, a plurality of microneedles may be provided upright on a substrate.

[0039] The three-dimensional shape of the microneedle is not particularly limited as long as it can be inserted into the skin, and examples of the shape include a truncated cone shape, a cone shape, a square pyramid shape, a truncated square pyramid shape, and other shapes.

[0040] In the microneedle array of this embodiment, the microneedles preferably include a plurality of pillars each having one small microneedle (see FIG. 2). Here, the three-dimensional shape of the small microneedle is not particularly limited as long as it can be inserted into the skin, but a cone shape is preferable. Also, the three-dimensional shape of the columnar body is not particularly limited, but a cylinder shape is preferable. FIG. 2 is a photograph showing an example of the microneedle array of this embodiment.

[0041] Suitable dimensions for the example MNA shown in FIG. The diameter Rp of the cylindrical support portion may be 0.2 to 1 mm. The height Hp of the cylindrical support portion may be 0.2 to 1 mm. The diameter Rb of the bottom circle of the cone-shaped small MN may be 20 to 500 μm, and from the viewpoints of ease of preparation, ease of piercing into the skin, and mechanical strength, it is preferably 100 to 400 μm. The height H of the cone-shaped small MN may be 20 to 1000 μm, and is preferably 30 to 600 μm from the viewpoint of penetrating the stratum corneum when applied to the skin, ensuring a sufficient contact area with the epidermis, and preventing invasion of the dermis. When the microneedles are arranged at equal distances in the vertical and horizontal directions, the distance (pitch) P between the microneedles MN (see FIG. 2(A)) may be 500 to 3000 μm, and preferably 1000 to 2000 μm. The thickness t of the substrate (see FIG. 2(A)) may be from 10 to 2000 μm, and preferably from 300 to 1000 μm.

[0042] In the microneedle array of this embodiment, the microneedle may include a plurality of pillars each having a plurality of small microneedles.

[0043] (Method of manufacturing a microneedle array) The microneedle array of this embodiment is not particularly limited and may be manufactured by a method commonly used in the art.

[0044] When the MNA is a porous body, for example, a water-soluble porogen (e.g., PEG) is added to a resin monomer (e.g., glycidyl methacrylate) and a polymerization reaction is carried out to obtain a porogen-containing resin, and then the porogen contained in the resin is dissolved in water to prepare an MNA having porogen traces as flow paths. The MNA may then be manufactured by introducing a polymer having an anionic or cationic functional group onto the surface of this MNA via a covalent bond (for example, by subjecting the surface of the MNA to a surface treatment and binding a polymer having a functional group to the reaction points introduced by the surface treatment, or by using the reaction points introduced by the surface treatment as polymerization initiation points to polymerize a monomer having a functional group and extend the polymer chain, thereby binding the polymer).

[0045] 3 is a diagram for explaining an outline of a method for introducing poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) onto the surface of a cone-shaped microneedle (MN) composed of a porous body made of polyglycidyl methacrylate (PGMA) in this embodiment. (A) is a diagram showing a schematic diagram of a porous body made of unmodified polyglycidyl methacrylate (PGMA), (B) is a diagram showing a schematic diagram of the state after the porous body shown in (A) is subjected to a surface treatment with 3-(trimethoxysilyl)propyl methacrylate, and (C) is a diagram showing a schematic diagram of the state after 2-acrylamido-2-methylpropanesulfonic acid is polymerized using the acrylic structure introduced by the surface treatment shown in (B) as a polymerization initiation point.

[0046] The microneedle array of this embodiment is used to transport a substance having a relatively large size, and is preferably used to transport a large molecule having a molecular weight of 1 kDa to 100 kDa, a particle having a particle diameter of 2 nm to 200 nm, etc. Such a large molecule or particle may be a substance to be administered or collected for the purpose of treatment, diagnosis, or detection. The particle size may be the average major axis, and can be measured using a particle size distribution measuring device (for example, a laser scattering type measuring device manufactured by Beckman Coulter, Inc.). These may be used alone or in combination of two or more.

[0047] Examples of the large molecules having a molecular weight of 1 kDa to 100 kDa include antibodies, proteins, peptides, carbohydrates, lipids, DNA, siRNA, and mRNA. Examples of the particles having a particle diameter of 2 nm to 200 nm include gold particles, silica particles, biodegradable particles, and vesicles.

[0048] (patch) The patch of this embodiment includes the microneedle array of this embodiment described above, and a plurality of electrodes provided in contact with the microneedle array. Here, the number of electrodes is not particularly limited as long as it is plural, but may be two, three, four, five or more including the cathode and the anode, and is preferably two consisting of the cathode and the anode. The patch of this embodiment further includes an electronically conductive member for electrically connecting the electrodes (not shown). From the viewpoint of obtaining an electroosmotic flow, the patch of this embodiment preferably includes a DC power source electrically connected to the electrodes. On the other hand, the patch of this embodiment may not include a DC power source itself, but may include a device (biorecharger) that obtains a DC current by utilizing an oxidation-reduction reaction caused by a catalyst such as an enzyme together with the microneedle. In this case, the patch generates a DC current by an oxidation-reduction reaction between an enzyme substrate contained in a body fluid obtained through the microneedle inserted into the skin or an enzyme substrate previously provided as a fuel inside the patch and an enzyme supported on the electrode, or between oxygen in the air and a catalyst supported on the electrode. Furthermore, the patch of this embodiment may further include an ion-conductive member between the MNA and the electrode, in which case the MNA and the electrode are in indirect contact with each other. The ion-conductive member may be a drug tank containing a drug solution such as an enzyme substrate as fuel for the biocell. The shape of the electrode in the patch of this embodiment is not particularly limited. In addition, the material of the electrode includes carbon materials such as carbon nanotubes, ketjen black, glassy carbon, graphene, fullerene, carbon fiber, carbon fabric, and carbon aerogel; conductive polymers such as polyaniline, polyacetylene, polypyrrole, poly(p-phenylene vinylene), polythiophene, and poly(p-phenylene sulfide); semiconductors such as silicone, germanium, indium tin oxide (ITO), titanium oxide, copper oxide, and silver oxide; metals such as gold, platinum, titanium, aluminum, tungsten, copper, iron, and palladium, and the like. In particular, carbon materials such as carbon fabric and carbon nanotubes are preferred from the viewpoints of flexibility and electrochemical stability. In particular, when the patch includes a device (biocell) that obtains a direct current by utilizing an enzyme-induced redox reaction together with the microneedle, the electrodes preferably include at least one positive electrode (cathode) or negative electrode (anode) carrying an enzyme that catalyzes the redox reaction. In this case, the electrode material is preferably the above-mentioned carbon material from the viewpoint of immobilizing the enzyme on the electrode at a high density, and in particular, carbon fabric modified with carbon nanotubes is preferable. Examples of catalysts for the reduction reaction carried on the positive electrode (cathode) include bilirubin oxidase (BOD), laccase, Cu efflux oxidase (Cueo), ascorbic acid oxidase, iron phthalocyanine, etc., and in particular, bilirubin oxidase (BOD) and iron phthalocyanine are preferable from the viewpoint of increasing resistance to pH, chloride ions, etc. Examples of the enzymes that catalyze the oxidation reaction supported on the negative electrode (anode) include glucose oxidase, glucose dehydrogenase (GDH), fructose dehydrogenase (D-Fructose Dehydrogenase, FDH), alcohol oxidase, alcohol dehydrogenase, lactate oxidase, lactate dehydrogenase, etc., and glucose dehydrogenase (GDH) and fructose dehydrogenase (FDH) are particularly preferred because they can simplify the enzyme reaction system. Among these, the combinations of BOD and iron phthalocyanine with GDH and FDH are particularly preferred because they can exhibit high activity under the condition of pH 5, which is equivalent to the pH on the outer surface of the living tissue. The enzymes that catalyze the reduction reaction and the enzymes that catalyze the oxidation reaction may each be used alone or in combination of two or more.

[0049] When electricity is applied to the patch of this embodiment, a current (ion flow) flows through the microneedle array, and the mobility of ions increases due to the presence of a fixed electric field in the flow path of the MNA, generating an electroosmotic flow in the flow path of the MNA. When the device is attached to the epithelial layer of the skin or an organ (with the needle inserted) and an electric current is passed through it, it is possible to inject an aqueous solution of medicine or collect interstitial fluid depending on the direction of the electric current, which can have the effect of improving the efficiency of transdermal drug administration and body fluid sampling using medical, health, and beauty devices.

[0050] The patch of this embodiment can be configured as a body fluid sampling device or a drug administration device.

[0051] (Patch manufacturing method) The patch of the present embodiment may be manufactured by a method commonly used in the art without any particular limitation.

[0052] The above describes exemplary embodiments of the microneedle array and patch of the present invention with reference to the drawings. However, the above embodiments can be modified as appropriate, and the microneedle array and patch of the present invention are not limited to the above exemplary embodiments. EXAMPLES

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0054] A. Reagents and Materials Glycidyl methacrylate (GMA, manufactured by Wako Pure Chemical Industries, Ltd.) 3-(Trimethoxysilyl)propyl methacrylate (Wako Pure Chemical Industries, Ltd.) 2-Acrylamide-2-methylpropanesulfonic acid (AMPS, manufactured by Wako Pure Chemical Industries, Ltd.) 2-Oxoglutaric acid (Wako Pure Chemical Industries, Ltd.) Ammonium persulfate (APS, manufactured by Wako Pure Chemical Industries, Ltd.) N,N,N',N'-Tetramethylethylenediamine (TEMED, manufactured by Wako Pure Chemical Industries, Ltd.) Dextran-FITC (Sigma-Aldrich) Albumin-FITC (Sigma-Aldrich) Gold nanoparticles (Sigma-Aldrich) Fluorescent silica nanoparticles (Sigma-Aldrich)

[0055] B. Microneedle Array Fabrication B-1. Preparation of template The preparation of MNAs using a template was carried out according to prior art (WO 2018 / 062530, etc.). A Teflon (registered trademark) mold (female mold) was created with multiple microneedle shapes engraved using a cutting machine (manufactured by Modia Systems), and a two-step transfer was performed using polydimethylsiloxane (PDMS) to obtain a female mold made of PDMS. The dimensions of the mold (the dimensions of the microneedles) were set to the desired dimensions in each test example described below.

[0056] B-2. Preparation of unmodified microneedle arrays Unmodified microneedle arrays were prepared according to prior art (e.g., International Publication No. 2017 / 183737, etc.). The shape of the fabricated microneedle array is -Diameter of cylindrical support part Rp: 0.4mm Height of cylindrical support part Hp: 0.3mm - Diameter Rb of the base circle of the cone-shaped small MN: 125 μm - Height of small cone-shaped MN: H250μm Distance between MNs (pitch) P: 1000μm · Substrate thickness: 1000μm PEG (20 g) was dissolved in 100 mL of 2-methoxyethanol by heating to prepare 100 mL of solution A. The monomer GMA (10 mL) was mixed with the crosslinking agents TRIM (5.23 mL) and TEGDMA (15.7 mL) to prepare 30.93 mL of solution B. Solution A and solution B were mixed in a volume ratio of 7:6, and immediately after mixing, the initiator Irgacure 184 was added so that it was 1% by mass relative to the volume of monomer solution B, and the mixture was quickly poured into a PDMS mold and left under reduced pressure for 1 hour to remove any microbubbles remaining in the PDMS mold. After that, the mixture was irradiated with ultraviolet light for 3 hours to polymerize. After removing it from the mold, it was immersed in a mixed solution of methanol:water=1:1 at 80° C. to elute the porogen PEG, thereby obtaining MNA2 having a porous structure. The composition of the monomer units in the polymer material constituting the microneedle array was 100% by mass of GMA. The porosity of the microneedle array (calculated by the water immersion method) was about 40%.

[0057] B-3. ​​Preparation of polymer-modified microneedle array (Example 1) B-3-1.Surface modification 1 After drying the porous needle, it was immersed for 1 hour in a mixed solution (about 6 mL) of an ethanol solution containing a silanization reagent (3-(trimethoxysilyl)propyl methacrylate) (10% by volume), and then thoroughly washed by immersing in about 50 mL of water for 1 hour. B-3-2.Surface modification 2 The moisture of the microneedle array that had been subjected to surface modification 1 was wiped off, and the array was immersed in monomer solution A containing AMPS (0.1 mg), 2-oxoglutaric acid (0.75 mg), ammonium persulfate (100 μL), and water (10 mL) containing N,N,N',N'-tetramethylethylenediamine (10 μL). Surface modification 2 was then performed by polymerization at 80°C for 1 hour. Microneedle arrays with different amounts of surface modification in which the AMPS concentration was changed at this time were also fabricated.

[0058] B-4. Preparation of polymer-modified microneedle array (Example 2) The polymer-modified microneedle array of Example 2 was prepared in the same manner as in Example 1, except that in Surface Modification 1, a solution containing a silanizing reagent (3-(trimethoxysilyl)propyl methacrylate) (17% by volume) in ethanol solution (approximately 6 mL) was used. Detailed conditions are shown in Table 1.

[0059] B-5. Preparation of polymer-modified microneedle array (Example 3) The polymer-modified microneedle array of Example 3 was prepared in the same manner as in Example 1, except that in Surface Modification 1, a solution containing a silanizing reagent (3-(trimethoxysilyl)propyl methacrylate) (3% by volume) in ethanol solution (approximately 6 mL) was used. Detailed conditions are shown in Table 1.

[0060] B-6. Preparation of unmodified microneedle array (Comparative Example 1) The unmodified microneedle array prepared in "B-2. Preparation of unmodified microneedle array" was used as the MNA of Comparative Example 1. Detailed conditions are shown in Table 1.

[0061] B-7. Preparation of gel-filled microneedle array (Comparative Example 2) The unmodified microneedle array prepared in "B-2. Preparation of unmodified microneedle array" was immersed in a mixed aqueous solution of sulfonic acid group-containing monomer AMPS (1.0 mass%), crosslinking agent MB (1.5 mass%), reaction accelerator APS (0.2 mass%), and TEMED (0.2 mass%), and reacted for 3 hours at 50°C. This MNA was an MNA in which PAMPS had turned into a gel and filled the voids in the porous body.

[0062] C. Evaluation of Microneedle Arrays Thereafter, a flat plate-like member (thickness: 1 mm, diameter: 18 mm) was prepared in the same manner as in the preparation of the microneedle array described above, and used for evaluation of the microneedle array. FIG. 4 is a diagram showing an outline of a test in this embodiment in which a flat plate-like member (thickness: 1 mm, diameter: 18 mm) composed of a porous body made of polyglycidyl methacrylate (PGMA) surface-modified with poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) is used, and the dynamics of the fluorescent dye is observed when a current is applied with or without dripping a fluorescent dye-tagged large molecule or particle into one cell of a Franz cell, thereby confirming the generation of an electroosmotic flow and the movement of large molecules or particles due to the application of current in the flat plate-like member.

[0063] C-1. Evaluation of electroosmotic flow 1 (water) The generation of electroosmotic flow was demonstrated by monitoring the electrical conductivity (G), which reflects the water content of the hydrogel, by applying a current of 2 mA. FIG. 5 shows the results of the test shown in FIG. 4, in which the generation of electroosmotic flow due to the passage of current in a flat member was confirmed by observing the movement of water from one side of a closed Franz cell to the other side.

[0064] Since the material transport efficiency of electroosmotic flow is often correlated with the water transport efficiency, this test to measure the water transport efficiency was performed on the flat plate members of Examples 1 to 3 to determine the experimental conditions (current flow at 2 mA) for subsequent tests on material transport efficiency.

[0065] C-2. Evaluation of electroosmotic flow 2 (dextran) The transport of large molecules by electroosmotic flow in polymer-modified porous materials was evaluated by experiments using a Franz cell. Figure 6 shows the results of confirming the movement of dextran-FITC in a flat member by observing the dynamics of the fluorescent dye dextran-FITC (10 kDa) from one side to the other side of a sealed Franz cell in the test shown in Figure 4. In Figure 6, black circles represent the results of Example 1, white triangles represent the results of Comparative Example 1, and black triangles represent the results of Comparative Example 2. In Figure 6, bars represent standard deviation (N=3). One Franz cell was filled with 4 mL of a solution of dextran-FITC (10 kDa) dissolved in pH 6 McIlvain buffer at a concentration of 0.75 mg / mL, and the other Franz cell was filled with 4 mL of pH 6 McIlvain buffer without dextran-FITC. While applying a current of 2 mA, 100 μL of the solution on the right was sampled (every 30 minutes), and the concentration of the fluorescent molecule dextran-FITC (10 kDa) was measured using a plate reader. The results are plotted in FIG.

[0066] Regarding C-2. above, in Example 1, the movement of fluorescent molecules to the right side of the cell was accelerated by applying electricity, and this experiment confirmed that an electroosmotic flow occurred in the direction of positive ion movement, and dextran-FITC moved to the right side of the cell. In Comparative Example 1, the movement of dextran-FITC was not observed very much. This is considered to be because in the MNA of Comparative Example 1, the flow path was not modified with a polymer and the flow path had a poor fixed charge, so that an electroosmotic flow was not effectively generated. Also, in Comparative Example 2, the movement of dextran-FITC was not sufficient. This is considered to be because in the MNA of Comparative Example 2, PAMPS was filled in the voids of the porous body in a gel form, and the PAMPS present in a mesh form in the flow path inhibited the movement of dextran-FITC.

[0067] C-3. Evaluation of electroosmotic flow 3 (albumin) Fig. 7 shows the results of confirming the movement of albumin-FITC in a flat plate-like member by observing the dynamics of the fluorescent dye albumin-FITC (66 kDa) from one side to the other side of a sealed Franz cell in the test shown in Fig. 4. In Fig. 7, the black circles represent the results of Example 1. In Fig. 7, the bars represent the standard deviation (N=3). Similarly, 100 μL of the solution on the right was sampled (every 30 minutes) while a current of 2 mA was applied, and the concentration of the fluorescent molecule albumin-FITC (Sigma-Aldrich) was measured using a plate reader. The results are plotted in FIG.

[0068] Regarding C-3 above, in Example 1, it was confirmed that albumin-FITC migrated to the right side of the cell when an electric current was applied, and this experiment also confirmed that an electroosmotic flow occurred in the direction of positive ion movement, causing albumin-FITC to migrate to the right side of the cell.

[0069] The results of C-2. and C-3 above demonstrated that fluorescent molecules can be transported by electroosmotic flow using this technology.

[0070] C-4. Evaluation of electroosmotic flow 4 (fluorescent silica particles) The transport of particles due to electroosmotic flow generated in a polymer-surface-modified porous material was evaluated by an experiment using a Franz cell as shown in Figure 4. One Franz cell was filled with 1.5 mL of citrate buffer containing fluorescent silica particles, and the other Franz cell was filled with 1.5 mL of citrate buffer not containing fluorescent silica particles. -2 In mg / mL, for fluorescent silica particles 50 nm, 4.45 x 10 -2 In terms of mg / mL, in the case of 100 nm fluorescent silica particles, a solution was prepared at 50 mg / mL. While applying a current of 2 mA, 100 μL of the solution on the right was sampled (every 60 minutes) and the concentrations of fluorescent silica particles (15, 50, 100 nm) were measured using a plate reader. The results are plotted in Figures 8, 9, and 10, respectively. During application of current, the amount of solution in the left cell decreased with the movement of water, so 100 μL of citrate buffer was added every 60 min of sampling.

[0071] Fig. 8 is a diagram showing the results of confirming the movement of gold nanoparticles (15 nm) in a flat plate-like member by observing the dynamics of the absorbance of gold nanoparticles (15 nm) from one side to the other side of a closed Franz cell in the test shown in Fig. 4. In Fig. 8, the black circles represent the results of Example 1. Fig. 9 is a diagram showing the results of confirming the movement of gold nanoparticles (50 nm) in a flat plate-like member by observing the dynamics of the absorbance of gold nanoparticles (50 nm) from one side to the other side of a closed Franz cell in the test shown in Fig. 4. In Fig. 9, black circles represent the results of Example 1. Fig. 10 is a diagram showing the results of confirming the movement of fluorescent silica nanoparticles (100 nm) in a flat plate-like member by observing the dynamics of the fluorescent dye of the fluorescent silica nanoparticles (100 nm) from one side to the other side of a closed Franz cell in the test shown in Fig. 4. In Fig. 10, the black circles represent the results of Example 1. In Fig. 10, the bars represent the standard deviation (N=3).

[0072] In the cases of gold nanoparticles (15 nm), gold nanoparticles (50 nm), and fluorescent silica nanoparticles (100 nm), the movement of the fluorescent particles to the right side of the cell was confirmed by applying an electric current. Note that the amount of gold nanoparticles and fluorescent silica particles transported differs for each particle size because the initial gold nanoparticles and fluorescent silica particles are different in each solution.

[0073] The above results demonstrate that this technology can be used to transport relatively large particles.

[0074] [Table 1] [Industrial Applicability]

[0075] According to the present invention, it is possible to provide a microneedle and a patch that are capable of generating a highly efficient electroosmotic flow and transporting molecules and particles of a relatively large size.

Claims

1. The flow channel is covalently modified with a polymer having a fixed charge, The porous body includes a void portion of the porous body that forms the flow path. A microneedle array.

2. The amount of the fixed charge in the porous body per unit surface area of ​​the porous body is 1×10 on average －６ C / cm ２ ~1 x 10 －１ C / cm ２ The microneedle array according to claim 1 ,

3. The microneedle array according to claim 1 or 2, wherein the polymer is modified on the surface of the porous body via a silane coupling agent.

4. The microneedle array according to any one of claims 1 to 3, wherein the polymer comprises a monomer unit containing a functional group having the fixed charge.

5. The microneedle array according to claim 4 , wherein the functional group includes at least one selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphate group, and an amino group.

6. The microneedle array according to claim 4, wherein the amount of the functional groups in the porous body per unit surface area of ​​the porous body is 1×10 −12 mol / cm 2 or more on average.

7. The microneedle array according to any one of claims 1 to 6, wherein the polymer has a degree of polymerization of 5 to 50,000.

8. The microneedle array according to any one of claims 1 to 7, wherein the polymer has a weight average molecular weight (Mw) of 2,000 to 5,000,000.

9. The microneedle array according to any one of claims 1 to 8, wherein the porous body contains a material other than a hydrogel material.

10. The microneedle array according to any one of claims 1 to 9, wherein a plurality of microneedles are provided upright on a substrate.

11. The microneedle array according to any one of claims 1 to 10, wherein the microneedles comprise a pillar with small microneedles.

12. The microneedle array according to claim 11 , comprising one or more small microneedles and a plurality of pillars.

13. The microneedle array according to any one of claims 1 to 12, which is used for transporting at least one selected from the group consisting of large molecules with a molecular weight of 1 kDa to 100 kDa and particles with a particle diameter of 2 nm to 200 nm.

14. A patch comprising the microneedle array according to any one of claims 1 to 13 and a plurality of electrodes provided in contact with the microneedle array.

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