WO2020179850A1 - Microneedle array and patch - Google Patents

Abstract

The purpose of the present invention is to provide a microneedle array and a patch that are capable of suitably generating a less-invasive electroosmotic flow. This microneedle array is characterized by having a fixed charge in a flow channel. This patch is characterized by comprising said microneedle array and a plurality of electrodes that are disposed so as to be in contact with the microneedle array.

Description

Microneedle array, patch

The present invention relates to a microneedle array and a patch.

Flow control through the epithelial layer of skin and organs is widely important in the fields of medicine and health and beauty.

The microneedle made of hydrogel is applied to the skin in a dry and hard state (the needle is inserted), and thereafter, absorbs subcutaneous tissue fluid or the like and swells to exert liquid permeability (see Non-Patent Document 1). ). Recently, a microneedle array made of a porous material has been developed (see Patent Document 1 and Non-Patent Document 2) and used for measuring swelling by measuring resistance of the skin epithelium (epidermis) (Patent Document 2, Non-Patent Document 2). 3).

International Publication No. 2018/062530 International Publication No. 2018/183737

R. F. Donnelly, et al. , Journal of Pharmaceutical Science, 2014, 103, 1478-1486. L. Liu et al. , "Poros Polymer Microneedles for Rapid Fluid Transport by Massive Parallel Microchannels", RSC Advances, 6 (2016) 48630. K. Nagamine et al. , "An Array of Poros Microneedles for Transdermal Monitoring of Intercellular Swelling", Biomedical Microdexes, 19 (2017) 68.

Injection of aqueous drug solution and collection of interstitial fluid are generally performed by a mechanical pump such as a syringe, but electrical transmission is used to improve controllability and miniaturization / automation. Liquid technology is advantageous.
The flow generated electrically is called "electroosmotic flow", which occurs when there is a large difference in ion mobility due to the presence of fixed charges, etc., and has been used for capillary electrophoresis and liquid transfer in microchannels. It was In this case, when the inner wall of the narrow flow path is glass, the flow of hydrated water becomes apparent with the movement of a cation whose mobility is relatively large with respect to the negative charge of the silanol group or the like. It becomes the mechanism of electroosmotic flow generation.

However, the prior art microneedles still have room for improvement in the use of the electroosmotic flow described above.
Therefore, an object of the present invention is to provide a microneedle array and a patch capable of suitably generating an electroosmotic flow with minimal invasiveness.

The gist of the present invention is as follows.
The microneedle array of the present invention is characterized by having a fixed charge in the flow path.
In one aspect, the microneedle array of the present invention may be a hydrogel including a hydrogel material.
In the microneedle array of the present invention, the amount of the fixed charge in the hydrogel per unit mass of the hydrogel is preferably 1 C / g to 200 C / g on average.
The microneedle array of the present invention is a polymer material in which the hydrogel material contains the monomer unit having the fixed charge, and the content of the monomer unit having the fixed charge in the hydrogel material is 0. It is preferably 1% by mass or more.
In the microneedle array of the present invention, it is preferable that the fixed charge monomer unit contains at least one selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphoric acid group, and an amino group.
In another aspect, the microneedle array of the present invention may be a porous body containing a material other than a hydrogel material.
In the microneedle array of the present invention, the amount of the fixed charge per unit surface area of the porous body in the porous body is 1 × ^10-7 C / cm ² to 5 × 10 ^-2 C / cm ² on average. preferable.
In the microneedle array of the present invention, it is preferable that the functional group having the fixed charge is introduced on the surface of the porous body.
The microneedle array of the present invention preferably contains at least one functional group selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphoric acid group and an amino group.
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 preferably 1 × ^10-13 mol / cm ² or more.
In the microneedle array of the present invention, the surface of the porous body is preferably subjected to oxygen plasma treatment.
In the microneedle array of the present invention, it is preferable that the voids of the porous body are filled with a filling material.
In the microneedle array of the present invention, the filling material is preferably a hydrogel containing a hydrogel material.
In the microneedle array of the present invention, it is preferable that the amount of the fixed charge in the hydrogel per unit mass of the hydrogel is 1 C / g to 5000 C / g on average.
Here, in the microneedle array of the present invention, the hydrogel material is collagen, glucomannan, carboxymethyl cellulose, sodium carboxymethyl cellulose, polyacrylic acid, sodium polyacrylate, polymethacrylic acid, sodium polymethacrylate, poly2-. It preferably contains at least one selected from the group consisting of hydroxyethylmethacrylic acid and poly-2-acrylamido-2-methylpropanesulfonic acid.
The microneedle array of the present invention preferably contains a material other than the hydrogel material at least one selected from the group consisting of resins, oxides and metals.
In the microneedle array of the present invention, it is preferable that a plurality of microneedles are erected on the base material.
In the microneedle array of the present invention, it is preferable that the microneedles include a columnar body having small microneedles.
Here, the microneedle array of the present invention preferably includes a plurality of the small microneedles and includes a plurality of the columnar bodies.
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.

According to the present invention, it is possible to provide a microneedle array or patch capable of suitably generating an electroosmotic flow.

FIG. 1 is a diagram showing an example of microneedles used in the microneedle array of the present embodiment. (A) is a figure which shows the microneedle comprised by the hydrogel containing the hydrogel material which has a fixed charge. (B) is a figure showing a microneedle composed of a porous body containing a material other than a hydrogel material having a fixed charge. (C) is a diagram showing a microneedle composed of a filling material having a fixed charge filled in a void of a porous body containing a material other than a hydrogel material having no fixed charge. Examples of the microneedles shown in (A) to (C) are all conical shapes, and (A) to (C) are cross-sectional views when cut by a surface along the axis of the cone of MN. In (A) to (C), the case where the electric charges are all anions is shown. FIG. 2 is a diagram showing an example of the microneedle array of the present embodiment. (A) is a diagram showing an example of MNA in a perspective view, and (B) and (C) are photographs showing a part of the microneedle of MNA shown in (A) in an enlarged manner. FIG. 3 is a diagram showing another example of the microneedle array of the present embodiment. (A) is a figure which shows the MNA of another example by a perspective view, (B) expands a part of MNA's microneedle shown in (A) (the part shown by a square frame in (A)). Is a photograph shown. (B)(i) is a photograph of a plurality of MNs in a perspective direction, (B)(ii) is a photograph of a single MN in a perspective direction, and (B)(iii) is a photograph of the surface of the MN. It is a photograph of the perspective direction which expands and shows a part. FIG. 4 is a diagram illustrating an outline of a method of introducing a functional group having a fixed charge on the surface of a microneedle composed of a porous body containing a material other than a hydrogel material having no fixed charge in the present embodiment. (A) is a photograph of an MNA in which a functional group is not introduced in a perspective direction, (B) is a photograph of an MNA of MN in an oblique direction shown in (A), and (C) is a photograph after introduction of a functional group. It is a figure explaining the state of the surface of MNA, and (D) is the figure which shows the reaction example for the introduction of a functional group especially when polyglycidyl methacrylate is used as a porous body. FIG. 5 is a diagram illustrating an outline of an example of a method of filling the voids of the porous body containing a material other than the hydrogel material with the filling material in the present embodiment. (A) is a diagram showing a state when MNA having no functional group introduced is impregnated with a monomer solution of a polymer material forming an anionic or cationic hydrogel material, and (B) is a diagram showing the state of MNA. It is a figure which shows the outline|summary of MNA with which the hydrogel material was filled as a result of having the monomer solution with which the inside of the void was impregnated turned into a hydrogel material by the polymerization of the monomer. FIG. 6 is a diagram showing an example of the patch of the present embodiment. (A) is a perspective view showing an example patch, and (B) is an enlarged cross-sectional view showing a part of the patch when the patch shown in (A) is applied to a means of drug administration. Yes, (C) is an enlarged sectional view showing a part of the patch when the patch shown in (A) is applied to a means for collecting body fluid, and (D) shows an example patch on the arm of a subject. It is a photograph showing the state when pasted. FIG. 7 shows the conductivity G (mS) of a flat plate-shaped member made of a hydrogel containing a hydrogel material having a fixed charge (hydrogel material: HEMA 80% by mass, methacrylic acid 10% by mass) in the present embodiment. It is a figure which shows the outline and the result of the test which confirms the generation of the electroosmotic flow by energization in a flat plate-shaped member by monitoring. (A) is a figure explaining the outline of a test, (B) is a photograph which shows the outline of a test, (C) is a figure which shows the result of a test. FIG. 8 shows the case where the flow path is not filled with the filling material by using a flat plate member made of a material (material: GMA 100% by mass) other than the hydrogel material having no functional group introduced in the present embodiment. By observing the dynamics of the fluorescent dye when the fluorescent dye dextran-FITC (10 kDa) was dropped in the well in the center of the monolith, when the filling material (material: AMPS 100% by mass) was filled in the channel, It is a figure which shows the outline|summary and the result of the test which confirms generation|occurrence|production of the electroosmotic flow by movement of electricity, and movement of a high molecular weight body. (A) is a figure explaining the outline of a test, and (B) is a figure showing the result of a test. In (B), (a) is a porous material with no functional group introduced/filling material unfilled, and (b) is a porous material with no functional group introduced/filling material unfilled, with current applied. In the case of, (c) is a porous material with no functional group introduced and filled with a filling material, and without electricity, (d) is a porous material with no functional group introduced and filled with a filling material, and with electricity. , Is shown. In the present embodiment, FIG. 9 uses a flat plate-shaped member configured by filling a void in a porous body (material: GMA 100% by mass) containing a material other than a hydrogel material with a filling material (material: AMPS 100% by mass). Then, by observing the dynamics of the fluorescent dye when the fluorescent dye dextran-FITC (10 kDa) was dropped into one of the Franz cells, the generation of electroosmotic flow and the movement of the high molecular weight polymer due to the current flow in the flat plate member were confirmed. It is a figure which shows the outline and the result of the test to confirm. (A) is a figure explaining the outline of a test, and (B) is a figure showing the result of a test. In the present embodiment, FIG. 10 uses a flat plate-shaped member configured by filling a void in a porous body (material: GMA 100% by mass) containing a material other than a hydrogel material with a filling material (material: AMPS 100% by mass). FIG. 3 is a diagram showing an outline and results of a test for confirming the generation of electroosmotic flow due to energization in a flat plate-shaped member by observing the movement of water from one of the closed Franz cells to the other. (A) is a diagram for explaining the outline of the test, and (B) is a diagram showing the result of the test. 11 (A) and 11 (a) are electron micrographs showing a part of a microneedle filled with a gel of AMPS 0.05M in an enlarged manner, and FIGS. 11 (A) and 11 (b) are filled with a gel of AMPS 0.5 M. It is an electron micrograph which shows a part of the microneedle enlarged. FIG. 11B shows the same as the evaluation in “C-4. Evaluation of electroosmotic flow 4” using a flat plate member formed by filling AMPS gels having different AMPS concentrations of 0 to 1.5M. It is a figure which shows the result at the time of performing the test which confirmed the generation of the electroosmotic flow. FIG. 11C shows the same as the evaluation in “C-3. Evaluation of electroosmotic flow 3” using a flat plate member formed by filling AMPS gels having different AMPS concentrations of 0 to 1.0 M. It is a figure which shows the result at the time of performing the test which confirms generation|occurrence|production of an electroosmotic flow and movement of a high molecular weight substance by observing the dynamics of the fluorescent dye when fluorescent dye dextran-FITC (10 kDa) is dripped. FIG. 12 (A) shows a microneedle (a) filled with an AMPS gel prepared by a monomer AMPS having a concentration of 1.5 M and a cross-linking agent MB (0.1 M), and a specimen of pig skin (a). It is a figure which shows the result when the moving speed of water was evaluated from the change of the height of the water surface using a Franz cell for each of the needle-inserted one (b) and the pig skin specimen only (c). .. 12 (B) and 12 (C) show microneedles in which a glucose-filled pig skin specimen is filled with an AMPS gel prepared with a 1.5 M concentration of monomeric AMPS and a cross-linking agent MB (0.1 M). For each of the punctured specimen (a) and the glucose-filled porcine skin specimen (b), a ² mA / cm ² current was passed through the Franz cell, and a glucose assay kit was used to remove the specimen from the inside of the skin to the outside. It is a figure which shows the result when the movement amount of glucose and the movement rate of glucose were evaluated. (B) shows the evaluation result of the amount of glucose transfer (black circles and solid lines indicate (a), white circles and broken lines indicate (b)), and (C) indicates glucose. The evaluation result of the moving speed is shown. FIG. 13 (A) shows a microneedle filled with AMPS gel prepared with a monomer AMPS having a concentration of 0.05 M and a cross-linking agent MB (0.1 M), and a microneedle not filled with AMPS gel, respectively. Was inserted into a porcine skin specimen, and they were separately sandwiched between Franz cells and a current of 0.5 mA / cm ² was passed to evaluate the amount of 10 kDa FITC-Dextran moving from the outside to the inside of the porcine skin. It is a figure which shows the result. 13 (B) and 13 (C) show a porcine skin specimen in which microneedles filled with an AMPS gel prepared with a monomer AMPS having a concentration of 0.05 M and a cross-linking agent MB (0.1 M) were inserted. When a 10 kDa FITC-Dextran solution was brought into contact with the skin and a current of 0.5 mA / cm ² was applied to each of the products without the microneedles, the FITC-Dextran inside the skin. It is a photograph which shows the state when the penetration was evaluated. FIG. 14 (A) shows an outline of the prepared biobattery and glucose-filled pig skin filled with an AMPS gel prepared with a monomer AMPS at a concentration of 0.05 M and a cross-linking agent MB (0.1 M). It is a figure which shows a mode that an electroosmotic flow generate|occur|produces when a biobattery produces electric power, when a microneedle is inserted. FIG. 14(B) is a diagram showing the time course of the current density that has flowed while the bio battery is generating power. FIG. 14C is a photograph showing a state in which a section of pig skin collected 1 hour after power generation was observed with a fluorescence microscope. In FIG. 14 (D), a porous microneedle filled with a gel containing a monomer AMPS (1.5M) and a cross-linking agent MB (0.1M) was inserted into a glucose-filled pig skin specimen, and the bio was inserted. It is a figure which shows the result of having evaluated the amount of glucose extracted on the upper surface of a needle by a glucose assay kit when it was driven by a battery and when it was not driven.

Hereinafter, embodiments of the microneedle array and patch of the present invention will be described in detail with reference to the drawings.
In the description below, the microneedle array is also referred to as “MNA” and the microneedle is also referred to as “MN”.

(Microneedle array)
FIG. 1 is a diagram showing an example of microneedles used in the microneedle array of the present embodiment. (A) is a figure which shows the microneedle comprised by the hydrogel containing the hydrogel material which has a fixed charge. (B) is a diagram showing a microneedle composed of a porous body containing a material other than a hydrogel material having a fixed charge. (C) is a diagram showing a microneedle composed of a filling material having a fixed charge filled in a void of a porous body containing a material other than a hydrogel material having no fixed charge. Examples of the microneedles shown in (A) to (C) are all conical shapes, and (A) to (C) are cross-sectional views when cut by a surface along the axis of the cone of MN. In each of (A) to (C), the charge is an anion.

The microneedle array 1 of one example of the present invention (hereinafter, also referred to as “microneedle array 1”) has a fixed charge in the flow channel (see FIGS. 1A to 1C).
The “fixed charge” refers to a charge that is fixed and exists in the region of the flow channel, such as a hydrogel material forming the flow channel, a material other than the hydrogel material, and another material included in the flow channel. It shall not include the electric charge contained in the substances flowing in and out of the flow path.

In the microneedle array 1, the fixed charge existing on the inner wall of the flow path or the like promotes the movement of the ion having the property (eg, anionic property) opposite to the property of the charge (eg, anionic property), and the migration of the ion. Accordingly, the flow of hydration water (also referred to as “electroosmotic flow”) can be realized. As described above, according to the MNA 1 of the present embodiment, when the MNA is inserted into the skin or an organ and used, an electroosmotic flow can be appropriately generated with minimal invasiveness.

In the present embodiment, in one aspect, the microneedle array 1 of the present invention may be a hydrogel 3 containing a hydrogel material, and in another aspect, the microneedle array of the present invention is made of a material other than the hydrogel material. It may be a porous body 4 including.

In one aspect of this embodiment, as shown in FIG. 1A, the microneedle array 1 may be a hydrogel 3 containing a hydrogel material. In such a case, a flow path is formed in the portion of the hydrogel 3 excluding the hydrogel material itself.

In this embodiment, the hydrogel 3 may include a hydrogel material, an aqueous liquid, and other additives.
The hydrogel material is a material that forms the hydrogel 3 by dispersing it in water (dispersion medium).

In the microneedle array 1, the amount of the fixed charge in the hydrogel 3 per unit mass of the hydrogel is preferably 1 C / g to 200 C / g on average.
The average amount of the fixed charges per unit mass is more preferably 10 C/g to 200 C/g, further preferably 30 C/g to 200 C/g.
The amount of the fixed charge per unit mass can be calculated by a method usually used in the art.
The individual fixed charges may be a mixture of anions and cations, but the amount of the fixed charges per unit mass is the total amount of the fixed charges, and refers to the absolute value of the anion or cation charges. And

Examples of the hydrogel material of the present embodiment include agar, gelatin, agarose, xanthan gum, gellan gum, sclerotiu gum, arabiya gum, tragant gum, karaya gum, cellulose gum, tamarind gum, guar gum, locust bean gum, glucomannan, chitosan, carrageenan, and quince. Seeds, galactan, mannan, starch, dextrin, curdran, casein, pectin, collagen, fibrin, peptide, chondroitin sulfates such as sodium chondroitin sulfate, hyaluronates such as hyaluronic acid (mucopolysaccharide) and sodium hyaluronate, alginic acid. , Alginates such as sodium alginate and calcium alginate, and natural polymers such as derivatives thereof; cellulose derivatives such as methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose and salts thereof; poly Poly (meth) acrylic acids such as acrylic acid, polymethacrylic acid, acrylic acid / alkyl methacrylate copolymer and salts thereof; polyvinyl alcohol, polyhydroxyethyl methacrylate, polyacrylamide, poly (N-isopropylacrylamide), polyvinylpyrrolidone, polystyrene Sulfonic acid, polyethylene glycol, carboxyvinyl polymer, alkyl-modified carboxyvinyl polymer, maleic anhydride copolymer, polyalkylene oxide-based resin, crosslinked product of poly (methylvinyl ether-alt-maleic acid anhydride) and polyethylene glycol, polyethylene glycol crosslinked Synthetic polymers such as body, N-vinylacetamide crosslinked product, acrylamide crosslinked product, starch / acrylate graft copolymer crosslinked product; silicone; interpenetrating network hydrogel and semi-interpenetrating network hydrogel; mixture of two or more of these. And so on.
These may be used alone or in combination of two or more.

Among these, the materials constituting hydrogel 3 include collagen, glucomannan, carboxymethyl cellulose, sodium carboxymethyl cellulose, polyacrylic acid, sodium polyacrylate, polymethacrylic acid, and poly from the viewpoint of load bearing capacity and biocompatibility. Sodium methacrylate, poly2-hydroxyethylmethacrylic acid, and poly2-acrylamide-2-methylpropanesulfonic acid are preferred.
These may be used alone or in combination of two or more.

Examples of the aqueous liquid used for the hydrogel 3 in the present embodiment include water (for example, ultrapure water), physiological saline, and a buffered aqueous solution.
The physiological saline solution preferably has a salt concentration of 0.85 to 0.95% by mass.
The buffered aqueous solution may be water to which a commercially available buffering agent is added or physiological saline. Examples of the buffer include a phosphate buffer, a Tris buffer, a HEPES buffer, a McIlvaine buffer, and the like.

In the present embodiment, the hydrogel material is preferably a polymer material containing a monomer unit having a fixed charge.
Here, it is preferable that the content of the monomer unit having a fixed charge in the polymer material is 0.1% by mass or more from the viewpoint of obtaining a good electroosmotic flow. The content is more preferably 1% by mass or more, further preferably 10% by mass or more.
Further, the content may be 100% by mass. Further, the upper limit of the content is not particularly limited as long as a good electroosmotic flow can be obtained, and may be 90% by mass or less, 60% by mass or less, and 30% by mass or less.

The monomer unit having a fixed charge used in this embodiment is a monomer unit having at least one functional group selected from a sulfonic acid group, a carboxyl group, a phosphoric acid group, and an amino group. preferable.
Among these, a sulfonic acid group having an ionization degree near neutral is more preferable.
These may be used alone or in combination of two or more.

In another aspect of the present embodiment, as shown in FIGS. 1B and 1C, the microneedle array 1 may be a porous body 4 containing a material other than the hydrogel material. In such a case, a flow path is formed in the void 6 of the porous body 4.

In the microneedle array 1 of the example of the present invention, from the viewpoint of obtaining a good electroosmotic flow, the average amount of fixed charges per surface area of the porous body in the porous body is 1 × 10 ^-7 C / cm ² to 5 ×. It is preferably ^10-2 C / cm ² .
The amount of the fixed charge per unit surface area can be measured by a zeta potential measuring device or the like.
The average amount per unit surface area of the porous body is more preferably 1 × 10 ^-6 C / cm ² to 5 × 10 ^-2 C / cm ² , and even more preferably 1 × 10 ^-5 C / cm ² to. It is 5 × 10 ^-2 C / cm ² .
The individual fixed charges may be a mixture of anions and cations, but the amount of the fixed charges per unit surface area is the total fixed charges and refers to the absolute value of the charges of the anions or cations. And

The porous body 4 in this embodiment has a void 6 inside. Such voids may be closed cells or open cells, but open cells are preferable from the viewpoint of obtaining a good electroosmotic flow.

The porosity of the porous body 4 of the present embodiment is preferably 10 to 80%, more preferably 20 to 60%.
The porosity can be measured by a method usually used in this technical field, such as a submersion method or a pycnometer.

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

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

When a material other than the hydrogel material (resin, oxide, metal, etc.) is used in the present embodiment, it is preferable that a functional group having a fixed charge is introduced on the surface of the porous body.

Here, the functional group is preferably at least one selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphoric acid group, and an amino group.

A good electroosmotic flow is obtained when the amount of the functional group having a fixed charge introduced into the surface of the porous body 4 per unit surface area of the porous body 4 is 1 × ^10-13 mol / cm ² or more. From the viewpoint of obtaining, it is preferable.
Such a content is more preferably 1 × ^10-12 mol / cm ² or more, and further preferably 1 × ^10-11 mol / cm ² or more. The content is preferably 5 × ^10-8 mol / cm ² or less.

Further, in the present embodiment, it is preferable that the surface of the porous body 4 is subjected to oxygen plasma treatment. Oxygen plasma treatment makes it possible to introduce a negative charge on the surface, and it becomes possible to obtain a better electroosmotic flow in the porous body 4.

Further, in the present embodiment, the material itself other than the hydrogel material forming the porous body may have a fixed charge.

Further, in the microneedle array 1 of another aspect, the filling material may be filled in the void 6 of the porous body 4 (see FIG. 1C).
With this configuration, it is possible to stably generate the electroosmotic flow.
The filling material may be filled in all or part of the void 6, preferably 20% by volume or more of the region of the void 6 (100% by volume), and more preferably 50% by volume or more. Has been done.

In this embodiment, when the void 6 of the porous body 4 is filled with the filling material (see FIG. 1C), the filling material may have a fixed charge. At this time, the material other than the hydrogel material forming the porous body 4 may or may not have a fixed charge. Further, the fixed charge of the filling material and the fixed charge of the material other than the hydrogel material may both be cations or anions, or may have different properties from each other.

As the filling material, hydrogel 3 containing a hydrogel material is preferable.
The hydrogel material of the filling material may be the same as the hydrogel material described above for the hydrogel 3 constituting the main body of the MNA.

The average amount of fixed charge in hydrogel 3 of the filling material per unit mass of hydrogel is preferably 1 C / g to 5000 C / g.
The average amount of the fixed charges per unit mass is more preferably 20 C/g to 5000 C/g, further preferably 30 C/g to 5000 C/g.

In the form in which the void 6 of the porous body 4 is filled with the filling material, preferably, polyglycidyl methacrylate resin is used as a material other than the hydrogel material forming the porous body, and poly 2-acrylamide-2-methyl is used as the filling material. Propane sulfonic acid, N, N'-methylenebisacrylamide (MB) as a cross-linking agent, N, N, N', N'-tetramethylethylenediamine (TEMED), ammonium persulfate (APS) as a reaction accelerator are used. You may
In such a case, in the polymerization reaction for preparing the filling material, the concentration of MB in the polymerization solution is preferably 0.01 M to 0.3 M, more preferably 0.02 M to 0.2 M, and particularly preferably 0.1 M. The concentration of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) in the polymerization solution is preferably 0.01 M to 2.5 M, more preferably 0.03 M to 2.0 M, and 0.05 M to 1.5 M. Is particularly preferable. In particular, for the migration of water, this concentration is more preferably 0.5M to 2M, particularly preferably 1M to 1.5M. In particular, for the migration of high molecular weight substances, this concentration is more preferably 0.01 M to 0.5 M, particularly preferably 0.03 M to 0.3 M.

The suitable shape of MN in MNA will be described below.

In the microneedle array 1 of this embodiment, a plurality of microneedles 2 may be erected on the base material.

The three-dimensional shape of the microneedle 2 is not particularly limited as long as it can penetrate the skin, and includes a truncated cone shape, a cone shape, a quadrangular pyramid shape, a quadrangular pyramid shape, and other shapes. ..

In the microneedle array 1 of the present embodiment, it is preferable that the microneedle 2 includes a plurality of columnar bodies including 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 conical shape is preferable. The three-dimensional shape of the columnar body is not particularly limited, but a columnar shape is preferable.
FIG. 2 is a diagram showing an example of the microneedle array of the present embodiment. (A) is a diagram showing an example of MNA in a perspective view, and (B) and (C) are photographs showing a part of the microneedle of MNA shown in (A) in an enlarged manner.

Suitable dimensions for an example MNA shown in FIG. 2 are as follows.
The diameter Rp of the columnar strut portion may be 0.2-1 mm and may be 0.5 mm as described in the examples.
The height Hp of the columnar post may be 0.2-1 mm, and may be 0.3 mm as described in the examples.
The diameter Rb of the bottom circle in the conical small MN may be 20 to 500 μm, and is preferably 100 to 400 μm from the viewpoint of ease of preparation, ease of insertion into the skin, and mechanical strength. , May be 500 μm as described in the Examples.
The height H of the small cone-shaped MN may be 20 to 1000 μm, and when applied to the skin, it penetrates the keratin and secures a sufficient contact area with the epidermis to prevent invasion of the dermis. It is preferably 30-600 μm and may be 300 μm as described in the examples.
When the microneedles 2 are arranged equidistantly in the vertical and horizontal directions, the distance (pitch) P between the MNs (see FIG. 2 (A)) may be 500 to 3000 μm, preferably 1000 to 2000 μm. It may be 1000 μm as described in the example.
The thickness t of the base material (see FIG. 2A) may be 10 to 2000 μm, preferably 300 to 1000 μm, and may be 1000 μm as described in Examples.

In the microneedle array 1 of the present embodiment, it is preferable that the microneedle 2 includes a plurality of columnar bodies including a plurality of small microneedles (see FIG. 3).
FIG. 3 is a diagram showing another example of the microneedle array of this embodiment. (A) is a view showing another example of MNA in a perspective view, and (B) is an enlargement of a part of the MNA microneedle shown in (A) (the part shown by a square frame in (A)). It is a photograph shown by. (B) and (i) are photographs of a plurality of MNs in the perspective direction, (B) and (ii) are photographs of one MN in the perspective direction, and (B) and (ii) are photographs of the surface of the MN. It is a photograph in the perspective direction which shows a part enlarged.

Suitable dimensions in another example of MNA shown in FIG. 3 are as follows.
The diameter Rp' of the columnar pillar portion may be 0.2-1 mm and may be 0.5 mm as described in the examples.
The height Hp' of the columnar strut portion may be 0.2-1 mm and may be 0.3 mm as described in the examples.
The diameter Rb′ of the circle on the bottom surface of the conical small MN may be 20 to 500 μm, and may be 100 μm as described in the examples.
The height H'of the small cone-shaped MN may be 50 μm to 1000 μm, and may be 0.1 mm as described in the examples.
When the microneedles 2 are arranged equidistantly in the vertical and horizontal directions, the distance (pitch) Q (see FIG. 3A) between the MNs is preferably 500 to 3000 μm, more preferably 1000 to 2000 μm. is there.
The number of the small MNs of the conical body arranged on the column of the columnar body may be 1 to 20, and preferably 3 to 9.
When the small MNs are arranged equidistantly in the vertical and horizontal directions on the circular top surface of the support column portion, the distance (pitch) between the MNs (not shown) is preferably 10 to 500 μm, more preferably 100. It is ~ 200 μm.
In particular, when the number of small MNs is 7, it is preferable to dispose one at the center of the circular top surface of the support column and six around the center. At this time, it is preferable that six pieces are arranged at equal intervals on a circumference having a radius of one center and a distance d.
The distance d may be 50 μm to 500 μm, preferably 100 μm to 300 μm, and may be 200 μm as described in the examples.
The thickness t of the base material (see FIG. 3(A)) may be 10 to 2000 μm, and preferably 300 to 1000 μm.

(Method for manufacturing microneedle array)
The microneedle array of the present embodiment is not particularly limited, and may be manufactured by a method commonly used in this technical field.

When the MNA is a hydrogel containing a hydrogel material, for example, an MNA having a flow path may be produced by adding water or a buffer solution to the anionic or cationic hydrogel material.

When the MNA is a porous body containing a material other than the hydrogel material, for example, a water-soluble pologene (for example, PEG) is added to a resin monomer (for example, glycidyl methacrylate) and then a polymerization reaction is carried out. A resin containing a pologene is obtained, and then the pologene contained in the resin is dissolved in water to prepare an MNA having traces of the pologene as a flow path, and anionic or cationic functionalities are formed on the surface of this MNA. MNA may be produced by introducing a small molecule having a group via a chemical bond (for example, introducing the small molecule by opening the epoxy group of the glycidyl methacrylate monomer unit of the resin).
FIG. 4 is a diagram illustrating an outline of a method of introducing a functional group having a fixed charge on the surface of a microneedle composed of a porous body containing a material other than a hydrogel material having no fixed charge in the present embodiment. (A) is a photograph of the MNA in which the functional group has not been introduced in the perspective direction, (B) is a photograph of the MNA shown in (A) in the perspective direction, and (C) is a photograph of the MNA after the introduction of the functional group. It is a figure explaining the appearance of the surface of MNA, and (D) is a figure showing a reaction example for introduction of a functional group especially when polyglycidyl methacrylate is used as a porous body.

Further, when the MNA is a porous body containing a material other than the hydrogel material, for example, other anionic or cationic material (eg, 2-acrylamide-2-methylpropanesulfonic acid) in the flow path of the porous MNA. May be filled with a hydrogel material) to produce MNA having a fixed charge in the channel.
The method of filling the flow path with other anionic or cationic material is not particularly limited, and a conventional method in the art may be used.
FIG. 5 is a diagram illustrating an outline of an example of a method of filling voids of a porous body containing a material other than the hydrogel material with a filling material in the present embodiment. (A) is a diagram showing a state when MNA having no functional group introduced is impregnated with a monomer solution of a polymer material forming an anionic or cationic hydrogel material, and (B) is a diagram showing the state of MNA. It is a figure which shows the outline|summary of MNA with which the hydrogel material was filled as a result of having the monomer solution with which the inside of the void was impregnated turned into a hydrogel material by the polymerization of the monomer.

In the present embodiment, the porous body may be subjected to a surface treatment such as oxygen plasma treatment to introduce a fixed charge on the surface of the porous body.

(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 including the cathode and the anode. ..
In addition, the patch of the present embodiment further includes an electron conductive member for electrically connecting the plurality of electrodes (see FIG. 6). Further, the patch of the present embodiment preferably includes a DC power supply in a form of being electrically connected to a plurality of electrodes from the viewpoint of preferably obtaining an electroosmotic flow. On the other hand, the patch of the present embodiment does not include a direct current power source by itself, and may include a device (biocell) that obtains a direct current by utilizing an oxidation-reduction reaction with a catalyst such as an enzyme together with a microneedle. In the case, the patch includes an enzyme substrate contained in a body fluid obtained through a microneedle inserted into the skin, an enzyme substrate previously provided as fuel inside the patch, an enzyme carried on an electrode, oxygen in the air, and the like. A direct current is generated by a redox reaction with a catalyst supported on the electrode.
Further, the patch of the present embodiment may further include an ion conductive member between the MNA and the electrode, and in this case, the MNA and the electrode are in an indirect contact state. As the ion conductive member, a drug tank containing a drug solution such as an enzyme substrate as a fuel for the biocell may be used.
The shape of the electrodes in the patch of this embodiment is not particularly limited. Further, as a material of the electrode, carbon materials such as carbon nanotube, Ketjen black, glassy carbon, graphene, fullerene, carbon fiber, carbon fabric, carbon aerogel; polyaniline, polyacetylene, polypyrrole, poly(p-phenylene vinylene), polythiophene , Poly (p-phenylene sulfide) and other conductive polymers; Silicone, germanium, indium tin oxide (ITO), titanium oxide, copper oxide, silver oxide and other semiconductors; gold, platinum, titanium, aluminum, tungsten, copper, iron , Metals such as palladium, and carbon materials such as carbon fabrics and carbon nanotubes are particularly preferable from the viewpoint of flexibility and electrochemical stability.
In particular, when the patch contains a device (biobattery) that obtains a DC current by utilizing the redox reaction by an enzyme together with the microneedles, the plurality of electrodes are positive electrodes carrying an enzyme or the like that catalyzes the redox reaction (biobattery). It is preferable to include at least one cathode) or negative electrode (anode). In this case, as the material of the electrode, the above-mentioned carbon material is preferable from the viewpoint of fixing the enzyme to the electrode at a high density, and in particular, a carbon fabric modified with carbon nanotubes is preferable. Examples of the catalyst for the reduction reaction carried on the positive electrode (cathode) include bilirubin oxidase (BOD), laccase, Cu efflux oxidase (Cueo), ascorbic acid oxidase, iron phthalocyanine, and the like. Bilirubin oxidase (BOD) and iron phthalocyanine are preferable from the viewpoint of enhancing resistance to chloride ion and the like. Examples of the enzyme that catalyzes the oxidation reaction carried on the negative electrode (anode) include glucose oxidase, glucose dehydrogenase (GDH), fructose dehydrogenase (D-Fructose Dehydrogenase, FDH), alcohol oxidase, alcohol dehydrogenase, lactate oxidase. , Lactose dehydrogenase and the like, and in particular, glucose dehydrogenase (GDH) and fructose dehydrogenase (FDH) are preferable because the enzyme reaction system can be simplified. Among these, the combination of BOD and iron phthalocyanine and each of GDH and FDH is particularly preferable because it 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 enzyme that catalyzes the reduction reaction and the enzyme that catalyzes the oxidation reaction may be used alone or in combination of two or more.
FIG. 6 is a diagram showing an example of the patch of the present embodiment. (A) is a perspective view showing an example patch, and (B) is an enlarged cross-sectional view showing a part of the patch when the patch shown in (A) is applied to a means of drug administration. Yes, (C) is an enlarged cross-sectional view showing a part of the patch when the patch shown in (A) is applied to the means for collecting body fluid, and (D) is an example patch on the arm of the subject. It is a photograph showing the state when pasted.

When the patch of this embodiment is energized, a current (ion flow) flows through the microneedle array, and the mobility of ions increases due to the presence of fixed electrolysis in the flow path of the MNA. Therefore, an electroosmotic flow flows through the flow path of the MNA. Occurs.
Then, when energized while attached to the epithelial layer of the skin or organ (with the needle inserted), it is possible to inject an aqueous solution of a drug or the like or collect interstitial fluid according to the direction of the electric current. As a result, it is possible to obtain the effect of improving the efficiency of transdermal medication or body fluid sampling by the medical/health/beauty device.

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

(Patch manufacturing method)
The patch of the present embodiment is not particularly limited, and may be manufactured by a method usually used in the art.

Although the embodiments of the microneedle array and patch of the present invention have been exemplified with reference to the drawings, the above embodiments can be appropriately modified, and the microneedle array and patch of the present invention are described above. It is not limited to the illustrated embodiment.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

A. Reagents, materials/glycidyl methacrylate (GMA, Wako Pure Chemical Industries, Ltd.)
-Triethylene glycol methacrylate (TEGDMA, Wako Pure Chemical Industries, Ltd.)
-Trimethylolpropane trimethacrylate (TRIM, SIGMA-ALDRICH)
-Polyethylene glycol (PEG, Sigma ALDRICH)
・ 2-Methoxyethanol (Wako Pure Chemical Industries, Ltd.)
・ Irgacure184 (BASF)
2-acrylamide-2-methylpropanesulfonic acid (AMPS)
・ N, N'-methylenebisacrylamide (MB)
・Ammonium persulfate (APS)
.N,N,N',N'-tetramethylethylenediamine (TEMED)
2-Hydroxyethyl Methacrylic Acid (HEMA)
・ Methacrylic acid (MA)
・ Dextran-FITC
・ Pig skin (Landrace pig, male, 6 months, DARD Co., Ltd.)
-Multi-walled carbon nanotubes (CNT, Bayer Material Science)
・ Carbon fiber (CF, Toho Tenax)
Triton X-100 (polyethylene glycol mono-p-isooctyl phenyl ether, MP Biomedicals)
・ Fructose dehydrogenase (FDH, Toyobo Co., Ltd.)
・ Bilirubin oxidase (BOD, Amano Enzyme Co., Ltd.)
・D-Fructose (D(+)-fructose, Wako Pure Chemical Industries, Ltd.)
・ D-glucose (D (+)-glucose, Wako Junyaku Co., Ltd.)
・ Cotton (BEMCOT (registered trademark), Asahi Kasei Corporation)

B. Preparation of microneedle array B-1. Preparation of template Preparation of MNA using a template was performed according to a prior document (International Publication No. 2018/062530, etc.).
Using a cutting machine (manufactured by Modia Systems), a Teflon mold (female mold) with multiple microneedle shapes engraved is prepared, and by performing two-step transfer with polydimethylsiloxane (PDMS), PDMS is used. A female mold was obtained.
The dimensions of the mold (dimensions of the microneedle) were set to the desired dimensions in each test example described later.

B-2. Preparation of Microneedle Array 1 The manufacturing process of the microneedle array 1 using hydrogel was as shown below.
The shape of the microneedle array 1 was conical (see FIG. 2).
The dimensions of the mold (dimensions of the microneedle) are as follows.
-Diameter Rp0.5mm of the columnar support
・ The height Hp of the columnar column is 0.3 mm.
-Diameter of the circle on the bottom Rb: 500 μm
・Height H: 500 μm
・ Distance (pitch) between MNs P: 1000 μm
-Base material thickness t: 1000 μm
10 mL of a mixed solution (HEMA: 80% by mass, MA: 10% by mass, other 10%) of a monomer, a cross-linking agent, a polymerization initiator, etc. was polymerized in a water tank (35 ° C., 20 hours, 50 ° C., 8 hours). Later, it was heated in a dryer (100 ° C., 1 hour) and peeled from the mold to prepare the product.
When pouring the mixed solution into the mold, deaeration was performed by depressurizing with a vacuum pump (-96 kPa, 45 minutes) to prevent the loss of the needle shape due to the remaining bubbles.
The composition of the monomer unit in the polymer material constituting the microneedle array 1 was HEMA: 80% by mass, MA: 10% by mass, and other 10%.
Here, the content of the monomer unit having a fixed charge in the polymer material was 10% by mass.

B-3. Preparation of Microneedle Array 2 The manufacturing process of the microneedle array 2 made of a porous material was as follows.
The shape of the microneedle array 2 was the shape shown in FIG. 3 (see FIG. 3).
Prior art documents (eg, WO 2017/183737, etc.) report that providing struts on microneedles, which are usually simple cones, improves the penetration rate into the skin to almost 100%. Has been done.
The inventors have further developed a structure in which a plurality of needles are arranged for each support in order to improve the insertion area.
The diameter and height of the supports, the distance between the supports, and the number of needles were systematically varied and evaluated by a porcine skin penetration test.
As a result, they have found that it is preferable to set the dimensions of the microneedles as follows.
-Diameter of the columnar support part Rp': 0.5 mm
・ Height of columnar column Hp': 0.3mm
・The diameter Rb′ of the circle at the bottom of the conical small MN: 100 μm
・ Height of small conical MN H'100 μm
・ Distance (pitch) between MNs Q: 1000 μm
-Number of small cone MNs placed on the column portion of the cylinder: 7 (1 in the center, 6 in the periphery, on the circumference with a radius of d200 μm around the center, etc.) (6 pieces are arranged at intervals)
-Base material thickness t: 1000 μm
PEG (20 g) was heated and dissolved in 100 mL of 2-methoxyethanol to prepare 100 mL of Solution A. GMA (10 mL) as a monomer and TRIM (5.23 mL) and TEGDMA (15.7 mL) as cross-linking agents were mixed to prepare solution B30.93 mL.
Solution A and solution B are mixed at a volume ratio of 4: 3, and immediately after mixing, the initiator Irgacure 184 is added so as to be 1% by mass based on the volume of the monomer solution B, and the solution is immediately poured into a PDMS mold to emit ultraviolet rays. It was irradiated for 1 hour to polymerize.
After taking it out from the mold, it was immersed in a mixed solution of methanol:water=1:1 to elute PEG which is a porogen to obtain MNA2 having a porous structure.
The composition of the monomer unit in the polymer material constituting the microneedle array 2 was 100% by mass of GMA.
The porosity of the microneedle array 2 was about 40%.

In the MNA having the above dimensions, by pressing the top surface of the columnar column portion against the skin, the skin surface can be made tense, and the small microneedles placed on the top surface can be easily inserted. I understood it. Then, by providing seven small microneedles, the insertion area (total cross-sectional area of the punctured needles) is increased to 4.2%, which is seven times that of one, under an insertion rate of 100%. I was able to do it.

B-4. Preparation of Microneedle Array 3 Oxygen-containing functional groups such as OH groups were generated on the inner wall of the pores of the porous material by oxygen plasma treatment on the microneedle array 2 (not shown).

B-5. Preparation of Microneedle Array 4 A fixed charge was introduced by molecularly modifying the microneedle array 2 (see FIG. 4).
A sulfonic acid group was introduced into MN2 using sulfanilic acid as a modifying molecule to prepare MN4 having a fixed charge on the surface of the porous body.

B-6. Preparation of Microneedle Array 5 Next, the pores were filled with idrogel by performing a gelation reaction in the porous material (FIG. 5).
As shown in FIG. 5, the microneedle array 2 having no functional group introduced is immersed in a mixed aqueous solution of a monomer AMPS having a sulfonic acid group, a cross-linking agent MB, and a reaction accelerator APS and TEMED, and at 50 ° C. The reaction was carried out for 3 hours.
In experiments using gels with different fixed charge densities, the MB concentration was fixed at 0.1M, and the AMPS concentrations were 0.05M, 0.075M, 0.1M, 0.125M, 0.25M, 0.5M, 1 AMPS gels were prepared by changing to 0.0 M.
In addition, the average amount of fixed charge per unit mass of the hydrogel is about 2.5 × 10 ^-4 C / cm ² , about 3.6 × 10 ^-4 C / cm ² , and about 5 × 10 ^-4 C. / Cm ² , about 6.3 x 10 ^-4 C / cm ² , about 1.3 x 10 ^-3 C / cm ² , about 2.5 x 10 ^-3 C / cm ² , about 5 x 10 ^-3 C /Cm ² can be calculated.

C. Evaluation of microneedle array C-1. Evaluation of electroosmotic flow 1
The generation of electroosmotic flow due to energization was verified by monitoring the conductivity (G), which reflects the water content of the hydrogel.

FIG. 7 shows the conductivity G (mS) of a flat plate-shaped member made of a hydrogel containing a hydrogel material having a fixed charge (hydrogel material: HEMA 80% by mass, methacrylic acid 10% by mass) in the present embodiment. It is a figure which shows the outline and the result of the test which confirms the generation of the electroosmotic flow by energization in a flat plate-shaped member by monitoring. (A) is a figure explaining the outline of a test, (B) is a photograph which shows the outline of a test, (C) is a figure which shows the result of a test.

As shown in FIGS. 7A and 7B, the conductivity was measured with one end of the gel sheet immersed in a buffered aqueous solution. The hydrogel used was mainly composed of HEMA, and the negative charge was fixed by copolymerizing 10% by mass of methacrylic acid during the polymerization. When the polymer material used was analyzed, it was found to be 80% by mass of HEMA and 10% by mass of methacrylic acid.
During the first 25 minutes, a decrease in conductivity due to natural drying was observed. After that, for 30 minutes, the buffer solution was pumped up by energization (about 0.2 mA) by applying 4 V to the carbon electrode, so that the conductivity reduced by natural drying was recovered. In this case, the polarity of voltage application is negative at the top of the gel sample and positive at the bottom of the sample. After that, when the polarity was reversed and a buffer aqueous solution was produced, a decrease in conductivity was observed, which indicates that it was dried again. These results indicate that the electroosmotic flow was generated in the direction of movement of positive ions by energization.

C-2. Evaluation of electroosmotic flow 2
The generation of electroosmotic flow due to a fixed charge was evaluated using a PGMA porous.
In FIG. 8, the fluorescent dye dextran-FITC (10 kDa) was added dropwise to the well in the center of the monolith of porous PGMA, and the spread after 8 hours was observed with a fluorescence microscope.

FIG. 8 shows the case where the flow path is not filled with the filling material by using a flat plate member made of a material (material: GMA 100% by mass) other than the hydrogel material having no functional group introduced in the present embodiment. By observing the dynamics of the fluorescent dye when the fluorescent dye dextran-FITC (10 kDa) was dropped in the well in the center of the monolith, when the filling material (material: AMPS 100% by mass) was filled in the channel, It is a figure which shows the outline|summary and the result of the test which confirms generation|occurrence|production of the electroosmotic flow by movement of electricity, and movement of a high molecular weight body. (A) is a diagram for explaining the outline of the test, and (B) is a diagram showing the result of the test. In (B), (a) is a porous material with no functional group introduced/filling material unfilled, and (b) is a porous material with no functional group introduced/filling material unfilled, with current applied. In the case of, (c) is a porous material with no functional group introduced and filled with a filling material, and without electricity, (d) is a porous material with no functional group introduced and filled with a filling material, and with electricity. , Is shown.

Using the untreated porous body (a, b) and the hydrogel-filled porous body (c, d), there was no energization ( ^2.5 mA / cm ² , direction from bottom to top in the figure) for 8 hours (a, The results were compared with c) and with (b, d).
The gel filling conditions used here were a monomer concentration of 0.5 M and a buffer solution of McIlvaine buffer (pH 6). When current is applied to the gel-filled porous body (d), the upward spread of the dye is observed, and under other conditions, the result can be interpreted by simple diffusion that is almost vertically symmetrical.
This result suggests that the electroosmotic flow was efficiently generated in the porous body by introducing the fixed charge by filling the hydrogel.

C-3. Evaluation of electroosmotic flow 3
The electroosmotic flow generated in the porous body filled with hydrogel was also evaluated by the experiment using Franz cell.
FIG. 9 uses a flat plate member formed by filling voids of a porous body (material: GMA 100% by mass) containing a material other than the hydrogel material with a filling material (material: AMPS 100% by mass) in the present embodiment. By observing the dynamics of the fluorescent dye when the fluorescent dye dextran-FITC (10 kDa) is dropped into one cell of the Franz cell, the generation of electroosmotic flow and the movement of high molecular weight bodies due to energization in the flat plate-shaped member can be observed. It is a figure which shows the outline and the result of the test to confirm. (A) is a figure explaining the outline of a test, and (B) is a figure showing the result of a test.
The porous body has a thickness of 1 mm and an area of 0.5 cm ² , and is filled with a gel containing the monomer AMPS (0.05 M) and the cross-linking agent MB (0.1 M).
0.1 mL of the solution on the right side was sampled while energizing 2 mA (every hour), and the concentration of the fluorescent molecule dextran-FITC (10 kDa) was measured with a plate reader and plotted in FIG. 9 (B).
The movement of fluorescent molecules to the right is accelerated by energization, and this experiment also confirmed that an electroosmotic flow is generated in the direction of movement of positive ions.

C-4. Evaluation of electroosmotic flow 4
In the experiments of FIGS. 8 and 9 using fluorescent molecules, it is difficult to evaluate the flow (the molecules move even if the flow occurs) because the size of the fluorescent molecules is not small (10 kDa), especially when the gel density is high. do not do). Therefore, we also directly evaluated the amount of water that moved.
FIG. 10 uses a flat plate member formed by filling voids of a porous body (material: GMA 100% by mass) containing a material other than the hydrogel material with a filling material (material: AMPS 100% by mass) in the present embodiment. FIG. 3 is a diagram showing an outline and results of a test for confirming the generation of electroosmotic flow due to energization in a flat plate-shaped member by observing the movement of water from one of the closed Franz cells to the other. (A) is a figure explaining the outline of a test, and (B) is a figure showing the result of a test.

As shown in FIG. 10 (A), the height of the water surface after energization for 6 hours by a Franz cell incorporating a porous body filled with a gel containing a monomer AMPS (0.05 M) and a cross-linking agent MB (0.1 M). The movement of water was evaluated from the change (Δh) of.
As shown in FIG. 10B, the moving speed of water changed in proportion to the applied current, and it was shown that the water moved at a flux of 3 mL/h·cm ^{2 in} the case of 40 mA.
However, since this experiment includes the effect that hydrostatic pressure suppresses the flow, it is necessary to use an experimental system (cell structure) that does not generate hydrostatic pressure in order to measure the accurate flux.
However, it is significant to show that the movement of water due to electroosmotic flow can be quantitatively measured.

Also, generation of electroosmotic flow was observed in MN3 that had been subjected to oxygen plasma treatment and MN4 that had sulfonic acid groups introduced.

D. Preparation and evaluation of microneedle array Similar to the preparation in "B-6. Preparation of microneedle array 5", prepared by monomer AMPS with different concentrations of 0.05M and 0.5M and cross-linking agent MB (0.1M). A microneedle array filled with the AMPS gel was prepared.
11 (A) and 11 (a) are electron micrographs showing a part of a microneedle filled with a gel of AMPS 0.05M in an enlarged manner, and FIGS. 11 (A) and 11 (b) are filled with a gel of AMPS 0.5 M. It is an electron micrograph which shows a part of the microneedle enlarged.
As shown in FIGS. 11A, 11A and 11B, in AMPS0.05M, the gel spreads thinly on the surface of the porous pores, and in AMPS0.5M, the pores are blocked by the gel. Was confirmed.

Similar to the preparation in "C-4. Evaluation of electroosmotic flow 4", the voids of the porous body (material: GMA 100% by mass) containing a material other than the hydrogel material are filled with the filling material (material: AMPS 100% by mass). The flat plate-shaped member configured as follows was used. In preparing the filling material, different concentrations of 0-1.5M (0M, 0.05M, 0.1M, 0.5M, 1.0M, 1.5M) monomer AMPS and crosslinking agent MB (0.1M) were used. The AMPS gel prepared by the above was used.
FIG. 11B is similar to the evaluation in “C-4. Evaluation 4 of electroosmotic flow” using a flat plate-shaped member configured by packing AMPS gels having different AMPS concentrations from 0 to 1.5M. It is a figure which shows the result at the time of performing the test which confirmed the generation of the electroosmotic flow.
As shown in FIGS. 11B and 11A, the moving speed of water fluctuated depending on the AMPS concentration. It was found that the moving speed of water had a peak once in the 0.05M part, then decreased to 0.5M, and then increased as the AMPS concentration increased.
This is considered as a mechanism as shown in FIG. 11 (B). In the case of AMPS 0.05M, the gel spreads thinly on the surface inside the pores as shown in FIGS. 11 (B) and 11 (c) inside the porous body shown in FIGS. 11 (B) and 11 (b). High electroosmotic force is generated inside the hole. In the case of AMPS 0.5M, the increase in the moving speed of water is weakened by filling the pores with gel as shown in FIGS. 11B and 11D. Then, in the case of AMPS 1.5M, it is considered that the phenomenon is that the electroosmotic force is further increased by increasing the charge density in the gel as shown in FIGS. Therefore, it was shown that a high concentration of AMPS is important for transporting water.

Similar to the preparation in "C-4. Evaluation of electroosmotic flow 4", the voids of the porous body (material: GMA 100% by mass) containing a material other than the hydrogel material are filled with the filling material (material: AMPS 100% by mass). The flat plate-shaped member configured as follows was used. In the preparation of the filling material, the monomer AMPS having different concentrations (0M, 0.025M, 0.05M, 0.075M, 0.1M, 0.25M, 0.5M, 1.0M) of 0 to 1.0M was used. An AMPS gel prepared with the cross-linking agent MB (0.1M) was used.
FIG. 11C shows the same evaluation as in “C-3. Evaluation 3 of electroosmotic flow” using a flat plate member configured by filling AMPS gels having different AMPS concentrations of 0 to 1.0M. It is a figure which shows the result when the test which confirmed the generation of an electroosmotic flow and the movement of a high molecular weight body was performed by observing the dynamics of a fluorescent dye when the fluorescent dye dextran-FITC (10 kDa) was dropped.
As shown in FIGS. 11C and 11A, the mobility of the fluorescent molecule varied depending on the AMPS concentration. It was shown that there was a maximum peak at 0.05M and that higher concentrations reduced migration.
This is considered as a mechanism as shown in FIG. 11 (C). When a 0.05 M AMPS gel is thinly spread on the surface as shown in FIGS. 11 (C) and 11 (c) inside the porous body shown in FIGS. 11 (C) and 11 (b), the 10 kDa dextran-FITC has high electricity. In contrast, in the 0.5 M AMPS gel shown in FIGS. 11 (C) and 11 (d) and the 1 M AMPS gel shown in FIGS. 11 (C) and 11 (e), the gel closes the pores and thus passes through. It is considered to be a phenomenon that the passage of dextran-FITC is physically inhibited. Therefore, there is an optimum concentration of monomer AMPS for transporting molecules of 500 Da or more, which are normally blocked by the keratin barrier of the skin, and 0.05 M is optimal for transporting large molecules of, for example, about 10 kDa. Was shown to be.

Similar to the preparation in "B-6. Preparation of Microneedle Array 5", a microneedle filled with AMPS gel prepared by a monomer AMPS having a concentration of 1.5 M and a cross-linking agent MB (0.1 M) was prepared. did.
In addition, a specimen of porcine skin was prepared.
FIG. 12 (A) shows a microneedle (a) filled with an AMPS gel prepared by a monomer AMPS having a concentration of 1.5 M and a cross-linking agent MB (0.1 M), and a specimen of pig skin (a). It is a figure which shows the result when the moving speed of water was evaluated from the change of the height of the water surface using a Franz cell for each of the needle-inserted one (b) and the pig skin specimen only (c). ..
As shown in FIG. 12(A), the amount of water transfer was low only in the skin, but increased by about 2 times due to the microneedle insertion. The amount of water transfer in the combination of the skin and the microneedle is lower than the amount of water transfer in the microneedle alone because the electroosmotic force of the skin is rate-determining with respect to the electroosmotic force increased by the microneedle. Conceivable.
12 (B) and 12 (C) show microneedles in which a glucose-filled pig skin specimen is filled with an AMPS gel prepared with a 1.5 M concentration of monomeric AMPS and a cross-linking agent MB (0.1 M). For each of the punctured specimen (a) and the glucose-filled porcine skin specimen (b), a ² mA / cm ² current was passed through the Franz cell, and a glucose assay kit was used to remove the specimen from the inside of the skin to the outside. It is a figure which shows the result when the movement amount of glucose and the movement rate of glucose were evaluated. (B) shows the evaluation result of the amount of glucose transfer (black circles and solid lines indicate (a), white circles and broken lines indicate (b)), and (C) indicates glucose. The evaluation result of the moving speed is shown.
As shown in FIGS. 12 (B) and 12 (C), since glucose penetrates the skin with a small molecule of about 180 Da, glucose movement was observed even in the skin alone, but when the electroosmotic force is increased by using microneedles, It was found that glucose moves at a rate as high as 3 times. Therefore, it was shown that interstitial fluid and small biomolecules can be sampled from the inside of the skin with high efficiency by using microneedles.

Similar to the preparation in "B-6. Preparation of Microneedle Array 5", a microneedle filled with AMPS gel prepared by a monomer AMPS having a concentration of 0.05 M and a cross-linking agent MB (0.1 M) was prepared. did. In addition, microneedles not filled with AMPS gel were also produced in the same manner.
FIG. 13 (A) shows a microneedle filled with AMPS gel prepared with a monomer AMPS having a concentration of 0.05 M and a cross-linking agent MB (0.1 M), and a microneedle not filled with AMPS gel, respectively. Was inserted into a porcine skin specimen, and they were separately sandwiched between Franz cells and a current of 0.5 mA / cm ² was passed to evaluate the amount of 10 kDa dextran-FITC moving from the outside to the inside of the porcine skin. It is a figure which shows the result.
As shown in FIG. 13 (A), the dextran-FITC did not move much with the needles not filled with AMPS, but it was shown that the needles filled with AMPS had high transport capacity.
13 (B) and 13 (C) show a porcine skin specimen in which microneedles filled with an AMPS gel prepared with a monomer AMPS having a concentration of 0.05 M and a cross-linking agent MB (0.1 M) were inserted. When a 10 kDa dextran-FITC solution was brought into contact with each other from the outside of the skin and a current of 0.5 mA / cm ² was passed, the dextran-FITC inside the skin It is a photograph which shows the state when the penetration was evaluated.
As shown in FIGS. 13B and 13C, in (C), dextran-FITC does not permeate due to the skin barrier function and is only deposited on the surface (the bright spots indicated by the double-headed arrows in the figure). (See Thickness), (B) showed that the needle penetrated deeper (see the thickness of the bright spot indicated by the double-headed arrow in the figure). Therefore, it was shown that a low current of 0.5 mA / cm ² , which does not cause inflammation even when flowed through the skin, allows large molecules that are normally blocked by the skin barrier function to be introduced into the skin through a needle.

A CNT-modified electrode made of carbon fiber, an anode electrode (1 cm ² ) that is further modified with FDH to generate an electric current in the presence of fructose, and a BOD is further modified to generate an electric current in the presence of oxygen. Cathode electrodes (1 cm ² ) were prepared so as to be generated, and each of them was arranged one by one on cotton to form one biobattery.
Three of these biobatteries were arranged in series, and one anode and one cathode were respectively placed on cotton filled with dextran-FITC (10 kDa) and connected with a lead wire to prepare a biobattery in series. One porous microneedle filled with AMPS gel with monomer AMPS (0.05M) and cross-linking agent MB (0.1M) is placed under cotton with one anode and one cathode separately placed. And it was inserted into a porcine skin specimen. It was observed that the battery on the upper surface generated electric power by using fructose and oxygen as fuel to generate electroosmotic flow, and dextran-FITC was introduced into the skin.
FIG. 14 (A) shows an outline of the prepared biobattery and glucose-filled pig skin filled with an AMPS gel prepared with a monomer AMPS at a concentration of 0.05 M and a cross-linking agent MB (0.1 M). It is a figure which shows a mode that an electroosmotic flow generate|occur|produces when a biobattery produces electric power, when a microneedle is inserted.

FIG. 14(B) is a diagram showing the time course of the current density that has flowed while the bio battery is generating power.
As shown in FIG. 14B, it was shown that a current of 0.5 mA / cm ² or less, which is safe for a living body, can be stably applied for 1 hour.

FIG. 14C is a photograph showing a section of pig skin collected 1 hour after power generation, which was observed with a fluorescence microscope.
As shown in FIG. 14(C), when a section of the skin collected after 1 hour was observed with a fluorescence microscope, it was shown that dextran-FITC deeply penetrated under the skin. This showed that large molecules, normally blocked by barrier function, could be introduced into the skin by a combination of small biobattery and microneedles.

In FIG. 14 (D), a porous microneedle filled with a gel containing a monomer AMPS (1.5M) and a cross-linking agent MB (0.1M) was inserted into a glucose-filled pig skin specimen, and the bio was inserted. It is a figure which shows the result of having evaluated the amount of glucose extracted on the upper surface of a needle by a glucose assay kit when it was driven by a battery and when it was not driven.
As shown in FIG. 14D, glucose was hardly extracted in the absence of the biobattery, but the biobattery generated an electric current to cause an electroosmotic flow, so that glucose was further extracted from the inside to the outside of the skin. It was shown to be extracted to the top of the microneedles. Therefore, it was shown that it is possible to sample small biomolecules from the inside of the skin by combining a small bio-cell and microneedles.

According to the present invention, it is possible to provide a microneedle array or patch capable of suitably generating an electroosmotic flow.

1 Microneedle array 2 Microneedle 3 Hydrogel 4 Porous body 5 Base material 6 Void 10 Patch 11 Electrode 12 Conducting means Rb Diameter of the bottom circle of the small conical MN H Height of the small conical MN Rp Cylindrical Diameter of strut part Hp Height of columnar strut part P pitch Rb' Diameter of circle on the bottom of small conical MN H'Height of small conical MN Rp'Diameter of columnar column Hp'Cylindrical Height of column part of shape Q pitch d distance t thickness of base material

Claims (20)

A microneedle array characterized by having a fixed charge in the flow path. The microneedle array according to claim 1, which is a hydrogel containing a hydrogel material. The microneedle array according to claim 2, wherein the amount of the fixed charges in the hydrogel per unit mass of the hydrogel is 1 C/g to 200 C/g on average. The hydrogel material is a polymer material containing a monomer unit having the fixed charge,
The content of the fixed charge monomer unit in the hydrogel material is 0.1% by mass or more.
The microneedle array according to claim 2 or 3. The microneedle array according to claim 4, wherein the monomer unit having a fixed charge contains at least one selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphoric acid group, and an amino group. The microneedle array according to claim 1, which is a porous body containing a material other than a hydrogel material. The microneedle array according to claim 6, wherein the amount of the fixed charge per unit surface area of the porous body in the porous body is 1 × 10 ^-7 C / cm ² to 5 × 10 ^-2 C / cm ² on average. .. The microneedle array according to claim 6 or 7, wherein the functional group having a fixed charge is introduced on the surface of the porous body. The microneedle array according to claim 8, wherein the functional group includes at least one selected from the group consisting of a sulfonic acid group, a carboxyl group, a phosphoric acid group, and an amino group. 10. The microneedle array according to claim 8, wherein the amount of the functional group in the porous body per unit surface area of the porous body is 1×10 ⁻¹³ mol/cm ² or more. The microneedle array according to claim 9, wherein the surface of the porous body is treated with oxygen plasma. The microneedle array according to any one of claims 6 to 11, wherein a filling material is filled in the voids of the porous body. The microneedle array according to claim 12, wherein the filling material is a hydrogel containing a hydrogel material. The microneedle array according to claim 13, wherein the amount of the fixed charges in the hydrogel per unit mass of the hydrogel is 1 C/g to 5000 C/g on average. Examples of the hydrogel material include collagen, glucomannan, carboxymethyl cellulose, sodium carboxymethyl cellulose, polyacrylic acid, sodium polyacrylate, polymethacrylic acid, sodium polymethacrylate, poly-2-hydroxyethylmethacrylic acid, poly-2-acrylamide-2. -The microneedle array according to any one of claims 2 to 5, 13 and 14, comprising at least one selected from the group consisting of methylpropanesulfonic acid. The microneedle array according to any one of claims 6 to 14, wherein the material other than the hydrogel material contains at least one selected from the group consisting of resin, oxide, and metal. The microneedle array according to any one of claims 1 to 16, wherein a plurality of microneedles are erected on a base material. The microneedle array according to any one of claims 1 to 17, wherein the microneedles include a columnar body including small microneedles. The microneedle array according to claim 18, comprising a plurality of the small microneedles and including a plurality of the columnar bodies. A patch comprising the microneedle array according to any one of claims 1 to 19 and a plurality of electrodes provided in contact with the microneedle array.

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