WO2007148714A1

WO2007148714A1 - Implant using rifamycin derivative

Info

Publication number: WO2007148714A1
Application number: PCT/JP2007/062385
Authority: WO
Inventors: Takaoki Saneyasu; Masaki Ichimura; Shinji Hayashi; Masaji Kawatsu; Kazunori Hosoe
Original assignee: Kaneka Corporation
Priority date: 2006-06-21
Filing date: 2007-06-20
Publication date: 2007-12-27

Abstract

It is intended to provide an implant which is excellent in antithrombogenicity and tissue compatibility and can inhibits stenosis. This problem can be solved by an implant containing a Rifamycin derivative as the active ingredient. In a preferable case, this implant contains a drug for treating a vascular disease or a drug for controlling cell proliferation comprising as the active ingredient the Rifamycin derivative. This Rifamycin derivative strongly inhibits the proliferation of vascular smooth muscle cells compared with vascular endothelial cells. Thus, the implant containing the Rifamycin derivative as described above is excellent in antithrombogenicity and tissue compatibility and can inhibits stenosis.

Description

Specification

Implants using rifamycin derivatives

Technical field

The present invention relates to an implant that has excellent antithrombogenicity and tissue compatibility and suppresses stenosis.

Background

[0002] In recent medical surgery, various medical devices are embedded in the body as an alternative organ to a malfunctioning organ, or to protect or maintain the function after surgery. Is done.

[0003] These medical devices are required to be compatible with body fluids such as blood, tissue fluid, and lymph fluid, as well as organs to be implanted and biological tissues of the site, while placed in the implanted site. . For example, in a medical device that is implanted in a site that is in contact with blood flow, such as a stent, an artificial blood vessel, or a catheter that is placed for a long time, blood adheres to the surface or blood clots and does not inhibit the blood flow. It is required to have excellent antithrombogenicity and tissue compatibility so that it does not become incompatible with living tissue and does not cause stenosis due to the formation of neointimal or phenotypic changes of fibroblasts. Similar characteristics are also required for medical devices embedded in ureters, urethra, lymphatic vessels, and the like.

[0004] Furthermore, even medical devices that are placed in the body to release a drug slowly have antithrombogenicity and tissue compatibility, and shika must exhibit its characteristics stably and continuously. It is done. For example, a drug-coated stent holds a drug that limits vascular restenosis and exerts its effect by the sustained release of the drug over time. To date, various drug coated stents have been developed, and attempts to reduce the restenosis rate have been reported (see Patent Document 1 and Non-Patent Document 1). Restenosis involves factors such as thrombus formation, inflammation, endothelial injury, and vascular smooth muscle cell migration and proliferation starting from vascular disorders, and many drugs (anticoagulants, antiplatelet substances) that target each factor. Antispasmodic agents, antibacterial agents, antitumor agents, antimicrobial agents, anti-inflammatory agents, antimetabolite agents, immunosuppressive agents, etc.) are being studied.

Patent Document 1: Japanese Patent Publication No. 5-502179 Non-Patent Document 1: Toru Yamaro et al. Drug-Eluting Stent Medical School January 1, 2004 Disclosure of Invention

Problems to be solved by the invention

[0005] The above-mentioned problems related to antithrombogenicity, tissue compatibility and stenosis are not limited to stents, but are common to various medical devices implanted in the body. In particular, medical devices such as stents that are implanted in the body for a long period of time after being implanted in the body are required to continuously and stably exhibit their antithrombogenicity, tissue compatibility, and restenosis suppressing action. Therefore, there is a need for a drug-coated stent that maintains superior antithrombogenicity and tissue compatibility and suppresses vascular restenosis compared to conventional drug-coated stents.

[0006] In recent years, the relationship between stenosis of blood vessels and microbial infection has been pointed out. In particular, the involvement of Chlamydia pnuemoniae is strongly suggested, and prophylactic administration of antibacterial drugs effective for pneumonia chlamydia is being implemented in patients with heart disease. However, the effect has not been fully confirmed (Kazunobu Onuchi Clinical and Winores 2003 31 (5) 358-365).

[0007] Here, rifamycin derivatives are known to be antibiotics that are extremely strong against pneumonia chlamydia and have antibacterial activity (JP-A-9-216824, Patricia M. Robhn, et al. al. Antimicrobial Agents and Chemotherapy, 2003, 47 (3), 1135- 11-6).

[0008] Therefore, the present inventors tried to apply to the implant a rifamycin derivative exhibiting an excellent antibacterial action against pneumonia chlamydia which is one of the causes of vascular stenosis.

Means for solving the problem

[0009] As a result of intensive research, the present inventors have found that a rifamycin derivative inhibits the proliferation of vascular smooth muscle cells without strongly inhibiting the proliferation of vascular endothelial cells, and by coating the rifamycin derivative, We have developed an implant that has excellent antithrombogenicity and tissue compatibility and can suppress stenosis.

[0010] That is, the present invention relates to an implant including a rifamycin derivative.

[0011] Another aspect of the present invention is an implant comprising a vascular disease treatment agent containing a rifamycin derivative as an active ingredient.

[0012] Another aspect of the present invention provides a cell growth regulator comprising a rifamycin derivative as an active ingredient. It is an implant characterized by including.

[0013] In the above invention, it is preferable that the rifamycin derivative is an implant that exhibits a strong growth inhibitory action on vascular smooth muscle cells compared to vascular endothelial cells. Of these, an implant characterized by exhibiting a non-cell growth inhibitory effect on vascular endothelial cells and a cell growth inhibitory effect on vascular smooth muscle cells by using the rifamycin derivative as an active ingredient is more preferable. .

[0014] In another embodiment of the present invention, the rifamycin derivative may be rifalazil {Rifalazil, 3'-Hydro xy-o— (4—isobutyl— 1— piperazmyl) benzoxazinorifamycin, KRMl648}, KRMl 5 /, KRM1671, KRM1689 The power of KRM1690 or their physiologically acceptable salts is preferred. The chemical formulas of KRM1648, KRM1657, KRM1671, KRM1689, and KR M1690 will be described in the later-described embodiment items.

[0015] In the above invention, the rifamycin derivative is preferably an implant present in a biocompatible polymer or biodegradable polymer. Of these, the biodegradable polymer is preferably a lactic acid-glycolic acid copolymer!

[0016] In the above invention, the rifamycin derivative may be filled in a vesicle. Of these, the vesicles are preferably in the form of microparticles, nanoparticles or ribosomes.

[0017] Another embodiment of the present invention includes one in which the implant is a stent.

[0018] Another aspect of the present invention includes a step of preparing a solution containing a biocompatible polymer or biodegradable polymer and a rifamycin derivative, and a step of applying or holding the solution to an implant. The manufacturing method of the characteristic implant is mentioned.

[0019] Another embodiment of the present invention includes a method for treating a vascular disease using the implant.

[0020] Other aspects of the present invention and their effects will become apparent from the following description and drawings.

The invention's effect

[0021] The rifamycin derivative used in the implant or the like of the present invention strongly suppresses the proliferation of vascular smooth muscle cells as compared with vascular endothelial cells. Therefore, the rifamycin induction of the present invention An implant including a conductor is excellent in antithrombogenicity and tissue compatibility, and can effectively suppress stenosis or restenosis of blood vessels.

Brief Description of Drawings

FIG. 1 is a development view of a stent according to an embodiment.

FIG. 2 is a schematic view of a stent as an embodiment.

FIG. 3 is a graph showing the relationship between each concentration of rifalazil and the growth inhibitory effect of CASMC.

FIG. 4 is a graph showing the relationship between each concentration of rifalazil and the growth inhibitory action of CAEC.

FIG. 5 is a graph showing the relationship between each concentration of ravamycin and the growth inhibitory effect of CASMC.

FIG. 6 is a graph showing the relationship between each concentration of rabamycin and the growth inhibitory action of CAEC.

FIG. 7 is an SEM image of a stent surface coated with rifalazil.

FIG. 8 is a graph showing the relationship between each concentration of KRM1657 and the growth inhibitory action of CASMC and CAEC.

FIG. 9 is a graph showing the relationship between each concentration of KRM1671 and the growth inhibitory action of CASMC and CAEC.

FIG. 10 is a graph showing the relationship between each concentration of KRM1689 and the growth inhibitory action of CASMC and CAEC.

FIG. 11 is a graph showing the relationship between each concentration of KRM1690 and the growth inhibitory action of CASMC and CAEC.

BEST MODE FOR CARRYING OUT THE INVENTION

[0023] Hereinafter, the force for explaining the implant as an embodiment of the present invention in detail. The present invention is not limited to these.

[0024] 1. Rifamycin derivative

(1) The rifamycin derivative used in the present application has the following formula (I):

[0025] [Chemical 14]

(In Formula (I), X ¹ represents an oxygen atom or a sulfur atom, R ¹ represents a acetyl group or a hydrogen atom, R ² represents a methyl group or a hydroxymethyl group,

R ⁴ is the same or different and represents a hydroxyl group, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a group represented by the formula (II), or a group represented by the following formula (IV). Or a physiologically acceptable salt thereof.

[0027] [Chemical 15]

, R5

(II)

■ R6

[0028] [Chemical 16]

R ⁷ R ⁸

N, X ² (IV)

In the above formula (II), R ⁵ and R ⁶ are the same or different and represent an alkyl group having 1 to 3 carbon atoms or a group represented by formula (III).

[0030] [Chemical 17]

[0031] (In the formula (ΠΙ), j represents an integer of 1 to 3.)

In the above formula (IV), R ⁷ and R ⁸ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ² represents an oxygen atom, a sulfur atom, a carbonyl group, A group represented by (V) or a group represented by the following formula (IV) is shown.

[0033] [Chemical 18]

[0034]

[0035] In the above formula (V), R ⁹ and R ^1Q are the same or different, and are represented by the following formula by combining a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or R ⁹ and R ^1Q. Indicates a group.

(CH) —

2k

(In the formula, k represents an integer of 1 to 4.)

In the above formula (VI), m represents 0 or 1, and R ¹¹ represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or a group represented by the following formula.

(CH) X ³

2 n

(In the formula, n represents an integer of 1 to 4, and X ³ represents an alkoxy group having 1 to 3 carbon atoms, a vinyl group, an ethynyl group, or a group represented by the following formula (VII).)

[0037] [Chemical 20]

In the above formula (I), R ³ , R ⁴ , R ⁵ , R ⁶ ,

Examples of the alkyl group having 1 to 3 carbon atoms of R ⁹ and R ^1Q include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a cycloalkyl group, and an alkyl group having 1 to 6 carbon atoms in R ¹¹ As methyl group, Group, propyl group, isopropyl group, cyclopropyl group, butyl group, isobutyl group, sec butyl group, tert butyl group, cyclobutyl group, cyclopropylmethyl group, pentyl group, isopentyl group, sec pentyl group, tert pentyl group, cyclopentyl group And a chain or cyclic alkyl group such as a group, a cyclobutylmethyl group, a hexyl group, a 4-methylpentyl group, a cyclohexyl group, a 3-methylcyclopentyl group, a heptyl group, and an isoheptyl group.

[0039] Examples of the alkoxy group having 1 to 3 carbon atoms of X ³ include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a cyclopropoxy group.

(2) Preferably, in the rifamycin derivative, X ^{1 in the} above formula (I) is an oxygen atom, R ¹ represents a acetyl group or a hydrogen atom, and R ² represents a methyl group or a hydroxymethyl group. R ⁴ is the same or different and is a hydroxyl group, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or formula (VIII):

[0041] [Chemical 21]

—— NNR ¹² (VIII)

[0042] (In formula (VIII), R ¹² represents a hydrogen atom or an alkyl group having 1 to 7 carbon atoms) or a physiologically acceptable salt thereof.

[0043] Examples of the alkyl group having 1 to 7 carbon atoms of R ¹² include methyl group, ethyl group, propyl group, isopropyl group, cyclopropyl group, butyl group, isobutyl group, sec butyl group, tert butyl group, cyclobutyl Group, cyclopropylmethyl group, pentyl group, isopentyl group, sec pentyl group, tert pentyl group, 1,2-dimethylpropyl group, 1-ethylpropyl group, cyclopentyl group, cyclobutylmethyl group, hexyl group, 4-methylpentyl group, cyclo Examples thereof include a linear or cyclic alkyl group such as a hexyl group, a 3-methylcyclopentyl group, a heptyl group, and an isoheptyl group.

[0044] (3) Hereinafter, five specific compounds will be described as examples of the rifamycin derivative. The rifamycin derivative according to the present invention is not limited to these compounds

(3-1) As an illustrative rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, and R ¹ Is a acetyl group, R ² is a methyl group, R ³ is a hydroxyl group, and R ⁴ is a compound represented by the formula (IX):

[0046] [Chemical 22] One N N CH.CH (CH,). (IX)

[0047] Rifalazil {Rifalazil, 3'-Hydroxy-5 '-(4-isobuty 卜 1- piperazinyl) benzoxaz inorifamycin, KRM 1648} or a physiologically acceptable salt thereof.

(3-2) As an illustrative rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ is a acetyl group, R ² is a methyl group, and R ³ is a hydroxyl group And R ⁴ is the formula (X):

[0049] [Chemical 23]

— N CH H.CH. (X)

v_ ^{2 2 3}

[0050] KRM1657 represented by or a physiologically acceptable salt thereof.

(3-3) As an illustrative rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ is a hydroxyl group, R ² cate group, and R ³ is a hydroxyl group. Yes, R ⁴ is formula (IX):

[0052] [Chem. 24] One N N CH „CH (CH,), (IX)

^{2 3 22 3 2}

[0053] KRM1671 represented by or a physiologically acceptable salt thereof.

(3-4) In the exemplary rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R is a acetyl group, R ² force S methyl group, R ³ and R ⁴ is the formula (IX):

[0055] [Chemical 25] One N N CH „CH (CH,), (IX)

^{2 3 22 3 2}

[0056] KRM1689 represented by or a physiologically acceptable salt thereof.

[0057] (3-5) An exemplary rifamycin derivative has the formula (I) in which X ¹ is an oxygen atom, R is a acetyl group, R ² is a hydroxymethyl group, and R ³ is a hydroxyl group. R ⁴ is the formula (IX) [0058] [Chemical 26] One NN CH.CH (CH,). (IX)

[0059] KRM1690 or a physiologically acceptable salt thereof.

[0060] 2. Action by rifamycin derivatives

In the present application, an implant containing a rifamycin derivative is used, and at this time, it has a strong antiproliferative action on vascular smooth muscle cells compared to vascular endothelial cells. The rifamycin derivative has been used at a very low concentration in the past when it was known to be an antibiotic having an extremely strong antibacterial activity against pneumonia chlamydia. The present invention was made when the present inventors found for the first time an unexpected effect unrelated to the antibacterial activity, that the “rifamycin derivative” has the above-described cell growth inhibitory action. Is. In addition, since the relationship between pneumonia chlamydia and vascular stenosis has been pointed out, an implant containing a rifamycin derivative can be expected to have an antibacterial effect that is conventionally known in addition to the above-mentioned cell growth inhibitory action. .

[0061] “Strongly suppresses proliferation of vascular smooth muscle cells compared to endothelial cells” means “does not exhibit cytostatic activity of vascular endothelial cells and proliferates to vascular smooth muscle cells. Including the case of “inhibiting action”. For example, rifamycin derivatives can be adjusted so as to show growth inhibitory activity against vascular smooth muscle cells but not against vascular endothelial cells by adjusting the concentration. . In addition, since the appropriate amount varies depending on the form of the vascular disease treatment agent or the cell growth inhibitor, it is necessary to appropriately adjust the amount depending on the form.

[0062] "Show cell growth suppression" refers to a case where the cell growth is statistically significantly suppressed. On the other hand, “does not exhibit a cell growth inhibitory effect” means a case where it is not statistically significant.

[0063] 3. Examples of vascular diseases

In the present invention, the rifamycin derivative is a vascular disease (for example, arteriosclerosis (atherosclerosis, medial calcification sclerosis, microarteriosclerosis), aneurysm, pseudoaneurysm, arterial dissection, Nature including inflammatory arterial disease, non-inflammatory arterial disease, or dialysis shunt It is used for the prevention or treatment of developmental vascular diseases, non-natural vascular diseases including vascular restenosis or reocclusion after percutaneous angioplasty. Examples of angioplasty include balloon dilation, stent placement, atherectomy, and laser angioplasty.

[0064] 4. Vascular disease treatment agent or cell growth regulator

“A vascular disease treatment agent comprising a rifamycin derivative as an active ingredient” is a concept including a composition or preparation (medicine) for treating a vascular disease comprising a rifamycin derivative as an active ingredient. The “cell growth regulator containing a rifamycin derivative as an active ingredient” is a concept including a cell growth regulating composition or preparation (medicine) containing a rifamycin derivative as an active ingredient. Among these, “therapeutic agent for vascular diseases or cell growth regulator based on rifamycin derivative as an active ingredient based on low cell growth inhibitory action on vascular endothelial cells and high cell growth inhibitory action on vascular smooth muscle cells” I like it.

[0065] "Treatment of vascular disease" is a concept of treating vascular disease or reducing its progression

In addition to (therapeutic agent for vascular disease), the concept of preventing the vascular disease by using the same action as that for treating the vascular disease (preventive agent for vascular disease) is included.

[0066] (4 1) Embodiments containing other drugs

In the preparation of preparations for the prevention or treatment of vascular diseases, other drugs (anticoagulants, antiplatelet substances, antispasmodics, antibacterial drugs, antitumor drugs, antimicrobial drugs, anti-inflammatory drugs, It may be combined with an anti-metabolite, an immunosuppressant, etc.

[0067] Also in this embodiment, the rifamycin derivative is used to suppress proliferation more strongly against vascular smooth muscle cells than vascular endothelial cells. Thereby, smooth muscle hypertrophy is suppressed without inhibiting vascular endothelium regeneration, and vascular stenosis or restenosis is prevented.

[0068] 5. Implant body

The material, shape, dimensions, form, etc. of the main body of the “implant” as an embodiment are not particularly limited, and are appropriately determined according to the size, compliance, tissue, cell type, etc. of the site where the medical device is placed. . The implant is hereinafter also referred to as “medical implant”, “implantable implant”, “medical device”, or “in-vivo device” as appropriate. [0069] For example, the material may have a required characteristic depending on a portion where the metal material or the polymer material is placed, that is, a blood vessel, a urinary tract, a lymphatic vessel, or a tissue such as a muscle. However, it is preferably a material having biocompatibility and biodegradability.

[0070] 6. Metallic materials

Examples of the metal material include stainless steel, titanium or titanium alloy, tantalum or tantalum alloy, platinum or platinum alloy, gold or gold alloy, correlate base alloy, magnesium or magnesium alloy, and the like. As stainless steel, SUS316L, which has the best corrosion resistance, is suitable.

[0071] 7. Biocompatible polymer

As the “biocompatible polymer” used for implants, any biocompatible polymer can be used as long as it does not show any irritation to tissues to which platelets hardly adhere and can dissolve drugs. Can be used. For example, synthetic polymers included in “biocompatible polymers” include polyether polyurethane and dimethyl silicone blends or block copolymers, polyurethanes such as segmented polyurethane, polyacrylamide, polyethylene oxide, polyethylene carbonate, polypropylene. Polycarbonates such as carbonates can be used, and fibrin, gelatin, collagen and the like can be used as natural biocompatible polymers. These polymers can be used alone or in appropriate combination.

[0072] "Biodegradable polymer" refers to any biodegradable polymer as long as it is enzymatically and non-enzymatically degraded in vivo, the degradation product does not exhibit toxicity, and the drug can be released. Can also be used. For example, polylactic acid, polydaricholic acid, copolymers of polylactic acid and polydaricholic acid, collagen, gelatin, chitin, chitosan, hyaluronic acid, poly (L-dartamic acid), poly (L) lysine and other polyamino acids, starch, poly (ε) -Force prolatatanes, polyethylene succinates, poly (mono-e8-hydroxyalkanoates), etc. may be used as appropriate. These polymers can be used alone or in appropriate combination. It is also possible to use a combination of both a biocompatible polymer and a biodegradable polymer as appropriate.

[0073] 8. Implant examples Examples of implants that can be placed in the body and exhibit desired medical effects include stents, stent grafts, artificial blood vessels, catheters (including balloon catheters), artificial heart valves, pacemaker leads, bone screws, artificial bones, artificial tracheas And sutures. Among them, a stent used to secure a sufficient lumen by being placed in a blood vessel, ureter, urethra, lymphatic vessel, or the like that causes stenosis of a living body is a specific example of the implant of the present invention. It is suitable as a mode. However, the rifamycin derivative as an embodiment is not limited to a stent but can be applied to implants well known to those skilled in the art. As a method for producing such an implant, for example, methods known to those skilled in the art disclosed in JP-A-9-38195 and JP-A-2003-24452 can be employed.

[0074] 9. Stent as an embodiment

Hereinafter, an example of the overall structure of a living indwelling stent as an embodiment of the present invention will be described with reference to FIG. 1 and FIG. Fig. 1 is a developed view of the stent, and Fig. 2 is a schematic view. As a method for producing a stent and a method for fixing a drug to the stent, which will be described later, for example, methods known to those skilled in the art disclosed in JP 2005-65981 A and JP 2004-222953 A may be employed. it can.

[0075] In order to treat various diseases caused by stenosis or occlusion of blood vessels or other in-vivo lumens, stents are used to expand the stenosis or occlusion site and reduce the lumen size. It is a medical device that is placed there for maintenance. A stent is typically inserted into a blood vessel by a catheter and expanded to contact an unhealthy part of the arterial wall to provide mechanical support for the blood vessel lumen. In addition, stent expansion is performed by either self-expansion due to its own physical characteristics (shape memory property, superelasticity, etc.) or forced expansion due to the expansion force of the balloon catheter.

[0076] (9 1) Material

The stent used as the base for coating the drug layer can be made of metallic forces such as stainless steel, Ni-Ti alloy, Cu-Al-Mn alloy, Co-Cr alloy, magnesium alloy, iridium, iridium oxide, and niobium. is there. The stent can be manufactured by cutting a cylindrical metal material tube into a stent design by laser cutting and performing electropolishing in the same manner as a method normally manufactured by those skilled in the art. However, the manufacturing method is It is not limited to the above methods, but it is also possible to use a processing method by etching, a method in which a flat metal is laser cut and then rolled and welded, or a method in which a metal wire is knitted.

[0077] Further, the polymer is not limited to a metal material, but is a high molecule such as polyolefin, polyolefin elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyester, polyester elastomer, polyimide, polyamideimide, polyetheretherketone. Inorganic materials such as materials, ceramics, hydroxyapatite can also be used.

[0078] (9 2) Polymer layer

A polymer layer may be provided on the stent surface for the purpose of fixing a drug or the like. Because it is used in living organisms, it is preferable to use biocompatible polymers or biodegradable polymers as the polymer.

[0079] As a method for providing a polymer layer on the stent surface, a method such as a method of dying a stent into a polymer solution or a method of spraying a polymer solution onto a stent by spraying can be used. The above-described methods are all coating methods, but a separately prepared polymer sheet may be attached to the stent surface. In the case of coating, an arbitrary solvent having a polymer solubility can be selected as the solvent used in preparing the polymer solution. In order to adjust the volatility of the solvent, a mixed solvent using two or more solvents may be used. The concentration of the polymer solution is not particularly limited, and can be set to any concentration in consideration of the surface properties of the polymer layer, the required amount of drug retained, the release behavior of the retained drug, and the like.

[0080] The polymer solution prepared using such a solvent is applied to the stent and dried, or the operation of immersing the stent in the solution and drying it is repeated at least once, thereby forming the polymer layer on the stent. Can be provided. When the coating is performed by spraying, the distance between the spray nozzle and the stent is preferably 50 cm or less in order to make the surface of the polymer layer uniform, more preferably 10 cm or more and 30 cm or less. Also, 50rpm or more is preferred to make the surface of the polymer layer even when the stent is rotated when spray coating or dating.

[0081] Further, in order to control the surface property of the polymer layer, a polymer solution is applied to the stent. Extra polymer solution may be removed during and after z or after application. Examples of the removing means include vibration, rotation, and decompression, and a plurality of these may be combined.

[0082] (9-3) Coating of drug (rifamycin derivative)

A drug (rifamycin derivative) layer is provided on the stent surface.

[0083] As a method of coating a stent with a drug (rifamycin derivative), the drug can be attached to the stent by removing the solvent after adding the drug to the stent in a solution state. It is also possible to attach the drug to the stent using the aforementioned biocompatible polymer or biodegradable polymer. For example, a biocompatible polymer and Z or biodegradable polymer together with a drug (rifamycin derivative) can be used in a liquid or suitable solvent, such as water, buffer, acetic acid, hydrochloric acid, methanol, ethanol, acetone, acetonitrile, A stent using a biocompatible polymer or a biodegradable polymer can be prepared by contacting the stent as a solution of methylene chloride, chloroform, tetrahydrofuran, etc. and then removing the solvent.

[0084] As a more specific example, a stent is coated with a solution obtained by dissolving or suspending a drug in a solution prepared by dissolving a biocompatible polymer and Z or a biodegradable polymer in a low boiling point solvent. By repeating the operation of drying or dipping the stent in the liquid and drying it at least once, the drug can be attached to the stent and coated with a biocompatible polymer and Z or biodegradable polymer. . As a coating method, a method of dating a stent into a solution or a method of spraying with a spray can be used.

[0085] Regarding the thickness of the coating layer, when the coating layer is thickened, there is a possibility that the formation of a thrombus may be promoted due to unevenness in the blood vessel, and the restenosis rate may be increased. However, a certain amount of thickness is required to coat the sufficient dose required for treatment. From this viewpoint, the thickness of the coating layer is preferably 1 m or more and 10 μm or less, more preferably 3 μm or more and 5 μm or less.

Example

[0086] Hereinafter, a stent will be specifically described as an example of producing an implant, but the present invention is not limited to this. [0087] The base stent was manufactured by cutting a stainless steel cylindrical tube into a stent design by laser cutting and performing electropolishing, in the same manner as a method usually produced by those skilled in the art. The developed view of the stent used is shown in Fig. 1, and the schematic diagram is shown in Fig. 2. The structure of this stent was a balloon etaspan double type, which is a type in which the stent is expanded and indwelled using a none catheter equipped with a balloon near the tip of the catheter. The stent is set in a deflated state on the balloon portion of the balloon catheter. After delivery to the target site using the balloon catheter, the stent is expanded and placed by expanding the balloon.

[0088] Hereinafter, three embodiments will be described as examples of manufacturing a stent.

[0089] (Stent production example 1)

A stent obtained by coating rifalazil on the above-described stent as a base using the polyether-type polyurethane resin is referred to as Production Example 1.

[0090] The coating procedure is as follows. First, the urethane solution is sprayed onto the base stent using an airbrush, followed by drying at 60 ° C for 10 minutes. The spraying and drying are repeated 5 times, and finally 100 g of the urethane per stent is coated on the stent. Next, the urethane-coated stent is immersed in a rifalazil solution for 1 hour and dried.

[0091] (Stent production example 2)

For the stent base material, a stainless steel (SUS316L) cylindrical tube with an inner diameter of 1.50 mm and an outer diameter of 1.80 mm is cut into a stent design by laser cutting and electropolished in the same manner as those usually produced by those skilled in the art. To make. The design is such that the length of the stent is 13 mm, the thickness is 120 mm, and the nominal diameter after expansion is 3.5 mm. Inner surface, an outer surface of the stent base material, the total surface area of the combined side surface is 88. 5 mm ^2.

[0092] Lactic acid-glycolic acid copolymer (lactic acid Z glycolic acid = 85 mol% Zl5 mol%) as biodegradable polymer, rifalazil as drug is dissolved in black mouth form, drug concentration Z biodegradable polymer concentration = 0. Make a solution that is 50wt% / 0.50wt%. Secure a 100 m diameter stainless steel wire to one end of the stent and the other end to a 2 mm diameter stainless steel rod. Connect the end of the stent bar to which the stent is not connected to the motor agitator. By continuing, the stent is held vertically in the length direction. While rotating the stent at lOOrpm using a motor agitator, spray the solution prepared using a spray gun with a nozzle diameter of 0.3 mm onto the stent, and attach the solution to the stent. The distance from the spray gun nozzle to the stent is 75 mm, and the air pressure when spraying is 0.15 MPa. After spraying, vacuum dry at room temperature for 1 hour. Adjust the spray time to adjust the weight of biodegradable polymer and drug per stent.

[0093] (Stent production example 3)

For the stent base material, a stainless steel (SUS316L) cylindrical tube with an inner diameter of 1.50 mm and an outer diameter of 1.80 mm is cut into a stent design by laser cutting and electropolished in the same manner as those usually produced by those skilled in the art. It was produced by. The stent was designed to have a length of 18 mm, a thickness of 120 mm, and a nominal diameter of 3.5 mm after expansion. Lactic acid glycolic acid copolymer (lactic acid Z glycolic acid = 85mol% / l 5mol%, molecular weight 84,000) as biodegradable polymer, rifalazil dissolved in acetone as drug, rifalazil Z lactic acid monoglycolic acid copolymer Four coating solutions with weight ratios of 40Z60, 30/70, 20/80, and 10Z90 were prepared. The coating solution prepared using an airbrush was sprayed onto the stent to attach the coating solution to the stent. At this time, the air pressure at the time of spraying was ² kgZcm2, and the weight of biodegradable polymer and drug per stent was adjusted by adjusting the spray time. After spraying, it was vacuum dried at room temperature for 3 hours. The appearance of the prepared coating stent was observed with a scanning electron microscope (SEM). In addition, a balloon was inserted into the stent and expanded to an outer diameter of 3.5 mm at a pressure of 8 atm.

[0094] FIG. 7 is an SEM image of the surface of a stent coated with a coating solution having a rifalazil Z lactic acid-glycolic acid copolymer weight ratio of 20Z80. As shown in Fig. 7, the coating surface was smooth both before and after the stent expansion, and no cracks, delamination or cracks were found. In addition, the same surface properties were exhibited even when the coating weight was increased to 810 g / stent with the same solution composition.

[0095] In the following examples, rifamycin induction as an embodiment of the present invention is performed using a cytostatic test of human coronary artery smooth muscle cells (CASMC) and human coronary artery endothelial cells (CAEC). Explain that the conductor has a stronger inhibitory effect on vascular smooth muscle cells than vascular endothelial cells.

[0096] (Example 1) CASMC culture

Using CASMC (manufactured by Takara Bio Inc.) and the attached medium (SmGM—2 BulletKit), 70 80% confluence at 37 ° C in 5% CO using 1 OOmm dish.

2

· ¾ 'and c>

[Example 2] CAEC culture

CAEC (manufactured by Takara Bio Inc.), using the attached medium (EGM-2—MV BulletKit), reaches 70 80% confluence in 5% CO at 37 ° C in a 100mm dish

2

.

[0098] (Example 3) CASMC and CAEC growth inhibition test

CASMC and CAEC that reached 70 80% confluence were collected from a 100 mm dish using a subculture reagent set (manufactured by Takara Bio Inc.). The obtained cells were seeded in a 96-well plate and cultured for 24 hours at 37 ° C in 5% CO. Next, 24 hours

2

After setting the state of nutrient depletion of cells under the absence of serum, the cells were cultured for 48 hours in the above-mentioned medium containing various concentrations (10 1 00 1, OOOnM) of rifalazil. After culturing, the BrdU uptake ability was measured using a cell growth ELISA (BrdU) (color development) manufactured by Roche Diagnostics. BrdU uptake ability represents DNA synthesis ability, which is a parameter of cell proliferation.

[0099] FIG. 3 and FIG. 46, which will be described later, are graphs showing the relationship between each concentration of the drug and the growth inhibitory action of both cells. The vertical axis represents the absorbance representing the BrdU uptake ability, and the value at each concentration relative to the absorbance in the non-drug-added group (control) was graphed. Also, in the graph

, ** indicates statistical significance. For statistical processing, Dunnett's test was performed as an example.

[0100] As shown in FIG. 3, rifalazil showed statistically significant inhibition of CASMC growth at 100 and 1, OOOnM, compared to the group without rifalazil.

[0101] On the other hand, as shown in FIG. 4, rifalazil was statistically significantly stronger than the rifalazil non-added group and showed no CAEC growth inhibition. [0102] In view of these facts, it was shown that rifalazil did not inhibit growth at all for CAEC, but inhibited growth for CASMC in 100 and 1, OOOnM.

[0103] (Example 4)

In Example 4, CASMC and CAEC growth inhibition tests were performed in the same manner as in Example 3 above, except that KRM1657, KRM1671, KRM1 689, and KRM1690 were used instead of rifalazil and the incubation time after addition of the test substance was 72 hours. I went.

FIGS. 8 to 11 are graphs showing the relationship between each concentration of the drug and the growth inhibitory action of both cells. The solid line indicates CASMC and the broken line indicates CAEC. The vertical axis represents the absorbance representing the BrdU uptake ability, and the value at each concentration relative to the absorbance in the rifalazil non-added group (control) was graphed. In the graph, ** indicates statistical significance. For statistical processing, Dunnett's test was performed as an example.

[0105] Fig. 8 ~: As shown in L 1, as with rifalazil, the four rifamycin derivatives tested tested strongly inhibited proliferation against CASMC compared to CAEC.

[0106] (Comparative Example 1)

In Comparative Example 1, CASMC and CAEC growth inhibition tests were conducted in the same manner as in Example 3 except that the test substance was changed to rifalazil and changed to rapamycin.

[0107] As can be seen from Fig. 5, rapamycin was statistically significant at all concentrations (1, 10, 100, 1, OOOnM) in which the growth of CASMC was compared to the group without addition of rapamycin. Inhibited growth.

[0108] In addition, as can be seen from Fig. 6, rapamycin is statistically significant at all concentrations (1, 10, 100, 1, OOOnM) at which CAEC growth was performed compared to the group without rapamycin. Intentionally, growth suppression was shown.

[0109] These results indicate that rapamycin inhibits the growth of both CAEC and CASMC cells.

[0110] From the above, difaradil, KRM1657, KRM1671, KRM1689, and KRM1690 were more potent than CAS to suppress cell proliferation compared to CASMC.

[0111] Therefore, implants coated with rifalazil, KRM1657, KRM1671, KRM1689, and KRM1690 (for example, including the stents of Preparation Examples 1 to 3 above) undergo endothelial regeneration. It is presumed to suppress the proliferation of vascular smooth muscle cells while not inhibiting the above. In other words, the implant (for example, the stent of Preparation Example 1, Preparation Example 2, or Preparation Example 3) is excellent in antithrombogenicity and tissue compatibility and is considered to be able to suppress stenosis.

Claims

Claims [1] An implant comprising a rifamycin derivative. [2] An implant comprising an agent for treating a vascular disease comprising a rifamycin derivative as an active ingredient. [3] An implant comprising a cell growth regulator comprising a rifamycin derivative as an active ingredient. [4] The implant according to any one of [1] to [3], wherein the rifamycin derivative is more potent in inhibiting proliferation of vascular smooth muscle cells than vascular endothelial cells. The implant according to any one of claims 1 to 4, which comprises a rifamycin derivative as an active ingredient, and exhibits a non-cell growth inhibitory action on vascular endothelial cells and a cell growth inhibitory action on vascular smooth muscle cells. [6] The rifamycin derivative has the following formula (I):

[Chemical 1]

R ⁴ is the same or different and represents a hydroxyl group, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a group represented by the following formula (II), or a group represented by the following formula (IV). ) Or a physiologically acceptable compound thereof The implant according to any one of claims 1 to 5, wherein the implant is a salt.

[Chemical 2]

[Chemical 3]

R ⁷ R ⁸

— “X ² (IV) In the above formula (II), R ⁵ and R ⁶ are the same or different and represent an alkyl group having 1 to 3 carbon atoms or a group represented by the following formula (ΠΙ).

[Chemical 4]

(In the formula (m), j represents an integer of 1 to 3.)

In the above formula (IV), R ⁷ and R ⁸ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ² represents an oxygen atom, a sulfur atom, a carbonyl group, and the following formula (V) Or a group represented by the following formula (IV).

[Chemical 5]

[Chemical 6]

(0),

(VI)

: NR "In the above formula (V), R ⁹ and R ^1Q are the same or different and are a hydrogen atom, an alkyl having 1 to 3 carbon atoms. Or a group represented by the following formula, wherein R ⁹ and R ^1Q are bonded.

(CH) —

2k

(In the formula, k represents an integer of 1 to 4.)

In the above formula (VI), m represents 0 or 1, R ¹¹ represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or a group represented by the following formula.

(CH) X ³

2 n

(In the formula, n represents an integer of 1 to 4, X ³ represents an alkoxy group having 1 to 3 carbon atoms, a vinyl group, an ethyl group, or a group represented by the following formula (VII).

[Chemical 7]

[7] In the rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ represents an acetyl group or a hydrogen atom, R ² represents a methyl group or a hydroxymethyl group,

R ⁴ may be the same or different and is a hydroxyl group, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a formula (VI II):

[Chemical 8]

— NR ¹² (VIII)

(In formula (VIII), R ¹² represents a hydrogen atom or an alkyl group having 1 to 7 carbon atoms), or a physiologically acceptable salt thereof. Item 6. The implant according to Item 6.

[8] In the rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ is a acetyl group, R ² is a methyl group, R ³ is a hydroxyl group, and R ⁴ is a formula (IX):

[Chemical 9] CH ₂ CH (CH ₃ ) ₂

Claims characterized in that it is a rifafunnel {Rifalazil, 3'— Hydroxy— 5′— (4—isobutyl—l—piperazinyl) benzoxaz inorifamycin, KRM 1648} or a physiologically acceptable salt thereof The implant according to 7.

In the rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ is a acetyl group, R is a methyl group, R ³ is a hydroxyl group, and R ⁴ is a formula (X):

[Chemical 10]

—— N CH, CH „CH, (X)

The implant according to claim 7, which is KRM1657 represented by ^{2 2 3} or a physiologically acceptable salt thereof.

In the rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ is a hydroxyl group, R ² force methyl group, R ³ is a hydroxyl group, and R ⁴ is a formula (IX):

[Chemical 11]

The implant according to claim 7, wherein the implant is KRM1671 or a physiologically acceptable salt thereof.

In the rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ is a acetyl group, R ² force S methyl group, R ³ and R ⁴ are represented by formula (IX):

[Chemical 12]

The implant according to claim 7, wherein the implant is KRM1689 or a physiologically acceptable salt thereof.

[12] In the rifamycin derivative, X ^{1 in the} formula (I) is an oxygen atom, R ¹ is a acetyl group, R ² is a hydroxymethyl group, R ³ is a hydroxyl group, and R ⁴ is Formula (IX): [Chemical 13]

The implant according to claim 7, wherein the implant is KRM1690 or a physiologically acceptable salt thereof.

13. The implant according to any one of claims 1 to 12, wherein the rifamycin derivative is present in a biocompatible polymer or a biodegradable polymer.

14. The implant according to claim 13, wherein the biodegradable polymer is a lactic acid-glycolic acid copolymer.

[15] The rifamycin derivative is filled in a vesicle.

4! Implants listed in the gap.

[16] The implant according to claim 15, wherein the vesicle is in the form of a microparticle, a nanoparticle or a ribosome.

17. The implant according to any one of claims 1 to 16, wherein the implant is a stent.

[18] A method for producing an implant, comprising a step of preparing a solution containing a biocompatible polymer or biodegradable polymer and a rifamycin derivative, and a step of applying or holding the solution to the implant.

[19] A method for treating a vascular disease using the implant according to any one of claims 1 to 18.