Porous body for capturing cancer cells

Abstract

To provide a porous body for capturing cancer cells, having biocompatibility and also having in vivo stability.SOLUTION: The present invention discloses a porous body for capturing cancer cells, including a biocompatible inorganic material.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a porous body for capturing cancer cells. [Background technology]

[0002] Since 1981, the number one cause of death among Japanese people has been malignant tumors, or "cancer," and currently, more than 300,000 people die from cancer each year, and more than 600,000 people are newly diagnosed with cancer each year. As Japan's population continues to age, the number of cancer patients is expected to continue to increase.

[0003] Early detection of cancer cells is one of the goals for optimal treatment and diagnosis. However, it can be difficult to detect cancer cells before metastasis or spread occurs, and even after metastasis or spread occurs, cancer cells may not be detected. Therefore, if cancer cells are detected and diagnosed late and the cancer cells have metastasized throughout the body, and surgery is not possible or is incurable, treatments include chemotherapy with anticancer drugs and special radiation therapy.

[0004] The mechanism of cancer metastasis is known to involve the process of cancer cells being released from the primary lesion, drifting to the target organ via the bloodstream, lymphatic flow, or migration within tissues, invading the tissue, and then growing in the cancer tissue. Attempts have been made in cancer treatment to inhibit any of these processes. For example, Patent Document 1 discloses a technology for suppressing metastasis of cancer to a target organ by collecting circulating tumor cells (CTCs) using a porous material containing polycaprolactone. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2019 / 0008971 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the porous body described in Patent Document 1 is made of polycaprolactone, which is a biodegradable material, and therefore, if implanted for a long period of time, the porous body that has captured metastatic cancer cells may biodegrade, releasing the captured cancer cells into the body.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a porous body for capturing cancer cells, which is biocompatible and stable in vivo. [Means for solving the problem]

[0008] The present inventors have conducted extensive research in view of the above problems, and as a result have found that the above problems can be solved by a porous body for capturing cancer cells, which contains a biocompatible inorganic material, thereby completing the present invention. Effect of the Invention

[0009] The present invention provides a porous body for collecting cancer cells, which is biocompatible and stable in vivo. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an optical microscope photograph showing the results of a cell adhesion test in Test Example 1 of the Examples. [Diagram 2] FIG. 2 is a scanning electron microscope photograph showing the results of the cell adhesion test in Test Example 1 of the Examples. [Diagram 3] FIG. 3 is an optical microscope photograph showing the results of a cell adhesion test in Test Example 2 of the Examples (left side: porous body for capturing cancer cells, right side: smooth and dense scaffold). [Figure 4] FIG. 4 is a scanning electron microscope photograph showing the results of a cell adhesion test in Test Example 2 of the Examples (left side: porous body for capturing cancer cells, right side: smooth and dense scaffold). [Diagram 5]Figure 5 shows optical microscope images of the porous material for capturing cancer cells (top left) and the smooth / dense scaffold (top right), as well as the results of measuring the surface roughness of the porous material for capturing cancer cells (bottom left) and the smooth / dense scaffold (bottom right). [Figure 6] FIG. 6 shows a schematic diagram (upper side) of the procedure in Test Example 3 of the embodiment, and a photograph (lower side) of a mouse in which a porous body for capturing cancer cells was embedded. [Figure 7] FIG. 7 is a graph showing the evaluation results of the life-prolonging effect in cancer-bearing mice in which a porous body for trapping cancer cells was implanted in Test Example 4 of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment according to one aspect of the present invention will be described below, but the present invention is not limited to the following embodiment.

[0012] In this specification, the range "X to Y" means "X or more and Y or less." Furthermore, unless otherwise specified, the operations and measurements of physical properties are performed under conditions of room temperature (20 to 25°C) and relative humidity of 40 to 50% RH.

[0013] <Porous material for collecting cancer cells> One aspect of the present invention relates to a porous body for capturing cancer cells, comprising a biocompatible inorganic material. In this specification, the term "porous body for capturing cancer cells" is also simply referred to as "the porous body of this aspect."

[0014] As used herein, "cancer cell capture" means that cancer cells adhere to the side surface or inside the pores of a porous body.

[0015] As used herein, the term "porous body" refers to a solid material or structure that contains a large number of pores.

[0016] In this specification, "biocompatibility" refers to the property of a material that allows it to coexist with a living body while performing its inherent functions for a long period of time without adversely affecting or causing strong irritation to the living body.

[0017] The biocompatible inorganic material according to the present embodiment is not particularly limited as long as it is an inorganic material having the above-mentioned biocompatibility. It may be crystalline, amorphous, or inorganic glass. By using the biocompatible inorganic material, adverse events can be suppressed, decomposition in the body can be suppressed, and stability can be ensured.

[0018] Examples of biocompatible inorganic materials include yttria-stabilized zirconia, titanium, titanium alloys, shape memory alloys such as Ni-Ti, silica, silicate compounds, phosphate compounds (e.g., calcium phosphate compounds), alumina, aluminum alloys, cobalt-chromium alloys, stainless steel, and mullite.

[0019] In one embodiment, the biocompatible inorganic material is preferably yttria-stabilized zirconia. The yttria-stabilized zirconia preferably contains 1 to 20 mol % of yttria, more preferably 3 to 10 mol % of yttria, based on the total of yttria and zirconia.

[0020] In one embodiment, the biocompatible inorganic material is preferably selected from the group consisting of titanium, silica, alumina, cobalt chromium alloy, stainless steel, and mullite. The cobalt chromium alloy is a metal mainly composed of cobalt, 25% or more chromium, 4% or more molybdenum, and other additives with the total of cobalt, nickel, and chromium being 85% or more.

[0021] In one embodiment, the porous body for capturing cancer cells has interconnected pores on the surface of the porous body for capturing cancer cells. The interconnected pores are pores in which adjacent pores are connected to each other. Therefore, when cancer cells enter the pores of the porous body, more cancer cells can adhere. In other words, more cancer cells can be captured.

[0022] The surface properties of the inner walls of the pores of the porous body of this embodiment are not particularly limited, but it is preferable that the surface has irregularities so as to increase the surface area of ​​the porous body.

[0023] The porosity of the porous body of the present embodiment is not particularly limited, but is, for example, 40 to 95%, preferably 60 to 95%, and more preferably 80 to 95%. The porosity of the porous body is a value measured by the method described in the examples.

[0024] The average pore size of the porous body of this embodiment is not particularly limited as long as metastatic cancer cells can enter it. The average pore size of the porous body is, for example, 20 to 1000 μm, preferably 100 to 800 μm, and more preferably 300 to 500 μm. The average pore size of the porous body is a value measured by the method described in the Examples.

[0025] The porosity of the porous body of the present embodiment is not particularly limited, but is, for example, 20 to 90%, preferably 30 to 80%, and more preferably 35 to 50%. The porosity of the porous body is a value calculated by the method described in the Examples.

[0026] In the porous body of this embodiment, the type of cancer to be collected is not particularly limited. For example, cancer of the nervous system (e.g., brain tumor, cervical cancer); cancer of the digestive system (e.g., oral cancer, pharyngeal cancer, esophageal cancer, stomach cancer, liver cancer, gallbladder cancer, biliary tract cancer, spleen cancer, large intestine cancer, small intestine cancer, duodenal cancer, colon cancer, colon adenocarcinoma, rectal cancer, pancreatic cancer, liver cancer); cancer of the musculoskeletal system (e.g., sarcoma, osteosarcoma, myeloma); cancer of the urinary system (e.g., bladder cancer, kidney cancer); cancer of the reproductive system (e.g., breast cancer, uterine cancer, ovarian cancer, testicular cancer, prostate cancer); cancer of the respiratory system (e.g., lung cancer, cancer); cancers of the hematopoietic system (e.g., leukemias such as acute or chronic myeloid leukemia, acute promyelocytic leukemia, acute or chronic lymphocytic leukemia, malignant lymphoma (lymphosarcoma), angiosarcoma, multiple myeloma, myelodysplastic syndrome, primary myelofibrosis, hemangiopericytoma); thyroid cancer, parathyroid cancer, tongue cancer, malignant melanoma, mast cell tumor, cutaneous histiocytoma, lipoma, hair follicle tumor, skin papilloma, sebaceous adenoma, basal cell carcinoma, etc.

[0027] In one embodiment, the cancer cell is a metastatic cancer cell. The metastatic cancer cell is not particularly limited, and is, for example, a metastatic cancer cell derived from the above-mentioned cancers, and is preferably a metastatic cancer cell derived from breast cancer, pancreatic cancer, lung cancer, liver cancer, and brain cancer.

[0028] The shape and size of the porous body of this embodiment are not particularly limited and can be appropriately selected depending on the use, purpose, and site of use, etc. Examples of the shape of the porous body include a sphere, a cylinder, a plate, a rod, a tube, and a lattice (e.g., a lattice structure).

[0029] [Manufacturing method] The method for producing the cancer cell-capturing porous body of this embodiment is not particularly limited, and known methods for producing porous ceramics can be appropriately referred to.

[0030] In one embodiment, the method for producing a porous body for capturing cancer cells of the present invention comprises the following steps: (1) A step of preparing a dispersion by mixing a biocompatible inorganic material, a dispersant, a pore-forming agent, and a dispersion medium; (2) filling the dispersion into a mold and freezing it to obtain a frozen body; (3) drying the frozen body to obtain a dry body; (4) degreasing the dried body; and (5) Sintering the degreased and dried body.

[0031] In step (1), a biocompatible inorganic material, a dispersant, a pore-forming agent and a dispersion medium are mixed together to prepare a dispersion.

[0032] As the biocompatible inorganic material, a powder of the above-mentioned biocompatible inorganic material can be used. The content of the biocompatible inorganic material is, for example, 20 to 50% by mass, preferably 30 to 40% by mass, based on the total mass of the dispersion.

[0033] The powder of the biocompatible inorganic material has an average particle size of, for example, 0.01 to 5 μm, and preferably 0.01 to 0.1 μm. The average particle size can be measured using a laser diffraction particle size distribution measuring device.

[0034] The dispersant not only contributes to the dispersion of the biocompatible inorganic material, but is also used to form interconnected pores. As the dispersant, a water-soluble polymer can be used. Examples of such water-soluble polymers include polysaccharides and their derivatives, polyvinyl alcohol, sodium salts of polyacrylic acid or polymethacrylic acid, and polyethylene glycol. In order to more effectively exert the effects of the present invention, the water-soluble polymer is preferably a polysaccharide.

[0035] Examples of polysaccharides include hydroxypropyl cellulose, carboxymethyl cellulose, agarose, methyl cellulose, cellulose ether, hydroxyethyl cellulose, modified starch, dextran, alginic acid, sodium alginate, etc. The polysaccharide is more preferably selected from hydroxypropyl cellulose, carboxymethyl cellulose, agarose, methyl cellulose, cellulose ether and hydroxyethyl cellulose, and particularly preferably hydroxypropyl cellulose.

[0036] The content of the dispersant is, for example, 0.5 to 5 mass %, and more preferably 1 to 3 mass %, based on the total mass of the dispersion.

[0037] The pore-forming agent has a function of generating pores. For example, resin beads can be used as the pore-forming agent. Examples of the resin beads include acrylic and urethane resin beads.

[0038] The shape of the pore-forming agent is not particularly limited, but is preferably spherical.

[0039] The size of the pore-forming agent is not particularly limited, and can be appropriately selected so as to obtain desired pores.

[0040] The content of the pore-forming agent is, for example, 30 to 60% by mass, and preferably 35 to 50% by mass, based on the total mass of the dispersion.

[0041] The dispersion medium is preferably water. For example, tap water, distilled water, ion-exchanged water, pure water, ultrapure water, etc. can be used as the water. Among them, the dispersion medium is preferably pure water or ultrapure water from the viewpoint of less impurities. In addition, the dispersion medium may be water containing an inorganic salt.

[0042] The content of the dispersion medium is, for example, 15 to 40% by mass, and preferably 20 to 30% by mass, based on the total mass of the dispersion.

[0043] The method of mixing the biocompatible inorganic material, the dispersant, the pore-forming agent and the dispersion medium is not particularly limited, and conventionally known knowledge can be appropriately referred to so that the biocompatible inorganic material and the pore-forming agent are well dispersed in the dispersion. For example, the biocompatible inorganic material, the dispersant and the dispersion medium are stirred and mixed to prepare a slurry in which the biocompatible inorganic material is uniformly dispersed. When stirring and mixing, heating may be performed as necessary. After that, the pore-forming agent is added to the prepared slurry and mixed to prepare a dispersion.

[0044] By adjusting the mixing ratio (mass ratio) of the biocompatible inorganic material, dispersant, pore-forming agent and dispersion medium, the porosity, pore rate, average pore size, etc. can be controlled.

[0045] In step (2), the dispersion prepared in step (1) is filled into a mold and frozen to obtain a frozen body.

[0046] The shape, size, etc. of the mold are not particularly limited and can be appropriately selected depending on the application of the porous body.

[0047] The material of the mold is not particularly limited, and alumina, stainless steel, iron, copper, aluminum, plastic, paper, etc. can be used.

[0048] By freezing the dispersion filled in the mold, ice crystals grow and form a tissue structure due to the ice crystals, thereby obtaining a frozen body consisting of a biocompatible inorganic material, a dispersant solution portion, and an ice crystal portion.

[0049] The freezing temperature can be appropriately selected depending on the dispersion medium used, and is, for example, −10° C. or lower, and preferably −30° C. or lower.

[0050] In step (3), the frozen body obtained in step (2) is dried to obtain a dried body. By drying the frozen body (e.g., freeze-drying or vacuum drying), the ice crystals sublimate and disappear, and pores are formed instead.

[0051] In step (4), the dried body obtained in step (3) is degreased. In this step, organic components such as the dispersion medium and the pore-forming agent are removed from the dried body. Specifically, the organic components are decomposed and removed under predetermined temperature conditions according to the type of biocompatible inorganic material used. The degreasing temperature is, for example, 300 to 900°C. The degreasing time can be appropriately adjusted so that the organic components can be removed by decomposition.

[0052] In step (5), the degreased dried body is sintered. The sintering temperature, sintering time, sintering atmosphere, etc. can be appropriately adjusted depending on the biocompatible inorganic material used, the porosity, etc. The sintering temperature is, for example, 1000 to 1700°C when yttria-stabilized zirconia is used as the biocompatible inorganic material, and 1000 to 1700°C when alumina is used as the biocompatible inorganic material.

[0053] In this manner, the porous body according to the present invention can be produced.

[0054] [Application] The porous body for collecting cancer cells of this embodiment can be used for cancer-related applications such as treatment, treatment support, examination, and diagnosis. In particular, the porous body for collecting cancer cells of this embodiment is suitable for treatment or treatment support applications. Specifically, the porous body for collecting cancer cells of this embodiment can be embedded in the body of a subject and used to collect metastatic cancer cells.

[0055] The present inventors found that cancer cells adhere to the porous body of this embodiment (Test Examples 1 and 2 described below). In an experiment in which the porous body of this embodiment was transplanted into mice, it was confirmed that no adverse events caused by the porous body occurred (Test Example 3 described below). Furthermore, it was confirmed that a life-prolonging effect was obtained in cancer-bearing mice in which the porous body of this embodiment was implanted after removal of the primary tumor (Test Example 4 described below).

[0056] One embodiment of the present invention relates to a cancer-collecting porous body, comprising a biocompatible inorganic material, for implantation into a subject.

[0057] Moreover, one embodiment of the present invention relates to the use of a porous body for collecting cancer cells, preferably for collecting cancer cells by implantation into a subject, wherein the porous body comprises a biocompatible inorganic material.

[0058] In the present specification, the "subject" is, for example, a mammal, a bird, etc., preferably a mammal or a bird that is afflicted with cancer or suspected of being afflicted with cancer. Here, the mammal includes both primates such as humans, monkeys, gorillas, chimpanzees, and orangutans, and non-human mammals such as mice, rats, hamsters, guinea pigs, rabbits, dogs, cats, pigs, cows, horses, sheep, camels, and goats. Birds include chickens, quails, and pigeons. Among these, preferred are humans, hamsters, guinea pigs, rabbits, dogs, cats, and pigs, and more preferred are humans or pet animals such as dogs, cats, and rabbits.

[0059] The site where the cancer-capturing porous body of this embodiment is implanted (embedded) is not particularly limited, but is preferably subcutaneous, intramuscular, intraperitoneal, or a tumor excision site. The cancer-capturing porous body can be implanted into one or more sites of a subject.

[0060] <Implant for collecting cancer cells> As described above, the porous body for capturing cancer cells of this embodiment can be transplanted into a subject for use. Thus, one embodiment of the present invention relates to an implant for capturing cancer cells, which includes the porous body for capturing cancer cells described above.

[0061] The cancer cell collecting implant is preferably implanted into a subject and used to collect metastatic cancer cells within the subject.

[0062] As used herein, "implant" refers to a device that is implanted into a subject by surgical or minimally invasive methods, and more specifically, a device that is completely or partially implanted within the body of a subject.

[0063] In one embodiment, the implant for collecting cancer cells comprises the above-mentioned porous body for collecting cancer cells.

[0064] The site where the cancer cell-capturing implant of the present embodiment is implanted is not particularly limited, but is preferably subcutaneous, intramuscular, intraperitoneal, or a tumor excision site. The cancer cell-capturing implant can be implanted into one or more sites of a subject.

[0065] The cancer cell-trapping implant may further contain a drug in addition to the cancer cell-trapping porous body. In this specification, the term "drug" refers to any compound that can be used for therapeutic purposes.

[0066] Examples of drugs include protein pharmaceuticals, alkylating agents, antibiotics, metabolic antagonists, hormones, platinum preparations, topoisomerase inhibitors, microtubule inhibitors, and angiogenesis inhibitors.

[0067] Examples of protein drugs include peptides, enzymes, structural proteins, receptors, cytokines, chemokines, hematopoietic factors, and growth factors. Specific examples include IL-1, IL-4, IL-8, IL-10, IL-13, IL-17, CCL2, CCL5, CCL9, CCL18, CCL19, CCL20, CCL21, CCL25, CCL27, CCR4, CCR5, CCR7 / CCL21, CCR9, CCR10, CCL18, CCL2 / MCP-1, MIP-1α / CCL3, CXCL1, CXCL2, CXCL3, CXCL4, CXCL5, These include CXCL8, CXCL12 / SDF-1α, CXCR2, CXCR3, CXCR4, CXCR7, erythropoietin (EPO), CCL5 / RANTES, hepatocyte growth factor activator (HGFA), insulin-like growth factor-1 (IGF-1), cyclooxygenase-2 (COX-2), CXCL14, prostaglandin E2, platelet-derived growth factor, and vascular endothelial growth factor (VEGF).

[0068] Examples of alkylating agents include mustards, nitrosoureas, triazenes, and ethyleneimine. More specific examples include cyclophosphamide, ifosfamide, busulfan, melphalan, nitrogen mustard, chlorambucil, glufosfamide, mafosfamide, estramustine, nimustine, ranimustine, carmustine, lomustine, semustine, streptozocin, procarbazine, dacarbazine, temozolomide, thiotepa, hexamethylmelamine, trabectedin, apaziquone, altretamine, bendamustine, and mitolactol.

[0069] Examples of antibiotics include anthracycline antibiotics (e.g., doxorubicin (adriamycin), daunorubicin, pirarubicin, epirubicin, idarubicin, aclarubicin, amrubicin, zorubicin, valrubicin, liposomal doxorubicin, pixantrone, and mitoxantrone, etc.), mitomycin C, bleomycin, peplomycin, actinomycin D, zinostatin stimalamer, etc.

[0070] Examples of antimetabolites include pyrimidine analogs, purine analogs, folic acid analogs, ribonucleotide reductase inhibitors, and DNA polymerase inhibitors. More specifically, examples of such drugs include fluorouracil (5-FU), tegafur, tegafur / uracil combination drug, tegafur / gimeracil / oteracil potassium combination drug, doxifluridine, capecitabine, carmofur, cytarabine, cytarabine ocfosfate, enocitabine, gemcitabine, azacitidine, decitabine, floxuridine, ethinylcytidine, 6-mercaptopurine, fludarabine, pentostatin, nelarabine, 6-thioguanine, cladribine, clofarabine, methotrexate, pemetrexed, raltitrexed, nolatrexed, pralatrexate, trimetrexate, idatrexate, and hydroxycarbamide.

[0071] Examples of hormone drugs include antiestrogens, aromatase inhibitors, progesterone derivatives, antiandrogens, adrenal cortex hormones, LHRH (luteinizing hormone releasing hormone) agonists, etc. More specifically, tamoxifen, toremifene, raloxifene, fulvestrant, anastrozole, exemestane, letrozole, aminoglutethimide, formestane, vorozole, methyltestosterone, medroxyprogesterone, megestrol, gestnorone, mepitiostane, flutamide, nilutamide, bicalutamide, finasteride, chlormadinone, estramustine, diethylstilbestrol, ethinylestradiol, fosfestrol, polyestradiol phosphate, prednisolone, dexamethasone, mitotane, goserelin, leuprorelin, buserelin, triptorelin, etc.

[0072] Examples of platinum agents include cisplatin, carboplatin, nedaplatin, oxaliplatin (Ox), satraplatin, miriplatin, lobaplatin, spiroplatin, tetraplatin, ormaplatin, and iproplatin.

[0073] Examples of topoisomerase inhibitors include topoisomerase I inhibitors and topoisomerase II inhibitors. More specifically, examples include topotecan, irinotecan, exatecan, nogitecan, the above-mentioned anthracycline antibiotics, etoposide, teniposide, zobuzoxane, etc.

[0074] Examples of microtubule inhibitors include vinca alkaloids and taxane compounds. More specifically, they include vincristine, vinblastine, vindesine, vinorelbine, vinflunine, monomethylauristatin E, epothilone B, eribulin, paclitaxel (taxol), docetaxel (DTX), cabazitaxel, etc.

[0075] Examples of angiogenesis inhibitors include VEGF (vascular endothelial growth factor) inhibitors such as anti-VEGF antibodies, angiogenesis signal inhibitors such as tyrosine kinase inhibitors, and MMP (matrix metalloprotease) inhibitors. More specifically, bevacizumab, aflibercept, MV833, cetuximab, pegaptanib, pazopanib, CBO-P11, sunitinib, sorafenib, ranibizumab, vatalanib, axitinib, zactima, NX1838, angiozyme, semaxanib, lestaurtinib, TSU-68, ZD4190, temsirolimus, angiostatin, endostatin, TNP-470, and CP-547632. , CPE-7055, KRN633, AEE788, IMC-1211B, PTC-299, E7820, lenvatinib, marimastat, neovastat, prinomastat, metastat, BMS-275291, MMI270, S-3304, vitaxin, orotate carboxyamidotriazole, thalidomide, genistein, interferon alpha, and interleukin-12.

[0076] <Method for collecting metastatic cancer cells> One aspect of the present invention relates to a method for collecting metastatic cancer cells, comprising implanting the above-mentioned cancer cell-collecting implant into the body of a subject.

[0077] The requirements for this embodiment are the same as those for the above-mentioned cancer cell-capturing porous body and cancer cell-capturing implant, and therefore a detailed explanation will be omitted. EXAMPLES

[0078] Hereinafter, the embodiments of the present invention will be described in more detail using examples, but the technical scope of the present invention is not limited to the following examples.

[0079] <Preparation of a porous body for capturing cancer cells: Example> A mixture of 5 g of ultrapure water and 0.5 g of hydroxypropyl cellulose was added with 12.1 g of yttria-stabilized zirconia powder (TZ3Y, Tosoh Corporation), and heated and stirred using a hot plate stirrer (60-70 ° C). After stirring, 15 g of resin beads (S-40, Sekisui Chemical Co., Ltd.) were added and mixed. This mixture was filled into an alumina ring (tube) (diameter 9.0 mm, thickness 2.7 mm), frozen at -30 ° C, and then dried for 24 hours in a freeze-drying device. After degreasing at 800 ° C for 2 hours (1 ° C / min temperature increase) in an electric furnace under air atmosphere, it was fired at 1400 ° C for 6 hours (5 ° C / min temperature increase) in an electric furnace to prepare a porous body for capturing cancer cells (porous scaffold, diameter 6.7 mm, thickness 2.1 mm).

[0080] (Porosity measurement) The volume (calculated from the actual measurements of the diameter and thickness) and weight of the prepared porous body for capturing cancer cells were determined, and the porosity was calculated from the ratio of the weight of the porous body for capturing cancer cells to the weight of a dense body of the same volume calculated from the specific gravity of yttria-stabilized zirconia.

[0081] The porosity of the prepared porous material for capturing cancer cells was 85%.

[0082] (Calculation of average pore diameter) The diameters of the pores observed in scanning electron microscopy (SEM) images were measured, and the average pore size was calculated from these measurements.

[0083] The average pore size of the prepared cancer cell-collecting porous material was 400 μm.

[0084] (Calculation of hole opening rate) The area of ​​the openings was measured from scanning electron microscopy (SEM) images, and the area ratio of the openings per unit area was defined as the opening ratio.

[0085] The porosity of the prepared cancer cell-collecting porous material was 50%.

[0086] <Preparation of smooth and dense scaffold: Comparative example> 0.8 g of yttria-stabilized zirconia powder (TZ3Y, Tosoh Corporation) was packed into a press jig with a diameter of 17.5 mm and subjected to uniaxial pressing (200 MPa, 1 min), followed by cold isostatic pressing (200 MPa, 1 min). Sintering was performed at 1400°C for 1 hour (heating rate of 5°C / min) in an electric furnace under air atmosphere to produce a smooth and dense scaffold (diameter 13.5 mm, thickness 1.2±0.2 mm).

[0087] <Preparation of cell suspension> Mouse mammary adenocarcinoma-derived 4T1 cells were cultured in culture medium (RPMI1640 containing 10% FBS) to prepare a cell suspension.

[0088] <Test Example> 1. In vitro evaluation of cell adhesion to porous materials for cancer cell collection 1.0×10 6 2 mL of a cell suspension of 1000 cells / mL was seeded on a Φ35 mm culture dish. A sterilized cancer cell-collecting porous body was immersed in the cell suspension. After incubation for 2 hours at 37°C and 5% (v / v) CO2, the cancer cell-collecting porous body was transferred to another culture dish and 2 mL of culture medium (RPMI1640 containing 10% FBS) was added. The cells were cultured for one week at 37°C and 5% (v / v) CO2. After the culture, the state of cell adhesion was observed using an optical microscope (magnification: 100x). In addition, the cultured cancer cell-collecting porous body was fixed and freeze-dried, and then observed using a scanning electron microscope (magnification: 1000x). The results are shown in Figures 1 and 2.

[0089] As shown in Figure 1, it can be seen that a large number of cancer cells adhere to the side surface of the cancer cell-capturing porous material. In addition, as shown in Figure 2, it can be seen that the cancer cells extend their pseudopodia and adhere to the cross section (inside) of the cancer cell-capturing porous material.

[0090] 2. Evaluating the necessity of a porous surface for cell adhesion 1.0×10 6 500μL of cell suspension at 100 cells / mL was dropped onto the dish. After incubation at 37℃ and 5%(v / v)CO2 for 2 hours, the porous body for collecting cancer cells or the smooth / dense scaffold was transferred to another culture dish and 2mL of culture medium (RPMI1640 containing 10% FBS) was added. The cells were cultured at 37℃ and 5%(v / v)CO2 for 1 week. After the culture, the state of cell adhesion was observed using an optical microscope (magnification: 100x). After the culture, the porous body for collecting cancer cells or the smooth / dense scaffold was fixed and freeze-dried, and then observed using a scanning electron microscope (magnification: 1000x). The results are shown in Figures 3 and 4.

[0091] In addition, the surfaces of the cancer cell-collecting porous body and the smooth and dense scaffolds before the test were observed with an optical microscope (magnification: 100 times), and the surface roughness was measured with a stereomicroscope (manufactured by Keyence Corporation). The results are shown in Figure 5.

[0092] As shown in Figure 3, it can be seen that a large number of cancer cells adhere to the side of the cancer cell-collecting porous material. On the other hand, it can be seen that almost no cancer cells adhere to the side of the smooth / dense scaffold.

[0093] In addition, as shown in Figure 4, it can be seen that a large number of cancer cells adhere to the cross section (inside) of the cancer cell-collecting porous material. On the other hand, it can be seen that almost no cancer cells adhere to the side surface of the smooth / dense scaffold.

[0094] As shown in Figure 5, the porous body for capturing cancer cells has a rough surface due to the pores, while the smooth / dense scaffold has both dense and smooth surfaces. Therefore, Figures 3 to 5 show that having pores and a rough surface is effective for cell adhesion.

[0095] 3. In vivo evaluation of implant safety in mice The back of an 8-week-old mouse (BALB / c, purchased from Japan SLC Co., Ltd.) under general anesthesia was shaved according to Figure 6. A scalpel was used to make a 1.5 cm incision along the short axis 1 cm cranially from the last rib margin. The subcutaneous tissue was peeled off caudally from the incision line, and the scaffold was inserted through the incision and placed in place, after which the incision was sutured. The same procedure was repeated on the other side. The implantation condition was observed for up to two months, and it was visually confirmed that there were no abnormalities in the health of the mouse and that there were no abnormalities at the implantation site.

[0096] Animal experiments using mice were conducted in accordance with Articles 8, 9, and 11 of the Osaka Prefecture University Animal Experiment Regulations (Approval Number: Animal Experiment No. 19-165).

[0097] 4. Evaluation of survival benefit in tumor-bearing mice implanted with a porous material for capturing cancer cells The cancer cell-collecting porous material was implanted into the mouse in the same manner as in 3 above. One month after implantation, cancer cells were transplanted in the following manner.

[0098] (1) The abdomen of a mouse under general anesthesia was shaved; (2) A 1-cm incision was made along the longitudinal axis at a location approximately 5 cm axially from the base of the right hind leg; (3) The fourth mammary gland adipose tissue was exposed through the incision; (4) A suspension of mouse mammary adenocarcinoma-derived 4T1 cells loaded in a tuberculin syringe was injected into the mammary fat area; (5) The mammary fat was returned to subcutaneous tissue and sutured.

[0099] Ten days after the cancer cell transplantation, the mammary gland of the mouse was incised under general anesthesia in the same manner as in procedure (2), and the primary tumor was removed and then sutured.

[0100] The mice were kept under observation for their health condition, and their survival time was compared with that of a control group (no scaffold implantation) (n=20 per group, day of primary tumor removal=0). However, mice in which re-growth of the primary tumor was observed were excluded from the analysis.

[0101] The results are shown in Figure 7. In Figure 7, the Zr group is a group of mice in which a porous material for capturing cancer cells was implanted, and the Mock group is a control group.

[0102] As shown in FIG. 7, it is clear that implanting the cancer cell-trapping porous material of the present invention can provide a life-prolonging effect in cancer-bearing mice.

Claims

1. A porous body for capturing cancer cells, comprising a biocompatible inorganic material which is yttria-stabilized zirconia.

2. 2. The cancer cell-trapping porous body according to claim 1, having interconnected pores.

3. 3. The porous body for capturing cancer cells according to claim 1, which has a porosity of 40 to 95%.

4. 4. The cancer cell-capturing porous body according to claim 1, wherein the average pore size is 20 to 1000 μm.

5. The porous body for capturing cancer cells according to any one of claims 1 to 4, which has a porosity of 20 to 90%.

6. The porous body for capturing cancer cells according to any one of claims 1 to 5, wherein the cancer cells are metastatic cancer cells.

7. An implant for capturing cancer cells, comprising the porous body for capturing cancer cells according to any one of claims 1 to 6.

8. The cancer cell-collecting implant according to claim 7, which is implanted into a subject and used for collecting metastatic cancer cells within the subject.

9. A method for capturing metastatic cancer cells, comprising implanting the cancer cell-capturing implant according to claim 7 or 8 into the body of a subject (excluding humans).

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