Abstract: The present invention provides the following method as an approach for enriching desired cells, particularly, yolk sac mesoderm cells or amniotic ectoderm cells, contained in an embryogenesis region-specific micropattern structure of a cell cluster formed by differentiation-inducing factors from a colony of pluripotent stem cells such as iPS cells: a method for producing a cell cluster enriched in desired cells from pluripotent stem cells, comprising the step of two-dimensionally culturing the pluripotent stem cells under Wnt signal regulation.

Abstract: The present invention provides drug toxicity evaluation platforms (such as an evaluation method and a kit therefor) that enable detailed analysis of the possibility and the like of developing drug-induced damage (such as DILI) to the liver and other organs. The method for evaluating drug toxicity of the present invention includes: a step of adding a drug to a co-culture system of an organoid and blood cells; and a step of evaluating the toxicity of the drug to the organoid.

Abstract: The present invention provides means for producing a parathyroid gland organoid. A culture method of the present invention includes a cell population containing a parathyroid gland cell in a ratio of 50% or more, and a mesenchymal cell in a ratio of 10% or more; and a step of culturing the cell population.

Abstract: The present invention provides a culture method capable of maturing an organoid through long-term culture, and suitable for producing a conformational organ. The culture method of the present invention is a method for culturing an organoid and/or cells constituting an organ immobilized in a chamber with a culture fluid perfused, and the culture fluid is perfused in such a manner as to generate a turbulent flow in the chamber.

Abstract: A method for screening for a therapeutic drug for a disease involving excessive activation of a complement, using a s cytotoxicity marker associated with the complement as an index, including (1a) a step of adding a complement to a cell produced from a stem cell to cause the cell to form a cytotoxicity marker associated with the complement, and (2a) a step of adding a therapeutic drug candidate, and selecting a substance that decreases the amount of the cytotoxicity marker is provided by the present invention.

Abstract: The present invention provides means for producing an organoid close to an organ in a living body and capable of secretion of a plasma protein and immune response. A matrix composition of the present invention provided as such means includes: (1) a first matrix containing one or more cells selected from the group consisting of vascular cells, nerve cells, and blood cells; and (2) a second matrix containing to cells constituting an organ and/or an organoid, in which the first matrix envelops the second matrix, and the first matrix has at least one opening.

Abstract: The present invention provides a composition suitable as a composition for treating blood coagulation and/or complement disorders (raw materials for producing therapeutic agents for these diseases) and a method for effectively producing the composition. A method for producing a composition for treating blood coagulation and/or complement disorders according to the present invention includes the following steps of: (1) embedding an organoid formed from vascular endothelial cells or vascular endothelial cells and hepatocytes, in an extracellular matrix; (2) culturing the extracellular matrix; and (3) collecting a culture supernatant from the culture obtained in the step (2).