Abstract: Healthy functional platelets are mass produced. A method for producing platelets, comprising: (1) a culture step of culturing megakaryocytes in a platelet producing medium in the presence of mechanical stress and platelet production promoting factors including MIF, NRDc, IGFBP2, TSP-1, PAI-1, and CCL5, and (2) a harvest step of harvesting the platelets obtained by the culture step; wherein the culture step comprises: (a) a step of promoting a release of the platelet production promoting factors from megakaryocytes by mechanical stress; and/or (b) a step of externally adding platelet production promoting factors including MIF, NRDc, and IGFBP2.

Abstract: Provided is a method for producing platelets, in which damage to platelets is suppressed compared with a method in which platelets are separated using a filter from a megakaryocyte culture, and then the platelets are concentrated using a hollow fiber membrane and are further washed using the hollow fiber membrane, and purified platelets can be produced in a shorter period of time compared with the time that is taken to perform the above-described method so as to reduce damage to platelets. The method for producing purified platelets of the present invention includes a concentrating step of concentrating a megakaryocyte culture, and a centrifuging step of centrifuging platelets from an obtained concentrate.

Abstract: An object of the present invention is to provide a novel preservation solution for preserving mammalian cells over a long period of time in a non-frozen state. Ascorbic acid and/or niacin is added to an isotonic solution to prepare a preservation solution. The preservation solution is mixed with platelets and preserved under shaking. Decrease in the functions and viability of the platelets can thereby be suppressed for at least 10 days. Alternatively, the aforementioned preservation solution is mixed with mesenchymal stem cells, megakaryocytes, or T cells and preserved in a non-frozen state. Decrease in the functions and viability of these cells can thereby be suppressed for at least several days to several tens of days.

Abstract: Provided is a method for inducing mesoderm, comprising a step of bringing pluripotent stem cells into contact with bone morphogenetic protein 4 (BMP4) or CHIR for at least 3 days.

Abstract: The present invention provides a method for screening for platelet production promoters, the method including a step for selecting a candidate substance that significantly increases expression of TUBB1 as a platelet production promoter.

Abstract: The present invention provides a highly functional platelet production promoting agent which comprises one or a plurality of aryl hydrocarbon receptor (AhR) antagonists and one or a plurality of Rho-associated coiled-coil forming kinase (ROCK) inhibitors.

Abstract: The present invention provides: a platelet production promoter that contains one or more substances selected from the group consisting of Wnt inhibitors and FMS-like tyrosine kinase (FLT) inhibitors; and a platelet production method that uses this platelet production promoter.

Abstract: The present invention provides a method for producing purified platelets from a culture of megakaryocytes, comprising a first centrifugal separation step of centrifugally separating the culture at a centrifugal force of 150×g to 550×g, and a second centrifugal separation step of centrifugally separating, at a centrifugal force of 600×g to 4000×g, a liquid component recovered in the first centrifugal separation step.

Abstract: The present invention provides a method for producing platelets, and the method comprises a step of culturing megakaryocytes in a culture solution in a culture vessel, wherein the culture solution is stirred with a stirrer in the culture step.

Abstract: The present invention provides: a platelet production promoter that contains one or more substances selected from the group consisting of Wnt inhibitors and FMS-like tyrosine kinase (FLT) inhibitors; and a platelet production method that uses this platelet production promoter.

Abstract: The present invention provides a method for screening for platelet production promoters, the method including a step for selecting a candidate substance that significantly increases expression of TUBB1 as a platelet production promoter.

Abstract: The present invention provides a method for producing platelets, including the step of culturing megakaryocyte cells in a culture solution in a culture vessel, wherein in the culturing step, the culture solution is stirred by a stirring blade moving reciprocally.