Patents by Inventor Yoshiki Sasai

Yoshiki Sasai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20180371409
    Abstract: The invention provides a method for producing a cell aggregate containing a ciliary marginal zone-like structure by culturing a cell aggregate containing a retinal tissue in which Chx10 positive cells are present in a proportion of 20% or more of the tissue in a serum-free medium or serum-containing medium, each containing a substance acting on the Wnt signal pathway for only a period before the appearance of a RPE65 gene expressing cell, followed by culturing the “cell aggregate in which a RPE65 gene expressing cell does not appear” thus obtained in a serum-free medium or serum-containing medium, each not containing a substance acting on the Wnt signal pathway and so on.
    Type: Application
    Filed: August 14, 2018
    Publication date: December 27, 2018
    Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Tokushige NAKANO, Satoshi ANDO, Yoshiki SASAI, Mototsugu EIRAKU
  • Patent number: 10077425
    Abstract: The invention provides a method for producing a cell aggregate containing a ciliary marginal zone-like structure by culturing a cell aggregate containing a retinal tissue in which Chx10 positive cells are present in a proportion of 20% or more of the tissue in a serum-free medium or serum-containing medium, each containing a substance acting on the Wnt signal pathway for only a period before the appearance of a RPE65 gene expressing cell, followed by culturing the “cell aggregate in which a RPE65 gene expressing cell does not appear” thus obtained in a serum-free medium or serum-containing medium, each not containing a substance acting on the Wnt signal pathway and so on.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: September 18, 2018
    Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Tokushige Nakano, Satoshi Ando, Yoshiki Sasai, Mototsugu Eiraku
  • Publication number: 20180245039
    Abstract: The present invention provides a production method of a retinal cell or retinal tissue, including the following steps: (1) a first step of culturing mammalian pluripotent stem cells in the absence of a feeder cell for a period not exceeding 30 days in a medium comprising 1) a factor for maintaining an undifferentiated state and 2) an MEK inhibitor, (2) a second step of culturing the cells obtained in the first step in suspension to form a cell aggregate, and (3) a third step of culturing the aggregate obtained in the second step in suspension in the presence of a BMP signal transduction pathway activating substance to obtain an aggregate containing retinal cells or a retinal tissue.
    Type: Application
    Filed: September 8, 2016
    Publication date: August 30, 2018
    Applicants: SUMITOMO DAINIPPON PHARMA CO., LTD., SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Satoshi ANDO, Takao KURODA, Yoshiki SASAI (Deceased)
  • Publication number: 20180195041
    Abstract: The present invention provides a method for inducing adenohypophysis or precursor tissue thereof in vitro from human pluripotent stem cells. The method includes culturing an aggregate of human pluripotent stem cells in suspension in a medium containing a bone morphogenetic protein signal transduction pathway activating substance and a substance acting on the Shh signal pathway to obtain a human cell aggregate containing a hypothalamus neuroepithelial tissue and a surface ectoderm, and further culturing the obtained human cell aggregate containing the hypothalamus neuroepithelial tissue and the surface ectoderm in suspension in a medium containing a bone morphogenetic protein signal transduction pathway activating substance and a substance acting on the Shh signal pathway to induce formation of hypophysial placode and/or Rathke's pouch in the surface ectoderm, thus obtaining a human cell aggregate containing 1) hypothalamus neuroepithelial tissue, and 2) hypophysial placode and/or Rathke's pouch.
    Type: Application
    Filed: July 24, 2015
    Publication date: July 12, 2018
    Applicants: RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Yoshiki Sasai, Chikafumi OZONE, Hidetaka SUGA
  • Publication number: 20170319748
    Abstract: The invention provides a method for producing a ciliary marginal zone stem cell induced to differentiate from a pluripotent stem cell, including either the following step (1) or step (2), or both of these steps: (1) a step of floating culturing cells obtained from a cell aggregate containing a ciliary marginal zone-like structure induced to differentiate from pluripotent stem cells, thereby obtaining a retinosphere; and (2) a step of collecting stage specific embryonic antigen-1 positive cells from cells obtained from a cell aggregate containing a ciliary marginal zone-like structure induced to differentiate from pluripotent stem cells.
    Type: Application
    Filed: October 16, 2014
    Publication date: November 9, 2017
    Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Atsushi KUWAHARA, Yoshiki SASAI (deceased)
  • Publication number: 20170313976
    Abstract: The present invention provides a method for producing neural cells or a neural tissue, including the following steps (1)-(3): (1) a first step of culturing pluripotent stem cells in the absence of feeder cells and in a medium containing 1) a TGF? family signal transduction pathway inhibiting substance and/or a Sonic hedgehog signal transduction pathway activating substance, and 2) a factor for maintaining undifferentiated state, (2) a second step of culturing the cells obtained in the first step in suspension to form a cell aggregate, and (3) a third step of culturing the aggregate obtained in the second step in suspension in the presence or absence of a differentiation-inducing factor to obtain an aggregate containing neural cells or a neural tissue.
    Type: Application
    Filed: October 23, 2015
    Publication date: November 2, 2017
    Applicants: SUMITOMO DAINIPPON PHARMA CO., LTD., RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Atsushi KUWAHARA, Suguru YAMASAKI, Yasushi HIRAMINE, Yoshiki SASAI, Masayo TAKAHASHI
  • Publication number: 20170313981
    Abstract: The present invention provides a method for producing retinal cells or a retinal tissue, comprising the following steps (1)-(3): (1) a first step of culturing human pluripotent stem cells in the absence of feeder cells and in a medium comprising a factor for maintaining undifferentiated state, (2) a second step of culturing the pluripotent stem cells obtained in the first step in suspension in the presence of a Sonic hedgehog signal transduction pathway activating substance to form a cell aggregate, and (3) a third step of culturing the aggregate obtained in the second step in suspension in the presence of a 1) a BMP signal transduction pathway activating substance to obtain an aggregate containing retinal cells or a retinal tissue.
    Type: Application
    Filed: October 23, 2015
    Publication date: November 2, 2017
    Applicants: SUMITOMO DAINIPPON PHARMA CO., LTD., RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Atsushi KUWAHARA, Suguru YAMASAKI, Yasushi HIRAMINE, Yoshiki SASAI, Masayo TAKAHASHI
  • Publication number: 20170253853
    Abstract: The present invention provides a method for producing a human cell aggregate containing a midbrain-hindbrain boundary neural progenitor tissue, including subjecting an aggregate of human pluripotent stem cells to suspension culturing in a serum-free medium containing insulin, and treating, in the suspension culturing, the aggregate of human pluripotent stem cells or a human cell aggregate derived therefrom with a ROCK inhibitor, a TGF? signal inhibitor, and a first fibroblast growth factor. Furthermore, the human cell aggregate containing the midbrain-hindbrain boundary neural progenitor tissue is subjected to suspension culturing in a serum-free medium to induce formation of a neuroepithelial structure by neural progenitor in the neural progenitor tissue, whereby the human cell aggregate containing the cerebellar plate tissue can be obtained.
    Type: Application
    Filed: September 8, 2015
    Publication date: September 7, 2017
    Applicants: RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Yoshiki Sasai (deceased), Keiko MUGURUMA
  • Publication number: 20170029771
    Abstract: Stem cells such as embryonic stem cells (ES cells), including human ES cells, are cultured in a medium comprising a ROCK inhibitor, and a stem cell culture medium, optionally serum free, comprises a ROCK inhibitor.
    Type: Application
    Filed: August 29, 2016
    Publication date: February 2, 2017
    Applicant: RIKEN
    Inventors: Yoshiki Sasai, Kiichi Watanabe
  • Publication number: 20160376554
    Abstract: The present invention provides a method for producing a cell aggregate containing a ciliary marginal zone-like structure, including a step of culturing a cell aggregate containing a retinal tissue in which Chx10 positive cells are present in a proportion of 20% or more and 100% or less of the tissue in a serum-free medium or serum-containing medium each containing a substance acting on the Wnt signal pathway and a substance inhibiting the FGF signal pathway for only a period before the appearance of a RPE65 gene expressing cell, followed by culturing the “cell aggregate in which a RPE65 gene-expressing cell does not appear” thus obtained in a serum-free medium or serum-containing medium each free of a substance acting on the Wnt signal pathway and so on. According to the production method of the present invention, a ciliary marginal zone-like structure can be produced with high efficiency.
    Type: Application
    Filed: October 16, 2014
    Publication date: December 29, 2016
    Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Atsushi KUWAHARA, Yoshiki SASAI
  • Publication number: 20160289635
    Abstract: The present invention provides a method of producing more mature telencephalon or a progenitor tissue thereof, in vitro, from mammalian pluripotent stem cells, comprising obtaining a telencephalon marker-positive aggregate by culturing an aggregate of pluripotent stem cells in suspension in the presence of a Wnt signal inhibitor and a TGF? signal inhibitor, and further culturing the telencephalon marker-positive aggregate in suspension under a high oxygen partial pressure condition. In one embodiment, the suspension culture under a high oxygen partial pressure condition is performed in the presence of a Wnt signal enhancer and a bone morphogenetic factor signal transduction pathway activating substance.
    Type: Application
    Filed: November 21, 2014
    Publication date: October 6, 2016
    Applicant: RIKEN
    Inventors: Yoshiki SASAI, Taisuke KADOSHIMA, Hideya SAKAGUCHI
  • Publication number: 20160264936
    Abstract: The present invention provides a method for producing a retinal pigment epithelial cell, including (1) a first step of subjecting pluripotent stem cells to floating culture in a serum-free medium to form an aggregate of pluripotent stem cells, (2) a second step of subjecting the aggregate formed in step (1) to floating culture in a serum-free medium or serum-containing medium each being free of a substance acting on the Sonic hedgehog signal transduction pathway and containing a substance acting on the BMP signal transduction pathway, thereby obtaining an aggregate containing retinal progenitor cells, and (3) a third step of subjecting the aggregate formed in step (2) to floating culture in a serum-free medium or serum-containing medium each being free of a substance acting on the Sonic hedgehog signal transduction pathway and a substance acting on the BMP signal transduction pathway and containing a substance acting on the Wnt signal pathway, thereby obtaining an aggregate containing retinal pigment epithel
    Type: Application
    Filed: October 2, 2014
    Publication date: September 15, 2016
    Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Tokushige NAKANO, Yoshiki SASAI, Chikafumi OZONE
  • Publication number: 20160251616
    Abstract: The present invention provides a method for producing a retinal progenitor cell, including (1) a first step of subjecting pluripotent stem cells to floating culture in a serum-free medium to form an aggregate of pluripotent stem cells, and (2) a second step of subjecting the aggregate formed in step (1) to floating culture in a serum-free medium or serum-containing medium each being free of a substance acting on the Sonic hedgehog signal transduction pathway but containing a substance acting on the BMP signal transduction pathway, thereby obtaining an aggregate containing retinal progenitor cells.
    Type: Application
    Filed: August 22, 2014
    Publication date: September 1, 2016
    Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Tokushige NAKANO, Yoshiki SASAI, Chikafumi OZONE
  • Publication number: 20160186136
    Abstract: The present invention provides a production method of a cell aggregate containing an anterior eye segment tissue or a partial structure thereof, or a precursor tissue thereof, including culturing pluripotent stem cell aggregates in suspension in the presence of a bone morphogenic factor signal transduction pathway activating substance to induce self-organization of an anterior eye segment tissue or a partial structure thereof, or a precursor tissue thereof. In one embodiment, the bone morphogenic factor signal transduction pathway activating substance is BMP4. In one embodiment, the suspension culture is performed entirely or partially in the presence of a fibroblast growth factor. The produced cell aggregate can further contain a neural retinal tissue.
    Type: Application
    Filed: August 6, 2014
    Publication date: June 30, 2016
    Applicant: RIKEN
    Inventors: Yoshiki SASAI (deceased), Miyuki SASAI (Legal Representive), Chikafumi OZONE, Yuko MARUYAMA
  • Publication number: 20150140652
    Abstract: Provided are a culture vessel with which an embryonic body can be formed efficiently from human embryonic stem cells, and a method for culturing human embryonic stem cells using the vessel. There is provided a vessel for culturing human embryonic stem cells, the culture vessel having two or more wells (1), wherein each of the wells (1) has a tubular body (2) and a funnel-shaped bottom (3) provided at one end of the body (2), the bottom (3) being a concave curved surface at the center (4) of the bottom (3) and the bottom (3) having an opening angle (?) in range of 60 to 100°. There is provided a method for culturing human embryonic stem cells by using said vessel for culturing human embryonic stem cells.
    Type: Application
    Filed: June 7, 2013
    Publication date: May 21, 2015
    Applicants: RIKEN, SUMITOMO BAKELITE CO., LTD.
    Inventors: Yoshiki SASAI, Keiko Muguruma, Ryouhei Tsukada, Hayao Tanaka
  • Publication number: 20150132787
    Abstract: The invention provides a method for producing a cell aggregate containing a ciliary marginal zone-like structure by culturing a cell aggregate containing a retinal tissue in which Chx10 positive cells are present in a proportion of 20% or more of the tissue in a serum-free medium or serum-containing medium, each containing a substance acting on the Wnt signal pathway for only a period before the appearance of a RPE65 gene expressing cell, followed by culturing the “cell aggregate in which a RPE65 gene expressing cell does not appear” thus obtained in a serum-free medium or serum-containing medium, each not containing a substance acting on the Wnt signal pathway and so on.
    Type: Application
    Filed: June 7, 2013
    Publication date: May 14, 2015
    Applicant: RIKEN
    Inventors: Yoshiki Sasai, Satoshi Ando, Mototsugu Eiraku, Tokushige Nakano
  • Publication number: 20150110749
    Abstract: The technology described herein relates to methods, assays, and compositions relating to causing a cell to assume a more pluripotent state, e.g. without introducing foreign genetic material.
    Type: Application
    Filed: April 24, 2013
    Publication date: April 23, 2015
    Inventors: Charles A. Vacanti, Martin P. Vacanti, Koji Kojima, Haruko Obokata, Teruhiko Wakayama, Yoshiki Sasai, Masayuki Yamato
  • Publication number: 20140342346
    Abstract: The invention provides a method of cryopreserving a tissue derived from a pluripotent stem cell, including the steps of (1) bringing a tissue derived from a pluripotent stem cell into contact with a cell protection solution that contains sulfoxide and chain polyol, (2) maintaining, in a cryopreservation solution, the pluripotent stem cell-derived tissue that was brought into contact with the cell protection solution in the first step, and (3) cryopreserving, in the presence of a coolant, the pluripotent stem cell-derived tissue that was maintained in the cryopreservation solution.
    Type: Application
    Filed: November 22, 2012
    Publication date: November 20, 2014
    Inventors: Satoshi Ando, Tokushige Nakano, Yoshiki Sasai, Mototsugu Eiraku
  • Publication number: 20140341864
    Abstract: The invention provides a method for producing a retinal tissue by (1) subjecting pluripotent stem cells to floating culture in a serum-free medium containing a substance inhibiting the Wnt signal pathway to form an aggregate of pluripotent stem cells, (2) subjecting the aggregate to floating culture in a serum-free medium containing a basement membrane preparation, and then (3) subjecting the aggregate to floating culture in a serum-containing medium. The invention also provides a method for producing an optic-cup-like structure, a method for producing a retinal pigment epithelium, and a method for producing a retinal layer-specific neural cell.
    Type: Application
    Filed: November 22, 2012
    Publication date: November 20, 2014
    Inventors: Tokushige Nakano, Satoshi Ando, Yoshiki Sasai, Mototsugu Eiraku
  • Publication number: 20140308743
    Abstract: The present invention provides a method of obtaining aggregates containing a rostral hypothalamus tissue and a rostral head ectodermal tissue, a hypophysis precursor tissue and a hypophysis hormone producing cell, by using a serum-free medium (preferably substantially free of growth factor and insulins), forming homogeneous aggregates of stem cells from pluripotent stem cells such as ES cell and the like, which are plated at a high cell concentration, and subjecting the formed aggregates to floating-culture.
    Type: Application
    Filed: October 31, 2012
    Publication date: October 16, 2014
    Inventors: Yoshiki Sasai, Hidetaka Suga