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).

  • Patent number: 10973854
    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: Grant
    Filed: November 22, 2012
    Date of Patent: April 13, 2021
    Assignees: Sumitomo Chemical Company, Limited, RIKEN
    Inventors: Tokushige Nakano, Satoshi Ando, Yoshiki Sasai, Mototsugu Eiraku
  • Patent number: 10934523
    Abstract: The present invention enables efficient suspension culture of stem cells in a serum-free medium by comprising a step for quickly forming a homogenous aggregate of stem cells, and provides a method of selectively inducing the differentiation of nerves from a stem cell, a method of forming a cerebral cortical nerve network in vitro, and a method of producing a steric structure of a brain tissue in vitro, as well as a method of producing hypothalamic neuron progenitor cells, comprising culturing pluripotent stem cells as a suspended aggregate in a serum-free medium that substantially does not contain a Nodal signal promoter, a Wnt signal promoter, an FGF signal promoter, a BMP signal promoter, retinoic acid and an insulin, and isolating hypothalamic neuron progenitor cells from the culture.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: March 2, 2021
    Assignee: RIKEN
    Inventors: Yoshiki Sasai, Takafumi Wataya, Mototsugu Eiraku
  • Publication number: 20210040444
    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 16, 2020
    Publication date: February 11, 2021
    Applicants: RIKEN, Sumitomo Chemical Company, Limited
    Inventors: Yoshiki SASAI, Hidetaka SUGA
  • Publication number: 20200370010
    Abstract: The 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: August 12, 2020
    Publication date: November 26, 2020
    Applicants: RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Yoshiki Sasai (deceased), Chikafumi OZONE, Hidetaka SUGA
  • Patent number: 10808224
    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: Grant
    Filed: October 31, 2012
    Date of Patent: October 20, 2020
    Assignees: RIKEN, Sumitomo Chemical Company, Limited
    Inventors: Yoshiki Sasai, Hidetaka Suga
  • Patent number: 10793830
    Abstract: Provided is a method of inducing the differentiation of a stem cell into nerve progenitor cells, comprising the step (1) of forming a homogenous aggregate of stem cells in a serum-free medium (1) and the step (2) of suspension-culturing the homogenous aggregate of stem cells in the presence of a basement membrane reference standard.
    Type: Grant
    Filed: November 5, 2010
    Date of Patent: October 6, 2020
    Assignee: RIKEN
    Inventors: Yoshiki Sasai, Mototsugu Eiraku
  • Patent number: 10781420
    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: Grant
    Filed: September 8, 2015
    Date of Patent: September 22, 2020
    Assignees: RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Yoshiki Sasai, Keiko Muguruma
  • Publication number: 20200277571
    Abstract: The present invention aims to provide a retinal tissue rich in cone photoreceptor precursors and/or cone photoreceptors, a retinal tissue rich in rod photoreceptor precursors and/or rod photoreceptors, and a production method thereof and the like.
    Type: Application
    Filed: September 14, 2018
    Publication date: September 3, 2020
    Applicants: RIKEN, SUMITOMO DAINIPPON PHARMA CO., LTD., SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Daiki NUKAYA, Mototsugu EIRAKU, Yuiko KINOSE, Akishi ONISHI, Masayo TAKAHASHI, Yoshiki SASAI (deceased)
  • Patent number: 10760050
    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: Grant
    Filed: October 2, 2014
    Date of Patent: September 1, 2020
    Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Tokushige Nakano, Yoshiki Sasai, Chikafumi Ozone
  • Patent number: 10760047
    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: Grant
    Filed: July 24, 2015
    Date of Patent: September 1, 2020
    Assignees: RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Yoshiki Sasai, Chikafumi Ozone, Hidetaka Suga
  • Publication number: 20200239838
    Abstract: The invention provides a method of differentiating human pluripotent stem cells to ectodermal cell by treating human pluripotent stem cells, which are dissociated single cells, and inducing differentiation to ectodermal cells under conditions where a ROCK (Rho-kinase) inhibitor is present in a culture medium in contact with the cells after dissociation of the human pluripotent stem cells.
    Type: Application
    Filed: April 17, 2020
    Publication date: July 30, 2020
    Applicant: RIKEN
    Inventors: Yoshiki Sasai (deceased), Kiichi Watanabe
  • Publication number: 20200208103
    Abstract: The present invention provides a method for maintaining a continuous epithelial structure of a retinal tissue including culturing the retinal tissue in a medium comprising a methyl group donor or a substrate of the methyl group donor at a concentration at which cell differentiation of a neural retinal progenitor cell is suppressed, and a neurite extension inhibitor at a concentration at which neurite extension is suppressed.
    Type: Application
    Filed: July 20, 2018
    Publication date: July 2, 2020
    Applicants: RIKEN, SUMITOMO DAINIPPON PHARMA CO., LTD., SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Hideya SAKAGUCHI, Yoshiki SASAI (deceased), Mototsugu EIRAKU, Daiki NUKAYA, Atsushi KUWAHARA
  • Patent number: 10626366
    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: Grant
    Filed: August 29, 2016
    Date of Patent: April 21, 2020
    Assignee: RIKEN
    Inventors: Yoshiki Sasai, Kiichi Watanabe
  • Publication number: 20200102535
    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: November 22, 2019
    Publication date: April 2, 2020
    Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Tokushige NAKANO, Yoshiki SASAI, Chikafumi OZONE
  • Patent number: 10501724
    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: Grant
    Filed: August 22, 2014
    Date of Patent: December 10, 2019
    Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Tokushige Nakano, Yoshiki Sasai, Chikafumi Ozone
  • Patent number: 10487310
    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: Grant
    Filed: June 7, 2013
    Date of Patent: November 26, 2019
    Assignees: RIKEN, SUMITOMO BAKELITE CO., LTD.
    Inventors: Yoshiki Sasai, Keiko Muguruma, Ryouhei Tsukada, Hayao Tanaka
  • Publication number: 20190218513
    Abstract: The present invention enables efficient suspension culture of stem cells in a serum-free medium by comprising a step for quickly forming a homogenous aggregate of stem cells, and provides a method of selectively inducing the differentiation of nerves from a stem cell, a method of forming a cerebral cortical nerve network in vitro, and a method of producing a steric structure of a brain tissue in vitro, as well as a method of producing hypothalamic neuron progenitor cells, comprising culturing pluripotent stem cells as a suspended aggregate in a serum-free medium that substantially does not contain a Nodal signal promoter, a Wnt signal promoter, an FGF signal promoter, a BMP signal promoter, retinoic acid and an insulin, and isolating hypothalamic neuron progenitor cells from
    Type: Application
    Filed: February 15, 2019
    Publication date: July 18, 2019
    Applicant: RIKEN
    Inventors: Yoshiki SASAI (deceased), Takafumi WATAYA, Mototsugu EIRAKU
  • Publication number: 20190169570
    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: February 5, 2019
    Publication date: June 6, 2019
    Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Atsushi KUWAHARA, Yoshiki SASAI
  • Publication number: 20190127690
    Abstract: The present invention provides a method for producing a retinal cell or a retinal tissue, including the following steps (1)-(3): (1) a first step of culturing pluripotent stem cells in the absence of feeder cells 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 in a medium containing a Wnt signal transduction pathway inhibiting 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 or absence of a Wnt signal transduction pathway inhibiting substance in a medium containing a BMP signal transduction pathway activating substance to obtain an aggregate containing a retinal cell or a retinal tissue.
    Type: Application
    Filed: April 21, 2017
    Publication date: May 2, 2019
    Applicants: SUMITOMO DAINIPPON PHARMA CO., LTD., RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Atsushi KUWAHARA, Suguru YAMASAKI, Yoshiki SASAI (Deceased), Masayo TAKAHASHI
  • Patent number: 10233423
    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: Grant
    Filed: October 16, 2014
    Date of Patent: March 19, 2019
    Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKEN
    Inventors: Atsushi Kuwahara, Yoshiki Sasai