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).
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Patent number: 12385008Abstract: 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: GrantFiled: September 8, 2016Date of Patent: August 12, 2025Assignees: SUMITOMO PHARMA CO., LTD., RIKENInventors: Satoshi Ando, Takao Kuroda, Yoshiki Sasai
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Patent number: 12378520Abstract: 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: GrantFiled: July 21, 2022Date of Patent: August 5, 2025Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKENInventors: Tokushige Nakano, Yoshiki Sasai, Chikafumi Ozone
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Patent number: 12291720Abstract: 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: GrantFiled: January 3, 2022Date of Patent: May 6, 2025Assignees: SUMITOMO PHARMA CO., LTD., RIKENInventors: Atsushi Kuwahara, Suguru Yamasaki, Yasushi Hiramine, Yoshiki Sasai, Masayo Takahashi
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Publication number: 20240399026Abstract: The present invention aims to provide a method for suppressing differentiation of ganglion cell, amacrine cell, horizontal cell and/or bipolar cell in a neural retina tissue containing photoreceptor precursor and/or photoreceptor, and the like. A method for suppressing differentiation of a ganglion cell, an amacrine cell, a horizontal cell and/or a bipolar cell in a neural retinal tissue containing a photoreceptor precursor and/or a photoreceptor, including a step of culturing a retinal tissue comprising a neural retinal progenitor cell and in any stage between a differentiation stage immediately after emergence of a ganglion cell and a differentiation stage where emergence rate of a cone photoreceptor precursor reaches maximum in a medium containing a thyroid gland hormone signal transduction pathway agonist.Type: ApplicationFiled: August 14, 2024Publication date: December 5, 2024Applicants: RIKEN, SUMITOMO PHARMA CO., LTD.Inventors: Daiki NUKAYA, Mototsugu EIRAKU, Yuiko KINOSE, Akishi ONISHI, Masayo TAKAHASHI, Yoshiki SASAI (deceased)
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Patent number: 12116593Abstract: 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: GrantFiled: August 12, 2020Date of Patent: October 15, 2024Assignees: RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Yoshiki Sasai, Chikafumi Ozone, Hidetaka Suga
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Patent number: 12090252Abstract: The present invention aims to provide a method for suppressing differentiation of ganglion cell, amacrine cell, horizontal cell and/or bipolar cell in a neural retina tissue containing photoreceptor precursor and/or photoreceptor, and the like. A method for suppressing differentiation of a ganglion cell, an amacrine cell, a horizontal cell and/or a bipolar cell in a neural retinal tissue containing a photoreceptor precursor and/or a photoreceptor, including a step of culturing a retinal tissue comprising a neural retinal progenitor cell and in any stage between a differentiation stage immediately after emergence of a ganglion cell and a differentiation stage where emergence rate of a cone photoreceptor precursor reaches maximum in a medium containing a thyroid gland hormone signal transduction pathway agonist.Type: GrantFiled: September 14, 2018Date of Patent: September 17, 2024Assignees: RIKEN, SUMITOMO PHARMA CO., LTD.Inventors: Daiki Nukaya, Mototsugu Eiraku, Yuiko Kinose, Akishi Onishi, Masayo Takahashi, Yoshiki SASAI
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Patent number: 12091680Abstract: Provided is a method of inducing the differentiation of a stem cell into nerve progenitor cells, comprising the step (1) of forming homogenous aggregates of stem cells in a serum-free medium (1) and the step (2) of suspension-culturing the homogenous aggregates of stem cells in the presence of a basement membrane reference standard.Type: GrantFiled: October 5, 2020Date of Patent: September 17, 2024Assignees: RIKEN, Sumitomo Chemical Company, LimitedInventors: Yoshiki Sasai, Mototsugu Eiraku
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Patent number: 11898161Abstract: 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: GrantFiled: April 17, 2020Date of Patent: February 13, 2024Assignee: RIKENInventors: Yoshiki Sasai, Kiichi Watanabe
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Patent number: 11834672Abstract: 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: GrantFiled: October 16, 2020Date of Patent: December 5, 2023Assignees: RIKEN, Sumitomo Chemical Company, LimitedInventors: Yoshiki Sasai, Hidetaka Suga
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Patent number: 11724005Abstract: 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: GrantFiled: October 16, 2014Date of Patent: August 15, 2023Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKENInventors: Atsushi Kuwahara, Yoshiki Sasai
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Patent number: 11542471Abstract: 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: GrantFiled: August 14, 2018Date of Patent: January 3, 2023Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKENInventors: Tokushige Nakano, Satoshi Ando, Yoshiki Sasai, Mototsugu Eiraku
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Publication number: 20220364054Abstract: 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: ApplicationFiled: July 21, 2022Publication date: November 17, 2022Applicants: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKENInventors: Tokushige NAKANO, Yoshiki SASAI, Chikafumi OZONE
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Patent number: 11473056Abstract: 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: GrantFiled: November 22, 2019Date of Patent: October 18, 2022Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKENInventors: Tokushige Nakano, Yoshiki Sasai, Chikafumi Ozone
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Patent number: 11371016Abstract: 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: GrantFiled: April 21, 2017Date of Patent: June 28, 2022Assignees: SUMITOMO PHARMA CO., LTD., RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Atsushi Kuwahara, Suguru Yamasaki, Yoshiki Sasai, Masayo Takahashi
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Publication number: 20220119764Abstract: 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: ApplicationFiled: January 3, 2022Publication date: April 21, 2022Applicants: SUMITOMO DAINIPPON PHARMA CO., LTD., RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Atsushi KUWAHARA, Suguru YAMASAKI, Yasushi HIRAMINE, Yoshiki SASAI (deceased), Masayo TAKAHASHI
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Publication number: 20220112457Abstract: 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: ApplicationFiled: December 22, 2021Publication date: April 14, 2022Applicants: SUMITOMO DAINIPPON PHARMA CO., LTD., RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Atsushi KUWAHARA, Suguru YAMASAKI, Yasushi HIRAMINE, Yoshiki SASAI (deceased), Masayo TAKAHASHI
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Publication number: 20220098550Abstract: 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: ApplicationFiled: December 13, 2021Publication date: March 31, 2022Applicants: RIKEN, Sumitomo Chemical Company, LimitedInventors: Yoshiki SASAI, Taisuke KADOSHIMA, Hideya SAKAGUCHI
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Patent number: 11274277Abstract: 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: GrantFiled: August 6, 2014Date of Patent: March 15, 2022Assignees: RIKEN, Sumitomo Chemical Company, LimitedInventors: Yoshiki Sasai, Chikafumi Ozone, Yuko Maruyama
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Patent number: 11234434Abstract: 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: GrantFiled: November 22, 2012Date of Patent: February 1, 2022Assignees: SUMITOMO CHEMICAL COMPANY, LIMITED, RIKENInventors: Satoshi Ando, Tokushige Nakano, Yoshiki Sasai, Mototsugu Eiraku
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Patent number: 11214772Abstract: 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: GrantFiled: October 23, 2015Date of Patent: January 4, 2022Assignees: SUMITOMO DAINIPPON PHARMA CO., LTD., RIKEN, SUMITOMO CHEMICAL COMPANY, LIMITEDInventors: Atsushi Kuwahara, Suguru Yamasaki, Yasushi Hiramine, Yoshiki Sasai, Masayo Takahashi