In addition, in order to address the global shortage of donor tissues, were are currently involved in a study of corneal regeneration using tissue stem cells and induced pluripotent stem cells (iPS). In order to anatomically and functionally restore the cornea, our current studies involve the following: 1) Isolation of stem cells from the 3 layers of the cornea. 2) Induction of corneal cells from iPS cells. 3) Devising of tissue engineering techniques to produce 3-dimensional corneal tissue constructs. 4) Development of new surgical techniques. 5) Establishing the infrastructure required for the processing of safe tissue-engineered products.
Research activities
Isolation of mouse corneal epithelial stem cells
We devised a protocol using cholera toxin and serum-free medium to isolate corneal epithelial progenitor cells from a single mouse cornea （Ma X, Invest Ophthalmol Vis Sci 2009）. One of the original cell lines has maintained a normal phenotype and karyotype through over 60 passages (Kawakita T. J Cell Mol Med. 2008).
Isolation of corneal stromal stem cells
We successfully isolated multipotent, neural crest-derived stem cells (COPs) from the adult murine cornea using the neurosphere technique (Yoshida S. Stem Cells 2006).
GMP grade cultivated epithelial sheets
We established a technique for engineering safe, transplantable epithelial sheets using donor human mesenchymal stem cells as feeder cells. The sheets are engineered in a cell processing center under strict sanitation standards. The initial clinical trial was approved by the Ministry of Health, Labour and Welfare.