Stem cells and methods for incorporating environmental factors as a means for enhancing stem cell proliferation and plasticity

Abstract

Disclosed are methods for expanding stem cells that use a unique combination of environmental factors and cell culture conditions to produce stem cells having enhanced proliferation and differentiation characteristics. Also disclosed are methods for enhancing the engraftment and/or migratory potential of stem cells for therapeutic uses. Stem cells having unique proliferation, differentiation, migratory and engraftment characteristics are also disclosed.

We claim: 
     
         1 . Ectodermal cells grown according to a process comprising:
 a) providing ectodermal cells; and   b) culturing said ectodermal cells under conditions comprising reduced oxygen tension and a medium containing serum and at least one purified growth factor.   
     
     
         2 . The ectodermal cells of  claim 1 , wherein said ectodermal cells have a faster replication rate than ectodermal cells grown in the absence of said conditions. 
     
     
         3 . The ectodermal cells of  claim 1 , wherein said ectodermal cells comprise neural stem cells. 
     
     
         4 . The ectodermal cells of  claim 1 , wherein said medium comprises between about 0.02 and 2 percent serum. 
     
     
         5 . The ectodermal cells of  claim 1 , wherein said reduced oxygen tension is less than about 10%. 
     
     
         6 . The ectodermal cells of  claim 1 , wherein said reduced oxygen tension is less than about 5%. 
     
     
         7 . The ectodermal cells of  claim 1 , wherein said at least one purified growth factor factor comprises epidermal growth factor, fibroblast growth factor, or a combination thereof. 
     
     
         8 . Ectodermal cells grown according to a process comprising:
 a) providing ectodermal   b) contacting said ectodermal cells with medium comprising serum and at least one purified growth factor; and   c) culturing said ectodermal cells under low oxygen.   
     
     
         9 . The ectodermal cells of  claim 8 , wherein said ectodermal cells are neural stern cells 
     
     
         10 . The ectodermal cells of  claim 8 , wherein said medium comprises less than about 5% serum 
     
     
         11 . The ectodermal cells of  claim 8 , wherein said medium comprises between about 0.02 and 2 percent serum. 
     
     
         12 . The ectodermal cells of  claim 8 , wherein said low oxygen is less than about 10% oxygen. 
     
     
         13 . The ectodermal cells of  claim 8 , wherein said low oxygen is less than about 5% oxygen. 
     
     
         14 . The ectodermal cells of  claim 8 , wherein said at least one purified growth factor comprises epidermal growth factor, fibroblast growth factor, or a combination thereof. 
     
     
         15 . A cell composition comprising ectodermal cells in contact with medium comprising serum and at least one purified growth factor, wherein said medium is saturated with oxygen under low oxygen conditions. 
     
     
         16 . The cell composition of  claim 15 , wherein said ectodermal cells are neural stem cells. 
     
     
         17 . The cell composition of  claim 15 , wherein said medium comprises less than about 5% serum 
     
     
         18 . The cell composition of  claim 15 , wherein said medium comprises between about 0.02 and 2 percent serum. 
     
     
         19 . The cell composition of  claim 15 , wherein said at least one purified growth factor comprises epidermal growth factor, fibroblast growth factor, or a combination thereof. 
     
     
         20 . A method for treating a central nervous system disorder in patient in need thereof comprising administering to said patient a therapeutically effective amount of ectodermal cells from any of  claims 1 - 14 , wherein said central nervous system disorder is selected from the group consisting of ischemic stroke, Alzheimer's disease, Parkinson's disease, multiple sclerosis, Huntington's disease, cerebral palsy, hemorrhagic stroke, and mechanical injuries to the brain and/or spinal cord.