CytoTherapeutics Inc. announced Thursday thatit has obtained an exclusive worldwide license toa technology for the isolation and proliferation ofneural stem cells.The technology, licensed from NeuroSpheresLtd. of Calgary, Alberta, will be developed byCytoTherapeutics for the treatment ofneurodegenerative disorders such asAlzheimer's disease, Parkinson's disease andmultiple sclerosis.CytoTherapeutics (NASDAQ:CYTO) ofProvidence, R.I., said all these diseases involvethe degeneration and death of a variety of neuralcell types within the central nervous system.Through NeuroSphere's technology,CytoTherapeutics continued, neural stem cellscan be proliferated in vitro almost indefinitely inthe presence of certain growth factors. Thecompany believes that transplant of neural cellsinto diseased patients could palliateneurodegenerative disorders by haltingprogressive loss of motor and cognitivefunctions.CytoTherapeutics plans to use the technology toproduce neural cells that can be deliveredthrough its microencapsulation technology, butalso through a standard transplant procedure,according to Ed Baetge, CytoTherapeutics'senior director of research. The company'smicroencapsulation technology allows singlecells to be enclosed in semi-permeable polymermembranes that shield the cell from the immunesystem but allow beneficial molecules from theencapsulated cells to escape.Joseph Hammang, CytoTherapeutics' associatedirector of cell and molecular biology, explainedthat the company is currently conductingresearch on how to control what type of neuralcells result from the differentiation of stem cells.In vitro, Hammang said, the company has foundthat use of different growth factors appear tosteer the stem cells toward mitosis into one oranother particular type of neural cell. When thecompany injected undifferentiated,unencapsulated neural stem cells into ratsdeficient in oligodendricites, he added, theyfound that stem cells naturally tended todifferentiate into oligodendricites, indicating thatdifferentiation of stem cells is heavily influencedby their environment.CytoTherapeutics has been evaluatingNeuroSpheres' technology since July 1992,NeuroSpheres' director of research and founderBrent Reynolds told BioWorld. After theexpiration of a one-year option and evaluationagreement, CytoTherapeutics decided to licensethe technology. NeuroSpheres will receive anundisclosed up-front payment for the technology.The companies will share responsibility for thedevelopment of therapeutics based on thetechnology, for which CytoTherapeutics willprovide financial support. NeuroSpheres also willreceive milestone payments and royalties on thesale of any eventual products.NeuroSpheres' technology was pioneered byReynolds and company co-founder SamuelWeiss. Their research on the isolation of murinestem cells, the subsequent proliferation of thesecells, and their differentiation into a variety ofneural cells, was published in the March 1992issue of Science.031894CytoTherapeutics

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