Preparation of temperature-responsive Pluronic immobilized membrane and storage of hematopoietic stem cells in culture flask

The bio-inert materials on which cells do not proliferate, differentiate nor de-differentiate should be useful for the culture and preservation of stem cells. The Pluronic F127 and F68, a triblock copolymer of ethylene oxide, and propylene oxide were activated using carbonyldiimidazole (CDI), and CDI-activated Pluronic was subsequently immobilized on the surface of a lysine-coated polystyrene tissue culture flask and culture bag. The morphology of fibroblasts on the Pluronic-immobilized flask was spherical, and did not show spreading behavior. This observation indicates that L929 cells on Pluronic-immobilized flasks were cultured in a bio-inert environment. The expression ratio of surface markers on hematopoietic stem cells (CD34) cultured in the Pluronic-immobilized flask and bag were significantly higher than nonmodified culture flask. This is caused by the existence of flexible brush-like segments of Pluronic on the Pluronic-immobilized flask and bag.