The Ability of Pluronics to Increase the Survival Rate of Cells Determined by a Hydrophilic Poly(ethylene oxide) Block

The influence of synthetic water-soluble uncharged block copolymers on the multiplication of cells in a culture is studied. Their hydrophilic blocks are represented by linear poly(ethylene glycol) or branched polyglycerol, and hydrophobic blocks, by poly(propylene oxide) or polydimethylsiloxane. MCF-7/Adr cells are incubated with the copolymers in a serum-free culture medium for one hour, and their number after three days of cultivation without a copolymer is determined. The number of cells increases only under the action of polymers containing a poly(ethylene glycol) block, i.e., the longer this block, the lower the concentration of the polymer sufficient for the increase. The replacement of poly(ethylene glycol) by a hydrophilic block with a different structure, branched polyglycerol, fully cancels such an effect, thus indicating the defining role of poly(ethylene glycol) in the ability of block copolymers to maintain the multiplication of cells.