SUNDAY, 6 NOVEMBER 2011
Written by Katherine Thomas LeGoo is a polymer based product that is liquid at room temperature. When warmed by the body it rapidly forms a gel. If placed in a blood vessel, the result is a firm barrier or plug that stops the flow of blood through the vessel. The polymer used in LeGoo is a block copolymer poloxamer, which has three blocks with distinct properties. A hydrophobic (water-repelling) block, polypropyleneglycol, is sandwiched between two hydrophilic (water-loving) blocks of polyethyleneglycol. At high temperatures the hydrophilic blocks align and the polymer aggregates. This causes LeGoo to change phase from a liquid to a gel, creating the plug. This process can easily be reversed by cooling the polymer by a few degrees, e.g., by applying a little ice. The viscosity decreases, the molecules dissolve into the blood and safely pass out of the body, and blood flow can continue as normal.