LABELING OF POLYSACCHARIDES USING [C-11] CYANOGEN-BROMIDE - IN-VIVO AND IN-VITRO EVALUATION OF C-11 HYALURONAN UPTAKE KINETICS

A method for the C-11-labelling of polysaccharides in high specific ra dioactivity is described. Dextran and hyaluronan were treated with [C- 11]cyanogen bromide in aqueous solution at pH 11.5 to give 30-47% radi ochemical yields with higher than 98% radiochemical purity in synthesi s times of 24-26 min counted from the end of bombardment. Specific rad ioactivities at the end of synthesis ranged from 0.12 to 3.1 Ci/mu mol . The biodistribution kinetics of [C-11]hyaluronan injected intravenou sly was studied in rats by means of positron emission tomography, show ing a rapid and displaceable uptake in liver. Uptake and displacement of [C-11]hyaluronan was also demonstrated in cultured rat liver endoth elial cells.