Probe of specific interaction between a simplified synthetic glycopolymer and erythrocytes as mediated by a glucose transporter (GLUT) on a cell membrane

In order to develop a biomimetic polymer for cell recognition, we synthesized poly [3-O-(4′-vinylbenzyl)-D-glucose] (PVG), a polystyrene derivative with reduced glucose moiety, and studied the specific interaction of this PVG with erythrocytes, carried by a glucose transporter (GLUT-1), on a cell membrane. To clarify the specific interaction between the PVG and the erythrocytes, fluorescence isothiocyanate- (FITC) labeled polymer was used to prove and visualize the specific interaction. We found that labeled polymer strongly binds to erythrocytes, probably due to the specific interaction mediated by the presence of GLUT-1 on the cell membrane. The fluorescence intensity of PVG on erythrocytes was time and dose dependent. To verify the specific interaction between the PVG and the erythrocytes, cells were pretreated with phloretin, an inhibitor of GLUT-1, before adding the FITC-labeled PVG polymer to the cell-culture medium. This treatment suppressed the interaction of PVG with erythrocytes. A confocal laser microscopic study further confirmed this interaction. The results from this study provide evidence that a biomimetic polymer of PVG interacts with erythrocytes mediated by GLUT-1 on cell membranes.