Determination of specific interactions between glucose ligand carrying polymer and glucose transporter type-1 (GLUT-1) using different cell types

Abstract

In order to develop a biomimetic polymer for cell recognition, poly [3-O-(4-vinylbenzyl)-D-glucose] (PVG) and different types of glucose transport (GLUT)-carrying cells, namely, HepG2 cells (GLUT-1), 3T3-L1 fibroblast cells (GLUT-1 and GLUT-4), and MIN6 cells (GLUT-2), were tested for specific interaction. To clarify the nature of interaction between PVG and the different cell types, rhodamine-B isothiocyanate (RITC)-labeled polymers were used to prove and visualize the interactions. In this study, we found that labeled polymer strongly binds to HepG2 cells. The fluorescence intensity of PVG with in the presence of HepG2 cells was found to be stronger than that of 3T3-L1 fibroblast cells (0.11 ± 0.05) and MIN6 cells, which carry GLUT-2 (0.028 ± 0.01); a confocal laser microscopic study confirmed this interaction. To confirm the specificity of the interaction mediated by GLUT, the cells were pretreated with phloretin, an inhibitor of GLUT-1, before adding RITC-labeled PVG polymer to the cell culture medium. This treatment suppressed the interaction of PVG with HepG2 cells and partially suppressed its interaction with 3T3-L1 fibroblast cells.