Effect of surface properties of liposomes coated with a modified polyvinyl alcohol (PVA-R) on the interaction with macrophage cells

The purpose of this study was to investigate the effect of a polymer coating using modified polyvinyl alcohol (PVA-R) on the interaction between liposomes and macrophage cells (J774 cells). The PVA-R-coated liposomes, which were labeled with 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocianin perchlorate (DiI) as a fluorescence reagent, were prepared with the conventional hydration method followed by extrusion and surface modification with PVA-R. The effects of polymer coating on the interaction with J774 cells were evaluated by using flow cytometry and confocal laser scanning microscopy (CLSM). When liposomes with or without PVA-R coating were incubated with J744 cells, the fluorescence emission intensity of DiI from J774 cells was significantly smaller than in the case of non-coated liposomes. This result indicates that decreased interaction of PVA-R-coated liposomes with macrophage cells could be well detected using flow cytometry and CLSM. These in vitro tests explained the differences in blood circulation of polymer-coated liposomes having different lipid formulations in rats.