EVALUATION OF THE DELIVERY SYSTEMS FOR PROTEIN DRUGS WITH CHEMICAL MODIFICATION USING CELL CULTURE SYSTEMS

Abstract

In order to establish the strategy for targeted delivery systems for protein drugs by chemical modification, cellular uptake characteristics and cytotoxicity of model proteins and macromolecules were systematically studied using cell culture systems. In uptake studies, it was demonstrated that succinylated proteins were taken up by macrophages and brain microvessel endothelial cells via scavenger receptor mediated pathway whereas cationized proteins were taken up by these cells via adsorptive endocytosis. Efficient cellular uptake was observed for mannosylated proteins by macrophages based on mannose receptor mediated endocytosis. In cytotoxicity studies, neutral polymer and polyanions showed no significant cytotoxicity while polycations showed diversity in cytotoxic effect. On the basis of these findings, we studied the inhibitory effect of superoxide dismutase (SOD) derivatives, mannosylated SOD and cationized SOD, on superoxide anion release from macrophages. These SOD derivatives showed remarkable effects compared with unmodified SOD, indicating mannosylation and cationization are useful methods for targeted delivery of SOD.