Cell Type-Dependent Uptake of PEGylated Nanoparticles

Poly(ethylene glycol) (PEG) has widely been used to endow “stealth” abilities for cell-targeted delivery of nanoparticles. However, few studies have examined the effect of PEG density on particle surfaces on the uptake through various endocytic pathways. Furthermore, different cell types may use different mechanisms to internalize nanoparticles, thus potentially reducing the “stealthy ability” of PEGylation. In this study, we systematically varied PEG density on polystyrene nanoparticles. We examined the uptake of PEGylated nanoparticles in a variety of cell lines derived from various tissues. Through the use of inhibitors, we demonstrated that PEGylation of nanoparticles was only able to reduce the uptake through receptor-mediated endocytosis. Our study provides insights into alternative strategies besides the prevention of protein adsorption on nanoparticles are required to increase the stealthy ability of nanoparticles.