ABSTRACT
PEG-modified gold nanoparticles (PEG-modified GNs) with diameters of 40 nm and 70 nm were prepared to elucidate the effect of extent of PEG (M.W. 5000) grafting and particle size on tumor accumulation and cellular uptake. Flow cytometry reveals that cellular uptake is strongly related to the size of PEG-modified GNs, rather than the extent of PEG-5K grafting level. Cytotoxicity analysis based on the intracellular release of drugs showed that the 70 nm PEG-modified GNs have the higher cytotoxicity, beccause of their greater cellular uptake. Also, particle size, rather than PEG-5K grafting level affects tumor accumulation. However, PEG-5K grafting level significantly affects the accumulation of particles in the liver and spleen. This finding is important in determining the proper PEG-5K grafting level and particle size for designing nano-medicines.
