Fig. 5

Representative cellular TEM images showed the relative number of PEGylated AuNPs within intracellular vesicles 10 and 24 h after incubation with Sk-Br-3 cells in various serum concentration conditions. At 10 h, the cells exposed to PEGylated AuNPs in serum-free conditions were observed to have the highest number of AuNPs per vesicle, followed by decreasing numbers of AuNPs per vesicle as the serum concentration increased. After 24 h, the largest numbers of AuNPs were found in vesicles when AuNPs were introduced to cells in serum-free conditions, while a comparable number of AuNPs was found in vesicles in the serum-containing conditions (10, 25, 50 % HuS)