Fig. 4

Intracellular uptake and MRI experiments with HUVECs treated with Au(FeCo). Figure 4a showing the plot of R2* and T2* against sample doses exhibiting significant relaxivity of Au(FeCo) and cells treated with the same (a). Cells were treated with different doses of (FeCo)Au for 2 h followed by extensive washing in PBS, finally fixed in 4 % formalin before MRI. b Intracellular uptake of (FeCo)Au in terms of Au content. HUVECs were grown in 100 mm collagen-coated tissue culture plates in triplicates and treated with different doses of (FeCo)Au for 2 h, washed extensively in PBS thrice. Finally, the cells were trypsinized, pooled together, thoroughly washed in PBS again, and finally resuspended in PBS for ICP analysis for gold