Abstract
We explored a very interesting gold nanoparticle system - pegylated gold in colloidal solution - and analyzed its uptake by cancer bearing mice. Large amounts of such nanoparticles are uptaken by the tumors as verified by quantitative inductive coupled plasma - optical emission spectroscopy (ICP-OES) and real time microradiology. With high time and lateral resolution phase contrast microradiology, we conclusively demonstrated at the animal level and by direct visual observation that the particles strongly accumulate in tumor regions - specifically more than in normal muscle tissue. This accumulation increases with the time after injection - whereas for most non-tumor regions it saturates or decreases. The potential impact of this result is discussed with special emphasis on passive targeted drug delivery and the delineation and early imaging of small tumors. © 2009 World Scientific Publishing Co. Pte. Ltd.