In the "don't like nanotox conclusions, then wait for the next study" department, this report says quantum dots are now safe to sail inside the body. A year or so back, during a talk I gave to a group of eye specialists on nanotech ophthalmologic applications, a guy from Pfizer told me that quantum dots are too toxic for a major drug company to work with. That was the common perception at the time, anyway.
Quantum Dots Pose Minimal Risk To Cells in Tests Conducted By Federal Lab (By Jennifer Rocha, Nano World News)
Using an advanced toxicogenomics tool to study quantum dots, Fanqing Frank Chen, PhD, a scientist at Lawrence Berkeley National Laboratory and his team (including first author Tingting Zhang) reported that quantum dots pose little impact to cells.
These findings provide further evidence that quantum dots that enter a cell can provide many benefits, such as researching the inside of cells and identifying cancer cells to deliver treatment. Dr. Chen tells NWN, "The coating chemistry allows the quantum dots to be used for almost all in vitro biological applications. The whole genome analysis paves way for in vivo application of quantum dots." More here
And, just an aside here, when Dr. Chen is not working on making life better for us Earthbound humans, he's on the scientific advisory board for the Lifeboat Foundation, a group dedicated to launching humanity off this dirty little blue marble.