A pilot
study in non-human primates shows no adverse response to intravenous injection
of quantum dots
Nature
Nanotechnology
Published
online 20 May 2012
Abstract
Quantum
dots have been used in biomedical research for imaging1, 2,
diagnostics3, 4 and sensing purposes5, 6. However,
concerns over the cytotoxicity of their heavy metal constituents7, 8 and
conflicting results from in vitro7, 9 and small animal10, 11,
12, 13, 14 toxicity studies have limited their translation towards
clinical applications. Here, we show in a pilot study that rhesus macaques
injected with phospholipid micelle-encapsulated CdSe/CdS/ZnS quantum dots do
not exhibit evidence of toxicity. Blood and biochemical markers remained within
normal ranges following treatment, and histology of major organs after 90 days
showed no abnormalities. Our results show that acute toxicity of these quantum
dots in vivo can be minimal. However, chemical analysis revealed that most of
the initial dose of cadmium remained in the liver, spleen and kidneys after 90
days. This means that the breakdown and clearance of quantum dots is quite
slow, suggesting that longer-term studies will be required to determine the
ultimate fate of these heavy metals and the impact of their persistence in
primates.
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