More on quantum dots: a toxicity study; Merck action in Israel

I have two items on quantum dots today. The first concerns a toxicity study performed on primates at the University of Buffalo (NY, USA). From the May 22, 2012 news item by Will Soutter for Azonano,

A multi-institute toxicity study on quantum dots in primates has discovered that these nanocrystals are safe for a period of one year.

This finding is encouraging for researchers and physicians looking for novel techniques to treat diseases such as cancer using nanomedicine. The organizations involved in the study included the University at Buffalo, Nanyang Technological University, ChangChun University of Science and Technology, and the Chinese PLA General Hospital.

On digging a little further, I found this information on the University of Buffalo website, from their May 21, 2012 news release,

– Tiny luminescent crystals called quantum dots hold great promise as tools for treating and detecting diseases like cancer.

– A pioneering study to gauge the toxicity of quantum dots in primates has found cadmium-selenide quantum dots to be safe over intervals of time ranging from three months to a year. The study is likely the first to test the safety of quantum dots in primates.

– The authors say more research is needed to determine quantum dots’ long-term effect on health; elevated levels of cadmium from the quantum dots were found in the primates even after 90 days.

The research, which appeared on May 20 in Nature Nanotechnology online , is likely the first to test the safety of quantum dots in primates.

In the study, scientists found that four rhesus monkeys injected with cadmium-selenide quantum dots remained in normal health over 90 days. Blood and biochemical markers stayed in typical ranges, and major organs developed no abnormalities. The animals didn’t lose weight.

Two monkeys observed for an additional year also showed no signs of illness.

The first  results are hopeful but there are some concerns,

The new toxicity study — completed by the University at Buffalo, the Chinese PLA General Hospital, China’s ChangChun University of Science and Technology, and Singapore’s Nanyang Technological University — begins to address the concern of health professionals who worry that quantum dots may be dangerous to humans.

The authors caution, however, that more research is needed to determine the nanocrystals’ long-term effects in primates; most of the potentially toxic cadmium from the quantum dots stayed in the liver, spleen and kidneys of the animals studied over the 90-day period.

The cadmium build-up, in particular, is a serious concern that warrants further investigation, said Ken-Tye Yong, a Nanyang Technological University assistant professor who began working with Prasad [Paras N. Prasad] on the study as a postdoctoral researcher at UB.

Unusually, this article seems to be open access at Nature Nanotechnology,

A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots

Ling Ye, Ken-Tye Yong, Liwei Liu, Indrajit Roy, Rui Hu, Jing Zhu, Hongxing Cai, Wing-Cheung Law, Jianwei Liu, Kai Wang, Jing Liu, Yaqian Liu, Yazhuo Hu, Xihe Zhang, Mark T. Swihart, and Paras N. Prasad

Nature Nanotechnology (2012) doi:10.1038/nnano.2012.74

The acquisition of an Israeli quantum dot company by Merck is my second bit of quantum dot news, from the May 22, 2012 news item on Nanowerk,

Merck announced today that within the scope of a capital increase by the Israeli start-up company QLight Nanotech, it is acquiring an interest in the Jerusalem-based company. QLight Nanotech is a spin-off subsidiary of Yissum, the technology transfer company of the Hebrew University of Jerusalem. QLight Nanotech develops products for use in displays and energy-efficient light sources based on semiconductor nanoparticles known as quantum dots.

I understood that Merck was a pharmaceutical company so I was bit surprised to see this (from the May 22, 2012 news item on the Solid State Technology website)

“I am excited that our basic science discoveries on semiconductor nanocrystals are now being realized in innovative technological applications. The partnership with Merck, a world leader in materials for display applications, is a synergistic one allowing us at Qlight Nanotech to implement advanced chemicals manufacturing and applications’ know-how,” said the scientific founder of  QLight Nanotech, Professor Uri Banin of the Hebrew University of Jerusalem, who will continue to support the company as a shareholder and advisor alongside of Yissum.

In fact, Merck bills itself as a pharmaceuticals and a s chemicals company.