Results of a pilot study on non-human primates and quantum dots

Several studies of possible toxic effects of quantum dots on humans have been done using cell cultures in petri dishes or rodents, usually white lab rats. But lab rats are related to humans only in that both are mammals.

In a recently published letter in Nature Nanotechnology,"A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots", published online 05/20/2012, Ling Ye and other authors based at PLA General Hospital in Beijing, SUNY-Buffalo, Nanyang Technological University, and Changchun University of Science and Technology, report the results of experiments where quantum dots where injected into male rhesus monkeys. Rhesus monkeys were chosen for this experiment since they are genetically and physiologically closer to humans than rodents and are less endangered than chimpanzees.

The authors report that the rhesus monkeys did not exhibit any ill effects from the injections:

A complete blood count (cbc) was performed at regular intervals and the results did not suggest any acute toxicity.

After 90 days, the study did find that quantum dots had accumulated in the liver, spleen, and kidneys and in lesser amounts in the heart, lungs, and other organs. Examinations of tissues from these organs found no abnormalities.

In conclusion, rhesus macaques intravenously injected with ~ 25 mg of a cadmium based quantum dot formulation survived without any evidence of toxicity. All measured biochemical markers were in the normal range. . . .However, given the persistence of elevated cadmium and selenium levels in organs after three months, longer term studies will be required to determine the ultimate fate of these heavy metals and any ill effects arising due to their presence. All data obtained in this pilot study suggest that the phospholipid micelle encapsulated quantum dot formulation has very low tosicity on the timescale considered. This suggests a potential role for quantum dots in human clinical applications, such as image guided surgery for tumour removal, where the advantages provided for quantum dots can outweigh the potential risk associated with accumulation of their constituent elements in the body.

 

Adjusting the picture: LCDs and Quantum Dots

An article, "Dotting the Eyes" published in the June 16, 2011 issue of The Economist, noted something that many of us who spend a good part of their day looking into Liquid Crystal Display (LCD) screens, such as the monitor for the pc that I'm writing this on or the one you're reading it on, have long known - the color range is very limited. Jason Hartlove, President and CEO of California based Nanosys, believes his company may have found a way to expand the color range available to LCDs, using plastic sheets coated with quantum dots that his company manufactures. which - according to the Nanosys website - enables

 LCDs to display about 50% more color than they can today. This means richer, more viscerally alive reds, a deeper palette of greens (the color the human eye sees more intensely than any other color) and vivid blues. Browsing through photos on a tablet is now more like holding a stack of high quality, professional prints. Watching a movie on a big screen in the living room is more akin to attending a private screening at a Hollywood studio.

Other companies, such as Samsung Electronics and QD Vision of Massachusetts, have also begun to design, test and market their own products with the same goal as Nanosys - using quantum dots to improve the picture quality and color range of LCDs, efficently and at low cost.

Quantum Dots, Patent Infringement and Chapter 11

All of us have seen or directly experienced some effect of the recession, ranging from friends or co-workers losing their jobs to budget cut backs to bankruptcy.

Nanoindustries have not been immune to the recession's effects. Many. if not the majority of nanoindustries are small businesses and lack the depth of financial resources that older, more established companies have.

Evident Technologies, Inc, located in Troy NY and specializing in the production of quantum dots and nanocrystals, filed a petition for Chapter 11 bankruptcy protection and reorganization in the US Bankruptcy Court for the Eastern District of New York on Monday. Evident's press release cites as the major contributing factor to the bankruptcy a patent infringement case in the US District Court for the Eastern District of Texas (Invitrogen Corporation et al v Evident Technologies In 08cv163). Evident Technologies was also involved in a trademark infringement suit (Evident Technologies Inc v Everstar Merchandise Company LTD et al 08cv10230) in the US District Court for the Southern District of New York, which was dismissed with prejudice and with each party having to bare the cost of counsel. The cost of the cases and a lack of clients are, presumably, the reason that Evident's monthly income was $10,000 while monthly expenses added up to $200,000 a month. No business can last for long bleeding cash like that.

Evident Technologies has arranged DIP financing of either 2.7 million or 1.35 million (the article in the Albany Business Review gives the 2.7 million figure, while the press release gives the lower one) to enable it to continue in business while reorganizing. In addition to its financial problems, the bankruptcy petition indicates that there's been some instability among the corporate officers, with the former CEO and COO both resigning in May of 2009.

Nanotechnologies and nanoindustries have often been seen as one of the keys to a brighter economic future - a newspaper in Sri Lanka described nanoindustries as the way to solve the current global recession - but nothing prevents nanoindustries from suffering the same business problems as any other industry. Evident Technologies probably isn't the first nanoindustry to file for bankruptcy nor will it be the last. Some, as with other companies, will not emerge intact, either having to file Chapter 7 petitions or being merged into other companies. Others will survive the recession and the venture capitalists will look at them again as viable investments.

Here's hoping that Evident Technologies is one of them.