Macmillan Lab: LEDs light the way for better drug therapies

By Liz Fuller-Wright
Thursday, November 9 2017

​Radioactivity may have a bad rap, but it plays a critical role in medical research. A revolutionary new technique to create radioactive molecules, pioneered in the lab of Princeton chemistry professor David MacMillan, has the potential to bring new medicines to patients much faster than before.

A blue LED shines on a vial containing heavy water...
A blue LED shines on a vial containing heavy water, a pharmaceutical compound and a light-activated catalyst. Princeton chemistry professor David MacMillan and his colleagues have developed a new photocatalytic approach to hydrogen isotope exchange (HIE) that turns a multi-month process into a one-day step, speeding the arrival of new drugs to the marketplace.
Image courtesy of the researchers

"Your average drug takes 12 to 14 years to come to market," said MacMillan, the James S. McDonnell Distinguished University Professor of Chemistry. "So everything that we can do to take that 14- or 12-year time frame and compress it is going to advantage society, because it gets medicines to people -- to society -- so much faster."

Every potential new medication has to go through testing to confirm that it affects the part of the body it is intended to affect. "Is it going to the right place? The wrong place? The right place and the wrong place?" MacMillan asked.

Tracing the path of a chemical that dissolves into the bloodstream presented a serious challenge, but one that radiochemists solved years ago by swapping out individual atoms with radioactive substitutes. Once that is done, "the properties of the molecule -- of the drug -- are exactly the same except that they're radioactive, and that means that you can trace them really, really well," MacMillan said.

But that introduced a new problem.

"Getting these radioactive atoms into the drug is not a trivial thing to do," he said. "People have developed long, sometimes month-long, two-month, three-month long sequences just to get a tiny amount of a substance with a few radioactive atoms."

But now he and his colleagues have found a better way, drawing on their work using blue LED lights and catalysts that respond to light, known as photocatalysts. Their research was published online in the journal Science on Nov. 9. ...

Read the full press release at: https://www.princeton.edu/news/2017/11/09/leds-light-way-better-drug-therapies

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