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.
“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.
“It was a wacky idea! Fortunately, it worked,” MacMillan said. “What we came up with was, if you shine light on them, and you have a photocatalyst, could these photocatalysts actually remove the non-radioactive atom and then install the radioactive atom?”
MacMillan’s technique uses “heavy water,” which replaces the hydrogen (H) in H2O with tritium, a radioactive version of hydrogen that has an extra two neutrons per atom.
“If you just let your drug sit in the radioactive water and shine light on it with a catalyst, the catalyst will remove the atom which is not radioactive — in this case it’s hydrogen — and replace it with tritium,” he said.
Suddenly, attaching one of these atomic labels takes hours instead of months, and the technique works on many kinds of frequently used compounds. The researchers have already tested it on 18 commercially available medicines, as well as candidates in the Merck drug discovery pipeline.
For compounds that don’t need radioactive tags, the same one-step process can swap in deuterium, a version of hydrogen with only one extra neutron. These “stable labels” (with deuterium) and “radio labels” (with tritium) have countless applications, in academia as well as drug discovery.
The simplicity of this new approach has another implication, said Jennifer Lafontaine, the senior director of synthesis and analytical chemistry for Pfizer in La Jolla, California, who was not involved in the research.
Because the previous process was so resource intensive, deuterium- or tritium-labeled molecules were often only created for chemicals that were “quite advanced in the drug discovery process,” she said. “This methodology could therefore open the door to earlier and expanded use of isotopic labeling in drug discovery, significantly enhancing our ability to study drug candidates on a deeper level, and across a range of applications.”
“No one’s patenting any of this, because we want it to be available for everyone to use,” MacMillan said.
Learn more: LEDs light the way for better drug therapies
The Latest on: Photocatalysts
- Covid-19 Impact on Perfluorosulfonic Acid (PFSA) Resin Market Size, Status and Forecast 2020-2026on May 9, 2020 at 11:24 pm
Perfluorosulfonic Acid Resin is a special polymer, with extraordinary stability and chemical resistance dielectric properties, which are widely used in chlor –alkali industry, proton exchange membrane ...
- Scientists use lasers and gold particles to turn titanium oxide into nanocomposite for photocatalystson May 8, 2020 at 9:22 am
(Nanowerk News) Oxides of different metals often serve as photocatalysts in various systems such as air purification, reactions of water decomposition and even in the production of self-cleaning ...
- Scientists have created new nanocomposite from gold and titanium oxideon May 8, 2020 at 6:39 am
ITMO University researchers together with their colleagues from France and the USA have demonstrated how a femtosecond laser can be used to tune the structure and nanocomposite properties for titanium ...
- Experimental and numerical study on photocatalytic activity of the ZnO nanorods/CuO composite filmon May 8, 2020 at 2:26 am
The photocatalytic activity of the ZnO NRs/CuO composite film was investigated by using both experimental and numerical methods. The ZnO NRs/CuO composite film exhibits significan ...
- Highly efficient hydrogen gas production using sunlight, water and hematiteon May 7, 2020 at 10:10 am
A research group led by Associate Professor Tachikawa Takashi of Kobe University's Molecular Photoscience Research Center has succeeded in developing a strategy that greatly increases the amount of ...
- Can a lamp that cleans the air of pollutants and bacteria work on the coronavirus?on May 3, 2020 at 2:00 pm
Designed by Kevin Chu, of Sugo Biophilia Furniture, the Foglia lamp uses a once expensive technology adapted to work with LED. A smaller design is due to be released in the summer.
- Photocatalysis against coronaviruson April 8, 2020 at 5:00 pm
The principle of photocatalysis, which is the basis of the new air purification system, is based on chemical reactions that take place under the influence of ultraviolet radiation on a catalyst ...
- One step synthesis of efficient photocatalysts by TCAP doped g-Con December 12, 2019 at 4:05 pm
thickness of g-C3N4 and CN/TCAP-100. The results are shown in Fig.S1. The g- C3N4 showed a thickness of ~7.0 nm (Fig.S1a, b), while CN/TCAP-100 showed a thickness of ~2.0 nm (Fig.S1c, d).
- Scalable Wearable Systems for Plasmonics and Photocatalysison October 2, 2019 at 10:35 am
There is always an imperative need for scalable, environment-friendly production and synthesis of nanoscale photonic materials for a variety of biomedical, energy harvesting, and quantum computing ...
- Hydrothermal/Solvothermal Synthesison February 3, 2019 at 10:59 am
Indoor air purification via photocatalytic oxidation technology using titanium dioxide is investigated. Hydrothermal/Solvothermal synthesis of titanium dioxide and ...
via Google News and Bing News