Tiny machines, big impact

From co-creating a line of skincare products to advocating for a new gold mining technique that will make the industry more environmentally-friendly, Sir Fraser Stoddart’s passion for chemistry has taken him into an array of fields and industries.

In late 2017, Sir Fraser, who was one of three scientists to be awarded the 2016 Nobel Prize in Chemistry, co-launched a line of skincare products that use miniscule organic cubes to deliver their ingredients into skin over time.

His laboratory at Northwestern University in the United States had discovered that three common and inexpensive materials – a type of sugar called gamma-cyclodextrin that can be derived from corn starch, an alkali metal salt such as table salt, and alcohol – could be used to create a framework of linked, harmless and biodegradable nano-cubes.

Sir Fraser created a chemical compound which he called a molecular shuttle, each nano-cube has a cavity that is just two-nanometres-wide, a tiny fraction of the width of a human hair. Since the cubes’ walls dissolve upon contact with water, including the low levels of moisture in skin, they can be used to contain and deliver substances such as vitamins into skin at a steady rate.

“Imagine a hotel with a lot of rooms, each containing cosmetic ingredients. The rooms closer to the outside would crumble and release the ingredients first, while the inner rooms would take longer to be reached. This ensures that you get a fresh, continuous supply of the ingredients,” said Sir Fraser in an interview ahead of the Global Young Scientists Summit (GYSS) 2019, which will be held in Singapore from Jan 20 to 25.

The annual event gathers young researchers and eminent scientists worldwide to give them the opportunity to interact with one another. Sir Fraser is one of 16 renowned scientists who will be delivering lectures and taking part in panel discussions at this year’s edition.

Apart from skincare products, the organic nano-cube technology could also be applied to other sectors, such as pharmaceuticals and supplements. Sir Fraser and other scientists, for example, have been researching the cubes’ potential to deliver ibuprofen, a common painkiller, more effectively within the human body.

Mining and machines

In recent years, Sir Fraser has also been involved in an effort to make the gold industry more environmentally-friendly. Currently, most of the methods to extract gold from crude sources involve the use of poisonous cyanides that hurt the planet.

In a serendipitous accident, a postdoctoral fellow in Sir Fraser’s laboratory had found that alpha-cyclodextrin, another form of sugar that can be derived from corn starch, could be used to isolate gold from a mix of raw materials.

Unlike the conventional extraction processes which produce toxic cyanide salts and gases, the new method creates only alkali metal salt as a by-product. It has been tested successfully on samples from about 50 gold mines worldwide, and Sir Fraser has also co-founded a company to promote its use.

“We’re poised to raise a few million dollars to take the company forward, but the trouble is that it’s very difficult to bring about disruption in a highly-conservative industry that has used cyanide for about 150 years. People are resistant to change. Still, we’re at a crucial stage now and we are hopeful,” Sir Fraser said.

He is equally optimistic about the future of molecular machines, which are tiny artificial machines made up of mechanically-linked molecules that could pave the way to longer-lasting batteries, new materials and sensors, nanostructures to deliver drugs in more efficient and controllable ways, and other innovations.

He helped to revolutionise the field when he invented a nanoscopic component, which he called a rotaxane that looks like a dumbbell with a ring that can move along its central bar. This component has been used to create many basic molecular machines, including Sir Fraser’s own development of artificial muscles and a molecule-based computer chip that could enable computers to become more powerful and smaller.

When he won the Nobel Prize in Chemistry for this work, sharing it with two other scientists who had also made breakthroughs in molecular machinery, the prize committee noted that their work had resulted in “a toolbox of chemical structures that are used by researchers around the world to build increasingly advanced creations”.

Sir Fraser said of molecular machines’ potential: “They are at the stage where electric motors were at in the early 1820s. Although the motors had been invented, we didn’t get hairdryers, food mixers and electric cars until decades or even centuries later. Molecular machines are in their infancy now.”

A science highlight

In the meantime, Sir Fraser has been traveling around the world to deliver lectures on his work on the machines and their promise. In 2018 alone, he gave about 100 talks in 22 countries on six continents.

He said that he is looking forward to the GYSS 2019. He explained: “Singapore is one of the countries in Asia where the government is very involved in science, and the summit itself is very well-organised. You get to interact with students who are incredibly engaged in the whole spirit of doing science, and that is a true highlight.”