Bradley Wiggins

Talking Nanoparticles Down The Vat and Fiddle at December's SciBar

20 December 16 words: Gav Squires

For the final SciBar of the year, The Vat & Fiddle hosted a talk on nanoparticles. As we all know, "nano" means small and "particle" means particle. Dr Gareth Cave explains more in his talk, Nanoparticles: From Therapeutic Vectors to Chicken in the Basket.

A nanometre is actually a billionth of a metre. A sheet of paper is 100,000 nanometres thick, while a gold atom is around a third of a nanometre. One nanometre is how long your fingernail grows in one second. This year, the Nobel Prize in Chemistry was awarded for the design and synthesis of molecular machines. This is nanotechnology. Sir J Fraser Stoddart, one of those Nobel laureates, says that if you can build something in Meccano then it can be built in nano in a lab.

Nanoparticles are those at the nano scale – between 1 and around 100 nanometres. As two reagents react, they form a particle. If you can control the reaction time, you can control the size of the particle and keep it within the nanoscale. The molecules can start to stick together, but we want individual ones. Gareth and his team have now developed a process that can create a kilogram of nanoparticles in an hour whereas before it would take a whole day to create a kilogram. By making the process faster, it also becomes cheaper.

Then you just need to functionalize the process to prevent the solution from coming apart. For example, iron filings are added to breakfast cereal to fortify them and if these are coated with vitamin C, they will be more easily absorbed in the gut. In fact, in tests, ferritin levels were increased by 2.9% compared to an increase of 17.8% when Boots Iron & Vitamin C supplement was used. Iron oxide is used in MRI scans and tin oxide is used in X-rays. Could we come up with a molecule that could be used in both? It turns out that it is possible to create something that gives dual contrast.

MRI is one of the fundamental uses of nanoparticle use and the aim is to develop MPI - Magnetic Particle Imaging. This measures the field created by paramagnetic particles (something is paramagnetic if it is magnetic once you place it in a magnetic field). There are also other medical uses, for example therapeutic vectors such as aspirin. For this kind of work, it’s vital that the particles are all a uniform size; this means you can trace where the particles are in the body.

Can we do this through the skin rather than by injection? For example, when trying to cure melanomas. Using magnets to move magnetic particles creates heat, which will kill the cancer cells, and by applying through the skin, the particles can be kept local to the cancer.

Can we bio-fortify chickens? There isn't much iron in chickens compared to red meat. Rather than mixing the iron with vitamin C, it was mixed with lysine and the amount of iron in chickens was increased by around a third. Broiler chickens are only alive for three weeks, so some of the feeding of nanoparticles took place during the three weeks that the chickens are in the egg. Kellogg's also asked if it was possible to bio-fortify potatoes after they had just bought Pringles.

In crop production, tomatoes fed with nano-formula gave 40% more fruit. Tesco's growers are now using nanotechnology for all the tomatoes they grow in the UK – some 260,000 plants. It's also possible to use nano-silicon and grow tomatoes that don't require canes to grow. Fortified chilli plants have 60% more fruit, increased iron and vitamin C and it contains 20% more capsicum, leading to the hottest chillies in the world. They measure 2.4 million on the Scoville Scale (the previous hottest had been 2.2 million). It's also possible to grow a potato that contains more iron than a steak, and is two weeks ahead size-wise of where it would be without the formula. It's now possible to buy this nanotechnology for your own chillies from a company that Gareth and his colleagues were involved in setting up, called Pharm2Farm.

It's amazing what else is nano, for example, Coffee Mate. However, Coffee Mate is actually explosive as it has such a large surface area compared to its weight (this sort of thing used to happen in mills). In the US, the biggest crop for nanotechnology is cannabis. In Colorado, it is now a bigger crop than maize. If it ever legalised in the UK, it would be worth close to £3 billion in tax revenues.

And what were those chillis like? Well, the two brave souls who tried them said that it felt like their teeth were burning while they were eating them. Then the heat came back in waves. Eventually, they had to drink all of the milk in the pub to dampen down the effect.

SciBar returns to The Vat & Fiddle on Wednesday 25 January, at 7.30pm. Hopefully by then, they'll have some more milk.

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