Drug development

Drugs from Corn? Harvesting Mirexus’ phytoglycogen nano-particle

For decades, scientists have been trying to produce safe, cost-effective nanomaterials. Now, Canadian company Mirexus may have found a way to do this, using technology to extract a non-toxic, nano-material from corn. Sally Turner spoke to CEO of Mirexus to find out more.

Not so long ago, nanotechnology was still in the realms of science-fiction, but remarkably scientists are now creating new devices and products which are the scale of individual molecules.

A ‘nanometre’ (from which ‘nano’ tech takes its name) is one-billionth of a metre, or one ten thousandth of the diameter of a human hair. The ability to measure these minute structures accurately is a relatively recent development, but now the technology is emerging at a pace and its global potential has been compared to that of the electricity, biotechnology, and digital information revolutions.

A 2010 report by the World Technology Evaluation Center (WTEC), which looked at societal needs for nanotechnology by 2020, revealed that the global market for these products had already reached about $254bn in 2009, and since then new and improved advances have ensured nanotech’s continued success.

The challenge

One of the leading innovators in the field is Dr Phil Whiting, president and CEO of Mirexus Biotechnologies Inc., a Canadian company successfully extracting nano-particles from corn. He explains that one of the most promising aspects of nanotechnology is that the properties of materials can alter dramatically as their size is reduced to the nanoscale.

“An inert material such as gold becomes reactive when it exists as nanoparticles, for example. Changes in the properties of materials can lead to new applications and will drive the technologies of the future,” he explains.

Changes in the properties of materials can lead to new applications and will drive the technologies of the future.

However, these changes at the nano level can also lead to increases in toxicity, which may have adverse effects for humans and the environment; the long-term effects of nano toxicity have not been fully explored.

“Synthetic nanomaterials are not only expensive to produce,” says Whiting, “but they are often toxic and bio-persistent. It is very difficult and expensive to produce mono-disperse nanomaterials synthetically, especially at large scales. Typical synthetic processes result in a wide variety of particle sizes, resulting in non-uniform pharmaco-kinetics.”

The Mirexus solution

Mirexus has addressed this challenge by harvesting an untapped natural nano-product from the local environment – the corn fields of Guelph, Ontario, where the company is based.

“Mother nature solved that problem herself and we found a way to piggy-back on that to allow us to produce such a material at the multi-ton scale,” comments Whiting. “Our material shows no toxicity or immunogenicity and is biodegradable. It is also water dispersible and stable for years.”

The initial discovery of this type of nano-glycogen was made at the University of Guelph ten years ago while the team was studying bacteria. (A phytoglycogen is a form of glycogen derived from plants; its highly branched structure means it has low viscosity, it retains moisture and has good stability in water. It can also stabilise bioactive compounds and form films on surfaces, making it a useful component in multiple technologies and products).

Our material shows no toxicity or immunogenicity and is biodegradable.

“The team decided to try similar experiments on sweet corn and discovered it was possible to produce mono-disperse (i.e. same sized particles) nano-glycogen from sweet corn,” Whiting reports. “This opened the door to a new process and a new material which became the foundation for Mirexus. We grind up sweet corn kernels, we extract the nano-glycogen with water (under proprietary conditions) and then physically separate the nanomaterial from the rest of the corn components.”

Using modular extruders and boilers, the company’s water-based extraction technique produces a purified carbohydrate in the form of a white powder. Demand for the product is increasing and the Guelph factory is now set to produce 16 tons of its novel phytoglycogen annually.

Phytoglycogens: the way forward

Mirexus’ product has been dermatologically tested as non-allergenic and is considered safe as a food ingredient, which means it is likely to have multiple pharma and consumer uses.

“It is being used for targeted drug delivery in oncotherapy for example,” says Whiting, “and in immunomodulation – novel antivirals.”

Phytoglycogens structure and non-toxicity will open the door to increased effectiveness in a diverse range of drug treatments. Nano-particles can be modified for use in imaging and diagnostics and as active ingredients for targeted drug delivery. Novel and existing pharmaceuticals are likely to benefit from improved stability and solubility.

“Consumer uses include as an anti-ageing ingredient in skincare products and as an anti-pollution/skin repair ingredient,” continues Whiting.

Nano-particles can be modified for use in imaging and diagnostics.

Several consumer brands have already run trial productions of nano-cosmetics using the Mirexus nano-particle. Mirexus has also launched its own personal care brand, Veriphy, which provides innovative moisturisers and anti-ageing products.

Whiting explains that its product is not classified as a nanomaterial by regulatory bodies, but rather as a foodstuff, which is a huge advantage in the marketplace.

“It’s not an engineered material, it’s water soluble and biodegradable,” he adds. “In fact it is certified as an edible material in Canada and Europe and is GRAS (Generally Recognised as Safe) in the US.”

Food scientists are already using nanoscale technology in some food packaging to indicate when a foodstuff such as fish has gone off. Nano-sized additives have also been used in an attempt to increase vitamin content and improve the flavour of low-fat foods. So the Mirexus nano-particle is likely to be in demand by manufacturers as a food ingredient, as well as for pharma and skincare products.

“We expect to introduce novel nutritional applications – sports nutrition for example,” confirms Whiting, “alongside the global adoption of our material in natural skincare products and as a key platform material in multiple healthcare applications.”

Bio-nanotechnology: a booming industry

Mirexus’ natural corn-derived product has come to market at an opportune time, as nanotechnologists continue to try to emulate and mimic nature’s mechanisms in a laboratory setting. In the natural world, a broad range of specialised biomolecules such as lipids, proteins, DNA and polysaccharides support life in its many forms.

“We often look to nature for exquisite examples of sophisticated bio-nanotechnology,” observes Whiting. “Prominent examples of this biologically inspired engineering include Velcro (emulating the tiny hooks on burrs), water repellent surfaces (emulating the lotus leaf), photonic crystals (emulating the iridescence of butterfly wings), and bio-responsive hydrogels.”

Phytoglycogen nanoparticles are a very promising example of bio-klepticism.

However, directly harvesting and manipulating Nature’s bio-molecules and bio-processes can often avoid the toxicity issues associated with synthetic mimicry.

“Ned Sheeman coined the term ‘bio-klepticism’ (stealing from nature). In this way, nature does all of the hard work in producing the molecules of interest, and we can use them in a range of different applications,” concludes Whiting.

“Phytoglycogen nanoparticles are a very promising example of bio-klepticism: particles produced by corn with special properties that can be exploited in a wide variety of applications.”

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