Curcumin is a major component of the spice turmeric, which has been used in Eastern medicine for thousands of years.  Curcumin and -carotene, another bioactive compound, both have limited use in Western medicine due to poor bioavailability, but all that could change thanks to mesoporous silica particles. 

Curcumin and -carotene are nutraceuticals - dietary supplements with a medicinal effect on human health - that show anti-inflammatory, anti-carcinogenic, anti-tumour and anti-cancer capabilities. Tests have found that neither compound remains in the bloodstream long after consumption, because of poor water solubility.  This means they are unsuitable as oral drugs. 

To overcome this hurdle, Colin Raston and colleagues, from the University of Western Australia, Perth, have encapsulated both curcumin and -carotene, respectively, inside mesoporous silica capsules. This means they can be used in the delivery and controlled release of the compounds. 

The silica capsules have well-defined nano-channels that ensure the drugs are released in a controlled way. They are also highly fluorescent, so can act as molecular trackers for monitoring drug dose. 

The nano-sized capsules are made in a continuous flow reactor called a spinning disc processor. This rapid approach is suitable for combinatorial techniques, as it uniquely makes nano-particles of a uniform size. Raston said he believes the reactor can be used to make a wide range of other nano-materials. 'The technology is not only scalable but also offers precise control over the particle size, shape and surface properties,' he said.

An advantage of spinning disc processing is that nano-toxicology issues, scalability, effluent treatment and hazardous work environments are dealt with at the conception stage rather than attempting to make a new process or product scalable and non-toxic after its development, explained Raston.

Challenges facing the future of this system are, according to Raston, adapting the technology to a wide range of therapeutics and turning it into a commercial product.

Elinor Richards