/ 3 September 2008

Nano-sized cargo ship to aid nutrition

Researchers from Monash University in Australia have designed a nano-sized armoured cargo vessel to ensure the human body can absorb healing anti­oxidants better.

Dr Ken Ng and Dr Ian Larson from the university’s faculty of ­pharmacy and pharmaceutical ­sciences have designed a nano­particle, one-thousandth the thickness of a human hair, that protects antioxidants from being destroyed in the gut and gives them a better chance of being absorbed from the digestive tract.

Antioxidants are known to neutralise the harmful effect of free radicals and the other reactive chemicals that are constantly ­generated by our body. Antioxidants are therefore thought to promote better health.

Normally our body’s own antioxidant defence is sufficient, but in high-risk individuals, such as those with a poor diet or those at risk of developing atherosclerosis, diabetes or Alzheimer’s disease, a nutritional source of antioxidants is required.

Larson said antioxidants taken by mouth were easily destroyed by acids and enzymes in the human body, with only a small proportion of what is swallowed actually being absorbed in the gut.

The solution is to design a tiny sponge-like biopolymeric chitosan nanoparticle as a protective vehicle for antioxidants. Chitosan is a natural substance found in crab shells.

“Antioxidants sit within this tiny [particle], protecting them from attack from digestive juices in the stomach,” Dr Larson said.

“Once in the small intestine the nanoparticle gets sticky and bonds to the intestinal wall. It then leaks its contents directly into the ­intestinal cells, which allows them to be absorbed directly into the blood stream.

“We hope that by mastering this technique, drugs and supplements also vulnerable to the digestive process can be better absorbed by the human body.”

The research project will proceed to trials early next year.

Dr Ng said although the research was still in its early stages, the longer-term aim of the project would be to include similarly treated nanoparticles into food items, as Omega-3 is added to bread or milk.

“For catechins — the class of antioxidants under examination and among the most potent dietary antioxidants — only between 0,1% and 1,1% of the amount consumed makes it into our blood. If we can improve that rate, the benefits are enormous.”