By Victoria Vaughan

THE web of mystery surrounding the structure of spider silk is being unravelled by Singapore scientists, who have managed to grow a piece of egg case silk synthetically in their lab.

Spider silk is known to be tougher than steel, yet it is lightweight and elastic.

Around the world, the race is on for researchers to figure out the structure of silk, so it can be mass-manufactured to produce anything from body armour to sutures. However, it is still too expensive to do so: the current cost of producing 1g of egg case silk from large silk molecules is about $40.

'At the moment, artificial silk is as expensive as gold,' said Associate Professor Yang Daiwen, a biochemist who has led a team of five in this area of research at National University Singapore (NUS) since 2004. 'Nobody has managed to produce silk as well as nature yet.'

He added that while other researchers had been able to reproduce silk from recombinant protein fragments, his group was the only one working on egg case silk.

'It could be used for things such as ligament regeneration or in medicine capsules as a way to control the delivery of drugs into the body,' said the father of two. The group has discovered the three-dimensional structure of silk.

'We also found what turns the liquid silk in the female spider to the fibrous product for the egg case silk,' said the 44-year-old Chinese national.

Spiders can produce seven types of silk, with web silk being the most widely studied. The NUS scientists chose to look at the egg case silk which is more resistant to water and temperature changes than the other types of silk.

They have managed to grow a part of the silk molecule in a petri dish, and hope to generate larger pieces.

The first challenge of their project was to find female Orb Web spiders, said Prof Yang. These spiders, which have a 4cm-long body, are native to Singapore but are getting harder to find. But the team got lucky, collecting specimens from the Changi area.

Next, they had to find the genetic code of the egg case silk from the silk glands before trying to produce it in the lab.

The scientists are planning to work on other types of spider silk to uncover their 3-D structure, and use that information to grow it on a large scale - a feat which is several years away, said Prof Yang.

The team from the Department of Biological Sciences has secured $600,000 funding from the Education Ministry to help them understand the mechanism of silk fibre and improve the way they produce the silk.

NUS Professor Li Daiqin has been studying the behaviour of spiders for 20 years. 'This research is an important step forward. We needed to know about the silk structure before it forms into a fibre,' he said.

As spiders are carnivores and require particular foods and their own space, it is not possible to mass-produce silk naturally with spiders, unlike silkworms, which are low-maintenance.

Professor Peter Ng, director of the Raffles Museum for Biodiversity Research, said the findings highlighted how much humans could learn from Mother Nature. 'We would be stupid if we do not learn from the designs and strategies that plants and animals have successfully used to survive.'

This article was first published in The Straits Times.