4TH YOUNG INVENTORS AWARDS: WINNERS: GOLD

Material Advantage

This wake-boarding scientist's tiny scaffolds could give a big boost to tissue engineering

By Trish Saywell/SINGAPORE

Issue cover-dated January 22, 2004

RYUJI INAI is no ordinary science geek. He wake-boards and plays beach volleyball. His hair is a little spiky, with a whisper of reddish highlights, and his favourite baseball player is Japan's Hideki "Godzilla" Matsui, the legendary power hitter from the Yomiuri Giants who signed a $21 million major-league contract to play for the New York Yankees in 2003.

Inai himself played baseball in junior and senior high school and wanted to become a professional player. But when at 15 he realized that he didn't have what it took for the big leagues, he diverted his attentions to an earlier passion: dismantling faulty electronic gadgets. "My father always told me if I spoiled something I should try to fix it myself," he says.

This early tinkering triggered his interest in engineering. But Inai got off to an inauspicious start in his earliest efforts. He gave himself an electric shock while taking apart his parents' video machine, and when he tried fixing his Walkman he couldn't put all the little pieces back together again.

Thankfully, these early setbacks didn't faze him. And after earning bachelor's and master's degrees in mechanical engineering at the Kyoto Institute of Technology, Osaka-born Inai moved to Singapore to work towards a doctorate in bioengineering.

In little more than a year at the National University of Singapore, Inai has made a big name for himself. The young inventor has succeeded in building minuscule two- and three-dimensional scaffolds from polymer nanofibres for cultivating living cells.

Inai's work won him the Gold Award in the REVIEW's 4th Young Inventors Awards. Applications for his scaffolds could include growing new skin for burn victims, as well as new muscle cells and blood vessels for transplants.

Tiny scaffolds are essential tools used in tissue engineering, or developing tissue grafts to grow body parts. Inai has modified and improved the existing method of building these scaffolds, known as electrospinning.

"He's taken the electrospinning process to the next level," says Seeram Ramakrishna, a professor at the National University of Singapore's Nanobioengineering Lab. Inai has designed a machine that can, for the first time, build three-dimensional scaffolds.

The machine also allows greater control of the alignment of fibres in two-dimensional and three-dimensional scaffolds. "He came up with this new design, how to automate the process, as well as how to include the various jigs, fixtures and instruments associated with the spinning process," says Ramakrishna.

So how are the scaffolds used? In tissue regeneration, cells are placed onto the scaffolds, where they attach themselves to polymer fibres--which are smaller than a human hair--and there they thrive.

Because the fibres are better aligned, than on existing scaffolds, Inai's scaffolds allow greater control of cell growth. In a written submission to the REVIEW's panel of judges, he cited the example of growing cells for a coronary-artery graft. He said smooth muscle cells could be grown in a scaffold that mimicked an artery. "[This will lead to] the improvement of the vascular-tissue regeneration speed and the probability of long-term success of the vascular graft."

What's more, the polymer nanofibres are biodegradable, meaning they can degrade naturally in the body. Inai hopes that, eventually, they could be used to grow tissue in vitro, or inside the body.

So far, Inai has made headway controlling the diameter of the nanofibres, the distance between each one, their orientation and stacking in three dimensions. The next step: to refine the size of the polymer nanofibres, the thickness of the scaffolding, and the distance between each nanofibre by using different kinds of polymers. "If we can control the direction in which cells grow on the scaffold, we may be able to regenerate tissue faster," he explains, adding that it's still early days.

Now Inai is applying for a patent for his technique of developing the nanofibres on his specially adapted electrospinning machine.

Jeffrey Goh, chief executive officer of Singapore-based Lightspeed Technologies and one of the judges in this year's Young Inventors Awards, describes Inai's work as "simple in concept" but having "a mind-boggling impact."

This small step makes it possible to create a predictable environment with hopefully predictable outcomes when used in the human body, Goh explains. "Imagine a vanishingly small fibre. Now put a bunch of them together [and] you get something like paper. Now, if you can make all the fibres line up like little soldiers on a parade ground and you get to control the two layers' alignment, you get something like a woven piece of cloth."

Inai says he likes working with polymer nanofibres because they can be used in a variety of disciplines--not just in medicine. The microscopic polymer nanofibres can be used to create "breathable" fabrics that are chemical barriers. They can also be used to make wound dressings, cosmetics, face masks, filtration systems, electrical conductors and medical prostheses. In addition, they can have drug-delivery applications.

"My research topic is to investigate the relationship between structure and properties of polymer nanofibres," he explains. "But our focus is on tissue engineering."

Inai won a Singapore government scholarship to the university and hopes to complete his doctorate within four years. "I want to be a researcher forever," says the 27-year-old who recently married his sweetheart of 10 years. "There are many famous materials scientists, but I just want to be a good one."
 

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