Opportunities in China Lure Scientists Home

Jin, who founded Beijing Biren Medical Technology, said the speed at which science is allowed to move in China is the main attraction for basing a company here.

"If I were in the United States, I think I'd never be able to create this company," Jin said.

Perhaps the most ambitious and most controversial work being done by returned scientists has been with stem cells.

Some stem cells can change into all the different types of cells that make up the body, leading scientists to think they can used to treat many diseases.

There's little controversy about the use of adult stem cells, which are contained in many organs and tissue but are less useful than embryonic stem cells.

In the United States, the use of embryonic stem cells has been hugely controversial. There is little such debate in China, where the government forbids the use of human embryonic stem cells for reproductive purposes but allows research on them and allows them to be cloned for medical purposes.

Li Lingsong, 45, who did his postdoctoral work on a National Institutes of Health fellowship at Stanford University and was a visiting scholar at the University of Virginia, founded a company that developed the first stem-cell treatment offered commercially. Dozens of foreigners -- including many from the United States -- have traveled to China for the treatment, because Li is allowed to use adult-stem-cell therapies that are still being tested in animals in the United States.

In the United States, sometimes scientists "cannot do more pioneering things . . . so China becomes the only place to come for this treatment," said Sherwood Yang, 39, a New Zealand-trained physician who manages the clinic in Beijing that uses Li's stem-cell injections. The clinic is a joint venture of the city-owned Tiantan Hospital and American Pacific, a health-care investment group run mostly by Chinese American medical researchers in California.

Opportunities in stem-cell research also lured Deng Hongkui, 44, back to China. He left in 1989 to study immunology at UCLA and New York University's medical school. Then he joined ViaCell, a biotech company in Cambridge, Mass. In 2001, Deng returned to China's Peking University to work on manipulating human embryonic stem cells into treatments for diabetes.

"China is in the stage repeating the period when the United States was developing the fastest," Deng said.

Then there is Sheng's work.

After 11 years at the NIH, she had learned a great deal but was frustrated. She had been researching mechanisms regulating early development and organ formation in mice using embryonic stem cells, which can develop into the multitude of cells that make body parts. Sheng thought it was time to study the same things using human embryonic stem cells. The money offered by the Chinese government gave her that chance.