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BEIJING, July 1, 2003 — For Cui Fuzhai, a material science professor at Beijing’s Tsinghua University, the only setback in his research came when Severe Acute Respiratory Syndrome, or SARS, struck Beijing in the spring.
For the past six years, Cui had been developing a new method of healing broken bones using nanotechnology. But with the threat of SARS lurking, he had to stop his experiments in late April. Hospitals where clinical trials on the new technology were being held were sealed off, making it impossible for Cui’s doctors to see patients. One clinical patient even came down with SARS and couldn’t undergo surgery to have the “nano bone” implanted.
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Fortunately for Cui, the threat of SARS has waned in China. After being halted for a month, experiments are once again being conducted and clinical trials are proceeding. Cui and his team of researchers have successfully implanted nano bones in dozens of patients and he hopes that the technology will be commercialized soon.
“I hope to bring nano bones to the world,” Cui said in a telephone interview from his laboratory in Beijing. Cui received his Ph.D. in material science from Tsinghua and was once a visiting scholar at Harvard University’s medical school.
The nano bone material is inserted where the bone needs to heal. The critical material is calcium phosphorus, which is reduced to 30 nanometers in thickness and 60 nanometers in width. At this size, the properties of calcium phosphorus change. “On a large scale (the calcium phosphorus) won’t degrade, but on a nanoscale it will,” Cui said.
The nanoscale material degrades after a minimum of six months, and the space is filled by natural bone. Cui said the new technology is better than current methods that use ceramics or metals because those materials remain in the patient’s body and can cause infection, pain and make the repaired bone more vulnerable to breaking.
Cui said the technology has been found to be “very effective” in repairing small bones ranging from 1 to 2 centimeters long, making the technology useful after removal of bone tumors. Research is currently being performed on larger bones up to 4 centimeters long.
The nano bone technology, which was approved by China’s Food and Drug Administration last November, may be available for commercial use in Chinese hospitals in a matter of months, Cui said. The cost of the nano bone implant, which will initially be more expensive, should be brought down over time to be economically competitive with other technologies available. He wouldn’t give further details on the company that is helping to commercialize the research.
Myron Spector, a professor of orthopedic surgery (biomaterials) at Harvard Medical School who has been following Cui’s research for the past six years, said that Cui has gotten further along in nano bone technology than other researchers because the Tsinghua professor has dedicated a lot of time to studying the makeup of bones.
“He used the highest standard of experimentation from the start,” said Spector. “This development is also important because it’s homegrown.” Spector added that Cui’s technology should have no trouble getting approved by the U.S. Food and Drug Administration in the next few years.
China has 250,000 patients each year who need to undergo bone repair procedures following the removal of bone tumors, according to the official Xinhua news agency. The nano bone has been successfully implanted in about 30 patients, all without complications. The patients are in hospitals in the capital city of Beijing and further south in coastal Jiangsu province. Cui hopes to have the nano bones implanted in more than 100 patients successfully before it is employed for commercial use.
Yu Xin, a post doctorate candidate at Tsinghua University who has been overseeing the clinical trials at Beijing Dongzhimen Hospital, said that the procedure has been successful in all 26 of the patients operated on there. But Yu added that the technology still needs time to mature. “We still have to increase the strength (of the bones) and build it in different shapes,” he said.
Cui said that he is currently experimenting with use of nanotechnology to detect and repair other parts of the body, such as the brain and the liver. He added, however, that he has yet to figure out all the intricacies and characteristics of bones, which still fascinate him.
“Six years ago, I wanted to know why the natural bone was so complex. Today, we still don’t know everything about bone structure. Though we have made progress, there are still unknowns,” he said.