Impressive, Hong Kong shows the benefits of a very strong education system. Bone repairs made as smooth as silk Elaine Yau Nov 18, 2009 Email to friend Print a copy Bookmark and Share A Polytechnic University researcher has invented a degradable material using silkworm cocoons and natural plastic that could be used in bone repairs, the main benefit being that patients could forgo the second operation needed to take out the metal implants used by orthopaedists. Dr Karen Cheung Hoi-yan, a doctoral graduate from the department of mechanical engineering, said silk was a sturdy and elastic material which, when combined with the bioplastic polylactic acid, could be a remedy for the shortcomings of current bone treatment. "Stainless steel is not self-degradable, and doctors have to perform a second operation to take the metal plates out after the broken bones heal," she said. Cheung said that patients who had metal implants were also vulnerable to relapse. "After the broken bone heals and new cells grow, the stainless steel [used as a splint] will be taken out. But stainless steel is much stronger than human bones. The human body might not get used to the new cells, which are weaker than the stainless steel, and suffer from bone fractures again." Cheung said the proposed implants would degrade into carbon dioxide and water, which would be excreted by the human body without any harmful side effects. Cheung said she gained inspiration from foreign journals. "Silk, which is protein, was used by ancient doctors to dress wounds," she said. Scientists overseas had researched using silk, but their work had been inconclusive and haphazard. "They stopped their research before they could yield worthy results," she said. "I picked up where they left off. "I devoted all my four-year doctoral study to this research. Only after many trials and tribulations did I come up with the implant." The invention helped her win the Young Scientist Award in the field of engineering science organised by the Hong Kong Institution of Science. Cheung is applying for a post-doctoral fellowship at PolyU. If she is accepted, she will continue her research and work with Cambridge University, the University of California and University of Hong Kong to test the implants on mice. Her supervisor in the research project, associate professor of mechanical engineering Dr Alan Lau Kin-tak, said the invention could be used on human patients in about four to six years. "The tests on mice will last two years. Wide application of the implant can be achieved after clinical trials are carried out on humans," he said.
