New approach to treating osteoporosis uses bone-seeking molecules
Osteoporosis researchers have long dreamed of strengthening bones, but haven't had a method that could stimulate bone growth to the areas that needed it. Now, Canadian researchers may have found such a vehicle, reports the August/September edition of Biotechnology Progress, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.
The researchers tied small bone-seeking molecules to large proteins capable of stimulating bone growth. The report - from animal testing - is the first successful clinical attempt at steering the proteins to bone, where they can accumulate in the desired areas and help build bone mass. Proteins do not normally go to bone and are cleared from the circulatory system unless they have something to cling to.
Additional research is needed to determine if the accumulated proteins can grow bone tissue, said lead researcher Hasan Uludag, Ph.D., of the University of Alberta in Canada. Translating the animal studies into human trials could take years, he noted. Still, the finding could ultimately lead to a new approach to treating bone disease.
"Therapeutic agents capable of stimulating new bone formation form the basis of a new class of drugs that will not only slow the bone loss, but also will have the potential to restore lost bone mass," Uludag said.
Other researchers have produced bone-aiding proteins, but have not succeeded in attaching them where they might help patients. Current treatments - like estrogen and calcitonin - aim to stem the loss of bone mass rather than rebuild the bone.
Proteins generally known as "growth factors" stimulate certain types of cells necessary for bone growth. The growth factors, the researchers hope, can help re-grow lost bone mass to the areas that need it. As we age, however, the number of such cells decreases. For that reason, it remains to be seen whether the growth factors are effective in an elderly population, Uludag said. If so, they might one day be injected in people who suffer from osteoporosis to stimulate the formation of new bone, he suggested.
"We are trying to 'engineer' the linkages that will target the growth factors to the bones," Uludag said. "If we can put together the proteins that stimulate bone growth with the molecules that go to the bone, we'll have an agent that could work."
Osteoporosis, a degenerative condition usually found in older people, is characterized by low bone mass and bone deterioration. People with osteoporosis have fragile bones that fracture easily. Approximately 10 million people in the United States suffer from the disease, and another 18 million have low bone mass, placing them at an increased risk of developing it, according to the National Osteoporosis Foundation.
Eighty percent of those who suffer from osteoporosis are women, according to foundation statistics.
The research was funded by the Medical Research Council of Canada.
The online version of the research paper cited above was initially published July 26 on the journal's Web site. Journalists can arrange access to this site by sending an email to tonewsroom@acs.org or calling the contact person for this release.
Dr. Hasan Uludag, Ph.D., is an assistant professor in the department of biomedical engineering at the University of Alberta in Edmonton, Alberta, Canada.
A nonprofit organization with a membership of 161,000 chemists and chemical engineers, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.
Journal
Biotechnology Progress