Drug Delivery System May Help Fight Osteoporosis

"The whole idea is to keep the therapeutic agent at the needed site," said Dr. Hasan Uludag, a professor in biomedical engineering and the lead author on a paper appearing in the current issue of Biotechnology Progress. "So we had to build a mechanism that chemically links biomaterial to the chemically therapeutic agent. Our interfacial engineering is what makes the concept unique."

Most current osteoporosis drugs do not directly reach the targeted bone but end up deposited in other areas of the body, which can eventually cause muscle and kidney damage, said Uludag.

His team uses a novel way of keeping the drug at the desired site by blending proteins known as growth factors that stimulate the cells necessary for growth. The unique method means more than half of the carrier molecules go directly to the targeted bone, and the body eliminates the rest. When his team injected the drug into the leg bones of rats, the researchers found an eight to 12-fold higher retention of the protein than normally expected. It is the first time a vehicle to deliver the drug directly to bones has been identified.

"One challenge with bones is that fractures heal very slowly, especially in the elderly," he said. "And there are also between five to 10 per cent which don't heal at all. Doctors will often take bone grafts from other parts of the body and transfer them to the fractured parts. We are trying to eliminate the invasive work with our drug-delivery vehicle."

Uludag's project received support from the U of A's Faculty of Medicine and Dentistry Start-up Funds and the Medical Research Council of Canada (now known as the Canadian Institute for Health Research).

The U of A in Edmonton, Alberta is one of Canada's premier teaching and research universities serving more than 30,000 students with 6,000 faculty and staff. It continues to lead the country with the most 3M Teaching Fellows, Canada's only national award recognizing teaching excellence.