Lower back pain is an all too common condition for many Americans. But someday, these back pain sufferers could see relief thanks to a new approach to treating degenerative disc disease being developed at Duke University.
Degenerative disc disease happens as the soft discs between the vertebrae break down. One approach to treatment is injecting cells to replace this jelly-like cushion between the spinal discs. But using these cell therapies requires keeping the cells alive, synthesizing the appropriate test material and getting it into the right place in the spine.
Some companies currently offer cell delivery therapies but Duke graduate student Aubrey Francisco says that their methods allow the cells to migrate, moving away from the injection site. Bioengineering research from Duke has found a way to keep those cells in place.
Duke keeps the cells in place by mimicking laminin, a protein native to this disc tissue that allows injected cells to attach and remain in place. The researchers developed a gel mix designed to to be injected with the cells at the disc site. The gel mixes the chemically modified laminin protein along with two hyrogels that can attach to the modified laminin. When separate, these substances are in liquid form. But combined into a gel, cells can be held in place upon injection.
“Our primary goal was to create a material that would be liquid at the start, gel after injection in the disc space and keep the cells in the location where they’re needed,” said Lori Setton, a professor of biomedical engineering, said in a statement. “Our second goal was to create a material that would provide the delivered cells with the environmental cues to promote their persistence and biosynthesis.”
The researchers tested the technique by injecting the gel into rats’ tails the same way a surgeon would inject cells into the spinal discs of a patient. The solution began to solidify after five minutes and was completely set at 20 minutes. The researchers also compared the technique to injecting cells in a liquid suspension. After 14 days, more of the cells injected with the Duke biomaterial stayed in place compared to cells delivered in a liquid suspension. Francisco said using the currently available delivery methods, 100 percent of the injected cells leak from the injection site within four days of the injection.
The findings are still too early to be applied in humans. Setton said more work is needed to optimize the equipment and technique for use in humans. The proof-of-concept study by was published online in the journal Biomaterials. The research was funded by the National Institutes of Health.
