A research group led by Lawrence Bonassar, PhD, professor of biomedical engineering at Cornell University, and graduate student Edward Bonnevie, MS, has discovered that another molecule, lubricin, helps anchor hyaluronic acid at the tissue surface, which, in turn, helps to move cartilage into a low-friction regime.
"The implication of this finding is that the efficacy of hyaluronic acid treatment might depend on how much lubricin is in the joint at the time of injection, which could explain why clinical trials of hyaluronic acid have such variable outcomes and may also suggest new formulations of hyaluronic acid that might be even more effective in the clinic," said Dr. Bonassar
The study, published online November 24 in the journal PLOS ONE
, examined how multiple formulations of hyaluronic acid lubricated cartilage.
The researchers found that all hyaluronic acid formulations worked by a similar mechanism, "one that is very similar to how a car hydroplanes on a wet road," said Dr. Bonassar
Essentially, the viscous hyaluronic acid solutions form pressurized films that lower the friction coefficient of cartilage, particularly at higher sliding speeds.
"For many years, people doubted that this mechanism could happen in cartilage because the tissue is both flexible and porous.
In this paper, we show definitively that cartilage can move to this low-friction domain in the presence of highly viscous hyaluronic acid solutions," Dr. Bonassar