Although today’s rheumatoid arthritis treatments can reduce symptoms, they often come with serious side effects. Results from a new mouse study suggest that a new light-activated drug delivery method helps confine treatments to the joints, which could reduce whole-body side effects.
In the U.S., 1.3 million people are currently diagnosed with rheumatoid arthritis, a chronic disease that causes painful joint swelling that can eventually lead to bone loss and joint deformities.
“Our delivery system decreased arthritis in our experimental model while carrying and delivering much lower quantities of drug than is required for currently approved treatment,” said Emilia Zywot, a doctoral candidate from the University of North Carolina in Chapel Hill and member of the team that developed the new drug delivery approach.
For the new delivery approach, a drug is attached to vitamin B12 molecules that are engineered to respond to low levels of laser light. Transfusion is then used to deliver red blood cells loaded with the vitamin B12 molecules into mice, where the cells circulate until activated.
To test their new method, the researchers administered the arthritis drug dexamethasone to arthritic mice via traditional injections and the light-based delivery system. Laser light was used to activate the light-responsive drug in an arthritic paw. They found that the light-based delivery system decreased arthritis using a three-fold lower dose of dexamethasone.
The researchers plan to further investigate the light responsive drug delivery system in mouse models of arthritis to better understand efficacy of the new system compared to current treatments.