New Technique May Improve Diagnosis of Osteoarthritis

Researchers from Boston University School of Medicine (BUSM) have developed a new imaging technique which may improve the diagnosis and treatment of osteoarthritis, a common condition caused by the erosion of protective cartilage found in joints like the hands, knees, and lower back.

In a recent issue of Angewandte Chemie, the technique is explained as an engineered nanoparticle that highlights areas of the affected cartilage that cannot be picked up by a standard x-ray. The nanoparticle used in the experiment was created by BUSM student Jonathan Freedman and postdoctoral fellow Hrvoje Lusic.

According to a BUSM report:

[Researchers] synthesized a new nanoparticle contrast agent made of tantalum oxide that diffuses into the cartilage, thus enabling clinicians to use CT-scans to assess cartilage thickness and pinpoint lesions and injuries in osteoarthritic tissue. Guided by their clinical collaborator, Beth Israel Deaconess Medical Center/Harvard Medical School physician Brian Snyder, Freedman and Lusic used the nanoparticles to successfully image rat articular cartilage in in vivo and ex vivo experiments, as well as in a cadaverous finger joint.

They chose tantalum as a contrast agent material because it absorbs a greater fraction of X-rays produced at clinical scanning voltages than traditional materials. In addition, the tantalum nanoparticles’ positive charge automatically directs the particles to the cartilage, which carries a negative charge.

The researchers say that the new technique may help clinicians diagnose osteoarthritis in its early stages, which could lead to more effective treatment.

“Today we have very poor capability to detect early stage osteoarthritis,” lead researcher Mark Grinstaff said in the report. “Most patients come into the clinic at stage three when the pain becomes significant, but if diagnostics based on our method is done proactively, many patients could get the treatment they need much earlier and avoid a lot of discomfort.”

Current treatments for osteoarthritis include over-the-counter and prescription medications, physical or occupational therapy, and surgical procedures including bone realignment and joint replacement.