Tracking Osteoarthritis with Nanoparticles
New imaging method promises earlier, more precise detection

The new osteoarthritis diagnostic method exploits tantalum oxide nanoparticles as contrast agents to image surface and interior regions of cartilage coating the joints.
A chronic disease afflicting more than 27 million Americans and 630 million worldwide, osteoarthritis occurs as the protective cartilage coating on joints in the knees, hips, and other parts of the body degrades. No cure for osteoarthritis exists, but treatments can slow its progression, reduce pain, and restore joint functioning. Now, a team of researchers led by Boston University College of Engineering Professor Mark Grinstaff (biomedical engineering, chemistry, materials science and engineering) has developed a sensitive imaging method that promises to enhance diagnosis of osteoarthritis and enable improved care through earlier detection and more targeted treatments.
Funded by the National Institutes of Health and described in the journal Angewandte Chemie, the method exploits new, biocompatible nanoparticles as contrast agents to image surface and interior regions of articular cartilage (the smooth, water-rich tissue that lines the ends of bones in load-bearing joints)—regions that traditional X-ray illumination cannot detect. In the short term, these contrast agents could be used to image cartilage over time to monitor the efficacy of proposed osteoarthritis drugs; with continued development, they may enable clinicians to diagnose and stage the disease so that the most appropriate course of treatment could be followed.

“Today, we have very poor capability to detect early-stage osteoarthritis,” said Grinstaff. “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.”
In the past five years alone, Grinstaff has produced more high-impact inventions than many researchers do in an entire career, from the new osteoarthritis detection method to a hydrogel wound sealant that can later be dissolved and gently removed. In addition, he has co-founded four companies to translate some of his ideas into clinical products.
In recognition of his ability to advance engineering and scientific principles to invent and translate new technologies to impact society, Grinstaff was named as the inaugural BU College of Engineering Distinguished Professor of Translational Research in June 2014, and awarded an annual discretionary fund of $20,000. The professorship came on the heels of his April 2014 appointment as director of the Center for Nanoscience & Nanobiotechnology, which combines BU’s strengths in nanotechnology, engineering, and medicine to improve our understanding of subcellular processes, biomolecular function, and human physiology, and to apply that knowledge to clinical challenges.