Fluorescent Probe to Track Osteoarthritis Development

Doctors treating patients with osteoarthritis may need to look no higher than their ceilings to see the inspiration behind the newest diagnostic tool.

According to recent research, a fluorescent probe could soon be used to not only diagnose the condition, but also monitor its effect on a patient’s body. While the device has so far only been tested in mice, it could be a beneficial option for humans in the near future.

The research, which was conducted by a team at the Tufts University School of Medicine and the Sackler School of Graduate Biomedical Sciences at Tufts utilized a fluorescent molecule which helped them observe cartilage loss in the mice. The authors noted that this is the first step in a process, which could eventually see the technology used to analyze the efficacy of patient treatment methods.

“Patients are frequently in pain by the time osteoarthritis is diagnosed,” said co-first author Averi A. Leahy, BA, an MD/PhD student. “The imaging tests most frequently used, X-rays, don’t indicate the level of pain or allow us to directly see the amount of cartilage loss, which is a challenge for physicians and patients.”

With this option, the authors commented it could be easier to diagnose the condition and get patients the help they need in a more effective manner.

“The fluorescent probe made it easy to see the activities that lead to cartilage breakdown in the initial and moderate stages of osteoarthritis, which is needed for early detection and adequate monitoring of the disease,” said co-first author Shadi A. Esfahani, MD, MPH, a post-doctoral fellow in the division of nuclear medicine and molecular imaging at Massachusetts General Hospital and in the department of radiology at Harvard Medical School.

By using the probe Esfahani said the team was able to look inside the knee in a non-invasive manner, making for a smoother procedure. The data was collected from the right knees of 54 mice who had “injury-induced osteoarthritis,” for which they received pain medication. The left knees were used as the control group.

The mice were examined every 2 weeks over a 2-month period. The researchers reported the signal from the probe “became brighter in the injured right knee, at every examined time point, through the early to moderate stages of osteoarthritis.” The left knee, they noted, “Emitted a lower signal,” and, “did not increase significantly over time.”

According to the authors the next step is to monitor the probe for a longer period of time to see if the results remain consistent. They will also observe whether this technology could help animals, particularly dogs, with treatment of the condition.

The corresponding and senior author was Li Zeng, PhD, associate professor at the medical school and a member of the cellular, molecular, and developmental biology program faculty at the Sackler School. Collaborating on the study was Umar Mahmood, MD, PhD, director of the Center for Translational Nuclear Medicine and Molecular Imaging, co-director of the Nuclear Medicine and Molecular Imaging at Massachusetts General Hospital, and associate professor in the department of radiology at Harvard Medical School.