Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo

 

Unsupported browser: Your browser does not meet modern web standards. See how it scores »

Osteoarthritis, which affects about 14 million people in the United States alone, occurs when cartilage between joints degrades and disappears, leaving joint bones to grind painfully against each other. Therapies can alleviate some of the pain, and some patients undergo joint replacements, but there is no cure. Now nanotechnologists at the University of Basel, in Switzerland, have demonstrated that the molecular changes characteristic of the disease’s earliest stages can be detected using an atomic-force microscope (AFM). The researchers hope that using the extremely sensitive technique to monitor response to osteoarthritis therapies will speed the development of more-effective drugs for the disease.

Other research groups have used AFM, one of the standard tools of materials science, to study the mechanical properties of tissues including bone and even individual cells such as cancer cells. The researchers, led by Martin Stolz, a nanotechnologist at the University of Basel, are the first to apply the technique to cartilage. AFM can detect cartilage breakdown decades earlier than can conventional diagnostics, the team reported in Nature Nanotechnology this week.

The symptoms of osteoarthritis are caused by molecular-level changes in the tissue that aren’t visible on conventional diagnostics such as x-ray images. “Osteoarthritis, like many other diseases, starts at the level of molecules, [and current techniques] don’t look at where it starts,” says Stolz. “The molecular scale is where you first have changes–that’s where you should address them.”

Cartilage is made up of tough collagen fibers that provide structure and soft, water-attracting supportive proteins that hold the collagen in position. In osteoarthritis, the supportive proteins in the cartilage disintegrate, drying out the joint and leading to disruption of the collagen fibers and eventual loss of cartilage altogether. Osteoarthritis is conventionally diagnosed with x-ray images or when a doctor, using a minimally invasive surgical probe called an arthroscope, notices changes in the appearance of the cartilage. Normal cartilage looks white and shiny under the arthroscope, but when osteoarthritis is under way and the tissue begins to break down, cartilage loses its shine and takes on a velvety appearance. By the time these changes are visible, Stolz notes, the greatest tissue damage has already happened.

Because AFM probes the mechanical properties of cartilage, not its appearance, it’s much more sensitive, says Hari Reddi, an orthopedist at the University of California, Davis, who was not involved in the research. In the AFM data, the tiny increases in spacing between the collagen fibers and their increasing stiffness–changes characteristic of the early stages of the disease–are visible.

0 comments about this story. Start the discussion »

Credit: Martin Stolz

Tagged: Biomedicine, diagnostics, drug development, molecular biology, molecular imaging, AFM, arthritis, biomechanics

Reprints and Permissions | Send feedback to the editor

From the Archives

Close

Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me
×

A Place of Inspiration

Understand the technologies that are changing business and driving the new global economy.

September 23-25, 2014
Register »