Scientists have long wrestled with how to aid those who suffer cartilage damage and loss. One popular way is to inject an artificial gel that can imitate cartilage's natural ability to act as the body's shock absorber. But that solution is temporary, requiring follow-up injections.
Now Brown University nanotechnology specialist Thomas Webster has found a way to regenerate cartilage naturally by creating a synthetic surface that attracts cartilage-forming cells. These cells are then coaxed to multiply through electrical pulses. It's the first study that has shown enhanced cartilage regeneration using this method; it appears in the current issue of the Journal of Biomedical Materials Research, Part A.
"Cartilage regeneration is a big problem," said Webster, an associate professor in the Division of Engineering and the Department of Orthopaedics at Brown. "You don't feel pain until significant cartilage damage has occurred and it's bone rubbing on bone. That's why research into how to regenerate cartilage is so important."
Webster's work involves carbon nanotubes, which are molecular-scale tubes of graphitic carbon that are among the stiffest and strongest fibers known and are great conductors of electrons. They are being studied intensively worldwide for a range of commercial, industrial and medical uses.
Webster and his team, including Brown researcher Dongwoo Khang and Grace Park from Purdue University, found that the tubes, due to their unique surface properties, work well for stimulating cartilage-forming cells, known scientifically as chondrocytes. The nanotube's surface is rough; viewed under a microscope, it looks like a bumpy landscape. Yet that uneven surface closely resembles the contours of natural tissue, so cartilage cells see it as a natural environment to colonize.
"We're tricking the body, so to speak," Webster said. "It all goes back to the fact that the nanotubes are mimicking the natural roughness of tissues in the first place."