In order for tissue grown in the lab to replace damaged or diseased tissue in the body, it needs to withstand complex mechanical loads – large forces regularly experienced over a lifetime of daily activities. Robert Mauck, PhD; Dawn Elliott, PhD; Nandan Nerurkar, MS, and colleagues from the McKay Orthopedic Research Laboratory at the University of Pennsylvania School of Medicine, are working on moving closer to engineering replacements for the annulus fibrosus, a soft tissue segment of the disc that resides between the vertebrae and allows for movement of the spine.
Bioengineered nanofibers. Credit: Robert Mauck, PhD.
Although disc degeneration affects as much of 97 percent of people over 50, current clinical treatments for this condition are aimed at reducing pain, often only succeeding temporarily.
“These engineered tissues could eventually be used as a patch for reinforcing herniated discs,” says Mauck.
The unique architecture – and so the mechanical behavior – of natural disc tissue was recreated when adult stem cells were coupled with a specialized scaffold consisting of organized, ultra-fine biodegradable nano-fibers. Using these engineered tissues, the investigators discovered a new mechanism by which tissues such as the annulus fibrosus are designed to withstand forces, advancing understanding of why tissues form the way they do, and how their architecture may be suited to a particular function.
These findings have implications for developing other biologic replacements for the cornea, heart, arteries, and knee meniscus. The group published their findings in Nature Materials.