Stem Cell Research Rebuilds Spinal Tissue

A piece of a spinal disc dissected from a cadaver spine.
A piece of a spinal disc dissected from a cadaver spine.

One of our defining features as humans is an upright stance. Standing up has freed our hands and elevated our gaze, but it has also been a real pain.

Literally.

Every year, Americans spend over $30 billion to ease their back pain, while countless millions more people around the world also suffer from chronic lower-back pain.

“Bipedalism is a relatively recent evolutionary adaptation and it has its advantages,” says Thomas Lufkin. “But it also puts a great deal of pressure on the spine, particularly in the lower back, or lumber region, where most injuries occur.”

Along the spine, intervertebral (or spinal) discs made up of fibrocartilage separate the vertebrae. Fibrocartilage is a strong connective tissue that is much more flexible than bone and allows the spine to move.

Discs can become herniated as a result of traumatic injuries incurred during strenuous activity or from lifting something that’s too heavy. Long hours spent sitting up straight in a chair and even the normal process of aging cause discs to wear out.

The current technique for reducing chronic back pain is to remove the herniated disc and fuse vertebrae. However, this causes a loss of flexibility, which can hamper activity. It also increases stress on the adjacent discs. And that raises the likelihood that patients will incur more damage to their back.

Enter Lufkin’s pioneering research in the field of regenerative medicine, which aims to improve patient outcome by replacing damaged vertebrae with new spinal discs created by a patient’s own repurposed cells.

In many cases, such as the human heart for example, you are not just building a tissue or two but an entire integrated organ system so it is very, very complex

Lufkin and his team have already shown that cells swabbed from a patient’s mouth or scraped from a patient’s arm can be turned into embryonic stem cells that are then reprogrammed to become spinal discs.

These new laboratory-grown discs could then, theoretically, be surgically implanted to replace the damaged disc.

A benefit of this technique is that unlike with the current method of tissue transplant, there is no risk of rejection. “In this case, the patient is the donor,” Lufkin says.

Not long ago, the idea of growing tissues and organs like spinal discs, livers or kidneys in a lab was like the stuff of science fiction.

But the field of regenerative medicine is quickly advancing, and today, scientists like Lufkin are making significant breakthroughs in re-engineering cells and engineering replacement tissues with a goal towards curing, rather than treating, disease.

However, there are still a number of obstacles.

“In many cases, such as with the human heart, for example, you are not just building a tissue or two, but an entire integrated organ system, so it is very, very complex,” says Lufkin.

This is one reason why Lufkin is focusing on intervertebral discs. “It’s a far simpler structure. It is avascular and is composed of only two cell types, so it’s a great model to start with.”

And if Lufkin and his research team are successful, millions of people might find relief from an aching back.