Gel plumps up spine’s shock absorbers

DUKE (US) — A new biomaterial that changes from a liquid to a gel after injection may stop or reverse the degeneration of spinal discs, researchers say.

The health conditions affect thousands of Americans. To use cell therapies, however, scientists have to keep the cells alive, synthesize the appropriate replacement material, and get it to the right place in a patient’s spine. With newly made biomaterials from Duke University’s Pratt School of Engineering, that goal could be closer.

In a proof-of-concept study published online in the journal Biomaterials, graduate student Aubrey Francisco and biomedical engineering professor Lori Setton describe a new biomaterial designed to deliver a booster shot of reparative cells to the nucleus pulposus, or NP—the jelly-like cushion naturally found between spinal discs. The NP tissue distributes pressure and provides spine mobility, helping to relieve back pain.

“Our primary goal was to create a material that would be liquid at the start, gel after injection in the disc space, and keep the cells in the location where they’re needed,” Setton says. “Our second goal was to create a material that would provide the delivered cells with the environmental cues to promote their persistence and biosynthesis.”

Disc degeneration

Disc degeneration is a common problem as people age. Over time, the soft, compressible discs that work as the spine’s shock absorbers break down. Although this intervertebral disc degeneration can occur anywhere along the spine, it mainly happens near the neck and lower back, causing intense pain. Individuals with this condition can also develop herniated discs, osteoarthritis, or spinal narrowing, known as spinal stenosis.

In the new approach, therapeutic cells are delivered to degenerated intervertebral discs within a biomaterial carrier that keeps them from leaking out of place. (Credit: Aubrey Francisco)

Previous lab research has shown that re-implanting NP cells, or even stem cells, can delay disc degeneration. Several companies already offer cell delivery strategies, but the methods are poor and ineffective. “They allow the cells to quickly migrate out of and away from the injection site,” Francisco says.

Cells stay put

The team’s delivery strategy keeps the cells in place and provides cues that mimic laminin, a protein in native nucleus pulposus tissue. Laminin is normally found in juvenile but not degenerated discs and allows injected cells to attach and remain in place with the delivered biomaterial.

Laminin may also enable the cells to survive longer and produce more of the appropriate extracellular matrix or structural underpinning of the discs that help stop degeneration, Setton says.

The researchers developed a gel mix designed to reintroduce NP cells to the intervertebral disc (IVD) site. The gel mixes together three omponents: the protein laminin-111 that has been chemically modified and two polyethylene glycol (PEG) hydrogels that can attach to the modified laminin. Separately, these substances remain in a liquid state. The gel, however, holds the cells in place upon injection.

The researchers worked with postdoctoral scholar Robby Bowles to tag NP cells with the bioluminescent marker luciferase and track their location. They then injected the gel into rats’ tails just as a surgeon would deliver cells to a patient. After puncturing the tail’s thin outer layer, they held the needle in place for one minute, delivered the injection to the rat’s IVD site, and closed the injection spot. The solution began to solidify after five minutes and was completely set at 20 minutes.

Images of the luciferase biomarker showed that more than 14 days after injection significantly more cells remained in place when delivered within the biomaterial carrier compared to cells delivered in a liquid suspension. Francisco explains that using the currently available cellular delivery strategies, 100 percent of the injected NP cells leak out of an IVD site within three to four days after injection.

The results, although preliminary, could have a positive impact on the future of cell therapy, Setton says. More work, however, is still needed to optimize equipment and models that deliver cells to a larger IVD sites closer to human size, the researchers says.

“The concept is that these cells will be promoted to produce matrix that can support tissue regeneration or arrest degeneration,” Setton says. “Additional studies that evaluate disc height or matrix hydration following cell delivery would be important to achieve this goal. There’s definitely interest and certainly real potential there.”

The National Institutes of Health funded the research.

Source: Duke University

chat13 Comments

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  1. Alistair Cargill

    As someone with a prolapsed disc in my neck, I wold interested to known injecting this into the damaged area can help cure me of pain? It may be that it could work but only decompression surgery to cut away the section of disc that is pushed out. Any helpful advice/ comment on this would be appreciated. Thank you.

  2. Kristi

    Let me know if you need a test subject! I have been waiting for this for the past eight years!

  3. Chris P

    With regular chiropractic care these individuals may have never needed this type of surgery. It is to sad that our medical industry is designed to take care of people after they get into pain rather than taking a proactive approach to prevent degeneration in the first place. Our sedentary lifestyle and belief in a magical pill to solve all our problems has created a fairy tale world that is causing us to fall behind other countries medical industries that we once surpassed many fold.

  4. Bill

    @Chris, I was a passenger in a car accident when I was 16 that dislocated my spine. I had a lower lumbar spinal fusion from L1-L5. It took me 6 months to recover and I now must wake up an hour early to do stretches and exercises for my lower back every morning. Despite, living a healthy lifestyle I still experience frequent back pain. I have been diagnosed with adjacent segment disease at the ripe old age of 27. Do you know how it feels to suffer from chronic back pain, knowing that you haven’t even lived half your life yet? Knowing that it will only get worse?

    Seeing this article was a bright spot in my day. I am happy to see that our country’s brightest minds are working toward a solution. You call it a fairy tale, I call it hope.

  5. Chuck

    Chris P, regular exercise and massage will do more for your spine than any chiropractor. Also, the medical industry has no reason to be involved in people’s lives until their services are needed. Also, what they’re describing isn’t surgery, it’s an injection.

  6. Andrew

    I agree, one of the very best things you can do is proper exercise. So many people miss this and over look the fact that many set backs can be cure or helped with just doing consistent exercise to stay healthy.

  7. GINA

    Do you need subjects to work on cause I am in need of help .

  8. Suzanne

    Please keep me in mind if you need to do testing. I had an L5 S1 disc herniation and had a laminectomy still no relief along with radiculopathy for the last two years in my left side. I am always in pain!!!

  9. Mildred

    I wood Kike. Moré información i can not sit or stand.

  10. Kathy

    I am very interested in this procedure. I have been suffering from back pain for over a year now and have done everything to avoid surgery, steroid shots, nerve block shots, physical therapy, and even acupuncture. Please let me know about availability and where it may be obtained. I live in Utah but would be willing to travel. Thank you, Kathy K.

  11. JC

    1. Thank you, Aubrey! Please keep going, we’re counting on you :).
    2. PSA – Do NOT get a spinal fusion if you have back pain. Unless you can’t walk, there is no reason to get a fusion. There is no such thing as a “minimally invasive” fusion…it will most likely change your life for the worse, forever. Surgeons are not there to help you, they are there to make money…that’s why they chose to be surgeons. 20 years we will view spine fusions as an archaic and disgusting practice.

  12. Bob Fritz

    I am healthy, ride my bikes, ski, work out, hike and eat right. However, after years of wear & tear, my L3L4, L4L5 & L5S1 discs are degenerated so I’m getting nerve pinching, numbness and atrophy. I refuse to go with fusion. This injection solution certainly looks great. Let me know where I can sign up for a clinical trial. Thanks.

  13. Carol Wagner

    Please keep me posted about your work. This is most exciting!

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