Cellular Healing

What made him a good candidate for this treatment?
The part of the muscle at the hip was intact, and the part at the knee was intact, so we were just replacing the section in between. Once you get the process started, the body takes over.

How do you initiate the process?
There are a number of approaches to regenerative medicine. But the one I've been working with involves harvesting the extracellular matrix (ECM) from a pig bladder or intestine and placing it at the wound site.

I doubt most people know what the extracellular matrix is.
If you take the bladder or small intestine and scrape away all the cells, what you're left with is structural tissue like collagen and functional molecules such as growth factors. There are literally hundreds of these proteins, all housed in the ECM. They instruct cells on how to behave—whether to multiply or migrate or differentiate into different types of cells. They tell cells at the site of a wound what to do. Equally important, they recruit cells to the wound site that wouldn't normally be there, such as stem cells. I wouldn't be smart enough to put them all together, but I can harvest what nature has done.

How does tissue from a pig's small intestine communicate to human muscle?
That's a great question. Certain things are so important to mammalian survival that they are conserved across species. The amino acid sequences are either identical or else so close to those in humans that they deliver the same message.

And because the ECM contains no cells, you can implant it in a person without causing an immune reaction?
Right.

Is that enough to stimulate growth?
Simply placing the ECM at the site might get cells interested. But if you don't recreate the micro-environment needed for tissue growth, it won't happen. That means you need the right pH, oxygen, moisture and nutrients. You also have to apply the correct mechanical forces. An Achilles tendon, for example, has to bear weight. Without those signals, it will turn into loose connective tissue.

I know you don't like to talk about this, but working with a powdered version of ECM, you helped three people regrow the tips of fingers that were accidentally severed.
The tips of fingers sometimes regrow anyway, especially in children, so we can't prove this was because of our work. You would need a clinical trial.

Obviously, you didn't start by regenerating large muscles. You began with smaller applications, such as rotator-cuff repair.
The rotator cuff is the tendon group around the shoulder that holds the arm in place and allows it to move in different directions. When it tears, there's nothing a traditional surgeon can use to repair it now. It's like trying to sew back wet Kleenex. But when we implant ECM, the body treats it as a scaffold on which it can build. The body's own cells invade. The scaffold is gone within 75 days, as the body replaces it with its own tissue. More than 1.5 million patients have been helped with our ECM product Restore—and those of two other companies. It's not true regeneration, because we're using a scaffold. But it might be just as effective.

Can you see this becoming standard practice one day?
There are lots of clever new approaches to regenerative medicine. We're learning which therapies work best for which applications. I believe we will get there.

© 2009