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  • This is actually a painting

  • that hangs at the Countway Library at Harvard Medical School.

  • And it shows the first time an organ was ever transplanted.

  • In the front, you see, actually, Joe Murray

  • getting the patient ready for the transplant,

  • while in the back room you see Hartwell Harrison,

  • the Chief of Urology at Harvard,

  • actually harvesting the kidney.

  • The kidney was indeed the first organ

  • ever to be transplanted to the human.

  • That was back in 1954,

  • 55 years ago.

  • Yet we're still dealing with a lot of the same challenges

  • as many decades ago.

  • Certainly many advances, many lives saved.

  • But we have a major shortage of organs.

  • In the last decade the number of patients

  • waiting for a transplant has doubled.

  • While, at the same time, the actual number of transplants

  • has remained almost entirely flat.

  • That really has to do with our aging population.

  • We're just getting older.

  • Medicine is doing a better job

  • of keeping us alive.

  • But as we age, our organs tend to fail more.

  • So, that's a challenge,

  • not just for organs but also for tissues.

  • Trying to replace pancreas,

  • trying to replace nerves that can help us with Parkinson's.

  • These are major issues.

  • This is actually a very stunning statistic.

  • Every 30 seconds

  • a patient dies from diseases

  • that could be treated with tissue regeneration or replacement.

  • So, what can we do about it?

  • We've talked about stem cells tonight.

  • That's a way to do it.

  • But still ways to go to get stem cells into patients,

  • in terms of actual therapies for organs.

  • Wouldn't it be great if our bodies could regenerate?

  • Wouldn't it be great if we could actually harness the power

  • of our bodies, to actually heal ourselves?

  • It's not really that foreign of a concept, actually;

  • it happens on the Earth every day.

  • This is actually a picture of a salamander.

  • Salamanders have this amazing capacity to regenerate.

  • You see here a little video.

  • This is actually a limb injury in this salamander.

  • And this is actually real photography,

  • timed photography, showing how that limb regenerates

  • in a period of days.

  • You see the scar form.

  • And that scar actually grows out

  • a new limb.

  • So, salamanders can do it.

  • Why can't we? Why can't humans regenerate?

  • Actually, we can regenerate.

  • Your body has many organs

  • and every single organ in your body

  • has a cell population

  • that's ready to take over at the time of injury. It happens every day.

  • As you age, as you get older.

  • Your bones regenerate every 10 years.

  • Your skin regenerates every two weeks.

  • So, your body is constantly regenerating.

  • The challenge occurs when there is an injury.

  • At the time of injury or disease,

  • the body's first reaction

  • is to seal itself off from the rest of the body.

  • It basically wants to fight off infection,

  • and seal itself, whether it's organs inside your body,

  • or your skin, the first reaction

  • is for scar tissue to move in,

  • to seal itself off from the outside.

  • So, how can we harness that power?

  • One of the ways that we do that

  • is actually by using smart biomaterials.

  • How does this work? Well, on the left side here

  • you see a urethra which was injured.

  • This is the channel that connects the bladder to the outside of the body.

  • And you see that it is injured.

  • We basically found out that you can use these smart biomaterials

  • that you can actually use as a bridge.

  • If you build that bridge, and you close off

  • from the outside environment,

  • then you can create that bridge, and cells

  • that regenerate in your body,

  • can then cross that bridge, and take that path.

  • That's exactly what you see here.

  • It's actually a smart biomaterial

  • that we used, to actually treat this patient.

  • This was an injured urethra on the left side.

  • We used that biomaterial in the middle.

  • And then, six months later on the right-hand side

  • you see this reengineered urethra.

  • Turns out your body can regenerate,

  • but only for small distances.

  • The maximum efficient distance for regeneration

  • is only about one centimeter.

  • So, we can use these smart biomaterials

  • but only for about one centimeter

  • to bridge those gaps.

  • So, we do regenerate, but for limited distances.

  • What do we do now,

  • if you have injury for larger organs?

  • What do we do when we have injuries

  • for structures which are much larger

  • than one centimeter?

  • Then we can start to use cells.

  • The strategy here, is if a patient comes in to us

  • with a diseased or injured organ,

  • you can take a very small piece of tissue from that organ,

  • less than half the size of a postage stamp,

  • you can then tease that tissue apart,

  • and look at its basic components,

  • the patient's own cells,

  • you take those cells out,

  • grow and expand those cells outside the body in large quantities,

  • and then we then use scaffold materials.

  • To the naked eye they look like a piece of your blouse,

  • or your shirt, but actually

  • these materials are fairly complex

  • and they are designed to degrade once inside the body.

  • It disintegrates a few months later.

  • It's acting only as a cell delivery vehicle.

  • It's bringing the cells into the body. It's allowing

  • the cells to regenerate new tissue,

  • and once the tissue is regenerated the scaffold goes away.

  • And that's what we did for this piece of muscle.

  • This is actually showing a piece of muscle and how we go through

  • the structures to actually engineer the muscle.

  • We take the cells, we expand them,

  • we place the cells on the scaffold,

  • and we then place the scaffold back into the patient.

  • But actually, before placing the scaffold into the patient,

  • we actually exercise it.

  • We want to make sure that we condition

  • this muscle, so that it knows what to do

  • once we put it into the patient.

  • That's what you're seeing here. You're seeing

  • this muscle bio-reactor

  • actually exercising the muscle back and forth.

  • Okay. These are flat structures that we see here,

  • the muscle.

  • What about other structures?

  • This is actually an engineered blood vessel.

  • Very similar to what we just did, but a little bit more complex.

  • Here we take a scaffold,

  • and we basically -- scaffold can be like a piece of paper here.

  • And we can then tubularize this scaffold.

  • And what we do is we, to make a blood vessel, same strategy.

  • A blood vessel is made up of two different cell types.

  • We take muscle cells, we paste,

  • or coat the outside with these muscle cells,

  • very much like baking a layer cake, if you will.

  • You place the muscle cells on the outside.

  • You place the vascular blood vessel lining cells on the inside.

  • You now have your fully seeded scaffold.

  • You're going to place this in an oven-like device.

  • It has the same conditions as a human body,

  • 37 degrees centigrade,

  • 95 percent oxygen.

  • You then exercise it, as what you saw on that tape.

  • And on the right you actually see a carotid artery that was engineered.

  • This is actually the artery that goes from your neck to your brain.

  • And this is an X-ray showing you

  • the patent, functional blood vessel.

  • More complex structures

  • such as blood vessels, urethras, which I showed you,

  • they're definitely more complex

  • because you're introducing two different cell types.

  • But they are really acting mostly as conduits.

  • You're allowing fluid or air to go through

  • at steady states.

  • They are not nearly as complex as hollow organs.

  • Hollow organs have a much higher degree of complexity,