Meet the scientists!

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 http://dl.dropbox.com/u/12578388/stem%20cells%20and%20broken%20bones.pptx

What I do

I am a doctor who specialises in reconstructive surgery and I am interested in what we call ‘regenerative medicine’ - which looks at how we can get the body to regenerate and heal itself after injury without forming a scar – kind of like how lizards can regenerate their tails even after they’ve dropped off! 

What are stem cells?  They’re kind of like you!

As you probably know, your body is made up of millions of cells (actually, 1 trillion, that’s 1000000000000!!) and there are many different types of cells.  If you take a bit of your skin and look at it under the microscope, you’d see that it is made up of thousands of tiny skin cells.  Similarly, your liver is made up of lots of liver cells, your brain is made up of brain cells (or nerves) and your bone is made up of bone cells, etc etc. You get the idea.  Well, you may also have heard of some pretty special cells called stem cells.  We all have them.  Many scientists believe that these cells may be the key to regenerative medicine.  Now, stem cells are special because they are different from all those other cells we just mentioned.  Stem cells are able to turn into almost any other type of cell found in your body! 

Let me explain it this way.  You guys all have the potential to become many different things.  You can become a soldier, scientist, doctor, artist, musician, footballer or whatever you want given the right training.  So, if the country goes to war and we have lots of wounded soldiers, we need to train some of you guys to replace these soldiers.  This is exactly the idea behind stem cells: we could use them to replace dead or injured cells!  For example, in my research, we are looking at bone repair.  Our aim is to get these stem cells to turn into specialised bone cells at the fracture site to speed up healing.  At the moment, we can get stem cells to turn into specialised cells that make bone in the lab.  But the question is, how can we get stem cells to turn into the types of cells we need inside the body in order to regenerate our injured body parts?

How can we use stem cells to heal?

There are different ways of approaching this.  One way would be to extract stem cells from your patient, grow them up in the lab so there are millions of them, inject them back into the patient where you need them (e.g. where the bone is broken) and hope these cells turn into bone-forming cells to mend the fracture.  But as you can imagine, there are many potential problems with this.  First of all, finding and isolating stem cells are not easy because they are rare and look a lot like many of the other cells that are around.  Even once you’ve managed to isolate them, growing them up in flasks in the lab can take ages – many many weeks; and if they get infected by bacteria (which may be floating about in the air), they can all die.  The biggest problem of all, though, is the risk of causing cancer when you inject these cells back into the patient, so it may actually turn out to be quite dangerous!

But, don’t worry, there is another way of making use of stem cells to heal.  You could say, well, first, we know there are stem cells already sitting around near the fracture site (e.g. inside the bone and in the muscles and fat around it); and second, these stem cells can respond to different chemical signals.  So if we can just work out what signals can activate these stem cells to get them to move towards the broken bit of bone and turn into bone-forming cells, then we don’t need to worry about all the problems we talked about earlier.  So, this is what I am currently working on – figuring out what signals we need to get the stem cells to move to where we want them to be and then turn into bone-forming cells.  In fact, we have already found a way of doing this in mice!  We’re now trying to see if we can get this to work in humans.

What’s the point of my research?

The ultimate aim is to be able to make fractures heal quicker – in humans, of course!  We all know somebody who has broken a bone.  It is an extremely common injury.  Many of these heal fine, especially in young people, but in older people who have poor bone quality (osteoporosis) or in people who have been involved in nasty fractures from traffic accidents or bombs, the bones do not heal properly and these patients become disabled for life and may even need amputation.  By understanding how to stimulate stem cells to do what we want them to do, or if you like, how to talk to them, we’ll be able to make a real difference to hundreds of thousands of people around the world so that they can walk again, get back to their jobs and do all the things they wouldn’t have been able to do otherwise.  That’s the inspiration that gets me out of bed every morning!

My cool experiments!

There are 2 main parts to my project.  I extract stem cells from samples of bone and other tissues from human patients and grow them in plastic flasks in the lab.  This means I get involved in the operations that are going on in the hospital next door (which is great fun!).  Obviously, I have to get the patients’ permission but they’re usually okay with it because this doesn’t affect their operation (the samples would’ve gone to the bin anyway) and people are usually happy to help future patients get better treatment.  I can then test different chemical signals in the lab and see what happens to the stem cells.  Do they move towards or away from the chemical?  Do they turn into bone-forming cells?

Operating on mice!

The other part of my project is to test these chemicals in animals.  I operate on mice.  Now let me stress that we do not cause the animals any pain at all!  It is very important that we test things in animals.  Because the DNA of mice and humans are actually very similar, if we can make bones heal quicker in mice, there’s a good chance we can do the same in humans too.  It would be too dangerous to test things in humans without trying them on animals first, but at the same time, we need to be ethical about what we do to the animals.  There are very strict rules about what you can and can’t do to animals and how to minimise any suffering they may experience, and it’d be against the law if you don’t follow them.

I put the animals to sleep with an anaesthetic, just like if you were to go for an operation, and I also give them strong pain killers.  When they are asleep, I open up the right shin and make a small break.  I then splint the inside of the bone with a narrow metal rod so it doesn’t fall to pieces when the mouse wakes up and tries to run on it.  Then I close up the wound with tiny stitches.  I do all this using a pair of custom-made magnifying glasses, which is great fun.  When the mice wake up, they do not feel any pain and are in fact scurrying around as if nothing happened!  The only thing is, you can’t be too squeemish otherwise you’d really struggle!  We then analyse how quickly the bones heal by using 3D x-rays, a microscope and a special machine which slowly bends the bones and measures how strong and elastic the bones are.  There are also other exciting things we can do, like making the stem cells light up green and tracking them as the bones heal.  Remember, we are doing all these experiments because we want to help our patients at the end of the day.

Science is exciting and can make a huge difference to the way we live.  It requires people who like to find out what’s going on, ask questions and solve puzzles, so it is important that we attract the next generation of young and enthusiastic budding scientists.  If you are a curious sort of person, then you’ll find science an unfailing source of fascination and discovery.  There are so many cool and crazy things that scientists have discovered (often when they are young), many of which have helped improve the lives of millions of people around the world.  It is so inspiring and so much fun – there aren’t many jobs in the world, other than being a sport star or musician, where you actually get paid to have fun! 

The problem is, sometimes, people get the impression that science is boring and for geeks.  Nothing can be further from the truth!  In science, everyday is different – you never know what’s going to happen, plus I’ve met some of the nicest and most interesting people in the science world.  But words don’t mean much. Which is why I want to SHOW people, through a documentary, the life of young scientists - how and why you should get involved and make an impact.