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Using x-rays to see the small scale

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Matt Smith:

Welcome to the La Trobe University podcast. I’ll be your host Matt Smith and I’m here today with Professor Leann Tilley, she’s the head of the Malaria Lab in the Department of Biochemistry at La Trobe University and also Associate Professor Andrew Peele from the Department of Physics. Thanks for joining me guys.

Leann Tilley:

Hi.

Andrew Peele:

Hi.

Matt Smith:

Now together you are both tied up with the ARC Centre of Excellence for Coherent X-ray Science. Did you want to tell me a bit about that?

Leann Tilley:

Yes, I can start. So yes, Matt, the Centre of Excellence for Coherent X-ray Science is a very unusual beast in that it involves a bunch of physicists, some pretty hardcore physicist who have agreed to work with a bunch of biologists in order to develop fundamentally new ways of imaging biological samples.

So this centre has bases all over Melbourne, Melbourne University and other university and CSIRO institutions around Melbourne. At La Trobe University, there are two programs, so Andrew is head of the Experimental Methods Program, that’s a physics program and Mike Ryan, also from the Department of Biochemistry is head of the Biology Program and I’m the Deputy Director of the centre.

Andrew Peele:

The nice thing about La Trobe is that we actually have two of the major groups in the centre. So we have the nexus between the physicists and the biologists here in one place.

Matt Smith:

And what is your group involved in doing?

Andrew Peele:

So my group is the Experimental Methods Program and we cover a lot of the different techniques that the centre uses, but primarily we’re interested in using x-rays to probe and image the structures, the biological structures that the Biology groups are interested - in particular things like malaria and red blood cells.

Matt Smith:

OK. So, well the purpose of the large x-ray machines I imagine is to get in on something on a really small scale to - how small a scale are we talking here?

Leann Tilley:

So yes, the Centre of Excellence is in fact involved in a number of different imaging technologies. We render what you might call sort of extreme imaging. So this is your fastest, your base, your biggest kind of microscopes, x-ray microscopy.

That sort of the core business of the centre but we’re also got interests in electron microscopy and in fluorescence light microscopy.

And we like with all of those techniques to see the best possible resolutions and we want to see structures that are inside so as the actual internal structure of cells, individual membranes, individual organelles within a cell and eventually individual molecules within a cell.

So the idea of our centre is that the physicists are developing new methods that enable us to see that better - always better and better resolution, better and better detail and we work with them as biologists to provide samples so that they can keep in mind when they’re actually developing these new technologies, what it is that the biologists are eventually going to need.

Andrew Peele:

And that’s the nice thing about the x-rays. It’s not just being able to see smaller and smaller, but also being able to see through things so we can see into the insides of a lot of these structures seen inside in the interior of cells and build up three dimensional pictures of what’s going on.

Matt Smith:

You sound a bit like Scotty from Star Trek. Excellent.

Andrew Peele:

Beam up a few pictures of cells.

Matt Smith:

So the thing now, you sound like you're continuously refining the instruments here?

Andrew Peele:

Yes, it’s never ending. We're often try to move on to the next technique before we’ve even really got the most out of the previous ones and I think that’s why the collaboration with the biologists is really good because it forces us to make sure that we’re getting the best pictures and the most useful information out of structures.

Matt Smith:

And I understand Andrew that you have a very impressive FRIEND.

Andrew Peele:

Yes. I prefer to think of it as a 'fiend' but the FRIEND is the acronym for the experiment that we've built, which is currently sitting over in Chicago.

And it looks like a thing because it’s a huge stainless steel box with an awful lot of electrical fittings and vacuum fittings that goes with it but it’s the core of one of the particular x-ray experiments that we did.

Matt Smith:

You might want to explain what it stands for.

Andrew Peele:

FRIEND is Fresnel Imaging End Station. But if you type the "r" out, that’s a fiend which I preferred to call it.

Matt Smith:

It’s a very large and accurate x-ray machine by its sound.

Andrew Peele:

Yes, what it let’s us do is it let us put the x-rays from this particular facility, which is a Synchrotron source and in fact we have a synchrotron in Australia which this - their end station will ultimately go to.

But at the moment, its being commissioned over at the Advance Photon Source in Chicago and what it does is it takes a beam of x-rays and puts them through essentially a very hardly developed x-ray lens and then let’s that illuminate the object that we’re interested in.

And the trick to it all is holding the object and the lens very, very stable with respect to each other. In fact, the figure that we try to keep them at is around about two nanometers with respect to each other.

So a nanometer is one billionth of a meter and we have to hold these two things stable to within two nanometers over long periods of time. So most of the apparatus is dedicated towards measuring where the lens and the sample are and then actively fading back to hold them stationary with respect to each other.

Matt Smith:

How is that managed?

Andrew Peele:

With great difficulty - yes, it’s very, very difficult and in fact, not too much earthquakes, but even just somebody opening and shutting the door in the lab - well, the neighbouring lab and in fact, the real big issue is temperature. If the temperature changes by a tenth of a degree, anywhere, then things will move around enormously just from thermal expansion. So, it’s very, very difficult pinning all of these effects down.

Matt Smith:

One question I do want to ask that how is - what is the longest amount of time they’ve been able to stay at two nanometers?

Andrew Peele:

We need to hold them stationary for periods of quarter hours and that’s basically we’re operating.

Matt Smith:

One of these that this imaging technique is to look at malaria and that’s where your research comes into it or what you’re chiefly interested in by the sounds of it, Leann. Did you want to tell me a bit about that?

Leann Tilley:

Sure, so we work on malaria. Malaria as you may know, is a really major disease of human kind. It kills about one million people every year, that’s one million kids age group zero to five years, mostly in Sub-Saharan Africa.

And the malaria parasites kills its victims, it’s transmitted from mosquitoes but then, when it gets inside healing, actually enters the red blood cells, starts to eat the red blood cells from the inside out.

So, effectively it destroys the red cell, changing what is the sort of life giving, you know, oxygen-carrying vessel into this agent of destruction. So as it eats the red cell haemoglobin, it also changes the properties of the red cell membrane and makes the red cells - become sticky.

And then they adhere to the blood vessel walls and organs such as the brain. And then the infected cells sticking in the brain causes the patient to go into a coma and very often, even with the best possible medical care, the patients don’t recover from that coma. And you can imagine in an African situation that’s really a very serious problem.

So what we’re trying to do fundamentally is to understand the inner workings of the malaria parasite while if you do interfering with the process whereby the malaria parasite kills a human and try to understand new ways of actually killing malaria parasites.

So, in order to do that, we need to be able to understand the molecular details within the parasite with the best possible techniques that are available. So, that’s why we’re always searching for a bigger, better, more sophisticated instrumentation so that we can actually really see the molecular detail, what changes if the parasite makes to the red cell.

And we can look at the effective drugs, we can try to develop new drugs that again will interfere with those processes.

Matt Smith:

One of the things that I do know about malaria - well, that most people know is that a spray by a mosquitoes wouldn’t that be the more direct way to address the treatment of malaria by trying to stop it at the source.

Leann Tilley:

They sent me options of trying to develop mosquitoes, which stay long or mosquitoes which don’t transmit malaria. The difficulty then is to try and introduce those mosquitoes into Sub-Saharan Africa.

You can imagine it’s not easy to control her biological agent in an African country, even in Australia where we’ve tried to do biological control. There have been some negative outcomes and you have to think of a TIN code and you would realize that things can go horribly wrong when you try to use biological control.

So, it certainly something that people are looking at to try and work at the level of the mosquito but what we desperately need at the moment is a vaccine and/or effective drugs. And we also need to keep the drugs that we have, so the number of the drugs that have been used in the past, the parasite has become resistant to those drugs.

So we need to develop new drugs and we need to understand how drugs work and how resistance develops in order to keep the new drugs from being lost due to the development of resistance.

Matt Smith:

And Andrew, how much Biology have you had to pick out working in this job?

Andrew Peele:

More than I expected, actually. So I think I have a passing knowledge of quite a few biological terms these days.

Matt Smith:

How much Physics have you picked up, Leann?

Leann Tilley:

Yes, I have to say not terribly much. I’m very excited by the instrumentation that we’re using and the techniques that we have access to and I really love the results that come out of it. In terms of trying to get communication between a physicist and a biologist, this is something that we have worked on as a centre.

We have developed programs that enable - if not ourselves, then at least the students to have some chance of being able to understand Physics and Biology. We’ve done a program which is called ‘Talking Backwards’ where we ask physicist to explain Biology to an audience and we ask biologist to explain Physics to an audience.

That was really a lot of fun. I think people really enjoyed that and I was amazed at how well the physicist did.

And it’s interesting that idea that scientists live in silos. I mean that’s not how the world works, the world is Physics and Biology working together and maybe we got to develop a new group of students, a new group of scientists who really feel comfortable working in both areas.

Matt Smith:

That’s something that must be coming up a bit though, I imagined you must be getting students that are starting to run away and develop new things with the project.

Andrew Peele:

Yes, that’s one of the really exciting things about this whole work. As people comes through and particularly as the students learn to speak each others language, they started to come up with ideas that we really win.

In fact, not even a quick to think of and in fact, I figured we’re having a retreat for the centre as a whole in the next couple of weeks. And one of the outcomes of that, we hope will be a lot of those junior academics and researchers in the centre will hopefully come up with a host of those ideas.

In fact, there’s a lot of signs already that they have many of those ideas.

Matt Smith:

So, who else at La Trobe University is involved in the centre?

Leann Tilley:

Mike Ryan - Professor Mike Ryan here in the Biochemistry Department is head of the Biology program so he have seized the Biology program but he also has his own area of research, which involves mitochondria.

So he’s interested in mitochondrial disease and the role of mitochondria and apoptosis. Apoptosis is so death, it’s involved in cancer. So Mark is using the instrumentation to actually see little organelles inside the cells that the powerhouses of the cells and how there’s mitochondria changed in disease process.

Andrew Peele:

And on the x-ray world, we have - in fact, when my group was coming from before we started this work, we had a lot of activity looking at x-ray tomography, which is basically the same as a CAT scan in the hospital.

But we do this on the micron scale. So it’s things that a thousandth of a millimetre or so in scale and we use that for looking at things like corrosion in metals and a host of other systems.

And that’s a facility that we have so we have a group of people who are working on basically, imaging and through dimensions on all sorts of structures. Other examples include the Cochlear Ear project which is also based here at La Trobe. And coupled with that, we also have labs, the make structures on this counts as well.

So we have a microfabrication laboratory and that makes a lot our test samples. Again, these are structures, thousandth or less of a millimetre in size that we need to have to be able to test our imaging unit to make sure that we’re confident that the pictures we get are actually what we put in.

And so that laboratory is something we’re very proud of because normally with these types of laboratories, you have to make clean room facilities and they’re very, very expensive. People walk around in white suits with masks and goggles and gloves and all sorts of things.

And we’re actually able to build this in one of our existing laboratories just using normal equipment and being very careful with how we do the various procedures. So, that lab actually serves a lot of the experiments that we run.

Matt Smith:

On your day off, what have you gone into the lab and put on to the microscope?

Andrew Peele:

Don’t have a day off.

Matt Smith:

It’s a very diplomatic answer. What would you like to put on the microscope?

Andrew Peele:

Well, we have many things. In fact, we have a school group coming through in the next couple of months. And one of the things that they’ll be asked to do is bring their own pit samples.

So these are things that the order of centimetres in size and they’ll be bringing them along, putting them in the x-ray bin and we’ll be taking three dimensional pictures of being the size of them. And one of the things that they’re all running around, trying to get at the moment from jewellery stores, insects in amber.

They say these things went prehistoric insects get trapped in the sap of from trees. It can be very difficult to see them in the amber sometimes. That’s a lot of examples of amber that’s almost opaque but there’s an insect in there and you can’t see it. So, using the x-rays, we can hopefully tease those structures out.

Matt Smith:

So what have you discovered using your FRIEND?

Andrew Peele:

Will my FRIEND answer that first?

Leann Tilley:

So yes, so we have got a number of different x-ray microscopes that are available to us through the centre, well, two in particular. So Andrew has his FRIEND, which has just being developed in Chicago. And there’s another x-ray microscope which is located at the Advance Light Source, that’s in Berkeley in California.

So both of these microscopes currently overseas but as Andrew said, we have to bring those kind of microscopes back to Australia. So what we’ve been doing is using the microscopes to actually look inside the malaria parasite and trying to understand how the parasite engulfs the haemoglobin.

I mean the actual feeding process, so we’re looking at the way that the haemoglobin has taken up into effectively the stomach of the parasite and then degrade it to form these crystals that’s called the malaria pigment. That’s a target for anti-malarial drugs.

So, understanding more about the way that the parasite take scopes of the haemoglobin, then helps us to design better drugs to interfere with that process.

Matt Smith:

And Andrew, what have you discovered using x-rays?

Andrew Peele:

Well, a lot of our work, I should concentrate around improving the imaging techniques so - and this is why we work with the biologist because it’s all very well having an imaging technique being in an application. So really most of our discoveries are based around how to improve pictures.

So recently we’ve been working on ways of understanding the x-rays that come in and illuminate the sample. If you understand that being, if you understand its properties and the technical term being coherence, the way that the parts of the being relate to each other.

Then you can actually improve the imaging process enormously. So, we might get a picture that looks very blurry and out of focus or have other artefacts like streaks, or lines, or blobs. Then if you understand the beam off them, it’s possible to essentially image process what you have and make it much crispier image.

So, we’ve recently had some excellent success in that area where pictures that we have that are very, very distorted and broken up, we can actually make them look crystal clear.

I look for my slightly designed drawings foreign object that’s so high in quality. So that’s something we’re very excited about.

Matt Smith:

So what are coherent x-rays?

Andrew Peele:

I’m glad you asked that question. Take a beam of x-rays that has properties something like a laser beam. So, the laser is the sort of the canonical picture of what coherent line is. I think a lot of people have a good idea of what that means.

It means that the light is very collimated, it’s very highly directional. But what it also means is that the light can undergo this process called interference very readily. And when that happens, you get patents that are quite different to what normal pictures look like.

So, if you illuminate something with a light bulb, that would be a source of light that’s very incoherent. Then we image things in that sort of light in the way that we expect to see things normally. We go around the world looking at the light in its incoherent form.

When you illuminate something with a laser, you get these pictures of an object which are quite difficult to interpret. So, really a lot of the goal about Coherent X-ray Science is taking beams of x-rays that are highly coherent and then interpreting the pictures that you get from them, to turn them into pictures that makes sense to us and to the biologist.

Matt Smith:

OK. Leann and Andrew, thank you for your time today.