Image of malaria parasite inside a human
blood cell.
Image: La Trobe University
In the close-up world of X-ray imaging it’s how things look on the inside that counts.
La Trobe physicist Associate Professor Andrew Peele has built a microscope which he says looks like a mess of stainless steel and cables from the outside. But at the heart of the instrument is a vacuum chamber in which prisms and beams of laser light interact to form a stabilising system that is not only beautiful but innovative.
The physicist’s system is able to control vibrations and thermal motion from the environment to create a very stable platform for delicate measurements undertaken at a scale a thousand times smaller than a micron.
His high-resolution microscope has earned the nickname FRIEND, an acronym formed from Fresnel (a famous physicist) Imaging End Station but also an appropriate title for a piece of equipment that is opening up biological as well as physical worlds.
The clever piece of engineering has helped win researchers at La Trobe an extra three and a half years of funding from the Australian Research Council for research by the multi-disciplinary team at the Centre for Excellence for Coherent X-Ray Science.
The annual funding of $2.2 million is the culmination of three years of hard work during which the La Trobe researchers published more than 50 papers. X-ray microscopy has the advantage over other methods of being able to penetrate cells and look at structures in great detail.
Biochemist Professor Leann Tilley will use FRIEND to study the malaria parasite. X-rays are able to penetrate the walls of the host blood cell and show the digestive vacuole (stomach) of the parasite within an intact cell.
The best-performing malaria drug, artemisinin, extracted from wormwood grown in the alpine regions of China and Vietnam, attacks the vacuole of the parasite and Professor Tilley has been able to observe its action.
‘It causes the vacuole to burst open and disintegrate,’ she says. ‘The important thing is that we’ve developed a model that is a good start for understanding how the drug works and ultimately undertaking drug screening.’
While working with physicists at the Centre, Dr Eric Hanssen from her laboratory performs multi-mode high resolution imaging and has obtained extraordinary pictures of the parasite that look like molten metal hurtling through space.
The third La Trobe group working under the umbrella of the Centre is led by Associate Professor Mike Ryan, who undertakes research into mitochondria. The mitochondrion is known as the powerhouse of the human cell. It also plays an important role in embryonic development and regulating the internal stability of tissue.
One way of visualising the process is to look at the form of the human hand. The foetal hand is webbed. Spaces need to be formed between the fingers. The process that sculpts the body involves programmed cell death which is initiated by the mitochondria.
Dr Ryan would like to image the holes in the wall of the mitochondria which causes it to release factors that kill cells.
‘No-one knows how the hole in the wall is formed,’ he says . ‘The super-resolution imaging methods being developed at the Centre will help us visualise the role of mitochondria in the process of cell suicide.’
Editor's Note: A story provided by La Trobe University. This article is under copyright; permission must be sought from La Trobe University to reproduce it.
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