When personnel are exposed (or potentially exposed) to nerve agents, they're treated with countermeasures known as oximes. Because the level of exposure is most often unknown, the maximum oxime dose is normally given, and that can cause liver damage.
Molecular biologist Natalie Withington is contributing to a research program investigating whether existing drugs can be used as countermeasures.
"For our research, we want to assess a drug's interaction with livers, and for that, we need access to liver cells," she said.
"Through a materials transfer agreement with Swinburne University, we have been given some human embryonic stem cells originally taken from an embryo back in the 80s. We are stepping through protocols using a new bioprinter and traditional cell culture processes to attempt to differentiate these stem cells to create miniature livers in the lab."
Ms Withington explained that the plan is first to expose the created mini livers to nerve agents and see if there are any drugs that can be repurposed to act as countermeasures, and then to measure the point at which countermeasures become toxic to the liver. The payoff for Defence is that if the research program succeeds, warfighters will have access to better treatments.
'For our research, we want to assess a drug's interaction with livers, and for that, we need access to liver cells.'
Long route to Fishermans Bend
The International Day of Women and Girls in Science on February 11 recognises and celebrates the achievements of people just like Ms Withington, who said she took a long route to a Defence science career - one that required patience and persistence.
"I really enjoyed science in high school, but someone said to me 'There's no money in science'," she said.
"I had it in my head, as a very naive girl, that I needed to buy my mum a house because we were renting. So, I set my sights on international trade and did an arts/commerce degree. I used that degree for a while - including as a Clark Rubber franchisee - [which] was pretty good while my husband and I had young kids because I could just work two school days a week and do a bit from home.
"As soon as I had my first child, I went back to university to study science, and just studied part-time for a couple of years, had a break while I had another child, did a couple of years, had a break while those kids were in kinder, and then had another child. And then, I just went back very slowly - one subject at a time while I still had a little child at home. Once he was at school, I was ready to get into it. But then COVID hit and I was homeschooling three children. So, then, back to one subject a semester again."
Ms Withington wasn't deterred, and graduated from Swinburne University in 2023 with a major in biotechnology.
"I applied for a DSTG [Defence Science and Technology Group] cadetship, got that and was supported to do my honours year in 2024. That was the first time studying full-time with all my kids, and it was very hectic because I was still working two days a week at Melbourne Pathology. I love cell culture, but it wasn't great for an honours project because I had to go in to tend to the cells seven days a week."
Aiming for organoids
Ms Withington spends about 20 per cent of her time in the lab, trialling two processes to differentiate liver cells from the stem cells.
"I've got some cells in the matrix that have been bioprinted, and a second lot in a traditional Falcon tube (a normal plastic tube sitting on a shaker platform in an incubator). It's around a three-week protocol to achieve differentiation and things look promising," she said.
The new cell bioprinter is a highly-precise RASTRUM Allegro 3D printer.
"The good thing with the bioprinted cells is that, once you bioprint them and start differentiating them, apart from changing the feeding media which they sit in, they're pretty low maintenance. They don't grow rapidly and need to be split," Ms Withington said.
'We'll hopefully end up creating true liver organoids, including some sort of vascularisation and nutrient flow.'
The differentiation protocol, which is defined in the open literature, requires Ms Withington to make up different media formulations and add them on different days - an initial formulation on day one, then a different one on days two to seven, changing the media every second day, and so on.
"I've reached out to the lead author on one of the papers that describes the liver cell differentiation protocol that we are following. I had a couple of questions and the author got back to me and suggested we meet. They're sending an advanced copy of a more detailed protocol they're about to publish," she said.
"We'll hopefully end up creating true liver organoids, including some sort of vascularisation and nutrient flow. So, if the mini liver was in a body, blood would be going through the veins. In our case we're hoping we get nutrients to flow into the organoid, otherwise the cells in the middle will die.
"Once we have successfully grown the mini livers, we'll use something like paracetamol (which causes liver damage in large doses) as a control, rather than actual nerve agents."
A great workplace
"I actually love the whole place," Ms Withington said.
"When I came and did my undergraduate placement, I thought it was fantastic because you get paid to investigate things in the lab. What's not to love? The people here are wonderful.
"I enjoy the variety in the work and the fact that the projects are generally three to five years in length and then you get to move on and try something else. I just really enjoy everything about working here at DSTG."
