A cracking idea: Could the humble egg unlock the secret to improved cancer treatments?

Chicken eggshells may be the key to better understanding how metastatic prostate cancer behaves and responds to treatments.

University of Southern Queensland (UniSQ) researchers have developed a new 3D structure for growing cancer cells, using eggshells as the main ‘ingredient’.

Alissa Reinke – a PhD student working on the project – said the 3D-printed, bone-like structure, known as a scaffold, was designed to mimic the biological environment to which cancer cells are exposed when they spread to the bone.

"When examining the cancer cells' interactions with a scaffold, most current methods use soft hydrogel scaffolds, which is in a 3D environment, but isn’t like bone,” Ms Reinke said.

“We’re aiming to recreate the environment that the cells are natively in to get a better indication of how they behave in real life, which could lead to more effective treatments or new information on what treatments could work.

“It’s like if you had a polar bear; it wouldn’t make sense to look at its behaviour in the desert because that’s not where they live.”

Despite drastic changes in treatments in recent years, prostate cancer that has metastasised or spread to the bone (stage 4) has a low five-year survival rate of about 35 per cent.

With many unanswered questions about how and why cancer cells spread to the bone, UniSQ researchers looked to the humble egg to crack the code.

The idea for the project was first hatched in 2021, and Ms Reinke has been working on it under the supervision of Dr Louisa Windus, Professor Eliza Whiteside, Dr Jessica Feldman and Associate Professor Polly Burey, with clinical expertise provided by Associate Professor Chris Wall, an orthopaedic surgeon from Toowoomba Hospital and Adjunct Associate Professor at UniSQ.

“Initially, when I looked at this project, I thought it was crazy that we could create a potential cancer research topic around eggshells – something I throw out in my kitchen every day,” Ms Reinke said.

“Eggshell is very similar to bone in terms of its calcium content, as well as the other minerals in there.”

So, how easy and simple is it to whip up a batch of scaffolds?

“We literally crack an egg, get the eggshell and grind it down into a fine powder before adding that with chitosan, which is found in the shells of crustaceans,” Ms Reinke explained.

“We mix that with acetic acids like vinegar and then print the scaffold on a 3D printer, which takes about 25 minutes.

“From one eggshell, I can get about 30 scaffolds, so it's very cost-effective, and because eggshell is a waste product, you can essentially get it for free.”

Although the project is still in its early stages, Ms Reinke was hopeful that the scaffold could play a critical role in developing or guiding new, more effective treatments for metastatic prostate cancer.

“Now that we’ve completed the recipe for the scaffolds, we’ve moved on to the initial stage of adding the cells to the scaffold to work out which environment they want to live in and how they interact with the scaffold and each other,” she said.

"There’s still a lot of work ahead, but I’m excited by the potential real-world benefits of this project.

“If we can get the model established successfully, we can look at other types of cancer that may cause bone metastasis using different cell lines and try and recreate those environments as well.”

The project was undertaken under the UniSQ-led SIMPLE (Sustainable Industry Manufacturing Planning for Long-Term Ecosystems) Hub. The Hub creates a step-change by focusing on capacity-building initiatives to enable industry and universities to co-design and develop new products and processes to support regional manufacturing priorities such as technical, environmental, economic, educational, and cultural aspects of green energy, resource recovery and waste reduction/recycling/upcycling.