Researchers at RMIT University have flipped traditional 3D printing to create intricate biomedical structures, advancing the development of technologies for regrowing bones and tissue. The emerging field of tissue engineering aims to harness the human body’s natural ability to heal itself and rebuild bone and muscle lost to tumors or injuries.

A key focus for biomedical engineers has been the design and development of 3D-printed scaffolds that can be implanted in the body to support cell regrowth. But making these structures small and complex enough for cells to thrive remains a significant challenge.

Enter a RMIT University-led research team, collaborating with clinicians at St. Vincent’s Hospital Melbourne, who have overturned the conventional 3D printing approach. Instead of making the bioscaffolds directly, the team 3D printed molds with intricately patterned cavities and then filled them with biocompatible materials before dissolving the molds away.

Using the indirect approach, the team created fingernail-sized bioscaffolds full of elaborate structures that, until now, were considered impossible with standard 3D printers.

Lead researcher Dr. Cathal O’Connell said the new biofabrication method was cost-effective and easily scalable because it relied on widely available technology.

“The shapes you can make with a standard 3D printer are constrained by the size of the printing nozzle – the opening needs to be big enough to let material through and ultimately that influences how small you can print,” said O’Connell, a Vice-Chancellor’s Postdoctoral Fellow at RMIT.

“But the gaps in between the printed material can be way smaller, and far more intricate.

“By flipping our thinking, we essentially draw the structure we want in the empty space inside our 3D-printed mold. This allows us to create the tiny, complex microstructures where cells will flourish.”