Scientists in Galway have taken a significant step forward in the development of lab-grown “mini brains”, a breakthrough that could accelerate research into conditions such as stroke, Alzheimer’s disease and Parkinson’s.
The study focuses on cerebral organoids – tiny clumps of human brain cells grown in laboratories that act as simplified models of the brain. These organoids, just a few millimetres wide and barely visible to the naked eye, are increasingly used by scientists to study how the brain develops and how neurological diseases progress.
A major challenge with cerebral organoids has been keeping their cells alive. Without a functioning network of blood vessels, cells in the centre of the organoid often die due to a lack of oxygen and nutrients. This limits how large the organoids can grow and how accurately they mimic real brain tissue.
Now, researchers at CURAM, the Research Ireland Centre for Medical Devices based at the University of Galway, say they have found a way to overcome part of this problem. By growing mini brains in a soft, biologically compatible gel known as a hydrogel, and introducing cells capable of forming blood vessels, the team was able to encourage vessel-like structures to grow deeper into the organoids.
Lead researcher Dr Mihai Lomora, a biomaterial chemistry lecturer and head of the CerebroMachines Lab at the University of Galway, said the work may sound futuristic but is firmly grounded in current science.
“When we started the project, we could see from the scientific literature that blood vessels in cerebral organoids were mostly superficial,” he said. “They didn’t reach the deeper cells, so those cells became starved of oxygen and nutrients over time and died.”
Using an adapted technique that altered the environment and timing of vessel growth, the researchers saw a marked improvement. The organoids grew larger, cell death in the centre was reduced by threefold, and blood-vessel-forming cells were seen penetrating towards the interior.
The team also observed behaviour similar to that of the blood–brain barrier, the protective layer that controls what enters the brain from the bloodstream. This finding suggests the improved organoids could be particularly valuable for studying neurological diseases and testing new treatments.
Dr Lomora stressed that the research does not involve growing full brains in the lab, but rather creating more realistic models of how brain tissue functions.
“We want these models to be as physiologically relevant as possible,” he said. “By increasing the vasculature, we believe we have taken an important step in that direction. It’s really at the edge of the state of the art.”
The research, led by CURAM, has been published in the journal Advanced Science and involved a multidisciplinary collaboration with scientists from RCSI University of Medicine and Health Sciences, Trinity College Dublin and the University of Edinburgh.
