They have modified an established approach to generate so-called neuroectoderm, a cell layer from which the nervous system derives. Fragments of this tissue were maintained in a 3D-culture and embedded in droplets of a specific gel that provided a platform for complex tissue growth. In order to enhance nutrient absorption, they later transferred the gel droplets to a spinning bioreactor. Defined regions of the brain - including a cerebral cortex, retina, meninges and a choroid plexus - developed after 20-30 days. After 2 months, full size "mini-brains" had been created that have continued to survive in a spinning bioreactor, and they are currently surviving at 10 months.
The researchers say that this method could potentially be used to create "model systems" for human brain disorders and will eventually allow for the study of a variety of neurodevelopment processes specific to human brain development.