Lab-grown brains just got one step closer to reality after scientists announced that experimental mini brains have begun sprouting their own blood vessels. Brain balls were created from stem cells and are used to study brain disorders, including Zika-related microcephaly. Researchers hope that vascularized brain balls may prove to be effective in someday encouraging the regrowth of damaged brain tissue. “The whole idea with these organoids is to one day be able to develop a brain structure the patient has lost made with the patient’s own cells,” UC Davis vascular neurosurgeon Ben Waldau told Wired.
Scientists at UC Davis have observed the generation of veins within brain balls, also known as cortical spheroids or neural organoids. Waldau and his team encouraged the vascularization of the brain balls by turning brain membrane cells extracted from a patient into stem cells as well as endothelial cells which line blood vessels. The brain balls grown from the stem cells were cultivated, then wrapped in a gel matrix composed of the endothelial cells and transplanted into a mouse brain. Two weeks after insertion, the organoid was healthy and had developed capillaries that had spread into the inner layers of the organoid.
Waldu was originally inspired to pursue this idea through his treatment of the rare Moyamoya disease, in which patients suffer from blocked arteries at the base of the brain, denying it blood. “We sometimes lay a patient’s own artery on top of the brain to get the blood vessels to start growing in,” explained Waldau. “When we replicated that process on a miniaturized scale we saw these vessels self-assemble.” This marks the first instance in which human organoids derived from stem cells create human blood cells. Previous experiments with mice had resulted in mouse blood cells infiltrating the organoid.