A Synergistic Engineering Approach to Build Human Brain Spheroids.

Self-assembling brain spheroids derived from human stem cells closely emulate the tangled connectivity of the human brain, recapitulate aspects of organized tissue structure, and are relatively easy to manipulate compared to other existing three-dimensional (3D) cellular models. However, current platforms generate heterogeneously sized and short-lived spheroids, which do not robustly and reproducibly model human brain development and diseases. Here, we present a method to generate large-scale arrays of homogeneously sized 3D brain spheroids derived from human-induced pluripotent stem cells (hiPSCs) or immortalized neural progenitor cells to recapitulate Alzheimer's disease (AD) pathology in vitro. When embedded in extracellular matrix, these brain spheroids develop extensive outward projection of neurites and form networks, which are mediated by thick bundles of dendrites. This array facilitates cost-effective, high-throughput drug screening and mechanistic studies to better understand human brain development and neurodegenerative conditions, such as AD .