Schematic 1.

Preparation of 3D in vitro bioengineered brain constructs infused with decellularized brain ECM-collagen I gel. Process starts with decellularization of porcine brains and silk scaffold preparation. Aqueous silk scaffold is punched into 6mm diameter constructs with 2mm diameter central hole to create donut-shaped scaffolds. The poly-D-lysine coated scaffolds are seeded with dissociated embryonic day 18 primary neurons. Decellularized ECM is mixed with Collagen I solution and added to the donut-shaped scaffolds seeded with cells. The cell-seeded silk-scaffolds are flooded with media after complete gelation of ECM-collagen I. After long-term culture, the center of the construct shows a dense axonal network representing white matter, surrounded by the neuronal cell body-containing grey matter