Networked Neuro-Spheres Formed by Topological Attractants for Engineering of 3-Dimensional Nervous System

The nervous systems including central and peripheral nervous system have an important role in transmitting signals from brain to organs and tissues. Due to such critical function of nervous system, considerable effort has been tried to establish in vitro nervous model. In this paper, the neuro-spheres networked by the nerve-like structure were created using concave well arrays connected by the hemicylindrical channels. The concave microwells and the hemicylindrical channels were fabricated using the surface tension of viscose liquid PDMS prepolymer for the creation of neuro-spheres-networking (NSN). To investigate the topological effect of the concave-well-hemicylindrical-channel-networking (CWHCN), comparative experiments were conducted on a conventional cylindrical-wells-rectangular-channel-networking (CWRCN). Neuro-progenitor cells from the rat were seeded on the concave well arrays connected by the hemicylindrical channels and cultured for 10 days. Small neuro-spehroids consisting of neurons and glia cells were autonomously formed in the concave microwell arrays. These neuro-spheres were networked by the nerve-like structures formed along the CWHCN. In order to confirm the interconnection of the neurites in the NSN, a calcium imaging experiment was performed to measure the calcium flux along the nerve-like networking. To demonstrate further use of the networked neuro-networking for brain regeneration, we transferred the NSN onto hydrogel maintaining approximately 90% viability, and this model is expected to be used for the regeneration of a damaged brain.