Self-assembly of magnetized microstructures for in vitro cell systems

In this paper, we conducted to assembly of microstructures for in vitro 3D cellular structures using self-assembly of magnetized hydrogels. The biocompatible hydrogel microstructures are fabricated by electrodeposition method and ferrite particles are coated on the structures with poly-L-lysine. The microstructures are magnetized by applying 3 T magnetic field, and assembled by the magnetic force. Biological cells can be encapsulated in the microstructures and cultured to achieve high density cell structures. The magnetic microstructures were assembled automatically to form tube structures. The magnetic force generated from the ferrite embedded microstructures was estimated and compared to the fluid resistance applied to the microstructures. The assembly of microstructures was achieved using a shaker to shake the structures inside liquid. The proposed method can be applied to assemble 3D cell structures with vascular-like channels for tissue engineering applications.