Abstract
Novel technologies to establish 3D constructs consisting of homotypic or heterotypic cells are desired for tissue engineering. In the present study, both of magnetic force and magnetite nanoparticles were used to construct a homotypic layered human keratinocyte sheet and a heterotypic layered co-culture system of rat hepatocytes with human aortic endothelial cells (HAECs). Magnetite cationic liposomes (MCLs) originally prepared by us, which have a positive surface charge in order to improve adsorption by cells, were taken up by the target cells (human keratinocytes or HAECs). Magnetically labeled target cells incorporating magnetite nanoparticles, specifically attracted at sites where a magnet (4,000 Gauss) was positioned, and then adhered to form homotypic keratinocyte sheets with 5-10 layers or heterotypic-layered co-culture of HAECs with hepatocytes 3D with tight and close contact. These results suggest that this novel use of magnetite nanoparticles and magnetic force, which we refer to as "Magnetic force-based tissue engineering (Mag-TE)", offers a major advancement in tissue engineering.
