(475p) Cell Micropatterning Using Magnetite Nanoparticles and Magnetic Force

Cells in tissue architecture are allocated complexity and precisely. Therefore, it is necessary for constructing functional tissue architecture to allocate cells complexity and precisely. Several cell patterning methods have been developed, such as micro contact printing or lithography. These methods require cell patterning on specialized surfaces, and it takes a lot of time to fabricate the substrate and cell patterning. In the present study, we demonstrated micropatterning of cells using magnetite nanoparticles and magnetic force, which is a novel technique able to easily allocate cells on arbitrary non-absorbing surface, including biological gels. We previously developed magnetite cationic liposomes (MCLs), which are cationic liposomes containing 10-nm magnetite nanoparticles. MCLs can be taken up easily by target cells. The magnetically labeled cells can be manipulated by means of magnetic force. The magnetically labeled cells were seeded into cell culture dishes, and magnetized steel plates (thickness, <100 um; length, 30 mm; height, 1 mm) on a magnet were placed at the reverse side of the dish. After 30 min of culture, the cells gathered a long the line of steel plates and the cells formed a straight line pattern (length, 30 mm). Line width of the patterned cells could be adjusted by seeding cell concentration. When the cells (10000 cells per a 35 mm-dish) were seeded, line with the width of single cells was formed. A parallel pattern or a curved pattern could be formed by parallelizing steel plates or bending a steel plate. By sequential patterning, a cross-pattern of the cells could be also formed. These results showed that this technique could form complex micropatterns of cells easily and speedy on non-absorbing surface with high resolution. Therefore, this technique is a useful tool for tissue engineering, cell-based assays and biosensors.