Simple magnetic cell patterning using streptavidin paramagnetic particles.

A simple methodology for cell patterning has been developed that can potentially be used to position different types of mammalian cells with high precision. In this method, cell membrane proteins were first biotinylated and then bound to streptavidin paramagnetic particles. The magnetically labeled cells were then seeded onto culture dishes and patterned using low magnetic fields. Highly defined cell patterns were achieved using HeLa, TE671 cells and human monocytes. HeLa and TE671 cells were also sequentially patterned and successfully co-cultured on the same plate using this technique. Cell viability studies proved that this magnetic labeling method was not toxic to cells. Transmission electron microscopy showed that the magnetically labeled HeLa and TE671 cells internalized some of the paramagnetic particles after two days of culture, while the labeled human monocytes did the same after only one hour. Uptake of these particles did not affect the cell patterning and cell viability. This magnetic labeling process is fast, as it involves affinity-based attachment of paramagnetic particles and does not rely on cellular uptake of magnetic materials. It may be adaptable and scalable for various applications.