Human embryonic stem (hES) cells are useful tools for regenerative medicine. Maintaining hES cells for research and clinical purposes remains a challenge. The hES cells have typically been grown on a mouse or human cell feeder layer, but these methods harbor potential health problems for the recipient. A culture system using magnetic field and iron oxide nanoparticles were previously demonstrated to sustain mouse embryonic stem cells in vitro. Now, by using the BG01v/hOG cell line, we could assess the effect of this culture system on the stemness of an embryonic stem cell of human origin.

Using a variant hES cell line, BG01V/hOG, expressing an emerald green fluorescent protein (EmGFP), we grown these cells in the presence of serum-free medium supplemented with magnetic nanoparticles functionalized with citrate. The cells were positioned over a circular magnet (4000 Gauss) and monitored daily by fluorescence microscopy.

We discovered that hES cells can proliferate when labeled with magnetic nanoparticles and in the presence of a magnetic field without losing pluripotency.

These results establish an alternative method for maintaining hES cells which would minimize health concerns as well as label cells for subsequent clinical tracking.