Nanoparticles:  Used to Levitate Cells in Tissue Culture Media


Nanoparticles. Note the scale bar which is usually in microns, but in this case is 1000-fold smaller.

Conceptualize the environment tissues have growing inside a mammalian body.  The cells are in constant contact with each other, giving and receiving signals within their milieu.  Now think of what it is like in a tissue culture setting.  The cells may or may not adhere to the tissue culture dishes.  Contact between cells is limited due to sparse populations.  The question becomes:  how can we change the in vitro tissue culture surroundings to more closely mimic those of nature?

One way to facilitate this is to get the cells to proliferate while in contact with each other. Technology by n3D Biosciences brings cells together in a dish using magnetic nanoparticles to levitate them in a magnetic field.[1]  This allows cells to develop into spheroids; if they touch the bottom of the dish, they spread out in a single layer.

To achieve this wonder, the first step is to attach magnetic nanoparticles to the cell’s surface.  This is done by crosslinking the gold and iron oxide nanoparticles with polylysine.  The company’s name for these nanoparticles:  NanoShuttle.  Application of a magnetic field follows in the second step, bringing the cells together while levitating them off the dish.  Now the cells can develop in surroundings more closely mirroring growth inside a body.  They are not in contact with the dish, but just with each other.  Media exchange is also simplified because a magnet holds the tissue in place.

What are the present day applications for these nanoparticles?

This all fits into the larger picture of one day being able grow organs to replace diseased ones.    Before all this takes place, however, n3D Biosciences is focusing on high-throughput toxicity testing and drug development in both academic and industrial settings.  Souza, the founder of n3D Biosciences states that microtissues grown with cell levitation have morphology closer to in vivo tissues than conventional cell culture.

n3D Bioscience's levitating cells with nanoparticles

Magnetically levitating cells with n3D Bioscience’s nanoparticle technology.

Before the hoped for end of growing organs from cells is realized, much work remains to be done.  One huge hurdle is the standardization of the handling of tissue culture cells.  Ideally, new tissues for a patient would be grown from their own cells, avoiding the issues of “rejection” of tissue as not the body’s own.  One problem is that cells are very sensitive to changes in temperature during the freezing, thawing, and recovery process.  Glauco Souza, CSO of n3D Biosciences recently told us Using Biocision’s products to aid in the control of this variable is one section of the road to realizing the full potential of these wonderful new technologies“. We couldn’t agree more!


1.  Marx, V.  “A Better Brew”.  Nature.  2013