Nanoparticles Used to Levitate Cells in Tissue Culture

Levitating Cells with Nanoparticles

Reported by: Irina Robu




n3Dbio’s Bioassembler

Technology: magnetic levitation
Materials: cells
Price: $500-750 kits

n3d-bioassembler bioprinting 3D printing industry
In magnetic levitation, cells are magnetized with NanoShuttle-PL (which consists of gold, iron oxide, and poly-L-lysine and magnetizes cells by electrostatically attaching to cell membranes) through overnight incubation and dispensed into a cell-repellent, multiwell plate, where they are levitated off the bottom of the dish by a magnet above the plate. In levitating cells off the bottom of a multiwell plate, the magnetic forces work as an invisible scaffold that rapidly aggregates cells, and induces cell-cell interactions and ECM synthesis. The 3D culture is formed without any artificial substrate or specialized media or equipment and can be cultured long-term. Additionally, adding and removing solutions is made easy by the use of magnets to hold down 3D cultures when removing solutions, limiting culture loss. 3D cultures can also be picked up and transferred between vessels using magnetic tools such as the MagPen.




Cell culture is essential tool in drug discovery, tissue engineering and stem cell research.  Conventional tissue culture produces a two dimensional cell growth with gene expression, signalling and morphology that can be different from those found in vivo. In some cases, cells may or may not adhere to the tissue culture dishes.

Technology developed by n3D Biosciences brings cells together in a dish using magnetic nanoparticles to levitate them in a magnetic field. This procedure allows cells to develop into spheroids, but if they touch the bottom of the dish, they spread out in a single layer.

The technology developed by n3D Biosciences provide an alternative to biodegradable porous scaffold and protein matrices. Conventionally, biodegradable scaffold may suffer from slow or delayed propagation of cells and establishment of cell-cell interactions. The technology allows adaptable magnetic-based cell levitation and can provide an improved three-dimensional cell growth condition in certain settings.

To achieve this, the first step is to attach magnetic nanoparticles to the cell’s surface which is done by crosslinking the gold and iron oxide nanoparticles with polylysine.  In the second step, the cells are brought together while levitating them off the dish. In this condition, the cells can develop in surroundings mirroring growth inside a body where the cells are in contact with each other.  The media exchange is also relatively simple because a magnet holds the tissue in place.


Souza, the founder of n3D Biosciences states that microtissues grown with cell levitation have morphology closer to in vivo tissues than conventional cell culture. According to Souza “One huge hurdle is the standardization of the handling of tissue culture cells.  Ideally, new tissues for a patient wouldbe 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. ”



One Response

  1. This is very insightful. There is no doubt that there is the bias you refer to. 42 years ago, when I was postdocing in biochemistry/enzymology before completing my residency in pathology, I knew that there were very influential mambers of the faculty, who also had large programs, and attracted exceptional students. My mentor, it was said (although he was a great writer), could draft a project on toilet paper and call the NIH. It can’t be true, but it was a time in our history preceding a great explosion. It is bizarre for me to read now about eNOS and iNOS, and about CaMKII-á, â, ã, ä – isoenzymes. They were overlooked during the search for the genome, so intermediary metabolism took a back seat. But the work on protein conformation, and on the mechanism of action of enzymes and ligand and coenzyme was just out there, and became more important with the research on signaling pathways. The work on the mechanism of pyridine nucleotide isoenzymes preceded the work by Burton Sobel on the MB isoenzyme in heart. The Vietnam War cut into the funding, and it has actually declined linearly since.

    A few years later, I was an Associate Professor at a new Medical School and I submitted a proposal that was reviewed by the Chairman of Pharmacology, who was a former Director of NSF. He thought it was good enough. I was a pathologist and it went to a Biochemistry Review Committee. It was approved, but not funded. The verdict was that I would not be able to carry out the studies needed, and they would have approached it differently. A thousand young investigators are out there now with similar letters. I was told that the Department Chairmen have to build up their faculty. It’s harder now than then. So I filed for and received 3 patents based on my work at the suggestion of my brother-in-law. When I took it to Boehringer-Mannheim, they were actually clueless.

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