Researchers here demonstrate a way to use magnetic levitation to make small pieces of tissue grow more naturally, though one suspects it won't scale to much larger tissue sections. The focus here, as for much of tissue engineering at this time, is to produce tissues as close to the real thing as possible, suitable for testing and research, applications where the small amount is not an issue:
The research is part of an international trend in biomedical engineering to create laboratory techniques for growing tissues that are virtually identical to those found in people's bodies. In the new study, researchers combined four types of cells to replicate tissue from the wall of the bronchiole deep inside the lung. "One of the unique things about the magnetic levitation technology is that it allows us to move cells around and arrange them the way that we want for a particular type of tissue. This is the first time anyone has arranged these four cell types in the same way that they are found in lung tissue."
The technology is said to rely on inert, non-toxic magnetic nanoparticles that are inserted into the living cells. Researchers can then use magnets to lift and suspend the cells as they grow and divide. "We conducted a number of tests, and the tissue has the same biochemical signature as native tissue. We also used primary cells rather than engineered cells, which is important for toxicological testing because primary cells provide the closest possible match to native cells."
"Bronchiole tissue could solve another problem that's frequently encountered in testing the toxicity of airborne agents. With traditional 2D cultures, it is very difficult to culture cells at the air-liquid interface, which is what you'd prefer for toxicity testing. With our technology, we can easily levitate the bronchiole tissue to the air-liquid interface so that airborne toxins are exposed to the epithelial layer of the tissue, just as it would occur in the lungs."