Clumps of Cells as a Novel Basis for Regenerative Medicine
Researchers here note an interesting project, the production of self-assembling, mobile clumps of cells propelled by cilia, formed from lung epithelium. These mobile bodies can encourage growth in nerve cells, at least in vitro. How exactly that happens remains to be determined, but the usual mechanism is via release of pro-growth factors, either directly, or encapsulated in extracellular vesicles. Whether this is a useful basis for future regenerative therapies remains to be seen; one might imagine concerns attending the introduction of large numbers of these epithelial cell bodies into other tissues. The full paper is nonetheless an interesting read.
Researchers had previously developed tiny robots using clumps of embryonic frog cells. But the medical applications of these 'xenobots' were limited, because they weren't derived from human cells and because they had to be manually carved into the desired shape. The researchers have now developed self-assembling 'anthrobots' made of human cells and are investigating their therapeutic potential using human tissue grown in the laboratory.
The researchers grew spheroids of human tracheal skin cells in a gel for two weeks, before removing the clusters and growing them for one week in a less viscous solution. This caused tiny hairs on the cells called cilia to move to the outside of the spheroids instead of the inside. These cilia acted as oars, and the researchers found that the resulting anthrobots - each containing a few hundred cells - often swam in one of several patterns. Some swam in straight lines, others swam in circles or arcs, and some moved chaotically.
To test the anthrobots' therapeutic potential, researchers placed several into a small dish. There, the anthrobots fused together to form a 'superbot', which the researchers placed on a layer of neural tissue that had been scratched. Within three days, the sheet of neurons had completely healed under the superbot. This was surprising because the anthrobot cells were able to perform this repair function without requiring any genetic modification. Going forward, researchers think anthrobots made from a person's own tissue could be used to clear arteries, break up mucus or deliver drugs, with or without genetic engineering.