Levin and his team 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, Levin and his colleagues 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, says study co-author Gizem Gumuskaya, a developmental biologist also at Tufts, because the anthrobot cells were able to perform this repair function without requiring any genetic modification. “It’s not obvious that you’re going to get that kind of response,” she says.

That’s wild, I wonder why spheres of tracheal tissue with cilia are able to heal neurons.