Constructed of silicone and heart cells, medusoid moves like the real thing

By Rachel Ehrenberg

Web edition: July 23, 2012
Print edition: August 25, 2012; Vol.182 #4 (p. 15)

Call it the Frankenjelly.

Scientists have created an artificial jellyfish that swims with the same synchronized body contractions used by real jellyfish. After analyzing the swimming dynamics and layout of tissues in the common moon jelly (Aurelia aurita), the scientists fashioned an umbrella-shaped frame with eight armlike structures out of an elastic silicone polymer. Then they seeded this frame with rat heart cells. Guided by minuscule patterning on the polymer, the rat cells grew into layers of muscle.

When the scientists let their creation, dubbed the medusoid, loose in a tank, the fake jellyfish’s muscles spontaneously began contracting. Applying an electric field spurred it into real swimming that matched the kinetics of live jellyfish. Key to their approach, the researchers note, was focusing on the propulsion — the function of jelly muscles — not on form alone. The work could lead to other tricks for engineering body parts, such as muscular pumps (aka hearts), other organs, or even whole body mimics of other creatures, the Caltech and Harvard researchers conclude online July 22 in Nature Biotechnology.