Rat muscle + rubbery film = world's first artificial jellyfish (+video)
Researchers say they've created a jellyfish that's one part artificial, one part biological. Creation of the 'pseudo organism' could yield new insights into medical research – or even cleaning up environmental pollution.
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The two researchers and their graduate students made exquisite measurements of the electrical signals controlling muscles of juvenile jellyfish. And they mapped the locations of jellyfish muscle cells, paying particular attention to how key internal components of the cells were oriented as the cells made up the muscle strands. Surprisingly, they found the same internal orientations in strands of cells taken from the heart muscles of rats.Skip to next paragraph
In Pictures Giant jellyfish
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That allowed the team to use the rat-heart cells as a surrogate for cells from jellyfish muscles. In addition, the jellyfish muscles were set out in a unique pattern – a halo of muscle atop the jellyfish's crown, with other muscles radiating into lobe-shaped flaps extending outward from the crown.
When those muscles contract, the flaps uniformly close, ultimately forming a narrow bell, expelling water, and propelling the jellyfish forward. When those muscles relax, the lobes' natural elasticity returns the lobes to their original, outspread positions. In the process, this recoil sets up eddies along the edges of the lobes that draws tiny bits of food into the center of the bell, where the jellyfish's digestive system is.
For robo-jellyfish, the team used an elastic polymer in place of the jelly-like material a jellyfish hosts. And it used a machine criminologists use to match fingerprints to ensure that the muscle patterns they wanted for their “android” jellyfish matched as closely as possible those of a real jellyfish.
With pattern in hand, the researchers set down a protein on their faux fish's elastic "body" to which cultured rat-heart-muscle cells would bind and develop.
They set their faux jellyfish swimming by applying a small electrical current to the nutrient-laden solution in which the medusoids – a jellyfish variant of "humanoid" – were immersed. The critters swam with the same motion real jellyfish swim, and the team noticed that the muscles contracted slightly even before they applied electrical current. Moreover, the moving lobes on the faux jellyfish set up the same types of eddies that the researchers saw in real jellyfish movements.
With refinements, the approach could be used to build test subjects for new heart drugs, CalTech's Dabiri says. Tiny robo-jellyfish could provide an initial indication of whether a drug is likely to work as advertised. It also can give an initial indication of potential side effects – if, for instance, some of the faux-jellyfish lobes contract more strongly while others don't move much.
While medical uses provide an initial impetus, the approaches could eventually be used in manufacturing more broadly, researchers say. Cell-based manufacturing and bio-inspired robotics could produce useful materials at room temperatures, unlike human-made structural materials.
And they would be far more energy efficient. "We're imagining a system that because its made of biological components, it gets its energy the same way you and I do – by harvesting nutrients from the environment," Dabiri says.
Indeed, Parker suggests that this could be the real payback from decades of public spending on biological research.
"If you take a look at how much money we've put into medical research since the 1990s, it has not resulted in lower costs for health care," he says, adding that "pharmaceutical companies will tell you that their pipelines are running dry and that they're heading for disaster because their patents are expiring."
After 20 years of funding, rising health-care costs, and promises of treatments that in some cases appear to perpetually lie just over the horizon, "We have to ask: What can we do besides medicine with all this biology we've learned?"
IN PICTURES: Giant jellyfish