July 23, 2012
Artificial Jellyfish Reverse-Engineered Using Silicone, Heart Cells
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redOrbit Staff & Wire Reports - Your Universe Online
Scientists from Harvard University and the California Institute of Technology (Caltech) joined forces on the "reverse-engineering project," the details of which were published Sunday in the journal Nature Biotechnology, Telegraph Science Correspondent Nick Collins said.
They implanted muscle cells from the hearts of rats onto the silicon frame, growing them into a pattern very much like the muscles of an actual jellyfish, Collins added. The researchers then applied an electric current into a container of conducting liquid, thus demonstrating that they could use the shock to force the muscle cells to contract, causing the synthetic jellyfish to start moving through the liquid.
“Morphologically, we´ve built a jellyfish. Functionally, we´ve built a jellyfish. Genetically, this thing is a rat,” Harvard biophysicist Kevin Kit Parker told Nature's Ed Yong. The creature, which Parker and colleagues dubbed a "medusoid" due to its resemblance to the mythological female whose gaze could turn people to stone, resembles "a flower with eight petals" and "pulses and swims exactly like its living counterpart" when placed in the electric field, Yong added.
"A big goal of our study was to advance tissue engineering," Janna Nawroth, a doctoral student in biology at Caltech and lead author of the study, said in a statement Sunday. "In many ways, it is still a very qualitative art, with people trying to copy a tissue or organ just based on what they think is important or what they see as the major components -- without necessarily understanding if those components are relevant to the desired function or without analyzing first how different materials could be used“¦ Our idea was that we would make jellyfish functions -- swimming and creating feeding currents -- as our target and then build a structure based on that information."
Parker and Nawroth, along with Caltech aeronautics and bioengineering professor John Dabiri, decided that the jellyfish, which is said to be the oldest multi-organ animal on Earth, was the best subject for their research because the way their muscles operate while swimming and their morphology is like that of a beating human heart, Harvard explained in a July 22 press release.
"To reverse engineer a medusa jellyfish, the investigators used analysis tools borrowed from the fields of law enforcement biometrics and crystallography to make maps of the alignment of subcellular protein networks within all of the muscle cells within the animal. They then conducted studies to understand the electrophysiological triggering of jellyfish propulsion and the biomechanics of the propulsive stroke itself," the university said.
"Based on such understanding, it turned out that a sheet of cultured rat heart muscle tissue that would contract when electrically stimulated in a liquid environment was the perfect raw material to create an ersatz jellyfish," they added. "The team then incorporated a silicone polymer that fashions the body of the artificial creature into a thin membrane that resembles a small jellyfish, with eight arm-like appendages."
They then managed to match the subcellular, cellular, and supracellular architecture of the jellyfish musculature with that of the rat heart muscle cells, and placed the synthetic creation into a container filled with salt-water similar to that found in the ocean. After applying the current, they observed that the construct had shocked into swimming, with the contractions of the rat muscles mimicking those of the synchronized motions of actual jellyfish.
According to Yong, the team now plans to expand their research, first by creating a medusoid that utilizes human heart cells, and then by reverse-engineering other forms of aquatic life. They also have filed for a patent that would allow them to use their design as a way to test the effectiveness of medications, and reportedly are looking to improve the current artificial jellyfish by making it so that it can turn and even respond to its environment.