July 23rd, 2012 by Michael Ricciardi
Bioengineering takes another big leap forward with the creation of an artificial jellyfish — called a “medusoid” — that undulates and swims just like the real thing. The medusa-like “cyborg” is modeled after the umbrella-shaped Moon jellyfish Aurelia aurita and is made from silicone. But the key “ingredient” is its infusion of heart muscle cells from rats which, following a Frankensteinian jolt of electricity, allow it to literally spring to life.
Even its creators, Kit Parker of Harvard and colleagues from Cal Tech, describe the feat as “a bit eerie.”
Despite the sci-fi-esque appearance, the experiment has an important, medical motive behind it: the goal is to aid the search for novel pharmaceuticals to treat heart problems.
The various physiological structures that make up the human heart also make the heart muscle work differently. Current drug discovery efforts do not take into account these structural differences, some of which can be caused by heart disease.
“Current drug discovery does not take into account [heart] structure, yet heart disease causes structural changes that lead to dysfunction,” says Parker [quote source]
The creation of the medusoid, which took four years to accomplish, was inspired by a trip to the New England Aquarium in Boston. Parker noticed the similarity between the jellyfish’s propulsion and a pumping heart muscle. Parker realized at that moment that he “could build a jellyfish.”
How To Build a Jellyfish
The ingenious artificial life form actually started with a mold fashioned from a computer 3D model of a juvenile sea jelly a mere 6mm in length. The mold was then covered with heart muscle cells cultured from an ordinary rat. But the trick there was proper alignment; the heart muscle fibers needed to line up with the fibers in the jelly fish mold. Finally, the whole entity was coated with a thin layer of liquid polymer (silicone).
After the coating had dried, the entire medusoid was peeled off the mold with its network of rat muscles intact. Another key step in the process was keeping the muscles well-nourished; the entire molding process occurred in a bath solution of magnesium (an element essential for proper heart functioning) and glucose (an energy molecule).
Curiously, or perhaps creepily, the cyborg jellyfish would begin moving the moment it was removed from the mold. However, this movement was uncoordinated. The team found that a tiny jolt (1 Hz AC) was sufficient to get it moving in a more realistic manner. With each contraction of the heart muscle, the medusoid’s body bends, propelling the creature through the water. Between each propelling contraction, the silicone sea jelly returns to its initial shape.
Through experimentation, the team was able to determine how the spatial arrangement of heart muscle cells and the frequency of electrical stimulation combined to produce the realistic propulsion. The team is currently working on mimicking the “elegant muscular structures” of other marine organisms.
Other possible uses for these cyborg sea creatures include aiding in the clean up of oil spills (based upon the manner in which such creatures filter water to extract food) — provided they are unleashed in large enough numbers.
The technology could also be used as implants in the human body — such as pacemakers — fed and powered by nutrients and electrolytes from bodily fluids.
Journal reference: Nature Biotechnology, DOI: 10.1038/nbt.2269
Author Comment: The word ‘living’ in the blog title is placed in quotes because although this experiment is a marvelous mimicry of a living creature, in my view it does not meet all the basic requirements for a living being, principally, autopoiesis, or self-replication. On the other hand, if it can be engineered to provide its own power source such that it can move independently (no external jolting of electricity), and perhaps were implanted with a simple chip program (to accomplish what? Avoid predators, mostly, I suspect), it could perhaps qualify as artificial life (ex silico).
…Oh, Brave New Bio-Engineered World…
Some source material for this post came from the New Scientist article ‘Heart muscle helps cyborg jellyfish come alive’
Top image: (artificial moon jellyfish made with rat heart muscle cells); Harvard and Cal Tech
Keep up to date with all the most interesting green news on the planet by subscribing to our (free) Planetsave newsletter.