07-22-12, 10:24 PM #1
Reverse Engineered Life Form.
Artificial jellyfish built from rat cells
Bioengineers have made an artificial jellyfish using silicone and muscle cells from a rat’s heart. The synthetic creature, dubbed a medusoid, looks like a flower with eight petals. When placed in an electric field, it pulses and swims exactly like its living counterpart.
“Morphologically, we’ve built a jellyfish. Functionally, we’ve built a jellyfish. Genetically, this thing is a rat,” says Kit Parker, a biophysicist at Harvard University in Cambridge, Massachusetts, who led the work. The project is described today in Nature Biotechnology1.
Parker’s lab works on creating artificial models of human heart tissues for regenerating organs and testing drugs, and the team built the medusoid as a way of understanding the “fundamental laws of muscular pumps”. It is an engineer’s approach to basic science: prove that you have identified the right principles by building something with them.
I can think of further uses, once this technology develops further. For example, what better substitute for a heart (temporary or maybe permanent) than something that is made from heart muscle, and pumps in the same way a heart does?
07-22-12, 11:17 PM #2
i say no on all three counts
07-23-12, 02:53 AM #3
It's really great to see advancement in this field of tissue synthesis. Immediately it struck me how well balanced the petals are, that the contractions are even and coordinated. Imagine the amount of difficulty in getting a mechanical device to do this, at (I'm guessing) relatively low weight for the amount of strength, and (guessing here, too) running on some chemical nutrient. I can't think of any mechanical analog quite like muscle tissue. The actin-myosin mechanism an excellent solution to the practical problem of producing a contraction. It certainly serves its purposes in nature remarkably well. And it exploits parallel and serial architecture to provide a measure of reliability, strength and function that is crucial to the way animals evolved so far beyond the monocyte stage. Of course we can trace the precursors of muscle tissue to the most primitive of organisms, but cnidaria is where this kind of tissue seems to have its evolutionary roots, so it's only fitting that they chose this specific architecture for their demo.
Like you, I also was struck by how appropriate this appears for a new artificial heart technology. Other things that come to mind are devices for industrial use such as fluid pumps, where mechanical devices have inadequate reliability, or some advantage yet to be seen. Or how about something that sirs up the air, like the old time hand held fans? And then imagine if it were possible to build one the size of an elephant, perhaps capable of lifting water from a well, or one of some colossal size that could lift the elephant sized water collectors maybe to fill a municipal water tank, or some other application that consumes a lot of energy.
It's kind of silly that the naysayers at the bottom of the article are worried about insisting that it's not a life form. We've seen every argument so far worried about the definition of life. Here comes another challenge. Is it a tissue? I would think so. Is it a dead tissue? Well, not if it moves on command. So it must be a living tissue of some new class. What motivates people to jump the gun and insist what it's not? I say give credit where due. This is a tangible sign that, if some day even one critic may suffer a particular injury or illness, a new medical technology could be available to treat the condition. I'm thinking of soldiers who lose, say, an entire muscle in combat, causing severe disability. For the optimists among us, this is a sign of hope. The choice of design was great. It's perhaps the most barebones design that gives pedestrians a chance to see it in action and marvel over it.
If it's living rat tissue, then presumably it does a little more than just respond to stimuli. The cells must have some rudimentary way of absorbing nutrients, transferring gases, and perhaps doing some repairs and/or regeneration.
07-23-12, 07:51 AM #4
We barely have a useful, practical, generally-accepted definition of "life" that applies to an entire organism. (I've posted it on this forum many times, if you missed it check http://en.wikipedia.org/wiki/Life.) It's a list of attributes of which "most" are sufficient, and it only covers the kinds of living things that are found on this one tiny planet, for obvious reasons.
To argue whether or not an organ or some other collection of cells or tissues is alive, when it's incapable of living without being embedded in a complete organism, or connected to artificial life-support technology in preparation for insertion, seems pointless to me. After all, the same question can be asked about our own hearts. Is one of them "alive" while it's being removed from a dead human and transplanted into a live one? If not, is it then "alive" when it's finally hooked up to the new host?
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