Regenerate missing limbs by creating an absorbable (biodegradable) sponge-like "scaffold" of the approximate size and shape of the missing limb. Cover the scaffold in skin grafts or sterile waterproof sheeting. Don't add stem cells, because it might cause cancer. Instead, allow blood to circulate through the scaffold, pumped by the patient's heart, by plumbing the patient's existing (severed) major vessels into the scaffold. If necessary to ensure circulation, blood could be drained from anywhere the blood stagnates (pools), filtered and re-injected.

The body's natural self-repair processes would replace the missing tissue. This approach has not been used in humans due to infection risk, which modern techniques could mitigate, as well as the question of whether the limb would be regenerated (instead of some weid mish-mash of skin, etc.).

I have observed that if a scab is left in place (acting as a scaffold and seal), the underlying skin regenerates nicely, but if the scab is removed, scarring may occur.
-- sninctown, Feb 10 2014

Will change everything http://www.independ...-cells-9117102.html
[leinypoo13, Feb 10 2014]

no.
-- WcW, Feb 10 2014


There'd be nothing to tell tissues how to organize themselves. You'd probably get something like skin on the outside, but inside would just be a mess.

Might be a good way of making autologous haggis, though.
-- MaxwellBuchanan, Feb 10 2014


I agree with the other posts. Maybe if you grafted on a limb from a chameleon as a seed, but I think that would be more like a plot of a horror movie. Maybe graft a human arm onto a chameleon? Nah, either way you'd probably end up with a dead hum- eleon.
-- MisterQED, Feb 10 2014


[Marked-For-Deletion] Magic.

The concept is fairly obvious, the execution is well beyond current tech. And wouldn't work as described. Adult humans can't regrow excised muscle tissue on an otherwise intact limb, so the lack of structure is not the problem.

And increased scarring from scab removal has to do with additional damage done to the healing tissue by the removal of the scab, nothing to do with the scab acting as a scafold.
-- MechE, Feb 10 2014


Maybe the reason salamanders can regenerate limbs and we cannot lies somewhere in the 10x amount of DNA they have over us [link]. A wild guess would be that the extra 9x somehow encodes position information for cells, so that they "know" where they are in the limb and grow/function appropriately.
-- the porpoise, Feb 10 2014


Or then again, maybe they just have a better medical insurance plan …

// Might be a good way of making autologous haggis, though //

[Marked-for-tagline]
-- 8th of 7, Feb 10 2014


//A wild guess would be that the extra 9x somehow encodes position information for cells//

Probably not. Genome size in general bears little relation to complexity, regenerability, adaptability or anything else once you get as far as vertebrates.

It's much more likely that salamanders' regenerative ability comes down to a handful of genes which regulate embryonic development, and which are turned off in one species and on in another, or whose expression is controlled differently, or something like that.

The human genome already specifies what cells go where - it's just that the relevant sets of genes aren't reactivated in response to damage. It's puzzling why this should be the case, but then again a great many things are puzzling.

Incidentally, hydatidiform moles (not the furry underground kind) are examples of tissues where the developmental genes get turned back on in humans. The results can include hair, teeth, bones and even some more complex structures. In such moles, tissues are often correctly organized (for instance, layers of fat and skin forming in the right arrangement; hair follicles forming at intervals on the skin), but are just in the wrong place.
-- MaxwellBuchanan, Feb 10 2014


This is far from a stupid idea [+] and has already been proposed by people.

// There'd be nothing to tell tissues how to organize themselves. You'd probably get something like skin on the outside, but inside would just be a mess.

There is a huge influence of the skin on tissue organization (called the apical ectoderm ridge) and also there is a huge regulation of cellular plasticity by O2 tension. Further, "Stem cells" may not even exist after this past months, once every 50 years discovery, that adult mouse and human cells can de-differentiate into stem cells just by dipping them in citric acid for 30 minutes. Local hypoxic acidosis may actually do this in vivo as a result from an injury, which flat out just makes sense. Also, bone morphogenetic protein laced scaffolds already exist thus you might even get some strength.
-- leinypoo13, Feb 10 2014


Muscles are the piece I see making trouble. It is hard for humans to grow new skeletal muscle. I am not sure it is possible. Autologous haggis is a nice idea.
-- bungston, Feb 10 2014


// The results can include hair, teeth, bones and even some more complex structures. In such moles tissues are often correctly organized (for instance, layers of fat and skin forming in the right arrangement; hair follicles forming at intervals on the skin), but are just in the wrong place. //

Is this what is called "Justin Bieber Syndrome" ?
-- 8th of 7, Feb 11 2014


//There is a huge influence of the skin on tissue organization (called the apical ectoderm ridge) and also there is a huge regulation of cellular plasticity by O2 tension.//

Yes yes, but those factors alone don't tell cells whether to make a thumb or an earlobe.
-- MaxwellBuchanan, Feb 11 2014


//don't tell cells whether to make a thumb or an earlobe.//

... or an arse or an elbow ...

Ah yes, it IS Justin Bieber ...
-- 8th of 7, Feb 11 2014



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