Let's face it, humans aren't too good at the whole "regenerating limbs" thing. In fact, the only way we can regrow bones is if we only lose the tip of one of our fingers or toes. But what makes that loss different to any other part of the body?
Research being presented at the American Society for Biochemistry and Molecular Biology annual meeting by Mimi Sammarco of Tulane University argues it's all about oxygen and timing.
This DARPA-funded lab has been experimenting with bone regrowth using oxygen as a trigger to kickstart the genes that cause the regeneration. What they found is that exposing the bone to 20% oxygen — roughly what's in the air, but much higher than the blood — will trigger the growth, but only at a specific point after the damage has been done. Says Sammarco:
What we found is that when you expose regenerating bone to 20 percent oxygen, it'll respond very favorably but only at a certain time. If you try it too early, like right after amputation, it doesn't do a whole lot.
It's going to be a long period of experimenting to figure out precisely when after losing a limb what levels of exposure are best, and how to apply that in the field. The end result might only be a couple of inches of bone growth, but those couple of inches can make a world of difference to recovery and ability.
Top image by Eduardo Risso from Wolverine: Logan, penned by Brian K. Vaughan.