For some years researchers have been investigating the mechanisms of limb and organ regrowth in lower animals like salamanders, with an eye to finding out how easy or hard it would be to recreate those same capabilities in mammals - such as we humans. Do we retain the core mechanisms, lying dormant in our biochemistry, or have they been completely lost? Time and ongoing research will tell.
But these are not the only areas of regrowth wherein researchers might learn something of interest to regenerative medicine. Consider that elk regularly regrow their antlers, for example - not a simple organ by any means. Further down the scale of impressiveness, we might consider the many higher animals that regularly regrow feathers or coats of hair. Is there anything in their biochemistry that might be discovered and adapted to cause humans to regenerate in situations where they normally do not?
If you buy into the argument that salamander biochemistry is worth investigation, then it's hard to reject similar investigations in other species capable of the lesser forms of regrowth mentioned above. An open access paper is presently doing the rounds on this topic; you can read the summary in the release, or look at the paper itself:
The concept of regenerative medicine is relatively new, but animals are well known to remake their hair and feathers regularly by normal regenerative physiological processes. Here, we focus on 1) how extrafollicular environments can regulate hair and feather stem cell activities and 2) how different configurations of stem cells can shape organ forms in different body regions to fulfill changing physiological needs.
Regenerative medicine has great potential. The main challenge is how to elicit and harness the power of regeneration. Currently, the major issues are how to obtain stem cells, how to pattern stem cells into organized tissues and organs, and how to deliver stem cell products to patients. Although human beings have very limited powers of regeneration, many animals have robust regenerative powers, distilled and selected over millions of years of evolution. Here, we review fundamental principles of regenerative biology learned from nature in the hope that they can be applied to help the progress of regenerative medicine.
Using the episodic regeneration of skin appendages as a clear readout, we have the opportunity to understand and modulate the behavior of adult stem cells and organ regeneration at a level heretofore unknown. Through this work, we hope to be able to establish or improve the stem cell environment so it can be applied to regenerative medicine.
In conclusion, we think it will be very productive to learn how nature manages the physiological regeneration process. This is a reprogramming process in which the genetic and epigenetic events converge to generate complex functional forms, depending on the physiological need in different parts of the body and at different stages of life. Principles learned from regenerative biology can then be applied toward regenerative medicine.