Two Israeli companies say they used a specialized 3-D printer to create an environment in which stem cells could grow into a specific tissue.

In the near future, the technology could be used for testing new drugs, but it also opens up the possibility of growing organ replacements.  

In 2006, Japanese scientist Shinya Yamanaka and his team discovered that common human cells, such as skin cells, can be turned into stem cells, previously harvested from embryos.

With ethical concerns about using embryonic stem cells removed, many researchers around the world started experimenting with tissue regeneration.

The so-called induced pluripotent stem cells, or IPS cells, are now being used for replacing simpler tissues in the human body lost to disease or injury.