Bulletproof vests may come from stem cells

In a breakthrough, Cambridge scientists have discovered a bizarre new property in the nuclei of embryonic stem cells that could pave the way for gen-next bulletproof vests.
Stem cells - the body's master cells - demonstrate the property never before seen at a cellular level, scientists said.
The property - known as auxeticity - is one which may have application as wide-ranging as soundproofing, super-absorbent sponges and bulletproof vests, they said.
Most materials when stretched will contract. The opposite is also true: squeeze a material and it will expand.
However, scientists have begun to explore auxeticity, an unusual property which has the opposite effect - squeeze it and it will contract, stretch it and it will expand.

This means that auxetic materials act as excellent shock absorbers or sponges, a fact that is being explored for various uses.

Until now, auxeticity has only been demonstrated in man-made materials and very rarely in nature, such as some species of sponge.
A team of University of Cambridge researchers observed auxeticity in the nuclei of embryonic stem cells, master cells within the body which can turn into any other type of cell.
"This is a pretty bizarre finding and very unexpected. When the stem cell is in the process of transforming into a particular type of cell, its nucleus takes on an auxetic property, allowing it to 'sponge up' essential materials from its surrounding," Dr Kevin Chalut from the Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, who led the study, said.

"This property has not, to my knowledge, been seen before at a cellular level and is highly unusual in the natural world," Chalut said.
The auxetic properties only appear in the stem cell's nucleus when it is in the transition stage, changing from an embryonic, non-specific stem cell into a differentiated, tissue-specific cell, such as a heart tissue cell.
The research was published in the journal Nature Materials.