An inexpensive nanometer-sized drug that can treat foot ulcers and other chronic wounds has been developed by a group of scientists from the Hebrew University of Jerusalem, Harvard Medical School and others in the U.S. and Japan.

Diabetes is a rapidly growing medical problem affecting close to 3% of the world’s population. Poor blood circulation arising from diabetes can cause skin wounds that do not heal.

Several proteins, called growth factors, have been found to speed up the healing process. But purifying these growth factor proteins is very expensive, and they do not last long on the injured site.

Now, scientists at the Hebrew University and Harvard have used genetic engineering to produce a “robotic” growth factor protein that responds to temperature. Increasing the temperature causes dozens of these proteins to fold together into a nanoparticle that is more than 200 times smaller than a single hair.

This behavior greatly simplifies protein purification, making it very inexpensive to produce. It also enables the growth factor to be confined and to remain at the burn or wound site.