Medical 3D printing has made great strides, but there's still a very long way to go before we reach the day when we can actually 3D print working organs and transplant them into humans. One issue that's been holding research back, according to a team of researchers at the Hebrew University of Jerusalem, is that there's a lack of satisfactory photo-initiators that are soluble in water and suitable for biocompatible materials. That's changing, however, thanks to a recent study the researchers conducted in which they used semiconductor-metal hybrid nanoparticles as photoinitiators for 3D printing processes. Learn more at 3DPrint.com: http://3dprint.com/178475/water-soluble-photo-initiators/