By Joseph Calamia
The red blood cells coursing through your veins transport the oxygen necessary for your survival, and if you lose blood during surgery or in an accident, for instance, you must seek donations. But instead of relying on the blood bank, researchers are now working to make their own supplies. Some start with biological materials, modifying cow’s blood or coaxing stem cells to make the much-needed oxygen carriers. Others hope to craft synthetic materials into blood cell substitutes that may deliver not only vital oxygen, but also medicine. Here, we look at five blood technologies in development.