Red blood cell are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish (family Channichthyidae); they live in very oxygen-rich cold water and transport oxygen freely dissolved in their blood. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome. Vertebrate red blood cells consist mainly of hemoglobin, a complex metalloprotein containing heme groups whose iron atoms temporarily bind to oxygen molecules (O) in the lungs or gills and release them throughout the body. Oxygen can easily diffuse through the red blood cell's cell membrane.
Genetically engineered blood protein and a substance of choice, such as a small-molecule therapeutic agent or an antibody. The modifications leave the cells and their surfaces otherwise intact. One application is to engineer red blood cells into drug-delivery vehicles. Mature red cells carry no genetic material, potentially presenting fewer safety risks than other gene and cell therapies. Human red blood cells circulate for as long as four months, meaning they could potentially form the basis of long-term therapies. The cells move throughout body via the bloodstream and are unnoticed by the immune system. Genetically engineered blood Genetically engineered blood is blood that has