Nicola Twilley writes about the challenges, historical context, and current research efforts surrounding the development of artificial blood substitutes, both from lab-grown red blood cells and synthetic alternatives. For something so abundantly produces by our bodies, we are still not very close to being able to produce blood outside of it, and the lack of it still contributes to a significant number of preventable deaths.
Modern on-demand blood, it turns out, is a logistical miracle: rubber tubing and milk bottles have been replaced by an engineered process that gathers the liquid, tests it, and then stores each of its elements for maximum shelf life, before getting it to the patients who need it. But not to all of them. Despite the high throughput of the N.H.S.B.T. blood factory, and despite the fact that a unit of blood is transfused every two seconds in the United States, there just isn’t enough.
… scientists don’t yet understand everything that blood does, or how it does it. Somehow, the various components of blood—red and white cells, platelets, and plasma—manage to perform an entire spectrum of life-promoting functions. In addition to picking up oxygen in the lungs and releasing it throughout the body, blood delivers nutrients; transports hormones; carts away toxic waste products such as carbon dioxide, urea, and lactic acid; regulates body temperature, pH, and over-all chemical and fluid balance; monitors for and raises the alarm about organ damage; recalls, detects, and defends against immune-system threats; and is even responsible for the hydraulics behind tissue engorgement, as the more prudish textbooks might put it.