Combined with the need for transfusions during surgery, the dangers of transmitting infectious disease through shared blood, and the continuing lack of qualified blood donor volunteers, we could soon face a serious medical crisis. If only there were a synthetic stand-in that we could use to keep patients alive until they reached a hospital and received proper medical care.

Of course, it isn’t like we haven’t been trying. The medical community has been working to find a suitable oxygen-carrying blood replacement since the 17th century after William Harvey figured out the pulmonary system. Early attempts were crude, at best. Beer, milk, urine, animal blood — even mixtures of wine and opium were considered, tested and failed.

Research continued in earnest through the 20th century, up until WWII, when interest in transfusion technology exploded. However, postwar research was almost immediately hamstrung by a number of debilitating side effects which couldn’t be resolved with the technical know-how of the time. The emergence of HIV in the 1980s and the Mad Cow Disease scares in the 1990s further impeded advancements in the field.

Turns out that synthesizing a suitable replacement for blood — even just its oxygen-carrying aspect — is incredibly difficult. Only two precursors have proved usable to date: recombinant hemoglobin and perfluorocarbons (PFCs). Both offer unique benefits but also a host of dangerous side effects. Hemoglobin-based treatments bind to oxygen more easily than PFCs because that’s what the molecule does naturally, but releasing raw hemoglobin into the…

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