Two categories of contenders soon emerged. The first was a red-colored substitute made in part from human or animal hemoglobin, the protein in our red blood cells that carries oxygen. The second was a snow-white, completely synthetic substance made from perfluorocarbons, or PFCs, a compound whose chemical makeup closely resembles the nonstick Teflon in your frying pan. PFCs have the highest gas-dissolving capacity of any liquid and, when used with supplemental oxygen, allow blood to carry many times more oxygen than it normally does (and to carry more oxygen faster and more easily than hemoglobin-based substitutes).
In large-scale clinical trials in the 1980s and 1990s in which researchers pitted the fake bloods against the real thing, patients who received the artificial stuff experienced a disproportionate number of heart attacks and strokes. Those outcomes–widely attributed to a combination of poorly designed trials and first-generation formulations–effectively shut down human studies and, in some cases, bankrupted biotech firms.
After two decades and a billion dollars' worth of research, the most valuable lesson learned was that real blood and these artificial bloods were apples and oranges: The life-giving liquid in our veins acts like a supply line for everything from nutrients to hormones to oxygen, even working double-time to regulate our blood pressure and fight infection. The manufactured substances, on the other hand, are one-trick ponies for oxygen delivery. But it's a trick they perform remarkably well-in the case of PFC-based substitutes, carrying oxygen at rates roughly 50 times that of our own blood.
Today, blood substitutes are often called "oxygen therapeutics" for this very reason, and manufacturers are no longer putting them up against real blood in clinical trials. In fact, sophisticated screening practices have made donated blood so safe that finding an alternative to diseased blood is no longer necessary. But there is still a significant need for a universal-type, oxygen-carrying fluid, particularly as a solution to ever-more-common shortages of donated blood and as a fool-proof substitute for the military, which poured at least $10 million into developing a blood proxy before giving up and waiting for pharmaceutical companies to solve the problem for them.
Doctors at VCU are betting that a successful pilot trial of Oxycyte will win the attention-and influence-of the armed forces, which would help usher the drug through the clinical-trial process and into the hands of doctors and medics in the near term. At least that's the hope–or rather, the careful, calculated plan-of Bruce Spiess.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.