Carbon monoxide or CO, poisoning accounts for 50,000 emergency room visits in the US each year and causes about 1,500 deaths, each one being lamented as a shameful waste and tragic oversight.

Currently, the only treatments for CO poisoning are oxygen-based therapies, which help the body eliminate the toxic gas. However, even with treatment, nearly half of survivors suffer long-term heart and brain damage. This has created an urgent need for faster, more effective interventions.

In a study published by University of Maryland School of Medicine (UMSOM) in PNAS, the research team developed a new engineered protein-based therapy called RcoM-HBD-CCC, which acts like a sponge to soak up carbon monoxide from the blood.

RcoM (short for "regulator of metabolism") is a natural protein isolated from the bacterium Paraburkholderia xenovorans which uses it to sense minute levels of carbon monoxide in its environment.

The researchers engineered a version that is highly selective, grabbing CO without interfering with oxygen or other important molecules in the bloodstream like nitric oxide, which is vital for the regulation of blood pressure.

In tests on mice, the new therapy worked quickly to remove CO from red blood cells and was safely flushed out of the body through urine.

CO is known commonly as the "silent killer," because this odorless, invisible gas, typically released from combustion sources, including stovetops, propane heaters, car exhausts, and firewood, poisons in a gradual manner that isn't immediately obvious to the victim.