Someone in the US needs a blood transfusion, alluding to the importance of blood supplies to modern healthcare. The problem is blood is in incredibly short supply, and the pandemic has only made things worse due to the forced cancellation of many collection drives. That’s why there has been a renewed interest from scientists to create artificial blood.

Donated blood comes with its own problems. Beyond its necessary reliance on willing donors, blood only has a shelf life of 42 days and must be refrigerated, which severely limits its use in places without reliable electricity. Blood types are also an issue. For example, a person with Type O blood can only receive transfusions of Type O—and the donated blood must be screened for the potential for viruses. With artificial blood, it could be possible to overcome these limitations.

Artificial blood would need to mimic the oxygen-carrying abilities carried out by red blood cells, which is difficult. One way to mimic this ability, Cambridge scientists say, is to manufacture red blood cells in a cell. In an upcoming trial, they plan to inject the cells into patients to test their survival compared to donated red blood cells. If this stem cell-derived artificial blood works, it could raise interesting possibilities for people with rare blood types who need regular transfusions as the cells could literally be grown from a recipient’s own body.

While Cambridge works on this, a biotech company called KaloCyte is taking a different approach by developing a synthetic red blood cell that contains purified human hemoglobin. Unlike donated blood, their product can be stored at room temperature, meaning hospitals could keep enough supplies of artificial blood on hand at all times. KaloCyte hasn’t reached the clinical trial stage with its synthetic blood cells yet but did recently receive a $373,000 grant from the National Institutes of Health to continue the product’s development after animal-based tests.

Scientists in Japan are taking a wholly different approach by attempting to recreate the platelets that give blood clotting abilities. Biotech company Haima Therapeutics is in the preclinical stage of testing its fully synthetic platelets, while researchers at Japan’s Kyoto University are already testing platelets grown from stem cells on humans.

As described in FreeThink, it could be a combination of all these efforts that end up bringing artificial blood to fruition after decades of research.