Blood transfusions can save the lives of patients who have suffered major blood loss, but hospitals don’t always have enough or the right type on hand. In search of a solution, researchers have developed a promising substitute using blood’s oxygen-carrying component, hemoglobin. The in vitro study, reported in ACS’ journal Biomacromolecules, found that the modified hemoglobin was an effective oxygen carrier and also scavenged for potentially damaging free radicals.