We all need oxygen. Individuals who are subjected to low enough levels of oxygen (whatever the cause) can be at major risk for organ dysfunction, cardiac arrest, and death—all within minutes. So when oxygen supply gets too low, medical attention can be needed to increase oxygen levels quickly. But most treatments for hypoxia—low oxygen levels—require an intact and functional respiratory system.

A great deal of research has focused on developing methods to safely administer oxygen directly into the bloodstream, where it can be quickly distributed to tissues and organs in need. In a recent investigation published in PNAS, a team of researchers at Harvard Medical School have developed hollow polymer particles that deliver oxygen to the bloodstream.

Microparticle Fabrication

The scientists developed a two-stage, emulsion-based fabrication process to make these oxygen-carrying polymers. In the first step, a two-phase oil-in-water emulsion was prepared—droplets of an oil-based phase are suspended in a water-based solution. In this case, the oil phase contained a key chemical, a biodegradable polymer called poly(D,L-lactic-co-glycolic) acid, or PLGA.