Scientists in the US have developed artificial blood cells that are capable of transporting drugs around the body more efficiently than if they were injected, and possibly without the side effects associated with direct injection too. These cells mimic their natural equivalents in appearance and in function, being able to traverse gaps smaller than them, and ingest and disperse substances as required, oxygen among them.

The artificial blood cells are the product of a team of US scientists spearheaded by the University of California's Samir Mitragotri.

Actual blood cells are biconcave in profile (in other words, both sides curve inwards), and its this shape that allows them to be so dextrous when manoeuvring around the human body. The US scientists artificial cells mirror this shape by drawing on a polymer known as PLGA Polylactic Co-Glycolic Acid. All the cells have a protein layer applied to them which, once the polymer nuclei are destroyed, remain as the shell of structures that are equal to real blood cells in terms of their mechanical composition. And this, according to Mitragotri, makes the cells nimble. "The soft protein shell makes them squishy and elastic," he explained, adding: "They can squeeze through capillaries smaller than their own diameter, just like real blood cells."

Artificial Red Blood Cells

Trials of these artificial red blood cells revealed that they were effective drug transporters. When exposed to heparin a widely-used anticoagulant they absorbed it and, later on, released it as specified by the new, lower-concentration environment they were in.

The scientists believe that the artificial cells could offer a more effective means of taking prescribed drugs than injections, which tend to be limited in terms of how far they propel medications around the body. In fact, injected medications lose strength at a rate constant to their distance from the injection site, whereas these artificial ones offer the prospect of more constant drug dispersal.

While previous artificial blood cells have been developed, the new ones, according to Mitragotri, are unprecedented in terms of their shape, and in the way they mirror the behaviour of actual cells.