Art imitates life, and sometimes drug-delivery mechanisms do, too. Scientists often draw inspiration from natural agents and the body’s processes when developing carriers for therapies. Synthetic red blood cells are a new product of this strategy that seems to raise new possibilities in drug delivery.

Researchers at the University of California, Santa Barbara and at the University of Michigan used a polymer to create a doughnut-shaped template. The scientists coated the template with layers of hemoglobin and other proteins, then removed the core. The result was a particle that mimicked the size (roughly 5 µm in diameter), flexibility, and functionality of red blood cells.

The synthetic red blood cells can carry oxygen like their natural counterparts do. But unlike the real thing, these synthetic cells can encapsulate drug particles or carry them on their surface for controlled release. The scientists say that the synthetic red blood cells could carry several drugs at once. Also, the synthetic cells can be squeezed to flow through channels (e.g., capillaries) that are smaller than the cells’ diameter when they are at rest. Like real red blood cells, the synthetic particles can stretch in response to flow and regain their original dimensions after they exit a channel.

Although these synthetic red blood cells are still being studied, it’s conceivable that they’d have great advantages for drug delivery. Their composition and physical properties might bypass the body’s immune response and deliver drugs to areas that are otherwise hard to target. The cells’ adaptability suggests that they could be effective vehicles for multidrug therapies for diseases such as cancer or diabetes. The researchers’ invention seems like a creative innovation that could inspire the imagination of drug developers and formulators.