Synthetic red blood cells developed

North American scientists have developed synthetic particles that closely mimic the characteristics and vital functions of natural red blood cells, including flexibility, softness and the ability to carry oxygen.

The principal function of natural red blood cells is to carry oxygen, and the synthetic red blood cells (sRBCs) do that exceptionally well, retaining 90% of their oxygen-binding capacity after a week. Also, the sRBCs have been shown to deliver therapeutic drugs effectively and with controlled release, and to carry well-distributed contrast agent for enhanced resolution in diagnostic imaging.

The sRBCs ability to deliver therapeutic and diagnostic agents opens up new perspectives in drug delivery and similar applications. The sRBC can also be possibly engineered to carry additional therapeutic agents, both enveloped in the sRBC and on its surface.

The American researchers successfully synthesized the particles by creating a polymer doughnut-shaped template, coating the template with up to nine layers of haemoglobin and other proteins, then removing the core template. The resulting particles have the same size, flexibility, and carry as much oxygen, as the natural red blood cells.

The flexibility, absent in "conventional" polymer-based biomaterials developed as carriers for therapeutic and diagnostic agents, gives the sRBCs the ability to flow through channels smaller than their resting diameter, stretching in response to flow and regaining their discoidal shape upon exiting the capillary, just as their natural counterparts do.