Artificial Red Blood Cells Match the Properties of Natural Cells and More

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The ability to create functional, artificial cells that closely mimic their natural counterparts would open up many possibilities in the field of medicine and beyond. Red blood cells are an excellent target for such research, as they are not only relatively simple, but offer unique possibilities for targeted drug delivery. For example, artificial red blood cells could be loaded with a drug that would be released slowly over time as the cells circulate around the body.

060320-synthetic-blood — An artificial red blood cell. Scale bar: 2μm
Biomimetic Rebuilding of Multifunctional Red Blood Cells: Modular Design Using Functional Components. (2020). *ACS Nano*. Retrieved from https://pubs.acs.org/doi/abs/10.1021/acsnano.9b08714

Artificial red blood cells should ideally mimic natural cells in terms of oxygen-carrying capacity and circulation time. Red blood cells also need to have the shape and flexibility that allows them to squeeze through the capillaries – the tiny blood vessels in which gas exchange occurs. Most artificial red blood cells created so far have lacked one or more of these qualities, but a study published in ACS Nano appears to have overcome this problem, producing cells that not only mimic red blood cells, but can also be loaded with various cargoes including an anticancer drug.

The researchers made the synthetic cells by first coating donated human RBCs with a thin layer of silica. They layered positively and negatively charged polymers over the silica-RBCs, and then etched away the silica, producing flexible replicas. Finally, the team coated the surface of the replicas with natural RBC membranes. The artificial cells were similar in size, shape, charge and surface proteins to natural cells, and they could squeeze through model capillaries without losing their shape. In mice, the synthetic RBCs lasted for more than 48 hours, with no observable toxicity. The researchers loaded the artificial cells with either hemoglobin, an anticancer drug, a toxin sensor or magnetic nanoparticles to demonstrate that they could carry cargoes. The team also showed that the new RBCs could act as decoys for a bacterial toxin. Future studies will explore the potential of the artificial cells in medical applications, such as cancer therapy and toxin biosensing.
Synthetic red blood cells mimic natural ones, and have new abilities – American Chemical Society. (2020). Retrieved 12 June 2020, from https://www.acs.org/content/acs/en/pressroom/presspacs/2020/acs-presspac-june-3-2020/synthetic-red-blood-cells-mimic-natural-ones-and-have-new-abilities.html