New and improved artificial red blood cells; these are what Wei Zhu, C. Jeffrey Brinker, and their colleagues have been up to these days. Natural red blood cells are flexible, capable of transporting oxygen and have long circulation times. A group of researchers have made a synthetic version of these essential bodily cells which could be likened to the original one, plus a few more upgrades.
Although this isn't the first time artificial RBCs have been created, the previous versions would only contain one or few key features of the cells. This latest version is the first to hold all the properties of natural RBCs and then some.
The researchers created the artificial cells by first coating donated human RBCs with a thin layer of silica. Next, they layered positively and negatively charged polymers over the silica-RBCs. The researchers then carved away the silica, which produced flexible clones of the cells. Finally, the team coated the surface of the replicas with membranes from organic RBCs.
The research was funded by the Air Force Office of Scientific Research, the Department of Energy Office of Science, the Laboratory Directed Research & Development Program at Sandia National Laboratories, the National Institutes of Health, and the National Natural Science Foundation of China.
The authors of the study published their paper in the journal ACS Nano on May 11, 2020.
What do RBCs do?
Red blood cells are round with a flat and concave center, like doughnuts except without a hole in the middle. According to the University of Rochester Medical Center, the primary function of RBCs is to carry fresh oxygen throughout the body. These essential cells take up oxygen from the lungs and distribute it to the body's tissues.
The disk-shaped cells consist of millions of molecules of hemoglobin, which is an iron-containing protein that fastens on oxygen. RBCs are exceptionally flexible, which allows them to squeeze through tiny capillaries and then spring back to their antecedent shape. Furthermore, the cells also contain proteins on their surface that would enable them to flow through blood vessels for a long time without being devoured by immune cells.
Red blood cells also remove carbon dioxide from your body, transporting it to the lungs for you to exhale.
Red blood cells are formed in the bone marrow and usually live for about 120 days before they disintegrate. Moreover, RBCs are also responsible for removing carbon dioxide from the body and transporting it to the lungs to allow respiration.
When Synthetic Might Outdo the Original
Researchers claim that their synthetic RBCs contain added features such as magnetic targeting, therapeutic drug delivery, and toxin detection.
During their experiments, the researchers supplied the artificial cells with either hemoglobin, a toxin sensor, an anticancer drug, or magnetic nanoparticles to exhibit that they could carry loads. The team also showed that the new RBCs could function as decoys for a bacterial toxin.
In a clinical trial with mice, the synthetic RBCs lasted for more than 48 hours, with no observable toxicity. Moreover, the researchers say that future studies will explore the potential of artificial cells in medical applications, such as cancer therapy and toxin biosensing.