Synthetic red blood cells could help to save more lives and help more people live healthily. Researchers have, however, found it difficult coming up with variants that could perform as well as the natural cells.
Now, a team of scientists has reported creating synthetic versions that possess all vital attributes of natural red cells. These artificial variants also showed a few extra abilities.
The synthetic red blood cells were able to carry hemoglobin, medications, and other substances around the body.
Findings from the new study were published in ACS Nano, a journal of the American Chemical Society.
Role of red blood cells
Red blood cells (RBCs) are a type of blood cell that comes from the bone marrow. They are mainly known as vehicles for oxygen. The cells assist in moving the essential gas from the lungs to different body tissues.
RBCs transport oxygen with the aid of hemoglobin, a protein with iron which is present within them. And in addition to carrying oxygen, they help to get rid of carbon dioxide from the body.
The key cells are very flexible. They are able to squeeze through very small spaces and then regain their shape after passing through. This high flexibility keeps RBCs from permanent damage.
On their surfaces, red blood cells have proteins that protect them from destruction by immune cells. They circulate within blood vessels for extended periods without being destroyed. This explains why they are seen as very helpful tools for drug delivery.
Researchers have made repeated attempts to create artificial RBCs to mimic the natural ones. But none of the versions developed before now has exhibited all the key qualities of the latter.
This new study led by University of New Mexico researchers aimed at making artificial RBCs that not only have the key features of the natural ones but also have more capabilities.
RBCs with impressive abilities
According to earlier research, nanoparticles offer greater biocompatibility and better drug release efficiency, compared to regular oral drugs. They also have a lesser risk of toxicity. RBCs can help to deliver these nanoparticles.
To make the artificial red blood cells, C. Jeffrey Brinker and colleagues started by coating RBCs from human donors with a thin silica layer. They then layered both positively charged and negatively charged polymers over the blood cells. The second step aimed at making the synthetic cells structurally stable by adding hydrophilic properties.
Next, the team etched away the coating of silica for flexibility. The final step in the process was to cover the surface of the fabricated RBCs with membranes from natural ones.
When the researchers were done, the resulting RBCs were of similar size and shape as the innate ones. They also had comparable charges and surface proteins. They were able to squeeze through tiny model capillaries without being damaged.
Testing done in mice revealed no observable toxicity after being injected and circulating in the animals’ bodies for over 48 hours.
The scientists also found that the fabricated RBCs could do more. They are able to carry cargoes, such as hemoglobin, drugs, toxin sensors, or magnetic nanoparticles. In addition, the biomimetics could serve as decoys that bind to bacterial toxins.
According to the team, future research will examine possible medical usefulness of synthetic RBCs. Potential uses include cancer treatment and toxin biosensing.