January 11, 2011

Synthetic Blood: A Real Possibility

(Ivanhoe Newswire) -- Researchers from the University of North Carolina at Chapel Hill have discovered a way to create red blood cell-mimicking particles, which are possible building blocks in the creation of synthetic blood. Leverage of these particles can potentially aid doctors in treating deadly diseases like cancer.

The researchers created the extremely soft, hydrogel particles using PRINT (Particle Replication in Non-wetting Templates) technology. This technology allowed them to create particles which successfully mimicked the shape, size and flexibility of red blood cells. Such traits enabled the particles to remain active in the body for prolonged periods of time.

The particles have not been tested for their ability to transport oxygen and medicinal drugs, but they show a lot of promise, according to the researchers. Since normal red blood cells must naturally deform in shape to travel into narrow blood vessels and the microscopic pores of organs, flexibility is key. The UNC researchers understood this, developing particles flexible enough to avoid the body's filtration process, which automatically discards inflexible red blood cells.

To achieve this level of flexibility, the researchers designed the hydrogel material for a desired amount of stiffness, made molds using the PRINT technology, and filled the molds with the hydrogel. The molds were then processed to yield thousands of red blood cell-resembling discs, each measuring up at only six micrometers.

The particles are believed to have potential in fighting cancer cells, which are soft and therefore able to stick to different areas of the body and spread the disease. If the researchers' particles were able to carry cancer-treating drugs and circulate in the bloodstream for a long enough time, they may prove to be an aggressive ally in the fight against these tricky cancer cells.

"Creating particles for extended circulation in the bloodstream has been a significant challenge in the development of drug delivery systems from the beginning," Joseph DeSimone, Ph.D., co-lead investigator of the study, Chancellor's Eminent Professor at UNC's College of Arts and Sciences, UNC's Lineberger Comprehensive Cancer Center member, and Distinguished Professor of Chemical Engineering at N.C. State University, was quoted as saying. "Although we will have to consider particle deformability along with other parameters when we study the behavior of particles in the human body, we believe this study represents a real game changer for the future of nanomedicine."

The research team used the circulatory system of field mice to test a series of particles ranging in flexibility. The more flexible ones lasted a half-life of 93.29 hours, largely beating the 2.88 hours of the stiffer ones. These less flexible particles were more likely to get lodged in the lungs instead of getting filtered out as red blood cells normally do when passing through organs. These results prove the particles' ability to successfully mimic red blood cells.

Source: Proceedings of the National Academy of Sciences, January 2011