The new discovery – outlined in a study appearing in the online Early Edition of the Proceedings of the National Academy of Sciences during the week of Jan. 10, 2011 – also could lead to more effective treatments for life threatening medical conditions such as cancer.
University of North Carolina at Chapel Hill researchers used technology known as PRINT (Particle Replication in Non-wetting Templates) to produce very soft hydrogel particles that mimic the size, shape and flexibility of red blood cells, allowing the particles to circulate in the body for extended periods of time.
Tests of the particles’ ability to perform functions such as transporting oxygen or carrying therapeutic drugs have not been conducted, and they do not remain in the cardiovascular system as long as real red blood cells.
However, the researchers believe the findings – especially regarding flexibility – are significant because red blood cells naturally deform in order to pass through microscopic pores in organs and narrow blood vessels. Over their 120-day lifespan, real cells gradually become stiffer and eventually are filtered out of circulation when they can no longer deform enough to pass through pores in the spleen. To date, attempts to create effective red blood cell mimics have been limited because the particles tend to be quickly filtered out of circulation due to their inflexibility.
Beyond moving closer to producing fully synthetic blood, the findings could affect approaches to treating cancer. Cancer cells are softer than healthy cells, enabling them to lodge in different places in the body, leading to the disease’s spread. Particles loaded with cancer-fighting medicines that can remain in circulation longer may open the door to more aggressive treatment approaches.
“Creating particles for extended circulation in the blood stream has been a significant challenge in the development of drug delivery systems from the beginning,” said Joseph DeSimone, Ph.D., the study’s co-lead investigator, Chancellor’s Eminent Professor of Chemistry in UNC’s College of Arts and Sciences, a member of UNC’s Lineberger Comprehensive Cancer Center and William R. Kenan Jr. Distinguished Professor of Chemical Engineering at N.C. State University. “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.”
Continue reading at http://uncnews.unc.edu/content/view/4208/107/.