Nanotech News

October 3, 2005

Common Nanoparticle Shown to Be Non-toxic to Blood Cells

Though many kinds of nanoparticles, loaded with a variety of drugs and imaging agents, are making their way toward the clinic, questions about nanoparticle toxicity remain to be answered. Given that the majority of nanoparticles are intended to travel to tumors through the bloodstream, the effects of nanoparticles on blood cells are of particular concern to those developing nanoparticle-based therapeutic and imaging agents. Now, a series of experiments by researchers at the University of Kentucky have found no ill effects when blood cells are exposed to one common type of nanoparticle.

Writing in the journal Pharmaceutical Research, a group headed by Russell Mumper, Ph.D., tested the compatibility of nanoparticles coated with polyethylene glycol, a polymer used to protect many types of nanoparticles from elimination by cells of the immune system. The investigators developed a testing methodology that enabled them to determine how nanoparticles affected a variety of in vitro and in vivo parameters, including blood clotting time, red blood cell damage, and platelet aggregation, or clumping.

Using a polyethylene glycol-coated nanoscale liposome as a generic nanoparticle, the investigators found that a concentration of nanoparticles one would expect to achieve in the blood stream produced no untoward biological effects on blood cells. Higher levels of the test nanoparticles did slow blood clotting, however. The researchers also noted that nanoparticle effects on blood cells are likely to depend on the particle size and surface properties, making the assays developed by these investigators useful for further studies of other nanoparticles.

This work is detailed in a paper titled, "Blood compatibility of cetyl alcohol/polysorbate-based nanoparticles." This paper was published online in advance of print publication. An abstract is available through PubMed.
View abstract.