Increasing popularity of nanoparticles for stem cell applications, such as therapeutic cloning, and the need for FDA approval to use them in clinical trials, has accelerated the accumulation of toxicity data. These studies need to address both nanoparticle toxicity to somatic cells when used in vivo, and their potential toxicity to the stem cells with which they were designed to function. While superparamagnetic iron oxide (SPIO) nanoparticles used to improve magnetic resonance imaging (MRI) in vivo, show little toxicity to the stem cells they associate with, quantum dots (qdots) have been shown to be cytotoxic under certain conditions and carbon nanotubes have demonstrated some genotoxicity.
In the past year, 6 individuals who used a German household cleaner supposedly containing nanoparticles were hospitalized with respiratory problems. However, a later report by the Federal Institute for Risk Assessment (BfR) in Berlin stated that the product did not even contain any nanoparticles. Despite this report, the damage was done and, although the real cause of their illness was not determined, this event triggered widespread public concern over the safety of products that use nanotechnology. Some even call for a moratorium on the production and sale of nanoparticles until more is known. The US EPA does not currently regulate nanoparticles but agrees there should be a review of certain compounds and is working on a proposal for standards.
Despite the unknowns, the general consensus seems to be that there is a lot of potential in nanotechnology and applications using nanoparticles. However, the bioethics of nanoparticle use in medicine are still in question, and much more research is needed before we can determine how they will react in the human body, and interact with biomolecules, and how to ensure their safe use.
Sources:
A. von Bubnoff. Study shows no nano in Magic Nano, the German product recalled for causing breathing problems. Small Times, PennWell Corporation, Tulsa, OK. May 26, 2006.
Ferreira, L. et al. 2008. New opportunities: The use of nanotechnologies to manipulate and track stem cells. Cell Stem Cell 3:136-146. doi:10.1016/j.stem.2008.07.020.