Almost too small to mention

The media is full of stories about stem cells and the hope for curing disease and slowing or reversing aging. Some are concerned about how these technologies will affect our children. Science fiction is full of utopias and dystopias based on genetically manipulated descendents of Homo sapiens. The cloning of a dog by Korean veterinarian Hoo Suk Hwang was anounced last week, raising the concern of some and drawing a pained sigh from others.


As though we didn't have enough to worry about with intentional manipulation of the genes and bodies of our children's grandchildren:

This report, reports on early evaluations of nanoparticles ( objects that are measured on the scale of molecules, in nanometers or one billionth of a meter long) on stem cells. The researchers hope to show that mouse spermatagonia are suitable to test for the toxity of these tiny particles which are believed to be little remote probes of the future for testing, treating and monitoring biological and all sorts of chemical and physical processes.

Here's the abstract:

IN VITRO CYTOTOXICITY OF NANOPARTICLES IN MAMMALIAN GERM-LINE STEM CELLS
Laura Braydich-Stolle; Saber Hussain; John Schlager; Marie-Claude Hofmann. Toxicol. Sci. published 13 July 2005, 10.1093/toxsci/kfi256

Gametogenesis is a complex biological process that is particularly sensitive to environmental insults such as chemicals. Many chemicals have a negative impact on the germ line, either by directly affecting the germ cells, or indirectly through their action on the somatic nursing cells. Ultimately, these effects can inhibit fertility, and may have negative consequences on the development of the offspring. Recently, nanomaterials such as nanotubes, nanowires, fullerene derivatives (buckyballs) and quantum dots have received enormous national attention to create new types of analytical tools for biotechnology and the life sciences. Despite the wide application of nanomaterials, there is a serious lack of information concerning their impact on human health and the environment. Thus, there are limited studies available on toxicity of nanoparticles for risk assessment of nanomaterials. The purpose of this study was to assess the suitability of a mouse spermatogonial stem cell line as a model to assess nanotoxicity in the male germ line in vitro. The effects of different types of nanoparticles on these cells was evaluated using light microscopy, cell proliferation and standard cytotoxicity assays. Our results demonstrate a concentration-dependent toxicity for all types of particles tested, while the corresponding soluble salts had no significant effect. Ag nanoparticles were the most toxic while MoO3 nanoparticles were the least toxic. Our results suggest that this cell line provides a valuable model to assess the cytotoxicity of nanoparticles in the germ line in vitro.
Keywords: nanoparticles; toxicity; cell line; spermatogonia; stem cells.