In a recent Nature Biotechnology publication, Dr. Atala of Wake Forest's regenerative medicine department demonstrating that amniotic fluid-derived stem cells (AFS) are in fact pluri-potent. This finding adds another cell line that side-steps any bioethical objection to regenerative research. Unfortunately, the banning of embryonic stem cell research has damaged the public's image of any type of stem cell research regardless of their potential benefits.

In the sited paper below, the Wake Forest group demonstrates that the AFS cells have less potential of forming tumors than does embryonic lines, due to being farther along in developmental process, but AFS cell lines do not grow as slow as adult stem cell lines.

Here is the reference to this article:

Paolo De Coppi, Georg Bartsch Jr, M Minhaj Siddiqui, Tao Xu, Cesar C Santos, Laura Perin, Gustavo Mostoslavsky, Angéline C Serre, Evan Y Snyder, James J Yoo, Mark E Furth, Shay Soker & Anthony Atala. Isolation of amniotic stem cell lines with potential for therapy. Nature Biotechnology - 25, 100 - 106 (2007) Published online: 7 January 2007.
doi:10.1038/nbt1274

Abstract:
Stem cells capable of differentiating to multiple lineages may be valuable for therapy. We report the isolation of human and rodent amniotic fluidderived stem (AFS) cells that express embryonic and adult stem cell markers. Undifferentiated AFS cells expand extensively without feeders, double in 36 h and are not tumorigenic. Lines maintained for over 250 population doublings retained long telomeres and a normal karyotype. AFS cells are broadly multipotent. Clonal human lines verified by retroviral marking were induced to differentiate into cell types representing each embryonic germ layer, including cells of adipogenic, osteogenic, myogenic, endothelial, neuronal and hepatic lineages. Examples of differentiated cells derived from human AFS cells and displaying specialized functions include neuronal lineage cells secreting the neurotransmitter L-glutamate or expressing G-protein-gated inwardly rectifying potassium channels, hepatic lineage cells producing urea, and osteogenic lineage cells forming tissue-engineered bone.

Full-text pdf link:
http://www.nature.com/nbt/journal/v25/n1/pdf/nbt1274.pdf