Human embryos frozen for as long as 18 years can continue to yield viable stem cells suitable for biomedical research, a new study has found.
The findings, reported in the journal BioResearch Open Access, suggest even human embryos frozen for long periods of time can be thawed, grown in the laboratory, and successfully induced to produce human embryonic stem cells.
Such cells represent an important resource for drug screening and medical research, according to researchers from Chulalongkorn University and Memorial Hospital in Bangkok who conducted the study. They also noted prolonged embryonic cryopreservation offers a potentially valuable alternative source of embryonic stem cells.
Lead researcher Kamthorn Pruksananonda demonstrated that stem cells derived from long-frozen embryos have a similar ability to differentiate into multiple cell types — a characteristic known as pluripotency — as do those derived from fresh embryos.
"The importance of this study is that it identifies an alternative source for generating new embryonic stem lines, using embryos that have been in long-term storage," said Jane Taylor, a specialist with the MRC Centre for Regenerative Medicine at the University of Edinburgh, and the journal’s editor.