01 August 2011
ByAppeared in BioNews 618
Currently, embryos are fertilised in a dish, and left there to culture for a few days before being implanted. However, Professor Gary Smith, a researcher on the project, says this doesn't mimic how embryos naturally gestate.
'You can see that embryos really grow in the body in a moist environment, not a fully fluid environment, it's continually moving because of muscle contractions... And also the embryos develop in a micro environment, in crypts in the female reproductive tract', he said, presenting the research at the European Society of Human Reproduction and Embryology's annual meeting last month.
Biomedical engineers at the University of Michigan, Ann Arbor, USA developed a culture chip half the size of a credit card to copy these conditions. The embryos sit in small wells, rather than free in a dish, with channels filled with a nutrient and hormone mixture underneath. The bed of pins - which was inspired by a device enabling blind people to read emails in Braille - pulses up against the channels, pumping the mixture over the embryos to rock them and remove waste products.
To see if this dynamic chip was more successful than the traditional static method in developing embryos for IVF, Professor Smith and his team recruited 25 women undergoing the procedure. With the 315 eggs they successfully fertilised, half from each woman were cultured using one of the two techniques.
After 48 hours there was no difference in the number of cells each zygote had, but the embryos grown dynamically were less fragmented, and so generally of better quality. Fifty-five percent of zygotes cultured in this way were 'good quality' compared to 42 percent of those cultured in dishes, although there wasn't a significant difference in the number of 'top quality' embryos.
Professor Smith said the next step would be to see if the chip increases cell count and improves blastocyst formation following 48 hours. 'And then obviously to move onto phase two trials, to look at implantation and ongoing pregnancy', he said.