An interesting paper from Avicenna Research Institute has tried to explore the biophysical, biomechanical, and molecular factors, which regulate post-implantation embryo upgrowth.
Arjmand, Fatemeh, et al. “Extended Culture of Encapsulated Human Blastocysts in Alginate Hydrogel Containing Decidualized Endometrial Stromal Cells in the Presence of Melatonin.” Molecular biotechnology (2016)
It is difficult or even impossible to monitor the molecular events underlying the development of embryos beyond blastocyst stage since blastocysts become inaccessible after implantation into the uterus.
The group have tried to develop an effective in vitro system to culture human embryo beyond blastocyst stage and have found for the first time evidence representing in vitro development of human embryos until day 10 post-fertilization. This achievement can facilitate the investigation of the mechanisms regulating human embryo development.
This involved maintenance of embryo in vitro by alginate coencapsulation of human blastocyst and decidualized endometrial stromal cells (EnSCs) under melatonin-fortified culture conditions. The culture medium fortification with melatonin significantly elevated the maintenance rate of expanded embryos in alginate beads by 65 % and prolonged survival time of human embryos to day 5. Furthermore, embryo co-culture with EnSCs using melatonin-fortified medium increased the survival time of encapsulated embryos to 44 %.
Link to full paper access.