Evaluation of mouse oocyte in vitro maturation developmental competency in dynamic culture systems by design and construction of a lab on a chip device and its comparison with conventional culture system

In conventional assisted reproductive technology (ART), oocytes are cultured
in static microdrops within Petri dishes that contain vast amounts of media. However, the
in vivo environment is dynamic. This study assesses in vitro oocyte maturation through the
use of a new microfluidic device. We evaluate oocyte fertilization to the blastocyct stage
and their glutathione (GSH) contents in each experimental group.
Materials and Methods: In this experimental study, we established a dynamic culture
condition. Immature oocytes were harvested from ovaries of Naval Medical Research Institute
(NMRI) mice. Oocytes were randomly placed in static (passive) and dynamic (active)
in vitro maturation (IVM) culture medium for 24 hours. In vitro matured oocytes underwent
fertilization, after which we placed the pronucleus (PN) stage embryos in microdrops
and followed their developmental stages to blastocyst formation after 3 days. GSH content
of the in vitro matured oocytes was assessed by monochlorobimane (MCB) staining.
Results: We observed significantly higher percentages of mature metaphase II oocytes
(MII) in the passive and active dynamic culture systems (DCS) compared to the static
group (P<0.01). There were significantly less mean numbers of germinal vesicle (GV) and
degenerated oocytes in the passive and active dynamic groups compared to the static
group (P<0.01). Fertilization and blastocyst formation rate in the dynamic systems were
statistically significant compared to the static cultures (P<0.01). There was significantly
higher GSH content in dynamically matured oocytes compared to statically matured oocytes
(P<0.01).
Conclusion: Dynamic culture for in vitro oocyte maturation improves their developmental
competency in comparison with static culture conditions.