A novel microfluidics-based device achieves automatic cumulus cells removal and optimal embryo development in cattle

Area of Science:

• Reproductive Biology
• Bioengineering
• In Vitro Fertilization

Background:

• Oocyte and zygote denudation is crucial for embryo visualization and assessment.
• Conventional manual denudation methods exhibit significant operator-to-operator variability.
• There is a need for standardized and automated oocyte handling techniques.

Purpose of the Study:

• To develop and evaluate an automated microfluidic prototype for denuding bovine cumulus oocyte complexes (COCs).
• To compare the efficacy and developmental outcomes of automated versus manual denudation.
• To assess the potential of automated denudation for future human applications.

Main Methods:

• Development of a microfluidic device capable of processing 16 COCs simultaneously.
• Randomized comparison of automated denudation with conventional manual stripping.
• Assessment of zona pellucida permeability, blastocyst formation rates, cell counts, and blastocyst transcriptome.
• In vitro evaluation of post-hatching developmental potential.

Main Results:

• Automated and manual denudation showed similar zona pellucida permeability.
• No significant differences in blastocyst formation rates or cell numbers were observed between groups.
• Blastocyst transcriptomes were highly similar, with fewer differentially expressed genes compared to in vivo controls after automated denudation.
• Post-hatching development rates were comparable between automated and manual denudation groups.

Conclusions:

• The automated microfluidic device provides a safe, repeatable, and efficient method for bovine COC denudation.
• Automated denudation results in developmental and molecular profiles comparable to manual methods.
• This technology represents a significant step towards automated oocyte handling in human assisted reproductive technologies.