Liquid Exchange and Positioning of Cellular Entities in a Liquid-air Interface

Technology 

An egg or embryo is first loaded into the disposable chamber (or hanging drop). From there, it sinks due to gravity and migrates towards the liquid-air interface of the chamber, which has an opening connected to the microfluidic channel in the housing. Once in the housing, the liquid exchange process commences by flowing different liquids (e.g., cryoprotectants) through the inlet and microfluidic channel and out through outlet. Once the specimen has been retrieved from the chamber via a vitrification carrier (such as a cryoloop which can be connected to a robotic arm), it is rapidly moved into a vitrification medium, such as liquid nitrogen, to complete the freezing process for long term storage.  

Problem Addressed 

The absence of an automated method for egg or embryo freezing has caused the egg vitrification market to have high costs, low scalability, and high variability in clinical outcomes. Egg freezing’s technical and sensitive nature necessitates highly trained embryologists, which are in limited supply. However, even with skilled embryologists, damage to eggs can still occur during several critical steps of vitrification, namely loading of the cryoprotectant, timing of the processes, and using too much liquid during freezing. An automated device operated by an entry-level embryologist could ensure consistent clinical outcomes comparable to top-tier experts and enable scalability. By significantly reducing the level of technical skill and clinical infrastructure needed to perform reliable egg freezing, this invention can simultaneously improve the quality of cryopreservation, lower costs, increase the number of viable cells upon thawing, and enable expanded access for patients.  

Advantages 

• Reduces the level of technical skill and clinical infrastructure needed for egg or embryo freezing

• Provides a fully automated and self-contained system for vitrification

• Can be fully operated by entry-level technicians

• Decreased likelihood of damaging eggs

• Improved reliability and quality of cryopreservation 

Publications

Haidong, F., et al. "A Microfluidic Hanging Droplet as a Programmable Platform for Mammalian Egg Vitrification." Lab on a Chip 24 (2024): 5225–5237. https://doi.org/10.1039/D4LC00428K.