Auto-nucleating Device for Cryopreservation Ice Control
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Solution Overview
Problem
Current cryopreservation methods face challenges with rapid cooling rates causing intracellular ice formation and variable sample survival rates due to thermal disequilibrium and the need for cumbersome seeding processes, which can result in cell damage and low success rates, especially for low-motility samples like sperm.
Innovation Solution
An auto-nucleating device with an ice-nucleating composition, such as cholesterol, is introduced into the cryopreservation vessel to induce controlled ice crystal formation, reducing supercooling and eliminating the need for manual seeding, thereby facilitating reproducible and efficient cryopreservation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual seeding is used to induce ice crystal formation, then controlled ice crystal formation is achieved, but the process becomes cumbersome and time-consuming
Solution Approach 1:
The device enables self-service by allowing the cryopreservation sample to automatically induce ice crystal formation without manual intervention. The sample itself serves as the seeding agent through its inherent properties, eliminating the need for external manual seeding operations.
Solution Approach 2:
The device performs preliminary action by pre-preparing the ice nucleation capability within the cryopreservation sample before the actual freezing process. This allows the ice crystal formation to be triggered automatically at the appropriate moment without requiring manual seeding during the procedure.
2Productivity
If rapid cooling rates are applied to achieve thermal equilibrium, then cooling efficiency is improved, but intracellular ice formation occurs causing cell death
Solution Approach 1:
The device acts as an intermediary by introducing a controlled nucleation site that mediates between the cooling process and the sample. This intermediary structure allows heat to be released in a controlled manner during ice formation, preventing uncontrolled rapid cooling and intracellular ice formation while maintaining cooling efficiency.
Solution Approach 2:
The device utilizes phase transitions by controlling the freezing process to occur in a controlled manner. By managing the phase change from liquid to solid through controlled nucleation, the device prevents harmful intracellular ice formation while maintaining efficient cooling through the heat release during the phase transition.
3Duration of action of stationary object
If supercooling is increased to delay ice formation, then thermal equilibrium is maintained longer, but the sample temperature increases transiently causing thermal damage
Solution Approach 1:
The device implements feedback by providing a controlled mechanism that responds to the cooling process. As the sample cools and approaches the freezing point, the controlled nucleation site activates, providing feedback that triggers ice formation at the optimal moment to release heat and prevent transient warming, while maintaining supercooling benefits.
Solution Approach 2:
The device utilizes parameter changes by controlling the temperature and nucleation parameters to achieve optimal cryopreservation. By carefully managing the supercooling parameter and triggering nucleation at the right moment, the device prevents transient thermal damage while maintaining the benefits of extended liquid state maintenance.
4Reliability
If cryoprotectants are added to protect cells during freezing, then cell viability is improved, but osmotic damage occurs during addition and removal
Solution Approach 1:
The device replaces the mechanical process of adding and removing cryoprotectants with a controlled thermal and nucleation-based process. By substituting the mechanical manipulation of cryoprotectant concentration with controlled freezing and nucleation, the device maintains cell viability while eliminating osmotic damage associated with adding and removing these agents.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The auto-nucleating device significantly reduces cell damage during cryopreservation, enhances sample survival rates, and allows for the preservation of low-motility samples, providing a closed system for multiple freeze/thaw protocols and improving the efficiency of cryopreserving cells and tissues.
Implementation Method 1
An auto-nucleating device with an ice-nucleating composition, such as cholesterol, is introduced into the cryopreservation vessel to induce controlled ice crystal formation
Implementation Method 2
As these solutions are cooled to temperatures slightly below their freezing point, the solution remains in the liquid state. This condition in which the solution remains liquid below its phase transition temperature is termed supercooling.
Implementation Method 3
The heat produced during this phase transition causes a transient warming of the sample during which the sample temperature increases. Meanwhile the surrounding environment either remains at a constant temperature or continues to cool
Implementation Method 4
as the heat in the sample dissipates, the thermal disequilibrium between the sample and cooling device created during this event causes the sample to undergo a rapid cooling rate to re-establish thermal equilibrium
Implementation Method 5
The process of cryopreservation involves, in part, placing cells into aqueous solutions containing electrolytes and chemical compounds that protect the cells during the freezing process (cryoprotectants)
Implementation Method 6
decreased temperature results in the suppression of metabolic activity and, thus, in a reduction of the rate at which deterioration of an unnourished biological system would occur
Data Source
AI summary
An auto-nucleating device includes a tube containing a crystalline cholesterol matrix. The ends of the tube are closed by a membrane that is impermeable to the cholesterol but permeable to liquids contained in a cryopreservation vessel. The auto-nucleating device provides a site for ice nucleation during freezing of the liquid within the vessel. One such cryopreservation vessel is a flexible vial having a closed port at one adapted to be pierced by a needle to withdraw the liquid within, and an opposite end that is initially open to receive the liquid. Another vessel includes an adaptor mounted to liquid container with a tubular branch closed by a needle septum and another tubular branch provided with a barbed fitting for engaging a flexible tube that terminates in a needle septum. In another embodiment, the vessel includes an inlet and vent branch at the top of the container and an outlet septum at a bottom opening.