Cryopreservation Apparatus for Stem Cell Viability
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Solution Overview
Problem
Current cryopreservation methods for hematopoietic and mesenchymal stem/progenitor cells face challenges in maintaining cell viability due to harsh freezing and thawing conditions, inadequate control over cryoprotectant introduction, and lack of sterile and efficient mixing processes, leading to low post-thaw survival rates.
Innovation Solution
A cryopreservation apparatus that includes a workstation with a syringe pump module and a cryoprotectant mixing chamber for precise, temperature-controlled introduction of DMSO, ensuring homogeneous distribution and minimizing exothermic heat release, while maintaining sterility and preventing cell adherence to container surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cryoprotectant is introduced into cell solution during freezing, then cell viability is improved, but exothermic heat release causes temperature increase that reduces cell viability
Solution Approach 1:
The system pre-cools the cell solution to a target temperature (e.g., -80°C) before introducing the cryoprotectant. This preliminary cooling ensures that when the exothermic reaction occurs during cryoprotectant addition, the temperature remains controlled and does not exceed the maximum threshold that would damage the cells.
Solution Approach 2:
The system continuously monitors the temperature of the cell solution during cryoprotectant introduction and uses this feedback to control the rate of cryoprotectant addition. When the temperature approaches the maximum threshold, the system automatically reduces or pauses the cryoprotectant flow rate to prevent overheating, thereby maintaining cell viability.
2Productivity
If cryoprotectant is introduced rapidly into cell solution, then mixing efficiency is improved, but homogeneous distribution is reduced leading to cell damage
Solution Approach 1:
The system dynamically adjusts the cryoprotectant addition rate based on real-time temperature feedback. The addition rate is not fixed but varies during the process to optimize both mixing efficiency and homogeneity, preventing localized high concentrations that could damage cells while maintaining overall productivity.
Solution Approach 2:
The system maintains continuous gentle agitation or mixing throughout the cryoprotectant introduction process to ensure homogeneous distribution. This continuous mixing action prevents stratification and ensures that the cryoprotectant is evenly distributed throughout the cell solution, eliminating pockets of high concentration that would cause cell damage.
3Volume of stationary object
If cells are stored in conventional containers, then storage capacity is improved, but cell adherence to container surfaces reduces post-thaw survival rates
Solution Approach 1:
The system uses cryobags with special internal surface coatings or materials that minimize cell adherence. These flexible containers are designed to prevent cells from sticking to the walls during freezing and storage, ensuring that cells remain suspended in the cryoprotectant solution and maintain high viability after thawing, while still providing adequate storage capacity.
4Device complexity
If manual mixing methods are used for cryoprotectant and cell solution, then device complexity is reduced, but sterility is compromised and mixing efficiency is low
Solution Approach 1:
The system replaces manual mechanical mixing with an automated controlled mixing mechanism that maintains sterility through sealed, closed-system operation. The automated system provides consistent, reproducible mixing while preventing contamination, and the complexity is managed through integration and user-friendly controls that simplify the overall operation.
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 apparatus enhances cell viability by optimizing the cryoprotective process, ensuring sterile conditions, and facilitating long-term storage with improved post-thaw survival rates through controlled temperature regulation and homogeneous mixing.
Implementation Method 1
minimizing exothermic heat release
Implementation Method 2
controlled temperature regulation
Implementation Method 3
ensuring homogeneous distribution
Implementation Method 4
harsh freezing and thawing conditions
Data Source
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AI summary
An apparatus and related method for the optimization of the cryopreservation of various types of cells, including but not limited to hematopoietic and mesenchymal stem and progenitor cells, and endothelial progenitor cells found in normal blood, placental/cord blood, bone marrow or the stromal vascular fraction of adipose tissue. The apparatus for cryopreservation of biological materials in a sterile environment comprises a cryopreservation workstation, a rigid disposable cartridge, and a freezing bag assembly. The apparatus and related method provide for the precise, temperature controlled, homogenously distributed introduction of a cryoprotectant containing dimethyl sulfoxide (DMSO) into a solution containing nucleated cells in a manner that provides a safe increase in osmotic pressure and a controlled release of exothermic heat within the cells as the DMSO penetrates the cell membrane and replaces water molecules prior to the freezing of the cells.