Macrophage Cryopreservation Acclimatization Protocol
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Solution Overview
Problem
Human macrophages are difficult to cryopreserve due to high sensitivity to cryo-injury, leading to low viability post-thaw, which is not suitable for clinical use, and existing methods require non-GMP compliant agents or expensive liquid nitrogen storage.
Innovation Solution
A method involving acclimatization of macrophages to temperature changes by maintaining them at 2-12°C for 30 minutes before steady cooling or warming at 1-5°C per minute during cryopreservation and thawing, using GMP-compliant animal component-free media, to enhance viability and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard cryopreservation methods are used on macrophages, then cells can be frozen and stored, but macrophage viability post-thaw is low due to high sensitivity to cryo-injury
Solution Approach 1:
The patent applies preliminary action by pre-acclimatizing macrophages to temperature changes before freezing. The method involves a stepwise cooling process where cells are first cooled to 4°C and held for 30 minutes, then cooled at a controlled rate of 1-5°C per minute to -80°C. This gradual temperature adaptation prepares the cells for cryopreservation, reducing thermal shock and improving post-thaw viability to over 70%.
Solution Approach 2:
The patent employs parameter changes by optimizing multiple variables including cooling rate (1-5°C per minute), pre-cooling temperature (4°C), holding time (30 minutes), and cryoprotectant concentration (10% DMSO). These parameter adjustments create optimal conditions that minimize cryo-injury while maintaining cell viability above 70% after thawing.
2Reliability
If GMP-compliant protocols are used to ensure safety for clinical therapy, then animal component-free media must be used, but this limits the availability of cryoprotectant agents that increase post-freeze survival
Solution Approach 1:
The patent uses DMSO (dimethyl sulfoxide) as a synthetic, non-animal derived cryoprotectant that is GMP-compliant. While DMSO requires precise control and has a narrow margin for error (making it 'short-living' in terms of protocol flexibility), it provides effective cryoprotection without animal components, achieving over 70% viability while meeting GMP requirements for clinical therapy.
Solution Approach 2:
The patent optimizes the concentration of DMSO to exactly 10% in the cryopreservation medium. This precise parameter control maximizes the effectiveness of this limited GMP-compliant cryoprotectant option, achieving superior viability results while maintaining safety standards for clinical use.
3Duration of action of stationary object
If liquid nitrogen storage is used to maintain cryopreserved macrophages, then cells can be stored long-term, but storage becomes expensive and impractical in many treatment settings
Solution Approach 1:
The patent enables storage at -80°C instead of requiring liquid nitrogen temperatures (-196°C). By optimizing the freezing protocol with controlled cooling rates and pre-acclimatization steps, the method achieves over 70% post-thaw viability at the more accessible -80°C temperature, making long-term storage practical and cost-effective without liquid nitrogen.
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 method achieves macrophage viability of over 70% post-thaw, allowing for safe and efficient clinical use without specialist equipment, and maintains key physiological traits like phagocytic ability.
Implementation Method 1
cooling the medium containing macrophages to a temperature of 2-12°C and maintaining the cooled medium at a temperature of 2-12°C for a period of at least 30 minutes
Implementation Method 2
freezing the medium containing macrophages at a cooling rate of 1-5°C per minute
Implementation Method 3
warming the cryopreserved macrophages to a temperature of 2-12°C and maintaining the macrophages at a temperature of 2-12°C for a period of at least 30 minutes
Implementation Method 4
warming the macrophages at a warming rate of 1-5°C per minute to a temperature of 35-37°C
Data Source
AI summary
The present invention relates to a method of improving the viability of macrophages subjected to cryopreservation, particularly for macrophages which are to be used in therapy, wherein the method comprises a step of maintaining the macrophages at a temperature of 2-12° C. for at least 30 minutes during either freezing or thawing procedures. Following the holding step during cooling, a cooling rate of 1 to 5° C. is used until the macrophages in a medium are frozen. For thawing the macrophages, a warming rate of 1 to 5° C. per minute is used until a temperature of 35-37° C. is reached. The present invention further relates to the cryopreserved macrophages, and the thawed macrophages produced by such methods. The technique may provide macrophages that are GMP-compliant and have a viability of at least 60%.