Stirred Tank Bioreactor Cell Aggregate Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for large-scale pluripotent stem cell culture face challenges such as inefficient seeding, cell release from carriers, physical separation issues, and sterility concerns in perfusion/suspension cultures, particularly in maintaining cells within bioreactors without human intervention and minimizing cross-contamination.
Innovation Solution
The method involves a closed system using a stirred tank bioreactor with automated perfusion and gravity settling of cell aggregates, eliminating the need for filtration and centrifugation, and employing a slicer for enzyme-free dissociation of aggregates during passaging, maintaining sterility and reducing human intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If filtration is used to retain cells in perfusion culture, then cell retention is improved, but filter clogging occurs over time
Solution Approach 1:
The patent removes the filter component from the system entirely, replacing it with a filterless perfusion approach where cells are retained through controlled sedimentation and aggregation rather than physical filtration, thereby eliminating clogging issues
Solution Approach 2:
The patent replaces the mechanical filtration system with a gravity-based sedimentation system, where cell aggregates naturally settle at the bottom of the bioreactor and are periodically harvested, eliminating the need for filters that clog over time
2Productivity
If centrifugation is used to separate cells, then cell separation efficiency is improved, but sterility is compromised in closed systems
Solution Approach 1:
The patent replaces centrifugal separation with gravity-based sedimentation, allowing cell aggregates to settle naturally in the bioreactor without requiring external centrifugation equipment that would breach the closed sterile system
Solution Approach 2:
The patent utilizes the natural gravity field to perform cell separation, allowing the system to self-separate cell aggregates from culture medium without requiring external mechanical intervention that would compromise sterility
3Productivity
If microcarriers are used for cell culture, then large-scale expansion is improved, but cell seeding efficiency and release efficiency deteriorate
Solution Approach 1:
The patent removes microcarriers from the culture system, transitioning to a free-floating aggregate culture model where cells grow as suspended clusters without requiring carrier surfaces, thereby eliminating seeding and release inefficiencies
Solution Approach 2:
Instead of attaching cells to carriers (traditional approach), the patent inverts the approach by allowing cells to grow as free-floating aggregates in suspension, reversing the cell-carrier interaction paradigm
4Adaptability or versatility
If manual intervention is used in cell culture operations, then process flexibility is improved, but cross-contamination risk increases
Solution Approach 1:
The patent implements automated systems for perfusion, feeding, and harvest operations that perform culture maintenance tasks independently, minimizing human contact with the sterile cell culture environment and reducing cross-contamination risk
Solution Approach 2:
The patent introduces automated robotic systems and closed-interface equipment as intermediaries between human operators and the cell culture system, allowing process control without direct human intervention in the sterile environment
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
This approach enables efficient expansion and passaging of pluripotent stem cells with high viability and reduced genetic drift, maintaining sterility and minimizing contamination, while allowing for large-scale industrial-scale operations.
Implementation Method 1
gravity settling of cell aggregates during the perfusion
Implementation Method 2
stirred tank bioreactor
Data Source
AI summary
Provided herein are novel methods for expansion and passaging of cell aggregates comprising stem cells and/or differentiated cells and comprising the use of closed systems in stirred tank bioreactors. The methods of the invention permit closed system serial passage expansion of pluripotent stem cells and/or progeny thereof with associated pluripotency markers and differentiation potential.