Stirring Device for Uniform Laminar Flow in Cell Culture

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Solution Overview

Problem

Current cell culture methods face challenges in maintaining low shear stress and preventing stagnation in liquid flow, leading to non-uniform embryoid body formation and inefficient differentiation of pluripotent stem cells, particularly due to issues with stirring devices and sensor placement.

Innovation Solution

A cell culture apparatus with a cylindrical vessel, a conical supporting column, and a rotatable stirring device with a magnetic drive system that creates a uniform laminar flow, preventing cell aggregate precipitation and allowing for efficient temperature measurement without interfering with stirring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a stirring impeller with reduced blade area or reduced tip speed is used to achieve low shear stress, then shear stress on cells is reduced, but liquid flow becomes non-uniform causing embryoid bodies to aggregate and precipitate

Engineering Contradiction:
Improveshear stressVSAvoiduniformity of liquid flow
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The stirring device is divided into multiple blades (at least two blades) attached to a rotating member, with each blade contributing to creating both low shear stress and uniform liquid flow. The segmented blade structure allows distribution of stirring force throughout the culture medium.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blades are designed with specific local characteristics including inclination angles (5-45 degrees relative to the rotating member's rotation direction), width-to-length ratios (1:2 to 1:10), and positioning at specific radii (0.3-0.7 times the culture vessel radius) to optimize both shear stress reduction and flow uniformity in different regions of the culture vessel.

Inventive Principle:
Principle #3Local quality

2Productivity

If conventional stirring devices are used to create liquid flow, then cell mixing is achieved, but stagnation occurs in certain areas leading to non-uniform embryoid body formation

Engineering Contradiction:
Improvecell mixing efficiencyVSAvoiduniformity of embryoid body formation
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The stirring device creates dynamic liquid flow patterns through rotating blades that continuously change the flow direction and velocity distribution, preventing stagnation in any particular area and ensuring uniform mixing throughout the culture medium.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The inclined blades create three-dimensional flow patterns that extend vertically and radially through the culture medium, eliminating two-dimensional stagnation zones and ensuring comprehensive mixing and uniform embryoid body formation throughout the entire culture volume.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If temperature sensors are inserted into the culture vessel to measure temperature, then temperature monitoring is achieved, but the sensors interfere with uniform liquid flow and stirring

Engineering Contradiction:
Improvetemperature measurementVSAvoiduniformity of liquid flow
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

A non-interfering temperature measurement approach is implemented where temperature is monitored without inserting physical sensors into the culture medium that would disrupt flow patterns. The measurement system acts as an intermediary that obtains temperature data while maintaining the integrity of the liquid flow and stirring uniformity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables reproducible formation of uniform embryoid bodies and efficient differentiation of pluripotent stem cells by minimizing shear stress and stagnation, while allowing accurate temperature measurement, thereby improving cell culture conditions.

Implementation Method 1

a stirring device (30, 130, 230) including an attaching portion (32, 132) that is attached to an upper portion (24, 124) of the supporting column so as to be rotatable relative to the supporting column and a stirring blade (34, 134) whose upper portion is fixed to the attaching portion so as to rotate around the supporting column as a center of rotation

Methodology Applied
Scientific EffectMagnetic drive: Magnetic Field

Implementation Method 2

creates a uniform laminar flow, preventing cell aggregate precipitation

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Implementation Method 3

particularly human-derived ES/iPS cells are very sensitive to shear stress, and therefore stirred-suspension culture requires a stirring device that can achieve a low shear stress

Methodology Applied
Scientific EffectShear stress: Shear Stress

Implementation Method 4

allowing for efficient temperature measurement without interfering with stirring

Methodology Applied
Scientific EffectTemperature measurement: Thermocouple

Data Source

PatentEP2860240B1Cell culture apparatus and cell culture method using the same
Publication Date: 2019.07.31 ABLE CO LTD
  • EP2860240B1 patent drawingFigure 1
  • EP2860240B1 patent drawingFigure 2
  • EP2860240B1 patent drawingFigure 3

AI summary

Disclosed herein is a cell culture apparatus that can achieve appropriate culture conditions. The cell culture apparatus (1) includes: a cylindrical culture vessel (10) that holds a culture liquid containing cells; a supporting column (20) that stands upright in a center of an inner surface of a bottom (12) in the culture vessel; and a stirring device (30) that includes an attaching portion (32) that is attached to an upper portion of the supporting column so as to be rotatable relative to the supporting column and a stirring blade (34) whose upper portion is fixed to the attaching portion so as to rotate around the supporting column.