Thermo Fisher Scientific’s DynaDrive Single Use Bioreactor Microcarrier Testing System

Abstract

Goal: Reduce the testing time by 90% for different iterations of the bottom bearing in the DynaDrive Single Use Bioreactor (S.U.B.).

Approach: Use the idea of interchangeable parts to integrate the modified bottom bearings.

Results: Fully interchangeable bottom bearing with the impeller drive train successfully incorporated.

Introduction

The DynaDrive S.U.B. is a bioreactor that consists of an impeller drive train that spans from the bottom bearing to the height of the reactor. This drive train results in excellent mixing. However, when microcarrier beads were used for adherent cultures, a large percentage of the beads were being damaged by the bottom bearing (Figure 1).

Figure 1. DynaDrive S.U.B. bottom bearing

Initially, multiple images were taken to quantify the damaged microcarrier beads (Figure 2).

As different iterations of the bottom bearing were created, they were integrated into the DynaDrive S.U.B. BioProcess Containers. However, the integration and irradiation processes were taking up to 6 months, so the need for a reusable test system arose.

Figure 2. Images of damaged microcarrier beads.

Methods

The initial test systems were 2 gal and 50 gal vessels with the bottom bearing incorporated into the container. However, to accurately reflect the mixing conditions of the DynaDrive S.U.B., we replaced our initial systems with a 50 L plexiglass container repurposed from an existing project.

The most important feature of this system is the incorporation of the bottom bearing. The SolidWorks piece our team designed operates with a leak proof seal that allows for the bearing to be changed out (Figure 3).

Figure 3. SolidWorks pieces that fit around the bottom bearing.

Results

Preliminary results show that our system can hold 50 liters, use the same motor as the DynaDrive S.U.B., and integrate the bottom bearing with minimal leaking (Figure 4).

Figure 4. Updated 50-L test system.

Conclusions

Next step: Though our microcarrier testing system successfully integrates an interchangeable bottom bearing design and the impeller drive train, the system needs to be properly sealed to guarantee the system can support the required test volume.

Testing: The first test we will conduct will be to ensure our system replicates what is seen in the standard 50 L DynaDrive S.U.B. This test will be conducted using the original bottom bearing design and the same testing procedure used in previous tests.

Project overview: These results of the aforementioned test will verify if our test system accurately reflects all conditions observed in the DynaDrive S.U.B. and that the time for each test will be reduced by 90%. If our test system is successful, we can reduce the amount of plastic waste produced in these tests from 180 kg/year to roughly 5 kg/year.

References

• Dynadrive sub brochure thermo fisher scientific. (n.d.). Retrieved March 17, 2023, from https://assets.thermofisher.com/TFS Assets/BPD/brochures/ dynadrive sub br ochure.pdf
• Mock, C.; Honda, J.; Bell, E. Interview with Paula Decaria , 2023.