Design and development of a new ambr250® bioreactor vessel for improved cell and gene therapy applications

Abstract

The emergence of cell and gene therapies has generated significant interest in their clinical and commercial potential. However, these therapies are prohibitively expensive to manufacture and can require extensive time for development due to our limited process knowledge and understanding. The automated ambr250® stirred-tank bioreactor platform provides an effective platform for high-throughput process development. However, the original dual pitched-blade 20 mm impeller and baffles proved sub-optimal for cell therapy candidates that require suspension of microcarriers (e.g. for the culture of adherent human mesenchymal stem cells) or other particles such as activating Dynabeads® (e.g. for the culture of human T-cells). We demonstrate the development of a new ambr250® stirred-tank bioreactor vessel which has been designed specifically to improve the suspension of microcarriers/beads and thereby improve the culture of such cellular systems. The new design is unbaffled and has a single, larger elephant ear impeller. We undertook a range of engineering and physical characterizations to determine which vessel and impeller configuration would be most suitable for suspension based on the minimum agitation speed (NJS) and associated specific power input (P/V)JS. A vessel (diameter, T, = 60 mm) without baffles and incorporating a single elephant ear impeller (diameter 30 mm and 45° pitch-blade angle) was selected as it had the lowest (P/V)JS and therefore potentially, based on Kolmogorov concepts, was the most flexible system. These experimentally-based conclusions were further validated firstly with computational fluid dynamic (CFD) simulations and secondly experimental studies involving the culture of both T-cells with Dynabeads® and hMSCs on microcarriers. The new ambr250® stirred-tank bioreactor successfully supported the culture of both cell types, with the T-cell culture demonstrating significant improvements compared to the original ambr250® and the hMSC-microcarrier culture gave significantly higher yields compared with spinner flask cultures. The new ambr250® bioreactor vessel design is an effective process development tool for cell and gene therapy candidates and potentially for autologous manufacture too.

CFD‐Aided and Experimental Characterization of Bioreactors under Low Power Input Conditions

“…Power curves for downflow operation and a working volume of 250 mL, based on power inputs by CFD simulation, original‐scale experiment, scale‐up experiment, and Rotondi et al 5.…”

Application of bioreactor technology for cell culture-based viral vaccine production: Present status and future prospects

“…The Ambr250 bioreactor developed by Sartorius can run up to 48 parallel bioreactors with a culture volume of 100–250 ml. It has a small-scale multi-module system, which is a defect of adherent bioreactors ( Rotondi et al, 2021 ). The advantage of suspension culture is to achieve large-scale production with more advanced automation technology.…”

Application of Ambr15 system for simulation of entire SARS‐CoV‐2 vaccine production process involving macrocarriers

“…As a result, new reactors were later designed and developed for improved cell and gene therapy applications. 14 …”

“…However, the system proved to be sub‐optimal for cell therapy candidates that require suspension of microcarriers or other particles such as Dynabeads. As a result, new reactors were later designed and developed for improved cell and gene therapy applications 14 …”

“…As a result, new reactors were later designed and developed for improved cell and gene therapy applications. 14 Thus far, all applications of the ambr15 system have focused on suspension cells or micro carriers cultured cells, but never macrocarriers. The aim of the present work was to demonstrate that the Ambr15 system is a suitable scale-down model for production processes involving macrocarriers.…”