High‐throughput miniaturized bioreactors for cell culture process development: Reproducibility, scalability, and control

Abstract

Decreasing the timeframe for cell culture process development has been a key goal toward accelerating biopharmaceutical development. Advanced Microscale Bioreactors (ambr™) is an automated micro-bioreactor system with miniature single-use bioreactors with a 10-15 mL working volume controlled by an automated workstation. This system was compared to conventional bioreactor systems in terms of its performance for the production of a monoclonal antibody in a recombinant Chinese Hamster Ovary cell line. The miniaturized bioreactor system was found to produce cell culture profiles that matched across scales to 3 L, 15 L, and 200 L stirred tank bioreactors. The processes used in this article involve complex feed formulations, perturbations, and strict process control within the design space, which are in-line with processes used for commercial scale manufacturing of biopharmaceuticals. Changes to important process parameters in ambr™ resulted in predictable cell growth, viability and titer changes, which were in good agreement to data from the conventional larger scale bioreactors. ambr™ was found to successfully reproduce variations in temperature, dissolved oxygen (DO), and pH conditions similar to the larger bioreactor systems. Additionally, the miniature bioreactors were found to react well to perturbations in pH and DO through adjustments to the Proportional and Integral control loop. The data presented here demonstrates the utility of the ambr™ system as a high throughput system for cell culture process development.

Cell Culture Processes for Biopharmaceutical Manufacturing

“…Concern over the lack of control of process parameters during screening led to significant interest in the use of microbioreactors to enable assessment of clones under controlled pH and DO conditions for better screening outcomes 60,61 . Simcell was among the first microbioreactor to be commercially available with culture volumes of less than a millilitre 62 .…”

The therapeutic monoclonal antibody market

“…The demand for monoclonal antibody products has resulted in a significant amount of global manufacturing capacity devoted to their production as well as to significant improvements in methods and approaches to monoclonal antibody manufacturing process design and optimization. [8][9][10][11][12] The forty-seven monoclonal antibody products on the market in the US and Europe as of November 10, 2014 are listed in Table 1. In 2013, eighteen of these monoclonal antibody products (Humira, Remicade, Enbrel, Rituxan, Avastin, Herceptin, Lucentis, Erbitux, Synagis, Eylea, Soliris, Tysabri, Stelara, Xolair, Orencia, Simponi, Actemra, and Xgeva) achieved annual sales of over $1 billion, while six of these products (Humira, Remicade, Enbrel, Rituxan, Avastin, Herceptin) had sales of greater than $6 billion.…”

Scale-down of CHO cell fed-batch cultures

“…Data presented in Chapter 5 and in other studies 34,169,170,[172][173][174]192,193 showed that the current mL-scale systems are promising tools to be integrated into process characterization and design space exploration during upstream process development. Current research is focusing on the further implementation of mL-scale systems into process development and replacing the traditional bench-scale bioreactors with mLscale systems (Figure 1).…”

“…It was shown that the physical environment between the ambr and conventional STRs differs in some aspects including the flow regime, gas superficial velocity, and volumetric power input. Several studies have been performed to compare the culture performance of the ambr system to STRs ranging from 2 L up to 1000 L for CHO cell fed-batch processes [169][170][171][172] . Overall, similar process performances were reported across all scales.…”

“…The mL-scale systems were originally designed for quick screening of clones, media, and culture parameters such as pH and temperature. In recent years, many studies 165,172,190,191 have shown that these mL-scale systems are quite representative for the bioreactors ranging from L-scale to kL-scale.…”