Scalable inoculation strategies for microcarrier‐based animal cell bioprocesses

Abstract

Scalability is a major demand for high-yield, stable bioprocess systems in animal cell culture-based biopharmaceutical production. Increased yields can be achieved through high-density cell culture, such as in the combination of microcarrier and fluidized bed bioreactor technology. To minimize inocula volume in industrial applications of fluidized bed fermentation systems, it is crucial to increase the bed volume in the reactor during the fermentation process. We tested scale-up strategy for the production of recombinant human arylsulfatase B (ASB) enzyme used in enzyme replacement therapy in patients afflicted with mucopolysaccharidosis type VI (MPS VI). This enzyme was derived from Chinese hamster ovary (CHO) cells cultivated as adherent cell culture on Cytoline macroporous microcarriers (Amersham Biosciences, Uppsala, Sweden) using a Cytopilot Mini fluidized bed bioreactor (FBR; Amersham Biosciences, Vogelbusch, Austria). Both 1:2 expansion (herein referred to as the addition of fresh, not-yet-colonized microcarriers) and 1:6 expansion of the carrier bed were performed successfully; the cells restarted to proliferate for colonizing these newly added carriers; and the stability of the culture was not negatively affected.

Polyethylene glycol‐based cationically charged hydrogel beads as a new microcarrier for cell culture

“…The macroporous gelatin microcarriers were shown to be effective for nasal chondrocyte expansion 22. Cytoline macroporous microcarriers were another class of materials tried in the cultivation of CHO cells by different researchers 23, 24…”

Cost‐effective engineering of a small‐scale bioreactor

“…It is a readily available technology and scales up from T-flasks without difficulty. We have used this reactor on the 1 L scale to produce recombinant perilipin for further biophysical characterization (Londos et al, 2005;Tansey et al, 2004), but results in the literature indicate that it may be scalable (Dürrschmid et al, 2003;Griffiths, 2001). This system attains cell densities as high as those reported in the literature (10 7 cells/mL) at significant cost savings (Hu and Aunins, 1997).…”

Application of Taguchi’s method in the optimization of bridging efficiency between confluent and fresh microcarriers in bead-to-bead transfer of Vero cells

“…Generally, the transfer of cells can be achieved by detachment of cells from confluent microcarriers and reattachment to freshly prepared bare ones (Cong et al 2001;Kong et al 1998) or by formation of cellular bridges between confluent and fresh microcarriers (Cherry and Papoutsakis 1988;Dürrschmid et al 2003). Wang and Fan (1999) found that the bead-to-bead transfer of Vero cells mainly followed the latter route, and the direct contact obtained by intermittent stirring could promote the formation of cellular bridges.…”