Bioreactor hollow-fiber

Keywords. Bioartificial liver, cell culture, hollow fiber bioreactor, flat membrane bioreactor, spheroids... 

Commercial scale cultivation of mammalian cells is accompHshed using different technologies roller bottles, microcarriers, suspension (batch, fed-batch or perfusion mode) and hollow fiber bioreactors (Table 2). However, especially for products needed in large amounts, suspension cultivation seems to be the most effective system [4, 5]. Suspension-based systems are characterized by a homogeneous concentration of cells, nutrients, metabolites and product, thereby facilitating scale-up [6] and enabling an accurate monitoring and control of the culture [7]. 

A Simple Hollow-Fiber Bioreactor for the In-House Production of Monoclonal Antibodies... 

The hollow-fiber bioreactor is a stenle renal dialysis cartridge, and may be obtained from distributors or hospital supplies departments There are various sizes, but we find the most useful to have an internal volume of 50 or 150 mL. Not all dialysis cartridges are suitable for growing cells The fibers should be of regenerated cellulose, about 10,000 in number, and approx 200-jum diameter and 8-10-pm wall thickness. 

Stirred-tank bioreactors Air-lift bioreactors Wave bioreactors Microcarrier-based systems Packed-bed bioreactors Fluidized-bed bioreactors Hollow-fiber bioreactors Bioreactors providing surfaces for attached cell growth (roller bottles, CellCube , Cell Factory)... 

The core part of a hollow-fiber bioreactor is the hollow-fiber membrane module, also simply known as the cartridge. It consists of a plastic cylinder containing hundreds of semi-permeable capillary tubes, known as hollow fibers. The cells are inoculated in the extracapillary space (ECS). The cells colonize the external surface of the fibers and grow in this region. The culture medium is pumped through the lumen of the fibers, known as the intracapillary space (ICS), as shown in Figure 9.11. 

The fibers can be made of different materials, such as cellulose esters and polysulfone. The total surface area of a hollow-fiber bioreactor varies in the range of 0.5-3.5 m2. The pore size of fibers commonly employed in animal cell culture corresponds to a molar mass cut-off between 10 and 100 kDa. 

Schematic representation of a hollow-fiber bioreactor fitted with an extracapillary recirculation...

Oxygen transfer is an important issue in the operation of a hollow-fiber bioreactor. In these bioreactors, a membrane-based aeration system is usually included in the intracapillary recirculation loop to enrich the recirculating culture medium with oxygen. However, due to the low solubility of oxygen in aqueous solutions, the recirculation speed through the fibers must be very high. 

Parameters that are traditionally used to evaluate the metabolic activity of the cell population inside a hollow-fiber bioreactor include glucose consumption rate (rQLc) and oxygen consumption rate (rcu)- However, these parameters are highly dependent on variations in nutrient feed and metabolic products removal (Gramer et al., 1999). The use of a strategy to overfeed the ICS with nutrients results in a rapid increase in tglc- On the other hand, an increase in product titer and an improved metabolic... 

Cultivation of NSO cells in an AcuSyst Jr hollow-fiber bioreactor comparison of two different operation strategies, designated basic and optimized strategy (Rodriguez et al., 2005). 

Gramer MJ, Poeschl DM, Conroy MJ, Hammer BE (1999), Effect of harvesting protocol on performance of a hollow fiber bioreactor, Biotechnol. Bioeng. 65 334-340. 

Products with less demand, such as those used in diagnosis, are developed in small-scale systems such as T-flasks, rollers, and hollow-fiber bioreactors (Kretzmer, 2002). The reduced size of these production systems makes it possible to operate various units in parallel to obtain different products. A small increase in scale can be reached by the multiplication of units. 

Hollow-fiber bioreactors constitute an optimized production system where it is possible to achieve higher cell concentrations (107 to 108 cells/ ml), and the product concentration can reach a level of 0.7-2.3 g/L, which is similar to what can be obtained with ascitic fluid (Hendriksen and Leeuw, 1998). This system can operate for over 3 months without affecting cell viability, but presents problems with mass transport, and the formation of nutrient gradients, which require specific solutions (Kretzmer, 2002). 

Figure 1. 3,P NMR spectrum of Chinese hamster ovary cells (CHO K1) growing in a hollow-fiber bioreactor (Callies, Jackson, and Brindle, unpublished observations). The assignments are PME, phosphomonoesters inorganic phosphate (predominantly extracellular) PDE, phosphodiesters (predominantly glycerophosphocholine) PCr, phosphocreatine ATP, adenosine-triphosphate (y-, a-, and (1-phosphates) NAD, nicotinamide adenine dinucleotide DPDE, diphosphodiesters.

Figure 2. H NMR spectra of mammalian cells growing in a hollow-fiber bioreactor without (left) and with (right) suppression of the water signal (4.7 ppm) using the CHESS pulse sequence (Haase et al., 1985). The spectra were acquired using the STEAM sequence with two, three-pulse CHESS cycles (Callies, Jackson, and Brindle, unpublished observations) (Moonen and Van Zijl, 1990).

Balcao, V.M., Malcata, F.X. 1998a. On the performance of a hollow-fiber bioreactor for acidolysis catalyzed by immobilized lipase. Biotechnol. Bioeng. 60, 114-123. 

Gloeckner, H. Lemke, H.-D. New miniaturized hollow fiber bioreactor for in vivo like cell culture, cell expansion, and production of cell derived products. Biotechnol. Prog. 2001, 17, 828-831. 

Tharakan, J.P. Chau, P.C. A radial flow hollow fiber bioreactor for the large-scale culture of mammalian cells. Biotechnol. Bioeng. 1986, 28, 329-342. 

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