Multiphase Bioreactor Design

Table 15.4 Shear sensitivity of different cells under

different conditions. Presented is the lowest shear

stress used in the reference and the exposure time

required to cause about 10% loss in viable cells. For

turbulent flows the average wall shear stress is

given

Cell Flow
type

Shear stress

N.m−^2

Exposure

time

Medium Ref.

Hybridoma Turbulent 5 1 h 15% FCS Abu-Reesh 1989

Hybridoma Laminar 20 1 h 15% FCS +dextran Abu-Reesh 1989

Hybridoma Laminar 86 10m Augenstein 1971

Hybridoma Laminar 200 10s 5% FCS+25%
dextran

Born 1992

Blood cells Laminar 10–20 10m 10% FCS Chittur 1988

Tn-5, Sf-
21

Laminar 7.3 20s 10% FCS Goldblum 1990

Myeloma Laminar 200 0.002s 10% FCS McQueen 1989

Myeloma Turbulent 180 0.01 s 10% FCS McQueen 1989

Hybridoma Laminar 5 10m 1% FCS Petersen 1989

Hybridoma Laminar 8 15 m 9% FBS Ramirez 1990

Hybridoma Laminar 15 3 m 10% FCS Schurch 1988

Kidney Laminar 2.6 1 h 10% FCS Stathopoulos
1985

Sf 21 Laminar 55 1 h 10% FBS+ 0.1
%MC

Tramper 1986

Hybridoma Turbulent 200 0.002s 5% FCS Zhang 1993

found damaging shear stresses of 5 N.m−^2 for exposure times of 10 minutes. No short-
term effect on shear sensitivity was observed for serum, Pluronic F68 and PEG, whereas
long-term exposure to these compounds before shearing resulted in a decrease in shear
sensitivity for serum only. Goldblum et al. (1990) studied the effect of Pluronic F68 on
insect cells. They found that Pluronic F68 adsorbs to cell membranes and protect cells
from shear. Al-Rubeai et al. (1995) and Murhammer and Goochee (1990a, 1990b) also
suggested that Pluronic adsorbs to cell membranes. The latter authors showed that block-
copolymers like Pluronics and reverse Pluronics may, depending on their structure either
lyse cells, inhibit growth, or have no influence on cell growth and offer protection.
Adsorption of Pluronics to the cell membrane is in accordance with studies of Ramirez
and Mutharasan (1990, 1992). They showed that Pluronic as well as cholesterol, serum
and a decrease of temperature reduce the plasma-membrane fluidity (PMF) and offer

Multiphase bioreactor design 462