(see Sect. 10 for more details). The dimensions of these housings were 9 mm in
diameter and 7 mm long. By packing such particles into a column, seeding with
hybridoma cells, and feeding medium continuously, it was possible to establish a
continuous production of monoclonal antibodies. Crucial factors to keep under
control are enrichment of ammonia and/or lactate in the medium. The cells are
sensitive to increased concentrations of these metabolites. Therefore, it was also
evaluated whether one could replace glutamine (a common component of cell
culture media) with α-ketoglutarate, which does not have any nitrogen atoms but
can be converted into glutamic acid via one enzymatic step, thereby capturing one
ammonium ion; later it can be converted into glutamine by taking up one more
Filter
Benzamidine
Sepharose
column
Recycling of
media
HT1080 cell culture in HFR
Bound
urokinase eluted
with 0.05 M
Glycine.HCl,
pH 3.0
Pure
urokinase
preparation
ECS media
reservoir
ICS media
reservoir
Fig. 4 In situ recovery of urokinase from HT1080 cells growing in a hollow fiber reactor (HFR).
Benzamidine Sepharose column is used to capture urokinase from the media circulating through
the extracapillary space (ECS). A separate media reservoir is used to circulate media through the
intracapillary space (ICS)
Fig. 3 SEM of cryogel prepared by crosslinking bovine blood diluted with phosphate-buffered
saline, shown at low (left) and high (right) magnification. The pores are replicas of the ice crystals,
and the individual blood cells are clearly seen in the walls. (From [49] with permission)
254
B. Mattiasson
diameter and 7 mm long. By packing such particles into a column, seeding with
hybridoma cells, and feeding medium continuously, it was possible to establish a
continuous production of monoclonal antibodies. Crucial factors to keep under
control are enrichment of ammonia and/or lactate in the medium. The cells are
sensitive to increased concentrations of these metabolites. Therefore, it was also
evaluated whether one could replace glutamine (a common component of cell
culture media) with α-ketoglutarate, which does not have any nitrogen atoms but
can be converted into glutamic acid via one enzymatic step, thereby capturing one
ammonium ion; later it can be converted into glutamine by taking up one more
Filter
Benzamidine
Sepharose
column
Recycling of
media
HT1080 cell culture in HFR
Bound
urokinase eluted
with 0.05 M
Glycine.HCl,
pH 3.0
Pure
urokinase
preparation
ECS media
reservoir
ICS media
reservoir
Fig. 4 In situ recovery of urokinase from HT1080 cells growing in a hollow fiber reactor (HFR).
Benzamidine Sepharose column is used to capture urokinase from the media circulating through
the extracapillary space (ECS). A separate media reservoir is used to circulate media through the
intracapillary space (ICS)
Fig. 3 SEM of cryogel prepared by crosslinking bovine blood diluted with phosphate-buffered
saline, shown at low (left) and high (right) magnification. The pores are replicas of the ice crystals,
and the individual blood cells are clearly seen in the walls. (From [49] with permission)
254
B. Mattiasson