using cryogels. There are many examples of such separations and, taking into
consideration the means to improve capacity while still keeping the tolerance to
operate at high flow-rates, it is realistic to think that sometime in the future there
will be technology that makes it possible to use cryogels as viable alternatives to
conventional chromatographic media for separation of proteins.
Table 3 lists some of the published examples where cryogels have been used for
separation of proteins and a few other biomolecules. The list is not complete, but it
covers different types of separations.
Cryogels are mainly used for separation of proteins on the basis of ion exchange,
hydrophobic interactions, and affinity. The large pores and the relatively few mesoor nanopores make cryogels less suitable for gel permeation chromatography.
As stated above, it is easy to scale-up column chromatography using cryogels.
Normally, there are no problems with pressure drop over the column unless very
viscose media are used. Cell homogenates, fermentation broth, and plasma are
examples of media that have been processed successfully.
9.1 High Through-Put Screening
The elasticity of cryogels has been mentioned earlier in this paper. Due to its
elasticity, it is possible to squeeze a cryogel into a somewhat smaller column
such that the gel will tighten towards the walls of the column. This property was
utilized when placing small cryogel monoliths into microtiter plates with no
bottom. The gels held the buffer due to capillary forces. When a volume of liquid
was added, an equal volume was displaced. This leads to the use of cryogels in
microtiter format for screening of cell homogenates for certain target proteins [94].
The same technology is very suitable for evaluating the conditions for binding of
cells to adsorbents, and the elution conditions. This was demonstrated by Dainiak
et al. [95, 96].
9.2 Environmental Pollutants
Cryogels have been used in environmental technology applications, both as matrices for immobilizing cells and/or enzymes for treatment of pollutants, and as
adsorbents for enriching pollutants. Some of the applications of microbial cells
and enzymes for remediation are listed in Table 1. The advantage of using cryogels
in treatment of pollutants is the high porosity that facilitates exchange of media
components. In some cases, improved stability of the immobilized cells has also
been reported. Furthermore, when cells are entrapped in cryogels and start to grow,
some cells are released to the surrounding medium. The cryogel then functions as a
seeding unit from where cells are continuously released.
Cryogels for Biotechnological Applications
267
consideration the means to improve capacity while still keeping the tolerance to
operate at high flow-rates, it is realistic to think that sometime in the future there
will be technology that makes it possible to use cryogels as viable alternatives to
conventional chromatographic media for separation of proteins.
Table 3 lists some of the published examples where cryogels have been used for
separation of proteins and a few other biomolecules. The list is not complete, but it
covers different types of separations.
Cryogels are mainly used for separation of proteins on the basis of ion exchange,
hydrophobic interactions, and affinity. The large pores and the relatively few mesoor nanopores make cryogels less suitable for gel permeation chromatography.
As stated above, it is easy to scale-up column chromatography using cryogels.
Normally, there are no problems with pressure drop over the column unless very
viscose media are used. Cell homogenates, fermentation broth, and plasma are
examples of media that have been processed successfully.
9.1 High Through-Put Screening
The elasticity of cryogels has been mentioned earlier in this paper. Due to its
elasticity, it is possible to squeeze a cryogel into a somewhat smaller column
such that the gel will tighten towards the walls of the column. This property was
utilized when placing small cryogel monoliths into microtiter plates with no
bottom. The gels held the buffer due to capillary forces. When a volume of liquid
was added, an equal volume was displaced. This leads to the use of cryogels in
microtiter format for screening of cell homogenates for certain target proteins [94].
The same technology is very suitable for evaluating the conditions for binding of
cells to adsorbents, and the elution conditions. This was demonstrated by Dainiak
et al. [95, 96].
9.2 Environmental Pollutants
Cryogels have been used in environmental technology applications, both as matrices for immobilizing cells and/or enzymes for treatment of pollutants, and as
adsorbents for enriching pollutants. Some of the applications of microbial cells
and enzymes for remediation are listed in Table 1. The advantage of using cryogels
in treatment of pollutants is the high porosity that facilitates exchange of media
components. In some cases, improved stability of the immobilized cells has also
been reported. Furthermore, when cells are entrapped in cryogels and start to grow,
some cells are released to the surrounding medium. The cryogel then functions as a
seeding unit from where cells are continuously released.
Cryogels for Biotechnological Applications
267