Biotechnological and Biomedical Applications of Magnetically Stabilized and Fluidized Beds - Porous Media: Applications in Biological Systems and Biotechnology - page 456

CONTENTS
12.1 Introduction ................................................................. 456
12.2 Historical Overview of Magnetically Stabilized and Fluidized Beds ....... 458
12.2.1 General .............................................................. 458
12.2.2 Biotechnology and Biomedicine ..................................... 459
12.3 MSBs and MFBs ............................................................ 460
12.3.1 Principles of MSBs and MFBs ...................................... 460
12.3.2 MSBs and MFBs as Porous Media ................................. 463
12.4 General Supporting Theory ................................................. 464
12.4.1 MSBs and MFBs .................................................... 464
12.4.1.1 Magnetic Forces ........................................... 464
12.4.1.2 Van der Waals Forces...................................... 465
12.4.1.3 Electrostatic Forces ........................................ 465
12.4.1.4 Collisional Forces .......................................... 465
12.4.1.5 Force Balances and Parameters Computation ............ 466
12.4.2 Extra Forces or Equations Usually Required When MSFBs Are
Applied in Biotechnology and Medicine ............................ 469
12.5 Main Biotechnological and Biomedical Applications ....................... 471
12.5.1 Particles (Beads) .................................................... 471
12.5.2 Applications ......................................................... 472
12.5.2.1 Enzyme or Cell Immobilization/Bioreactions ............. 472
12.5.2.2 Protein Purification/Adsorption .......................... 473
12.5.2.3 MSFB Chromatography ................................... 474
12.5.2.4 Novel Separations.......................................... 475
12.6 Conclusion and Future Perspectives ........................................ 477
12.7 References ................................................................... 478
12.1 Introduction
The processing of cells, biomedical substances, and/or high-valued biotech-
nological products has always been a major issue in bioengineering and
biomedicine. In fact, from approximately 5% (in the case of wholesale prod-
ucts) up to 90% (in the case of pharmaceuticals) of the production costs are
due to downstream processing (Bohm and Pittermann 2000). Isolation, separa-
tion, and purification of various types of proteins, peptides, and other specific
molecules are required in almost all branches of biosciences and biotechnolo-
gies (Safarik and Safarikova 2004). Therefore, separation technologists are
under constant pressure to develop more ecient separation processes, both
at laboratorial and large scale levels, capable to separate and/or purify the
target biosubstances, even if present at very small concentrations, and also
even when they are in the presence of particulate matter.
The mostly used technologies to achieve the separation and purification of
peptides and proteins are based on chromatographic, electrophoretic, ultrafil-
tration, and precipitation methods. Actually, the most commonly used tech-
nique is the anity chromatography due to its good performance (both