Bioseparation systems applications

The ability to control the interaction between a wide diversity of biomolecules with surfaces can be also exploited as an effective way to develop reagentless, sensitive, reusable, and real-time biosensors [51-56]. Such sophisticated biosensors are expected to impact a wide range of applications, from clinical diagnosis[57] and environmental monitoring [58] to forensic analysis [59]. Another significant potential application of dynamic surfaces is in bioseparation of proteins and other biomolecules for basic life science research, as well as industrial applications [60-63]. With the rapid development of recombinant proteins in the treatment of various human diseases, the dynamic surface-based bioseparation systems could meet the demand for more reliable and efficient protein purification methods [64]. Stimuli-responsive surfaces are also expected to play a crucial role in the search for more controllable and precise drug delivery systems [65]. 

The bioseparation technique which is probably the most readily adapted to modern process control techniques is extraction. Liquid-liquid extraction is a mature unit process with application in industrial-scale protein separation.30 Control techniques used on similar systems in other industrial applications should be readily adaptable to bioprocessing, the primary difficulty being the lack of data on the partitioning and related behavior of the product. 

Albertsson, P.-A. (1995). Aqueous polymer phase systems properties and applications in bioseparation. In S.E. Harding, S.E. Hill, and J.R. MitcheU, (Eds.), Biopolymer Mixtures, Nottingham University Press. Nottingham, UK, pp. 1-12. 

Understanding and mimicking of the cellular transport processes are both challenging and rewarding from scientific and technological point of view. For example in certain inherited diseases (such as cystinuria), specific transport systems are either defective or missing [1]. Cystinuria is a human disease characterized by the absence of a transport system that carries cystine and other amino acids into kidney cells. Kidney cells normally reabsorb these amino acids from the urine and return them to the blood, but a person inflicted with cystinuria develops painful stones from amino acids that accumulate and crystallize in the kidneys. Similarly, there are many technological applications of these transport processes, e.g., bioseparations, bioextractions, and synthetic nano-bioreactors. 

Scaling up of the processes to large surface areas (i.e. to obtain asymmetric membrane systems with several layers) as is necessary for large-scale operations has been successfully demonstrated for micro/ultrafiltration and bioseparation processes, but not for other applications such as gas/vapour separation and membrane reactors, for which only small-scale laboratory equipment is available. 

Most of the research conducted with aqueous two-phase systems has been experimental and empirical few studies of the fundamental thermodynamic mechanisms of phase separation and partitioning have been conducted (5, 23, 24). Furthermore, the systems which have been described use highly purified, expensive polymers, for model laboratory-scale applications. Novel bioseparation research based on aqueous two-phase systems needs to focus more on fundamental aspects needed to design phase diagrams and calculate partition coefficients. This... 

Particularly evident is the lack of systematic reports on polymer-mixed solvents data (VLE or LLE) in the open hterature, especially in form of full-phase equilibrium measurements. Most experimental studies for mixed solvent systans have been reported by Chinese and Japanese investigators - and only a few by other investigators. Data are often reported simply as soluble/nonsoluble or as theta temperatures (critical solution temperature at infinite polymer molecular weight). Several reported polymer-mixed solvent data concern supercritical fluid applications (e.g., polypropylene/pen-tane/C02, and PEG/C02/cosolvent ) and bioseparations, especially for systems related to the partitioning of biomolecules in aqueons two-phase systems, which contain PEG and dextran. A recent review for data on solnbihty of gases in glassy polymers is also available. ... 

Harris DP, Andrews AT, Wright G, et al. The application of aqueous two-phase systems to the purification of pharmaceutical proteins from transgenic sheep milk. Bioseparation, 1997 7(1) 31-37. 

Certain interesting applications for synthetic polymers in the life sciences are unfortunately not treated in this short book. The use of hybrid molecules (bioconjugates) for drug delivery and other purposes is one example, and the use of polymers in bioseparation by aqueous two-phase systems is another. However, the authors nevertheless hope to have given some indication of the importance of polymeric materials for the life sciences and look forward to future results of the continuous research in this area. As an editor, I would like to thank all contributors to this book for their work and their patience with my sometimes sporadic editing efforts. Last but not least, 1 would like to thank Ms. Francoise Wyssbrod, who has read and reread (and sometimes retyped) the chapters making sure that they adhered in every detail to the House Style Manual provided by the publisher. Without her help, this book would not have been possible. 

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