Magnetic beads for bioseparation processes synthesis and application properties [Elektronische Ressource] / Birgit Hickstein

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Informations

• Publié par: technische_universitat_clausthal
• Publié le: 01 janvier 2010
• Nombre de lectures: 82
• Langue: English
• Poids de l'ouvrage: 12 Mo

Extrait

Magnetic beads for bioseparation processes
- Synthesis and application properties



Doctoral Thesis
(Dissertation)

to be awarded the degree of
Doctor in Chemical Engineering (Dr.-Ing.)


submitted by
Dipl. Ing. (FH) Birgit Hickstein
from Oldenburg


approved by the Faculty of Mathematics/Computer Science and
Mechanical Engineering, Clausthal University of Technology,




Date of oral examination
nd22 October 2009




































Chairperson of the Board of Examiners: Prof. Dr.-Ing. Norbert Müller

Chief Reviewer: Prof. Dr.-Ing. Urs Alexander Peuker
Reviewer: Prof. Dr.-Ing. Clemens Posten, Prof. Dr.-Ing. Alfred Weber
Preface
Preface

This dissertation is the outcome of my work done for the Ph.D. degree during my
time as scientific co-worker at the Institute of Chemical Process Engineering at the
Clausthal University of Technology Clausthal-Zellerfeld, Germany. The project was
financed by “Deutsche Forschungsgemeinschaft”.
Supervision was done by Professor Dr.-Ing. Urs Alexander Peuker, to whom I have
to express my special thanks for providing me with such a great opportunity. All the
time, he was present for fruitful discussions and he always supported me in focussing
on my own interests. With his supervision he contributed a lot to the development
and success of the project as well as to my personal development as I gained a lot of
knowledge from his broad engineering expertise.
For the excellent co-operation within the project I have to thank Dr.-Ing. Tobias
Käppler and Professor Dr.-Ing. Clemens Posten from the Institute of Engineering in
Life Sciences, University of Karlsruhe (TH), Germany. I further thank Professor
Posten, as well as Professor Dr.-Ing. Alfred Weber from the Institute of Mechanical
Engineering, Clausthal University of Technology, for taking the second referee.
Several students have contributed to this work and their results have been included
into this thesis. Thus, I sincerely want to thank Lars Spelter, Jie Li, Michael Altenhoff
and Stefan Huskamp. Special thanks are reserved for Nadine Kruse who was the
most important support during the past three years. I wish all of them good luck for
their future careers.
Further on I have to thank all the hard-working people in the background, doing a lot
of analytical and preparative work for me: Hans Langer, Peggy Knospe, Ulrike
Köcher, Arne Langhoff and Klaas Mennecke. Last but not least, I want to thank all my
colleagues from the Institute of Chemical Process Engineering, who helped a lot to
make the institute a pleasant place to work.

Finally I want to express my gratefulness and respect to the most important persons
in my life, Bernhard Pfeuffer and my family, for their never-ending support and trust.
With you, this world is a better place to work and to live.

Birgit Hickstein
Clausthal-Zellerfeld, October 2009




























Wer glaubt etwas zu sein hat aufgehört etwas zu werden.


Philip Rosenthal


Abstract
Abstract

The “High gradient magnetic fishing” technique (HGMF) represents an innovative
technique for current downstream processing challenges. In HGMF nanoscale to
micron scale superparamagnetic magnetic particles with different functionalities,
termed magnetic beads, are employed for the capture of a target molecule from
diluted suspensions.
With the application of the HGMF technology in downstream processing, the
integration of several individual unit operations in one single process step can be
achieved. As a consequence, the final number of process steps can be reduced and
product losses will be minimised. Thus, the HGMF technology with magnetic beads
as functional adsorbents represents a process concept with high potential for process
optimisation of current downstream processes. Nevertheless, strategies for the
manufacturing of magnetic beads in large scale for the implementation in
downstream processing are still missing.
Within this work, a process scheme for the manufacturing of magnetic beads in large
scale was developed. The work focuses on the scalability of the whole synthesis
procedure. Due to the proposed application in bioseparation the magnetic beads
were characterised concerning their chemical and physical properties as well as their
applicability for the separation of proteins.
The developed process scheme for the synthesis of magnetic beads for
bioseparation purposes is characterised by its flexibility and modular construction.
The magnetic beads consist of three different components: superparamagnetic
magnetite, functionalised nanoscale polymer particles and a matrix polymer. Each
component is responsible for one important bead property: the superparamagnetic
character, the adsorption of the target molecule and the stability and morphology of
the magnetic bead particle. Due to the modular process design, the three different
components can be varied in quantity and quality. The final integration of the s in the magnetic beads was done via a spray drying process.
Chemical and physical characterisations delivered a proof of the modular process
concept. Adsorption experiments showed that the manufactured magnetic beads are
generally suitable for the selective separation of proteins. Scale-up efforts of the final
spray drying procedure resulted in a scale-up factor of 3. The resulting magnetic
showed comparable magnetic properties but differed in their particles sizes.
Index
Index of contents
1. Motivation.........................................................................................1
2. Introduction – State of the art.........................................................3
2.1. Downstream processing ........................................................................ 3
2.1.1. Fundamentals........................................................................................... 3
2.1.2. Challenges................................................................................................ 6
2.1.3. Optimisation approaches .......................................................................... 7
2.1.4. Magnetic beads for downstream processing .......................................... 10
2.2. Magnetic beads..................................................................................... 11
2.2.1. History of magnetic separation and magnetic beads .............................. 11
2.2.2. Characteristics and synthesis procedures of magnetic beads ................ 13
2.2.3. Application of magnetic beads for protein separation ............................. 17
2.3. Engineering challenges in magnetic bead technology ..................... 21
3. Fundamentals of components & synthesis procedures ............24
3.1. Process scheme of magnetic bead synthesis.................................... 24
3.2. Process components ........................................................................... 26
3.2.1. Superparamagnetic magnetite................................................................ 27
3.2.2. Nanoscale functional particles 31
3.2.2.1. Adsorption principle of proteins ....................................................... 32
3.2.2.2. Fundamentals of particle synthesis ................................................. 34
3.2.3. Matrix polymer and solvents ................................................................... 39
3.3. Spray drying.......................................................................................... 40
3.4. Scale-up................................................................................................. 42
4. Materials & methods......................................................................45
4.1. Material list............................................................................................ 45
4.2. Precipitation of magnetite.................................................................... 47
4.3. Synthesis of nanoscale functional particles ...................................... 47
4.3.1. Nanoscale anion exchanger ................................................................... 47
4.3.2. Nanoscale cation exchanger .................................................................. 48
4.3.3. Nanoscale IMA particles ......................................................................... 49
4.4. Spray drying.......................................................................................... 50
4.4.1. Lab scale spray dryer ............................................................................. 50
4.4.2. Pilot plant spray dryer 51
4.4.3. Comparison between lab scale and pilot scale spray dryers .................. 53
4.5. Magnetic bead synthesis ..................................................................... 54
4.6. Cha