Polymer Immobilization to Metal Oxide Substrates through Catechol Derivatives as Surface Anchors

148 Pages·2010·2.2 MB·English

ETH Library
Polymer immobilization to metal
oxide substrates through catechol
derivatives as surface anchors
Doctoral Thesis
Author(s):
Malisova, Barbora
Publication date:
2010
Permanent link:
https://doi.org/10.3929/ethz-a-006253027
Rights / license:
In Copyright - Non-Commercial Use Permitted
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DISS. ETH NO. 19307

Polymer Immobilization to Metal Oxide Substrates
through Catechol Derivatives as Surface Anchors

A dissertation submitted to
ETH Zurich

for the degree of
Doctor of Sciences

presented by
Barbora Malisova
Master, University of Chemistry & Technology (VSCHT), CZ

Born on April 20, 1979
citizen of Czech Republic

accepted on recommendation of
Prof. Dr. Marcus Textor, examiner
Prof. Dr. Karl Gademann, co-examiner
Prof. Dr. Markus Niederberger, co-examiner
Dr. Stefan Zürcher, co-examiner

2010

For my family

"Science is like sex: sometimes something useful comes out,
but that is not the reason we are doing it."
Richard P. Feynman

Acknowledgement
This work would not have been possible without the help of many people. At this point
I would like to thank all of them who contributed to this work and supported me during
the last few years.
First, I would like to thank Prof. Dr. Marcus Textor for giving me the opportunity to
work in his group as well as to learn a new single-molecule force technique at
Northwestern University in US and for supervising my thesis.
I would like to thank my supervisors Dr. Stefan Zürcher, Dr. Samuele Tosatti and Prof.
Dr. Karl Gademann for their helpful advice and input for my work: Karl and Stefan for
their help in synthesis, and Samuele together with Stefan for introducing me to the XPS
and for corrections of my thesis and/or paper writing.
I also would like to thank Prof. Dr. Markus Niederberger who accepted being a co-
examiner of my thesis and Prof. Dr. Jörg Löffler representing the Department of
Materials.
Many thanks go to Prof. Dr. Phillip Messersmith and Dr. Haeshin Lee from
Northwestern University for their support during my stay at NU and for introducing me
into the topic of single-molecule spectroscopy.
I would like to thank also Prof. Dr. Manfred Heuberger who contributed in the final
discussions and data interpretation of my AFM project as well as Dr. Jan Koutnik for
consulting the data analysis and introducing me to the Mathematica software for data
evaluation.
In addition, I would like to thank Dr. Yann Bethuel for his help in synthesis during the
initial stage of my thesis and J.-Y. Wach for synthesizing some of the molecules I used
in this work.
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I would like to thank Esther Stähli and Josephine Bear for taking care of all the
administrative affairs and Tomas Bartos for technical support.
A warm thank you goes to Sina Saxer, Christian Zink and Esther Amstad for being such
great office mates: Esther, almost invisible through all her multi-collaborations, but very
nice when you managed to catch her; Zink, always happy when distracted with
(non-)scientific questions and always glad to help. A special thank you to Sina, who was
my (almost) everyday support, not only in work related issues. She always found time
for discussions and encouragement, and through her many words, she was very often
right.
A big thank you goes to all my former and current colleagues for their support and the
very friendly atmosphere. I enjoyed a lot working with you and also spending time “out
of the lab” with you, including coffee breaks, partying, skiing, badminton, relaxing spa
and so on. Although I am not mentioning everybody by name, I would like to thank
every single member (from the old and present days) for making the LSST such a
unique and great group.
I should not forget my friends “out of ETH” and my Czech friends who have never “let
me go” and managed to keep me close to them during the whole time
Finally, my biggest thanks go to my wonderful parents for their love and unconditional
support during all these years as well as to my great sisters and my brother-in-law for
giving me the confidence, encouragement and continuous support. Thank you for
everything you have done for me!

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Abstract
Abstract
There is a general interest and need for surface modifications for tailoring the properties
of materials devices and providing additional functionalities. This covers applications
such as lubrication, corrosion protection as well as biomedical applications. For the later
one of the important areas covers approaches to generate biocompatible surfaces by
controlling non-specific protein adsorption. Examples of applications include blood-
contacting devices such as stents, biosensors in genomics, proteomics and glycomics, as
well as the stabilization (dispersion) of micro- and nanoparticles for drug delivery or
medical imaging, providing longer circulation times in the body.
Polymeric films are particularly attractive for providing non-fouling properties to
surfaces. Among others, poly(ethylene glycol), PEG, has been widely used for this
purpose due to its known outstanding properties, low toxicity and immunogenicity.
Frequently used methods for the immobilization of polymers to metals, oxides or
polymeric substrates (via thiols, phosph(on)ates, silanes or polyelectrolyte interactions)
are, however, limited in terms of substrate choice and/or binding strength that can be
achieved. The method used in this thesis combines two approaches inspired by
adhesives and chelators found in mussels and cyanobacteria, respectively. In the first
case, mussel adhesive proteins are known to contain high proportion of 3,4-dihydroxy
phenylalanine (DOPA) that play an essential role in the adhesion of the mussel to a
variety of substrate types, while in the latter case, cyanobacteria, use highly specialized
siderophores (anachelin) to strongly coordinate Fe(III) ions in (sea) water.
Building upon published work, we have aimed first to search for catechol derivatives
that potentially show a higher affinity for surfaces than the reference DOPA anchor. Our
interests further focused on a better understanding of the binding mechanism of
different functionalized catechol derivatives on selected metal oxides with the aim of
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