The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
Aalto

A Novel Biomembrane Model for Electrochemical Studies. Characterisation and Applications

Annika Mälkiä

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Department of Chemical Technology for public examination and debate in Auditorium KE 2 at Helsinki University of Technology (Espoo, Finland) on the 5th of November, 2004, at 13 o'clock.

Overview in PDF format (ISBN 951-22-7302-0)   [1294 KB]
Dissertation is also available in print (ISBN 951-22-7282-2)

Abstract

This thesis describes the development and characterisation of a novel biomembrane model suitable for electrochemical investigation, and its applicability in studies of biologically related phenomena. The model system consists of a lipid monolayer, deposited at a polarisable liquid–liquid interface with the Langmuir–Blodgett technique. Combinations of ac and dc electrochemical techniques with theoretical models are employed to obtain information on the phase transfer and membrane interactions of charged therapeutics at the monolayer-covered interface. The thesis comprises six publications and a thorough introduction to biological and model membranes.

The first part of the thesis surveys background literature with relevance to the present work. Basic properties of biological membranes are discussed and existing biomembrane models reviewed. The presented literature serves as a reference point for the development and evaluation of the model system described in this thesis, and is frequently referred to in the discussion of the results.

In the second part of the thesis, the essential results of the publications are summarised. Instead of an article-by-article approach, results from various publications are jointly presented under appropriate headings. The development, characterisation and applicability of the model system are discussed. In the last-mentioned section, emphasis lies on methods applicable to drug development and delivery. To this end, the usefulness of the model system in the construction of pH – potential diagrams, determination of drug membrane activity, and studies of drug transfer through polyelectrolyte multilayers, is investigated. Finally, in view of the obtained results, the future prospects of the system are assessed.

This thesis consists of an overview and of the following 6 publications:

  1. Liljeroth P., Mälkiä A., Cunnane V. J., Kontturi A.-K. and Kontturi K., 2000. Langmuir–Blodgett monolayers at a liquid–liquid interface. Langmuir 16, number 16, pages 6667-6673.
  2. Mälkiä A., Liljeroth P. and Kontturi K., 2001. Drug transfer through biomimetic Langmuir–Blodgett monolayers at a liquid–liquid interface. Analytical Sciences 17 Supplement, pages i345-i348.
  3. Mälkiä A., Liljeroth P., Kontturi A.-K. and Kontturi K., 2001. Electrochemistry at lipid monolayer-modified liquid–liquid interfaces as an improvement to drug partitioning studies. Journal of Physical Chemistry B 105, number 44, pages 10884-10892.
  4. Mälkiä A., Liljeroth P. and Kontturi K., 2003. Membrane activity of ionisable drugs – a task for liquid–liquid electrochemistry? Electrochemistry Communications 5, number 6, pages 473-479.
  5. Mälkiä A., Liljeroth P. and Kontturi K., 2003. Membrane activity of biotechnological peptide drugs. Chemical Communications 2003, number 12, pages 1430-1431.
  6. Slevin C. J., Mälkiä A., Liljeroth P., Toiminen M. and Kontturi K., 2003. Electrochemical characterization of polyelectrolyte multilayers deposited at liquid–liquid interfaces. Langmuir 19, number 4, pages 1287-1294.

Keywords: liquid–liquid electrochemistry, Langmuir–Blodgett, drug-membrane interactions, lipid monolayer, polyelectrolyte multilayers

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© 2004 Helsinki University of Technology

Last update 2011-05-26