Focus and outline of the present
Paper 1 This paper discusses the conformational freedom of the molecule in general and its appearance in solid crystallites and in solutions in particular. A first conformational analysis using [η]-M data is shown.
T-SAR guided Conformational Analysis of Chitosan M.X. Weinhold, J.C.M. Sauvageau, B. Tartsch, P. Clarke, B. Jastorff, J. Th¨omingAdvances in Chitin Science,10, 66-71 (2007)
Contribution to the paper The entire manuscript was written by me and all experiments were performed by me.
Paper 2 A multi-dimensional analysis is proposed by use of physical, chemical and bi-ological methods. The physicochemical characterization (including determination of the pattern of acetylation) is combined with purity control (including deter-mination of elements, protein, and inorganic matter) followed by further testing of biological effects on two bacteria. Solubility behavior is discussed in detail as well as the inhibiting effects onEscherichia coli and Vibrio fischeri.
Strategy to improve the characterization of chitosan for sustainable biomedical applications: SAR guided multi-dimensional analysis M.X. Weinhold, J.C.M. Sauvageau, N. Keddig, M. Matzke, B.
Tartsch, Ingo Grunwald, Christian K¨ubel, B. Jastorff, J. Th¨omingGreen Chemistry,11, 498-509 (2009)
Contribution to the paper Coordination of the different types of analysis and the whole physicochemical characterization (FA, MW, [η], PA, protein deter-mination) were performed by me. Writing of the manuscript, except parts of the method description and parts of the introduction, was done by me.
Paper 3 Within this paper, an improved method for determining the microstructure of chitosan, called the pattern of acetylation PA, is shown. The influence of de-N -acetylation as well as re-N-acetylation processes on PAis observed and compared to studies from literature.
Studies on acetylation patterns of different chitosan preparations M.X. Weinhold, J.C.M. Sauvageau, J. Kumirska, J. Th¨omingCarbohydrate Polymers,78, 678-684 (2009)
Contribution to the paper Parts of the NMR experiments, all characteriza-tion experiments and evaluacharacteriza-tion of the NMR data, including curve fitting and PAcalculation, were performed by me. The entire manuscript was writ-ten by me.
Paper 4 This is the second paper dealing with the pattern analysis. Herein the sen-sitivity and the precision of the method, especially the standard deviation of intra-day and inter-day repeats of the line fitting by three independent persons, is assessed. It results in an estimation of the expected standard deviation of PA for different FA values.
Determination of the pattern of acetylation of chitosan samples: comparison of evaluation methods and some validation parameters, J. Kumirska, M.X. Weinhold, S. Steudte, J. Th¨oming, K. Brzo-zowski, P. Stepnowski,Int. J. of Biol. Macromol.,45, 56-60 (2009)
Contribution to the paper Parts of the intra-day and inter-day precision test, all physicochemical characterization experiments and parts of the manuscript were done by me.
Paper 5 Two different chitosan samples are analyzed according to their conforma-tional behavior using [η]-M and Rg-M data. Results are compared to theoretical approaches like the Benoit-Doty, Odjik-Houwart and the Bohdaneck´y model with
subsequent determination of the stiffness parameterlK. Deviations from the lin-ear chain behavior of one sample were observed after comparison to a sample with complete ”semi-flexible” behavior.
On conformational analysis of chitosan M.X. Weinhold and J. Th¨omingCarbohydrate Polymers,84, 1237-1243 (2010)
Contribution to the paper The entire manuscript was written by me and all experiments were performed by me.
Paper 6 Within this paper, conformation of chitosan is compared to the conformation of hyaluronic acid, a biopolymer with a cellulose type backbone. Herein the same methods are used for the determination of lK as mentioned previously for paper 5.
Comparison between the conformational behavior of chitosan and hyaluronic acid M.X. Weinhold and J. Th¨omingAdvances in Chitin Science,11, 523-528 (2009)
Contribution to the paper The entire manuscript was written by me and all experiments were performed by me.
Paper 7 This paper deals with the solubility of chitin and chitosan in different types of ionic liquids. The impact on solubility by variation of side-chain, headgroup and anion is shown and discussed.
Dissolution of chitin/chitosan with ionic liquids M.X. Weinhold, J.C.M. Sauvageau, B. Jastorff and J. Th¨omingCarbohydrate Polymers, submitted (2011)
Contribution to the paper The entire manuscript was written by me and parts of the solubility experiments were done by me.
5.3 Further publications
In the following all publications and contributions which were authored during the work for this thesis - but not included in the thesis - are shown.
Permeation enhancer effect of chitosan and chitosan derivatives: Comparison of formulations as soluble polymers and nanoparticulate systems on insulin absorption in Caco-2 cells A.M.M. Sadeghi, F.A.
Dorkoosh, M.R. Avadi,M. Weinhold, A. Bayat, F. Delie, R. Gurny, B. Larijani, M. Rafiee-Tehrani, H.E.
JungingerEuropean Journal of Pharmaceutics and Biopharmaceutics,70, 270-278 (2008)
Determination of the pattern of low-molecular-weight chitosan used in biomedical applications J. Kumirska, M.X. Weinhold, J.C.M. Sauvageau, J. Th¨oming, Z. Kaczynski, P. StepnowskiJ. Pharm. Biomed. Anal., 50, 587-590 (2009)
Chiqual- A Multi-dimensional Analysis for Quality Assessment of Chitosan N. Keddig,M.X. Weinhold, J. Sauvageau, M. Matzke, S. Stolte, K. Heppe, B. Tartsch, P. Clarke, J. Th¨oming, W. Heyser, B. Jastorff, J. WarrelmannAdvances in Chitin Science,10, 61-65 (2007)
5.3.1 Talks and posters
Talk: Conformational and Branching Analysis of Chitosan M.X. Weinhold and J. Th¨oming Session P4-3, Tue. 12.00, 9th International Conference of the European Chitin Society (EUCHIS), 23-26th May, Venice-Italy (2009)
Talk: T-SAR guided Conformational and Pattern Analysis of up to 40 different Chitosan PreparationsM.X.
Weinhold, J. Sauvageau, K. Heppe, B. Tartsch, B. Jastorff, J. Th¨oming Session 01-4, Sun. 11.45, 8th In-ternational Conference of the European Chitin Society (EUCHIS), 9-12th September, Antalya-Turkey (2007)
Poster: Concept for a T-SAR guided Multi-dimensional Analysis of Chitosan M.X. Weinhold, J.
Sauvageau, N. Keddig, S. Risse, U. Stoll, C. Kuhlmann, S. Stolte, M. Matzke, D. Waterkamp, B. Tartsch, P. Clarke, J. Warrelmann, W. Heyser, B. Jastorff, J. Th¨oming, 3. Statusseminar Chitin/Chitosan, 14th June, B¨usum-Germany (2007)
Poster: Dissolution of chitin in ionic liquids S. Steudte, M.X. Weinhold, J.C.M. Sauvageau and J.
Th¨oming Session PO3-9, Tue. 14.30, 9th International Conference of the European Chitin Society (EUCHIS), 23-26th May, Venice-Italy (2009)
Poster: Determination the degree and the pattern of acetylation in thirteen commercial chitosan preparations J. Kumirska,M.X. Weinhold, J.C.M. Sauvageau, J. Th¨oming, Z. Kaczynski and P. Step-knowski , 19th International Symposium on Pharmaceutical and Biomedical Analysis, Gdansk-Poland (2008)