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Master's Thesis
Author of thesis: Bc. Michal Kianička
Acad. year: 2025/2026
Supervisor: doc. Ing. Petr Sedláček, Ph.D.
Reviewer: prof. Ing. Miloslav Pekař, CSc.
This thesis focuses on the detailed study of interactions between alginate systems and selected multivalent cations (Ca2+, Ba2+, Cu2+, Mg2+). The main objective was to clarify the mechanism of their cross-linking and complexation at the structural and thermodynamic level. The research proceeded from an initial screening of binding mechanisms on pure homooligomeric units of guluronic (G) and mannuronic (M) acid, through the analysis of their defined mass mixtures, to the application of the developed models to complex commercial alginates. For a comprehensive characterization of these processes, a combination of analytical techniques was employed, including conductometry, dynamic light scattering (DLS), turbidimetry, and detailed thermodynamic analysis using ITC. The results confirmed that cross-linking is a multiphase process that strongly depends on chain conformation and the properties of the multivalent ion. Detailed analysis revealed that Ca2+ exhibits a strong affinity and selectivity for poly G, while its interaction with poly M is significantly limited. Ba2+ acts similarly selectively, also showing a dominant affinity for G blocks, and due to its low desolvation energy, it forms the thermodynamically most stable networks with them. Cu2+ behaves entirely specifically; their coordination is not spatially restricted and they can effectively saturate binding sites on both poly G and poly M, although they are much more effectively immobilized within the poly G structure. Conversely, Mg2+ is unable to overcome its hydration barrier with either homooligomer, and its interaction is strictly limited to non-specific electrostatic association. The thesis thus provides a comprehensive view of the relationships between the primary structure of alginates and the type of multivalent ions.
alginate, cross-linking, egg-box model, conductometry, dynamic light scattering, thermodynamics of interactions, multivalent cations
Date of defence
21.05.2026
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Obhajoba proběhla podle následujícího schématu: prezentace studentky-vyjádření vedoucí/ho-oponentský posudek-reakce na posudek-diskuse s komisí. Studentka přednesla výborný výtah výsledků své diplomové práce, řádně zodpověděla všechny dotazy oponentské i členů komise, pohotově reagovala na připomínky. V diskusi tak studentka prokázala výbornou schopnost orientace v teoretických i praktických základech problematiky diplomové práce. Komise zhodnotila její diplomovou práci celkově jako výbornou. Pekař: Jak si vysvětlujete oboustranný pík u ITC s vápenatými ionty?
Language of thesis
Slovak
Faculty
Fakulta chemická
Department
Institute of Physical and Applied Chemistry
Study programme
Chemistry for Medical Application (NPCP_CHMA)
Specialization
Processes and Materials of Medical Applications (BF)
Composition of Committee
doc. PharmDr. Ing. Radka Ješinová, Ph.D. (člen) doc. Ing. Zdenka Kozáková, Ph.D. (člen) prof. Ing. Stanislav Obruča, Ph.D. (místopředseda) prof. Ing. Miloslav Pekař, CSc. (předseda) doc. Ing. Petr Dzik, Ph.D. (člen)
Supervisor’s reportdoc. Ing. Petr Sedláček, Ph.D.
Grade proposed by supervisor: A
Reviewer’s reportprof. Ing. Miloslav Pekař, CSc.
Grade proposed by reviewer: A
Responsibility: Mgr. et Mgr. Hana Odstrčilová