The topic of my Master degree thesis is the development of a conceptually new class of contrast agents for the 31P magnetic resonance imaging (31P MRI). These agents are based on nanoparticles of calcium(II) phytate. Phytate (myo-inositol-1,2,3,4,5,6-hexakisphosphate) is largely present in plants, seeds and grains. It is non-biodegradable but nontoxic for animals and human beings and most importantly around 22% of its mass is phosphorus, so it is easily detectable by 31P NMR/MRI. These nanoparticles of Ca(II) phytate were doped with paramagnetic Fe3+ ions which broaden the 31P signal, making the nanoparticles invisible in healthy tissues. In the presence of bacteria producing siderophores (for example in Helicobacter pylori in gastric ulcers), Fe3+ is released from the gel and 31P MRI signal becomes detectable. In vitro simulation of this release was performed with deferroxamine, a compound possessing high affinity to Fe3+ ions forming coloured complex with it exploitable for the UV-VIS evaluation. The Ca(II) phytate can be synthesized in two possible ways. The first way is by direct precipitation of the Ca2+ salt with sodium phytate. The second way is ion exchange of phosphate in the nanoparticles of hydroxyapatite which creates electrostatically stabilized calcium phytate nanoparticles. Both...
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:397025 |
| Date | January 2019 |
| Creators | Pechrová, Zdislava |
| Contributors | Hrubý, Martin, Kotek, Jan |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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