Study of penetration of selected substances from elderberry extracts through biological membrane

Tato diplomová práce se zabývá studiem prostupu vybraných fenolických látek obsažených v extraktu bezu černého (Sambucus nigra) přes modelové systémy reprezentované dvěma typy syntetických membrán a reálný systém reprezentovaný biologickou membránou. Jako biologická membrána byla zvolena kůže z prasečího ušního boltce. Experimenty transdermální absorpce a absorpce přes syntetické membrány byly realizovány prostřednictvím vertikálních (Franzových) cel. Vybranými látkami obsaženými v extraktu bezu černého byly rutin a kyselina chlorogenová. Hlavním bodem této práce bylo zjistit jak ochotně nebo zda vůbec tyto dvě vybrané fenolické látky prostupují kůži a zvolenými syntetickými membránami. Procentuální vyjádření absorbovaného množství látky bylo stanoveno pomocí analýzy HPLC.This Diploma thesis focuses on the study of penetration of selected phenolic substances contained in extract from black elder (Sambucus nigra) via modelling systems represented by two types of synthetic membranes and a real system represented by a biological membrane. As a biological membrane, we have chosen skin from pig´s earlobe. Experiments of transdermal absorption and absorption through synthetic membranes were conducted through vertical (Franz´s) cells. Selected substances contained in the extract from black elder were rutin and chlorogenic acid. The main focus of this work was to determine how readily, or if at all, these two selected phenolic substances penetrate the skin and selected synthetic membranes. The percentage of absorbed amount of the substance was determined by HPLC analysis.

Effect of apoferritin surface-biomacromolecular modification on cellular uptake and inhibition of protein corona

The effects of surface modifications (PEGylation and PASylation) of natural nanocarriers based on apoferritin (FRT) were tested in this work. The main goals of performed PEGylation/PASylation were decreased protein corona formation leading to better internalization of drugs into diseased cells and therefore higher efficiency of treatment. The influence of created protein coronas on the amount of internalized experimental drug ellipticine (Elli) was evaluated via fluorescence microscopy. Various properties of these modified nanoparticles were studied, such as their cytotoxicity or release kinetics of Elli. According to performed experiments, PAS-10 modification appeared as the most appropriate surface modification

Evaluation of cytotoxicity of biphasic TiO2 nanoparticles with organic surface coatings

Titanium dioxide nanoparticles (TiO2 NPs) are used in lots of human applications because of their extraordinary nano scaled properties. Particularly, due to their photoprotective properties, they are used in topical dermatologic preparation and also as white pigment. Due to these properties their use in human life is more and more frequent. Despite the fact that nano dimension brings various beneficial properties, it could bring also bad features. Therefore, in this study, we evaluated a cytotoxicity of two types of biphasic TiO2 NPs using distinct cells of epithelial origin. We found that TiO2 NPs can induce cytotoxic stress resulting in fragmentation of DNA

Improving cytocompatibility of CdTe quantum dots by Schiff-base-coordinated lanthanides surface doping

Background: Suitable fluorophores are the core of fluorescence imaging. Among the most exciting, yet controversial, labels are quantum dots (QDs) with their unique optical and chemical properties, but also considerable toxicity. This hinders QDs applicability in living systems. Surface chemistry has a profound impact on biological behavior of QDs. This study describes a two-step synthesis of QDs formed by CdTe core doped with Schiff base ligand for lanthanides [Ln (Yb3+, Tb3+ and Gd3+)] as novel cytocompatible fluorophores. Results: Microwave-assisted synthesis resulted in water-soluble nanocrystals with high colloidal and fluorescence stability with quantum yields of 40.9-58.0%. Despite induction of endocytosis and cytoplasm accumulation of Yb- and TbQDs, surface doping resulted in significant enhancement in cytocompatibility when compared to the un-doped CdTe QDs. Furthermore, only negligible antimigratory properties without triggering formation of reactive oxygen species were found, particularly for TbQDs. Ln-doped QDs did not cause observable hemolysis, adsorbed only a low degree of plasma proteins onto their surface and did not possess significant genotoxicity. To validate the applicability of Ln-doped QDs for in vitro visualization of receptor status of living cells, we performed a site-directed conjugation of antibodies towards immuno-labeling of clinically relevant target-human norepinephrine transporter (hNET), over-expressed in neuroendocrine tumors like neuroblastoma. Immuno-performance of modified TbQDs was successfully tested in distinct types of cells varying in hNET expression and also in neuroblastoma cells with hNET expression up-regulated by vorinostat. Conclusion: For the first time we show that Ln-doping of CdTe QDs can significantly alleviate their cytotoxic effects. The obtained results imply great potential of Ln-doped QDs as cytocompatible and stable fluorophores for various bio-labeling applications