Showing papers by "Vojtěch Adam published in 2013"

Effect of Magnetic Nanoparticles on Tobacco BY-2 CellSuspension Culture

Abstract: Nanomaterials are structures whose exceptionality is based on their large surface, which is closely connected with reactivity and modification possibilities. Due to these properties nanomaterials are used in textile industry (antibacterial textiles with silver nanoparticles), electronics (high-resolution imaging, logical circuits on the molecular level) and medicine. Medicine represents one of the most important fields of application of nanomaterials. They are investigated in connection with targeted therapy (infectious diseases, malignant diseases) or imaging (contrast agents). Nanomaterials including nanoparticles have a great application potential in the targeted transport of pharmaceuticals. However, there are some negative properties of nanoparticles, which must be carefully solved, as hydrophobic properties leading to instability in aqueous environment, and especially their possible toxicity. Data about toxicity of nanomaterials are still scarce. Due to this fact, in this work we focused on studying of the effect of magnetic nanoparticles (NPs) and modified magnetic nanoparticles (MNPs) on tobacco BY-2 plant cell suspension culture. We aimed at examining the effect of NPs and MNPs on growth, proteosynthesis-total protein content, thiols-reduced (GSH) and oxidized (GSSG) glutathione, phytochelatins PC2-5, glutathione S-transferase (GST) activity and antioxidant activity of BY-2 cells. Whereas the effect of NPs and MNPs on growth of cell suspension culture was only moderate, significant changes were detected in all other biochemical parameters. Significant changes in protein content, phytochelatins levels and GST activity were observed in BY-2 cells treated with MNPs nanoparticles treatment. Changes were also clearly evident in the case of application of NPs. Our results demonstrate the ability of MNPs to negatively affect metabolism and induce biosynthesis of protective compounds in a plant cell model represented by BY-2 cell suspension culture.

Femtogram Electrochemical Sensing of Prion Proteins Using Quantum Dots

Abstract: The prion protein (PrP) is involved in neurodegeneration via its conversion from the normal cellular form, PrP C , to the infectious form, PrP Sc , which is the causative agent of the transmissible spongiform encephalopathies (TSEs) including Creutzfeldt-Jakob disease (CJD). In spite of great effort in this field, diagnostics of prion protein caused diseases represents a sort of challenge. In this study, we aimed our attention on studying of prion protein interaction with CdTe quantum dots (QDs) by voltammetry as a new and extremely sensitive tool for sensing of these proteins. Primarily, we characterized fluorescent and electrochemical properties of QDs. Further, electrochemical study of their interactions was carried out to find the most suitable conditions for sensitive detection of prion proteins. Detection limit (3 S/N) was estimated as 1 fg in 5 µl. This makes labeling of proteins with QDs of great importance due to easy applicability and possibility to use in miniaturized devices, which can be used in situ. Based on our results it can be concluded that QDs-prion protein complex is stable and can be quantified in extremely low amounts. This should open new possibilities how to determine the presence of these proteins on surgical equipment and other types of materials, which could be contagious.

Liposomes as drug carriers and their characterization usingdifferent analytical methods

Abstract: The physicochemical properties of liposomes are significantly affected by the composition of phospholipid bilayer; differences in composition allow the use of liposomes for analytical purposes and for therapeutic purposes. One of the most used components of phospholipid bilayer is cholesterol. Its concentration plays a significant role in the behaviour of liposomes. This study points to changes in the properties of liposomes and its influence on encapsulated doxorubicin according to the content of cholesterol in the phospholipid bilayer. The influence of SDS addition to liposomal variants was also evaluated. Three variants of liposomes differing in various concentrations of cholesterol were assessed. Firstly, the toxicity of all types of liposomal doxorubicin was evaluated and it was found that the content of cholesterol increases the IC50 values of encapsulated doxorubicin in liposome. The highest concentration of cholesterol in liposome increased the IC50 value even four times compared to liposomes without cholesterol.