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Effect of nanodiamond particles on neuronal tissue
Šimková, Veronika ; Benson, Veronika
High-Pressure High-Temperature nanodiamonds are considered to be highly biocompatible due to\ntheir low acute toxicity, which makes them suitable for biomedical applications. However, next to interaction with the cell membrane, nanoscale allows particles to penetrate the plasma membrane and even accumulate in the cell cytoplasm. Recently it brought up questions regarding sustainable nanoparticle application in vivo and potential toxicity hazards. The neuronal tissue consists of neurons and glial cells, and it is separated by a bloodbrain barrier from the peripheral blood system. Neurons are nerve cells forming a complex network of synapses that carry signals in the brain. The neurons are nourished and protected by glial cells. This project aims to find out whether nanodiamonds pass the blood-brain barrier when applied intravenously as a drug carrier and whether they directly interact with the neuronal tissue.
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Nanodiamonds as an innovative system for intracellular delivery of mirna-34a inprostatic cancer therapy
Bitti, G. ; Abate, M. ; Neuhoferová, Eva ; Kindermann, Marek ; Petráková, V. ; Boccellino, M. ; Quagliuolo, L. ; Filová, Eva ; Benson, Veronika ; Caraglia, M. ; Amler, Evžen
The microRNA(miRNA)-34a is an important regulator of tumor suppression. It controls the expression of several target proteins involved in cell cycle, differentiation and apoptosis, and antagonizes processes that are necessary for basic cancer cell viability as well as cancer stemness, metastasis, and chemoresistance. It is downregulated in numerous cancer types, including prostatic cancer, and inhibits malignant growth by repressing genes involved in various oncogenic signaling pathways. Given the anti-oncogenic activity of miR-34a, here we proved the substantial benefits of a new therapeutic concept based on nanotechnology delivery of miRNA mimics. In order to monitor the miRNA-34a replacement, we used a fluorescent nanodiamond particles (FND) system with linked miRNA-34a mimic, which was delivered to PC3 and DU145 prostatic cancer cell lines. We used functionalized nanodiamonds coated with polyethylenimine to transfer miRNA-34a into PC3 and DU145 prostatic cancer cell lines and we measured the zeta-potential of these complexes before using them for in vitro experiments. A replacement of miRNA-34 was observed by monitoring levels of miRNA-34 via real-time PCR. Moreover, our in vitro experiments demonstrated that miRNA-34a replacement, using this FND delivery system, decreased viability and induced apoptosis in prostatic cancer cell lines. Our findings suggest the replacement of oncosuppressor miRNA-34a provides an effective strategy for cancer therapy and the FND-based delivery systems seems to be an excellent strategy for a safe and effective targeting of the tumor.
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Targeted biocompatible nanoparticles for therapy and cancer diagnostics.
Neburková, Jitka ; Cígler, Petr (advisor) ; Benson, Veronika (referee) ; Schirhagl, Romana (referee)
Nanoparticles (NPs) have considerable potential in targeted medicine. NPs can merge various functions and serve as labels for imaging or as nanocarriers in therapy. Modification of NPs with targeting ligands can lead to highly specific interactions with targeted cancer cells. However, the efficacy of targeting depends on the ratio between specific and non-specific interactions of a NP with the cell. Non-specific interactions of NPs are unrelated to targeted receptors and need to be eliminated in order to decrease background noise during imaging and adverse effect of drugs on healthy tissues. In this thesis, surface modifications of NPs were explored mainly on biocompatible carbon NPs called nanodiamonds (NDs), which have exceptional fluorescent properties such as long fluorescence lifetime, no photobleaching and photoblinking and sensitivity of their fluorescence to electric and magnetic field. Main issues addressed in this thesis are low colloidal stability of NDs in buffers and media, their non-specific interactions with proteins and cells and limited approaches for ND surface modifications. These issues were solved by coating NDs with a layer of biocompatible, hydrophilic, and electroneutral poly(ethylene glycol) or poly[N-(2- hydroxypropyl) methacrylamide] polymers. Optimized polymer coating...
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Design and synthesis of surface architectures on fluorescent nanodiamonds
Havlík, Jan ; Kotek, Jan (advisor) ; Lang, Kamil (referee) ; Štěpánek, František (referee)
anks to their unique properties and high biocompatibilities, fluorescent nanodiamonds are promising representatives of modern carbon nanomaterials with a broad range of applications. Nevertheless, their wider use is limited because of weak fluorescence intensity and low colloidal stability in the biological environment. e optimization of treatment procedures and development of new suitable surface designs is therefore critically needed. In this study, several key steps for fluorescent nanodiamond treatment have been optimized, leading to both a substantial increase in fluorescence intensity and to significantly lower surface damage caused by graphitization. Further, a new high-throughput irradiation technique was developed. e influence of surface chemistry on the fluorescence parameters was studied using partial fluorination of the functional groups on the nanodiamond surface. A novel method which significantly affects the interaction of nanodiamonds with biological systems by increasing of the homogeneity and circularity was developed. e potential of nanodiamonds for future medical and biological research was demonstrated on particles with complex surface architectures that enabled targeting and therapy of tumor cells. Moreover, a strong and highly selective affinity of fibroblast growth factors to diamond...
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Carbon nanomaterials and their interactions with bacteria
Jurková, Blanka ; Beranová, Jana (advisor) ; Kuthan, Martin (referee)
Recently, carbon nanomaterials gain attention especially for their interesting, often unique, properties. They can be used in wide range of applications, such as electronics, optics, cosmetics, solar cells, construction materials, air filters, polishing materials, protective coatings and dry lubricants. Whereas their physical and chemical attributes have already been intensively examined, the research on their effects on living organisms is still at the preliminary stage. This work is focused on the interactions of carbon nanomaterials, namely graphene, fullerene, carbon nanotubes and nanodiamonds, with bacterial cells and their antibacterial and antiadhesive properties. The mechanisms of the toxic action of carbon nanomaterials against bacteria include damage of outer cell structures as a consequence of the direct contact with a nanomaterial, impairment of bacterial metabolism or reactive oxygen species production. Exact understanding of the processes that take place between bacterial cell and carbon nanomaterials can contribute to the research on their medical applications and ecological recycling in the future.
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Bioapplications of novel nanostructured materials
Fučíková, Anna ; Valenta, Jan (advisor) ; Polívka, Tomáš (referee) ; Plášek, Jaromír (referee)
Title: Bioapplications of novel nanostructured materials Author: Anna Fučíková Department / Institute: Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University in Prague Supervisor of the doctoral thesis: Doc. RNDr. Jan Valenta, Ph.D., Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University in Prague Abstract: This work is aimed at development of new fluorescent labels based on silicon nanocrystals. Nanodiamonds and commercial CdSe quantum dots have been used as comparative materials. Silicon nanocrystals are relatively small (1-4 nm) compared to other studied nanomaterials. They are prepared by electro-chemical etching and their surface can be activated by various molecules which strongly influences luminescence properties. Luminescence quantum efficiency can be as high as 30 % and perfectly photostable even in biological environment. Si nanocrystals are biodegradable in a living organism within reasonable time scale and non-toxic. We are able to detect luminescence of single nanocrystals, even inside living cells, with use of our micro-spectroscopy apparatus. Nanodiamonds have weak luminescence; they are toxic at higher dosages and very stable in living bodies (without available technique how to remove them). Studied CdSe...
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Influence of incorporated nanodiamond particles on mechanical properties of composite material based on multi-layer PVA nanofiber textiles
Prošek, Zdeněk ; Indrová, K. ; Rácová, Z. ; Ryparová, Pavla ; Nežerka, V. ; Topič, J. ; Tesárek, Pavel ; Kromka, Alexander
The present study investigates the influence of NDP on mechanical properties of multi-layer PVA nanofiber textiles. The particles of a diameter equal to 5 nm were incorporated into double- and triple-layer textiles, while the single-layer samples were prepared as the reference. The diameter of PVA nanofibers varied from 100 to 300 nm. We characterized the tensile strength, stiffness and ductility of fabricated nanofibers by using a conventional method – a tensile test. We found that the NDP-enriched nanofibers reveal antibacterial character. However, none or negligible influence of NDP additions on the tested mechanical properties was observed.
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Non-destructive determination of nitrogen in biological and other materials by the photon activation analysis
Krausová, Ivana ; Mizera, Jiří ; Chvátil, David ; Krist, Pavel ; Řanda, Zdeněk ; Kučera, Jan ; Štursa, Jan
The study presents a procedure for assaying nitrogen in biologocial materials by means of instrumental photon activation analysis (IPAA). The determination has been based on counting of the non-specific 511 keV annihilation gamma rays of 13N, product of the photonuclear reaction 14N(γ, n)13N, which is a pure positron emitter. IPAA allowed determination of nitrogen down to 1 wt.%. in selected biological reference materials - NIST RM 8433 Corn Bran, 1547 Peach Leaves, 8414 Bovine Muscle, and 1577b Bovine Liver. The optimized procedure was applied also to assaying nitrogen in pulverized nanodiamond intended for medical purposes.
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