|
| |
|
|
Aliphatic polyester-based nanoparticles as drug delivery systems
Jäger, Alessandro ; Štěpánek, Petr (advisor) ; Sedláček, Jan (referee) ; Sikora, Antonín (referee)
Nanoparticles from biodegradable polymers are considered one of the most promising systems for biomedical application as drug delivery systems. Therefore, the synthesis and characterization of a new aliphatic biodegradable copolyester named PBS/PBDL (poly(butylene succinate-co- butylene dilinoleate)) intended to the application as drug delivery system is reported in the thesis. Surfactant-free biodegradable and narrowly distributed, nanosized spherical particles (RH < 60 nm) have been produced from the biodegradable material by applying a single-step nanoprecipitation protocol. The size of the generated polymer nanoparticles (PNPs) could be controlled by adjusting the polymer concentration, the choice of organic solvent, mixing different organic solvents or by changing temperature and ionic strength. By optimizing such parameters sub-100 nm uniform PNPs can be produced through this methodology including the advantage and ability to scale-up production. The nanoparticles structure was characterized in detail by employing a variety of scattering techniques and transmission electron microscopy (TEM). Combined static light scattering (SLS) and dynamic light scattering (DLS) measurements suggested that the nanoparticles comprise a porous core conferring them a non-compact characteristic. Their porosity...
|
|
|
Cell viability changes after interaction with TiO2 nanoparticules and anthracycline cytostatics
Kondělková, Regina ; Štenglová Netíková, Irena (advisor) ; Merta, Ladislav (referee)
The goal of this thesis is to conduct a literary research about cell viability changes after interaction with TiO2 nanoparticules and anthracycline cytostatics. Anthracycline cytotoxic agents are one of the most commonly used groups of antineoplastic drugs, particulary doxorubicin. A serious side effect of anthracyclines in para drug administration (extravasation) is necrosis of the surrounding tissue. Effective treatment for this side effect is not available as of yet. One possible way could be to use sorption and degradation characteristics of nanoparticles of TiO2, which are non-toxic to the human body. Anthracyclines are characterized by rapid adsorption to the surface of nanoparticles of TiO2 and subsequent degradation to non-toxic products. Therefore further I deal with the use of nanoparticles of TiO2, their unique chemical properties and the way they affect cell viability, especially keratinocyte cell lines in vitro. It has been shown that there is no reduction in cell viability when culturing keratinocytes together with TiO2 nanoparticles and thus it opens the door for further studies on the use of nanoparticles of TiO2 for the treatment of necrotizing anthracycline extravasation.
|
|
|
The study of properties of anticancer drugs ellipticine, etoposide and doxorubicin in the forms of nanocarriers
Lengálová, Alžběta ; Stiborová, Marie (advisor) ; Martínková, Markéta (referee)
Currently available anticancer therapies are inadequate and spur demand for improved technologies. Among others, the utilization of nanocarriers for anticancer drug delivery has shown great potential in cancer treatment. Nanocarriers can improve the therapeutic efficiency of the drugs with minimization of the undesirable side effects. To evaluate potential application of this technology, two forms of nanocarriers have been studied: multi-walled carbon nanotubes (MWCNTs) and apoferritin. The aim of this study was to determine, whether given cytostatics (ellipticine, etoposide and doxorubicin) are bound to these nanotransporters and how are they released from them, especially depending on pH. Since the pH of the tumor cells is lower than the pH of healthy cells it would be preferred that the drugs would release from nanocarriers at the lower pH while at the physiological pH the release of the drug would be eliminated. The results found show that ellipticine is actually released from its MWCNT- and apoferrtin-encapsulated form at acidic pH (5.0), while at pH 7.4 its interaction with nanocarriers is stable. Ellipticine released from MWCNT is activated by microsomal enzymes to reactive metabolites (13- hydroxyellipticine and 12-hydroxyellipticine) forming DNA adducts. The results indicate that both...
|
|
|
The comparison of properties of cell lines resistant to ellipticine, doxorubicin, and cisplatin
Černá, Tereza ; Poljaková, Jitka (advisor) ; Eckschlager, Tomáš (referee)
7 Abstract Neuroblastoma is the most common extracranial solid tumor of childhood. Despite advances in cancer diagnosis and therapy, the treatment of some forms of neuroblastoma is still complicated. One of the major complications of the chemotherapy is a developed drug resistance. This master thesis deals with the effect of cytostatics on protein and gene expression of selected proteins, which may contribute to chemoresistance of the human neuroblastoma cell line UKF-NB-4. The sensitive line UKF-NB-4 and the resistant line UKF-NB-4CDDP , UKF-NB-4DOXO and UKF-NB-4ELLI were exposed to cisplatin, doxorubicin, ellipticine for 24, 48 and 72 hours. The Western blot analysis showed that cytostatic agents cisplatin, doxorubicin or ellipticine added to the sensitive neuroblastoma cell line UKF-NB-4 in amounts which are added to resistant neuroblastoma cell lines in order to maintain resistance induced expression of p53 and reduced expression of retinoblastoma protein pRb after 72 hours of cultivation. Differences in the expression of RAS protein, cytochrome P450 1A1, 3A4 and cytochrome b5 has not been shown. Changes in the expression of the studied proteins in resistant lines UKF-NB-4CDDP , UKF-NB-4DOXO and UKF-NB-4ELLI cultured with and without cytostatic agents were not detected by the Western blot analysis....
|
|
|
Immunocomplexes of IL-2 and anti-IL-2 mAbs as a novel class of selective and extremely potent immunostimulators
Tomala, Jakub ; Kovář, Marek (advisor) ; Smetana, Karel (referee) ; Špíšek, Radek (referee)
vi ABSTRACT IL-2 has been used in cancer therapy and also for other applications like treatment of chronic viral infections or as an adjuvant for vaccines. However, treatment with IL-2 is rather difficult due to its severe side effects. These toxicities, associated with high-dose treatment necessary for IL-2 to function, have been found the most limiting factor for IL- 2 applications. Further, particular anti-IL-2 monoclonal antibodies (mAb) can actually increase biological activity of IL-2 rather than block it. Binding of IL-2 to anti-IL-2 mAb creates a superagonistic immunocomplexes which have dramatically higher and selective biological activity in comparison to free IL-2 in vivo. Such approach may finally over- come the difficulties associated with administration of IL-2, thus opening brand new scopes for IL-2 and its application not only in the field of tumor therapy. We have shown that IL-2 immunocomplexes composed of IL-2 and anti-IL-2 mAb S4B6 (IL-2/S4B6) stimulate predominantly cells expressing CD122 and CD132 (dimeric IL-2 receptor), i.e. NK and MP CD8+ T cells, with Treg, T and NKT cells being expanded as well. IL-2/S4B6 are able to drive the expansion of activated naive CD8+ T cells into functional memory-like CD8+ T cells. Moreover, these immunocomplexes exert therapeu- tical potential alone...
|
|
|
Depletion of Treg cells for potentiation of cancer treatment with HPMA copolymer-bound cytostatic drug conjugates"
Dvořáková, Barbora ; Kovář, Marek (advisor) ; Reiniš, Milan (referee)
Tumor diseases are severe problem worldwide with increasing number of patients suffering from various types of malignancies. Many of approved therapeutics cause serious side toxicities. Therefore, there are intensive efforts to improve cancer treatment protocols. The aim of this study was to deplete regulatory T (Treg) cells without affecting other immunocompetent cells playing a positive role in tumor eradication. Treg cells were reported to hamper anti-tumor immunity and promote tumor growth and survival. Thus, their selective elimination could lead to induction of anti-tumor responses and tumor rejection if combined with chemotherapy with selected N-(2- hydroxypropyl)methacrylamide (HPMA) copolymer-bound drug conjugates. Original approach was to deplete of Treg cells without the use of anti-CD25 mAb that has been widely exploited for Treg cell elimination; however, its long-term persistence in circulation together with inhibitory effect on activated effector cells (CD25+ ) are its main disadvantages. Thus, Treg cells were sensitized to cell cycle-specific cytostatic drugs via application of IL-2/anti-IL-2 JES6.1 mAb immunocomplexes that induce vigorous selective proliferation of this cell population. Subsequent application of cell cycle-specific cytostatics showed steep decrease of Treg cell...
|
|
|
Study of expression of transferrin receptors (TfR1) and their utilization in nanomedicine
Krausová, Kateřina ; Fohlerová, Zdenka (referee) ; Heger,, Zbyněk (advisor)
Bachelor thesis deals with the expression of the transferrin receptor (TfR1) and its use in nanomedicine. During the last decade, nanotechnology emerged as one of the central milestones in connecting all scientific and technological disciplines. Nanomedicine already demonstrated efficacy not only in animal models of cancer but also in clinical practice. The theoretical part is not only aimed at cancer of the human population, but also at the possibilities of targeted drug delivery into the tumor tissue, which greatly reduces the otherwise serious side effects of conventional treatment – systemic toxicity. The practical part is focused on optimization for studying the expression of the transferrin receptor, a protein overexpressed by neoplastic cells aiming to enrich the higher metabolic needs of tumor cells. The optimal conditions were as follows: lysate of 50 000 cells applied with nonreducing nondenaturing buffer and the concentration of the primary antibody of 1.0 𝜇g/ml. Different levels of TfR1 expression were detected, depending on the type of tumor cells. The cell lines of neuroblastoma, prostate cancer (occurence in every 7th man) and breast cancer (occurence in every 8th woman) were selected for the next experiments. Via this transferrin receptor, apoferritin, which is a protein storaging iron ions in many organisms, can be internalized into cells. Artificially, the internal cavity of apoferritin may be used for encapsulation and transport of any molecules. In the case of this bachelor thesis, the apoferritin was used for delivery of doxorubicin. Doxorubicin has been used for cancer treatment for more than 30 years; however, its administered dose is limited by its high toxicity. This can be reduced by its encapsulation in a suitable vector for targeted transport to the tumor cells only. Apoferritin could serve as such suitable vector. In this thesis, the suitable usage of apoferritin as a nanocarrier for chemotherapeutic delivery was confirmed. Its molecule size of 10-12 nm allows it to employ the effect of increased permeability and retention. At the same time, this size makes it possible to avoid renal clearance. The properties of encapsulated doxorubicin are not affected by apoferritin, thus preserving its toxicity for cells with a high level of TfR1 expression (30% growth inhibition of these cells after 24 h of treatment).
|
|
|
The proteomic study of abiotic stress of plants.
Barabášová, Kamila ; Podlipná, Radka (advisor) ; Smrček, Stanislav (referee)
Keywords: Arabidopsis thaliana, phytoremediation, abiotic stress, ibuprofene, doxorubicin, two-dimensional electrophoresis Nowadays, develop of the pharmaceutical industry is very fast. Reason of this trend is ever-increasing number of diseases, lifestyle and still increasing demand for the drugs. With this trend growing interest in the analysis of the residues of pharmaceuticals in the environment which is result of incomplete wastewater treatment. This diploma thesis is studying effect of cytostatic drugs, specifically doxorubicin and one of the most widely used analgesics - ibuprofen, at the proteome level of the model plant Arabidopsis thaliana. Proteins isolated from plants exposed to the drugs were separated by two-dimensional electrophoresis. Comparing of protein maps by PDQest program (Bio-Rad, USA) was found several proteins whose expression was affected by the presence of drugs in the culture medium. Selected proteins were identified by LC - MS / MS.
|
|
|
Nanomaterials as a platform for the doxorubicin transport - Fluorescence imaging
Blažková, Iva
Doxorubicin (DOX) is an important anthracycline antineoplastic drug used to treat a variety of cancers. As well as other antineoplastic agents, DOX has negative side effects; the most serious one is cardiotoxicity. Conjugation of DOX with nanomaterials could help to reduce its adverse effects. The presented thesis entitled ,,Nanomaterials as a platform for the DOX transport -- Fluorescence imaging" is primarily focused on the study of DOX interaction with biomolecules such as amino acids and albumin. The interaction was analysed by fluorescence spectrometry and by other analytical methods and significant interaction with amino acids as well as with protein albumin was detected. Next work was focused on the utilization of nanoparticles in DOX transport. DOX was conjugated with fullerenes or encapsulated in liposomes and properties of these nanoconstructs, in vitro and in vivo, were analysed. Both of these nanomaterials seemed to be good nanotransporters for DOX targeted delivery.
|
guest ::
