Antibody conjugated PLGA nanocarriers and superparmagnetic nanoparticles for targeted delivery of oxaliplatin to cells from colorectal carcinoma

Anti-CD133 monoclonal antibody (Ab)-conjugated poly(lactide-co-glycolide) (PLGA) nanocarriers, for the targeted delivery of oxaliplatin (OXA) and superparamagnetic nanoparticles (IO-OA) to colorectal cancer cells (CaCo-2), were designed, synthesized, characterized, and evaluated in this study. The co-encapsulation of OXA and IO-OA was achieved in two types of polymeric carriers, namely, PLGA and poly(lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) by double emulsion. PLGA_IO-OA_OXA and PEGylated PLGA_IO-OA_OXA nanoparticles displayed a comparable mean diameter of 207 ± 70 nm and 185 ± 119 nm, respectively. The concentration of the released OXA from the PEGylated PLGA_IO-OA_OXA increased very rapidly, reaching ~100% release after only 2 h, while the PLGA_IO-OA_OXA displayed a slower and sustained drug release. Therefore, for a controlled OXA release, non-PEGylated PLGA nanoparticles were more convenient. Interestingly, preservation of the superparamagnetic behavior of the IO-OA, without magnetic hysteresis all along the dissolution process, was observed. The non-PEGylated nanoparticles (PLGA_OXA, PLGA_IO-OA_OXA) were selected for the anti-CD133 Ab conjugation. The affinity of Ab-coated nanoparticles for CD133-positive cells was examined using fluorescence microscopy in CaCo-2 cells, which was followed by a viability assay. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Grantová Agentura České Republiky, GA ČR: 19-02889S, A2_FCHI_2021_01

Nanosized TiO2: a promising catalyst for the aldol condensation of furfural with acetone in biomass upgrading

Nanosized TiO2catalyst was successfully prepared by a simple green procedure and used in liquid phasealdol condensation of furfural with acetone, a key step in bio-fuel processing. In order to determinethe effect of calcination temperature on catalytic properties of TiO2, the as-prepared TiO2and calcinedTiO2(150–900◦C) were studied by XRD, BET, TPD-CO2/NH3, TGA/DTG and FTIR evaluation. The catalyticperformance of TiO2samples in aldol condensation of furfural with acetone was evaluated and comparedwith that of Mg–Al hydrotalcites and a BEA zeolite. These experiments showed that uncalcined TiO2possessed reasonable activity in aldol condensation of furfural to acetone and resulted in commonlyproduced condensation products. The observed catalytic behavior of TiO2could be competitive withthat reported for other inorganic solids. The calcination of TiO2resulted, however, in a decrease in itscatalytic activity due to extensive dehydration and surface dehydroxylation as well as due to changes oftextural properties resulting in a decrease in the amount of accessible active sites. Thanks to its advancedproperties, nanosized TiO2is a promising catalyst for aldol condensation of furfural with acetone andcould broaden possibilities for optimizing conditions for bio-fuel production

Automatický platební terminál řízený pomocí programovatelného automatu

Prezenční455 - Katedra měřicí a řídicí technikyNeuveden

Automatické řízení provozu parkoviště pomocí programovatelného automatu

Import 11/10/2006Prezenční455 - Katedra měřicí a řídicí technik

Targeting the Virus Capsid as a Tool to Fight RNA Viruses

Several strategies have been developed to fight viral infections, not only in humans but also in animals and plants. Some of them are based on the development of efficient vaccines, to target the virus by developed antibodies, others focus on finding antiviral compounds with activities that inhibit selected virus replication steps. Currently, there is an increasing number of antiviral drugs on the market; however, some have unpleasant side effects, are toxic to cells, or the viruses quickly develop resistance to them. As the current situation shows, the combination of multiple antiviral strategies or the combination of the use of various compounds within one strategy is very important. The most desirable are combinations of drugs that inhibit different steps in the virus life cycle. This is an important issue especially for RNA viruses, which replicate their genomes using error-prone RNA polymerases and rapidly develop mutants resistant to applied antiviral compounds. Here, we focus on compounds targeting viral structural capsid proteins, thereby inhibiting virus assembly or disassembly, virus binding to cellular receptors, or acting by inhibiting other virus replication mechanisms. This review is an update of existing papers on a similar topic, by focusing on the most recent advances in the rapidly evolving research of compounds targeting capsid proteins of RNA viruses

Liquid-Phase Synthesis of Nickel Nanoparticles stabilized by PVP and study of their structural and magnetic properties

We have synthesized nickel nanoparticles using nickel chloride as a precursor in ethanol using PVP (Poly Vinyl Pyrrolidone) as a surfactant and hydrazine hydrate as reducing agent at 60 °C in a facile manner. The structural analysis showed that particles are face-centered cubic and monodisperse within the PVP matrix with average size about 3 nm. The magnetic analysis shows the superparamagnetism of the single-domain nickel nanoparticles with the blocking temperature (Tb) exists around 14 K with clear hysteretic effect observation below this blocking temperature

Sekvenace vybranych casti genomu bakterie Rhodobacter capsulatus SB1003

The international sequencing genome project of Rhodobacter capsulatus SB1003 was started in 1996 with the objective to determine the complete nucleotide sequence of the genome and to analyze it. The project started with construction of a cosmid library. This dissertation describes a part of the project, namely sequencing and analysis of cosmide clones c24-c26 and c77-c81. These clones represent two parts of Rhodobacter chromosome. Subclone libraries were prepared from the cosmids and DNA of the subclones was isolated and sequenced. The methods of shotgun sequencing and "RANDI" together with methods of targeted cloning were used to obtain the final nucleotide sequence. All together about 1600 DNA samples were sequenced and assembled to two contigs (c24-c26 and c77-c81). Nucleotide sequence of these contigs was analyzed using computer-based programs. Open reading frames representing genes were identified and translated into corresponding amino acids sequences. These sequences were compared with entries in protein databases. Based on homologies potential biological functions of these proteins were predicted. In the first part of the project, covering cosmids c 24, c25 and c26, 89 open reading frames were identified and functions were predicted for 49 proteins. 27 proteins had significant homologies to hypothetical proteins of unknown function. No significant homologies were found for 13 proteins. In the second part of the project, covering cosmids c77, c78, c79, c80 and c81, 115 open reading frames were identified. 86 potential proteins were found to be highly homologous to proteins in databases. 20 proteins had significant homologies to hypothetical proteins of unknown function. 9 proteins had no significant homologies to proteins in databases. Several gene clusters were found. These clusters are involved in biosynthesis and metabolism of amino acids, lipids and sugars, photosynthesis, production of polyhydroxyalkanoic acids, biosynthesis of carriers and transport systems and DNA replication. In addition, genes of viral origin were identified and characterized. The nucleotide sequence encoding transfer RNA for leucin was also determined. The clusters of genes for photosyntesis and production of polyhydroxyalkanoic acids were characterized in detail. The resulting sequences will be deposited in gene and protein databases. The set of subclones, prepared from individual cosmids, will be used in further studies of individual gene functions using methods of functional genomics. The results of our work are available on the internet page http://charon.img.cas.cz/rhodo/ target=NewWindow> http://charon.img.cas.cz/rhodo/ Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Synthesis and Properties of Nanosized Stoichiometric Cobalt Ferrite Spinel

Nanoparticles with controllable sizes of ferrite spinel CoFe2O4 were formed by thermal treatment of cobalt-iron glycerolate. Thermal behavior during the heating was studied by differential thermal analysis combined with thermogravimetry. The precursor, as well as the prepared nanoparticles, were analyzed by a broad spectrum of analytic techniques (X-Ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), Energy dispersive spectroscopy (EDS), Atomic absorption spectroscopy (AAS), Scanning electron microscopy (SEM), and Raman spectroscopy). The particle size of nanoparticles was obtained from Transmission electron microscopy and also calculated using Scherrer formula. A vibrating sample magnetometer (VSM) in a Physical Property Measurement System was used to analyze the magnetic properties of nanoparticles

Effect of Small Polyanions on In Vitro Assembly of Selected Members of Alpha-, Beta- and Gammaretroviruses

The assembly of a hexameric lattice of retroviral immature particles requires the involvement of cell factors such as proteins and small molecules. A small, negatively charged polyanionic molecule, myo-inositol hexaphosphate (IP6), was identified to stimulate the assembly of immature particles of HIV-1 and other lentiviruses. Interestingly, cryo-electron tomography analysis of the immature particles of two lentiviruses, HIV-1 and equine infectious anemia virus (EIAV), revealed that the IP6 binding site is similar. Based on this amino acid conservation of the IP6 interacting site, it is presumed that the assembly of immature particles of all lentiviruses is stimulated by IP6. Although this specific region for IP6 binding may be unique for lentiviruses, it is plausible that other retroviral species also recruit some small polyanion to facilitate the assembly of their immature particles. To study whether the assembly of retroviruses other than lentiviruses can be stimulated by polyanionic molecules, we measured the effect of various polyanions on the assembly of immature virus-like particles of Rous sarcoma virus (RSV), a member of alpharetroviruses, Mason-Pfizer monkey virus (M-PMV) representative of betaretroviruses, and murine leukemia virus (MLV), a member of gammaretroviruses. RSV, M-PMV and MLV immature virus-like particles were assembled in vitro from truncated Gag molecules and the effect of selected polyanions, myo-inostol hexaphosphate, myo-inositol, glucose-1,6-bisphosphate, myo-inositol hexasulphate, and mellitic acid, on the particles assembly was quantified. Our results suggest that the assembly of immature particles of RSV and MLV was indeed stimulated by the presence of myo-inostol hexaphosphate and myo-inositol, respectively. In contrast, no effect on the assembly of M-PMV as a betaretrovirus member was observed

Distinct Roles for Nucleic Acid in In Vitro Assembly of Purified Mason-Pfizer Monkey Virus CANC Proteins

In contrast to other retroviruses, Mason-Pfizer monkey virus (M-PMV) assembles immature capsids in the cytoplasm. We have compared the ability of minimal assembly-competent domains from M-PMV and human immunodeficiency virus type 1 (HIV-1) to assemble in vitro into virus-like particles in the presence and absence of nucleic acids. A fusion protein comprised of the capsid and nucleocapsid domains of Gag (CANC) and its N-terminally modified mutant (ΔProCANC) were used to mimic the assembly of the viral core and immature particles, respectively. In contrast to HIV-1, where CANC assembled efficiently into cylindrical structures, the same domains of M-PMV were assembly incompetent. The addition of RNA or oligonucleotides did not complement this defect. In contrast, the M-PMV ΔProCANC molecule was able to assemble into spherical particles, while that of HIV-1 formed both spheres and cylinders. For M-PMV, the addition of purified RNA increased the efficiency with which ΔProCANC formed spherical particles both in terms of the overall amount and the numbers of completed spheres. The amount of RNA incorporated was determined, and for both rRNA and MS2-RNA, quantities similar to that of genomic RNA were encapsidated. Oligonucleotides also stimulated assembly; however, they were incorporated into ΔProCANC spherical particles in trace amounts that could not serve as a stoichiometric structural component for assembly. Thus, oligonucleotides may, through a transient interaction, induce conformational changes that facilitate assembly, while longer RNAs appear to facilitate the complete assembly of spherical particles