Synthesis and characterization of poly (e-kaprolakton) / selenium nanoparticles biocomposite.

Ova doktorska disertacija predstavlja multidisciplinarno istraživanje u okviru kojeg su utvrđeni optimalni uslovi sinteze sfernih čestica poli (ε-kaprolaktona) (PCL-a) sa inkorporiranim, sintetisanim nanočesticama selena; izvršena je detaljna karakterizacija novodobijenog biokompozita različitim metodama fizičkohemijske analize; i ispitana su biološka svojstva značajna za njegovu potencijalnu primenu. Istraživanja su realizovana kroz tri faze...This doctoral dissertation represents a multidisciplinary study in which optimal synthesis conditions of poly-(ε-caprolactone) (PCL) spherical particles with incorporated selenium nanoparticles were determined, comprehensive characterization of obtained systems by various physicochemical methods was conducted and investigations of biological properties significant for the potential application of this biocomposite material were performed. In order to complete these tasks investigations were carried out into three consequent stages..

Nobelova nagrada za hemiju 2011 - kristali koji to nisu bili

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry for 2011 to Daniel Shechtman, professor of material science at Israel Institute of Technology - Technion, Haifa 'for the discovery of quasicrystals' - new form of solid materials with regular patterns that never repeat themselves. However, the configuration found in quasicrystals was considered impossible, and Daniel Shechtman had to fight a fierce battle against established science. The Nobel Prize in Chemistry 2011 has fundamentally altered how chemists conceive of solid matter.Dobitnik Nobelove nagrade za hemiju za 2011. godinu je Danijel Šehtman sa Izraelskog instituta za tehnologiju - Technion u Haifi. Švedska kraljevska akademija je 70-godišnjem profesoru nauke o materijalima dodelila prestižnu nagradu za otkriće kvazi-kristala - čvrstih supstanci koje su ispoljavale svojstva kristala, ali se nisu uklapale u osnovne definicije kristalografije, nauke o kristalima. Školski udžbenici su nas učili da su atomi u kristalima raspoređeni u okviru osnovnih obrazaca, tzv. jediničnih ćelija, koji se periodično ponavljaju u sva tri pravca u prostoru. Ako zamislimo da su jedinične ćelije LEGO kockice, onda slaganjem kockica na određen način možemo ispuniti trodimenzionalni prostor. Ovako se jednostavno mogla opisati struktura svih kristalnih supstanci, ali je otkriće kvazikristala sredinom osamdesetih godina prošlog veka unelo pravu pometnju u naučnu zajednicu i uzdrmalo same temelje kristalografije. Priča koja sledi, između ostalog, ukazuje da otvorenost uma, istrajnost i spremnost ka preispitivanju postojećih naučnih 'istina' jesu možda najvažnije osobine koje bi trebalo da krase svakog naučnika

Cobalt Complex with Thiazole-Based Ligand as New Pseudomonas aeruginosa Quorum Quencher, Biofilm Inhibitor and Virulence Attenuator

Pseudomonas aeruginosa is one of the most dreaded human pathogens, because of its intrinsic resistance to a number of commonly used antibiotics and ability to form sessile communities (biofilms). Innovative treatment strategies are required and that can rely on the attenuation of the pathogenicity and virulence traits. The interruption of the mechanisms of intercellular communication in bacteria (quorum sensing) is one of such promising strategies. A cobalt coordination compound (Co(HL)(2)) synthesized from (E)-2-(2-(pyridin-2-ylmethylene) hydrazinyl)-4-(p-tolyl) thiazole (HL) is reported herein for the first time to inhibit P. aeruginosa 3-oxo-C12-HSL-dependent QS system (LasI/LasR system) and underling phenotypes (biofilm formation and virulence factors). Its interactions with a possible target, the transcriptional activator protein complex LasR-3-oxo-C12-HSL, was studied by molecular modeling with the coordination compound ligand having stronger predicted interactions than those of co-crystallized ligand 3-oxo-C12-HSL, as well as known-binder furvina. Transition metal group 9 coordination compounds may be explored in antipathogenic/antibacterial drug design

Visoki antioksidativni potencijal i mali toksični efekat selenosemikarbazonskih kompleksa

Novel metal-based compounds with therapeutic potential have become the subject of intense investigations in inorganic chemistry and biomedical science. Recently, strong dose-dependent cytotoxic activities of selenosemicarbazone metal complexes against several human cancer cell lines were demonstrated. The aim of the present study was to investigate in vitro antioxidative potential of Ni(II), Cd(II) and Zn(II) selenosemicarbazone complexes. All three investigated complexes exhibited high 2,2'-azinobis(3-ethyl-benzothiazoline-6-sulphonic acid) radical cation (ABTS(center dot+)) scavenging capacity, comparable with ascorbic acid. In an acute toxicity study, administration of the compounds was performed orally to mice at single doses. The mice were observed for clinical signs, body weight effects and mortality for 14 days, after which they were sacrificed for gross organ necropsy. The body weight did not vary after administration, and the autoptic analysis failed to show appreciable macroscopic alterations of internal organs. Generally, the compounds exhibited low toxic effects as required for further in vivo therapeutic studies.Nova jedinjenja na bazi metala sa terapeutskim dejstvom postala su predmet istraživanja u neorganskoj hemiji i biomedicinskim naukama. Pokazana je jaka dozno-zavisna citotoksična aktivnost kompleksa selenosemikarbazona na većem broju ćelijskih linija humanih ćelija kancera. Cilj rada je ispitivanje in vitro antioksidativnog dejstva selenosemikarbazonskih kompleksa nikla, cinka i kadmijuma. Sva tri ispitivana kompleksa pokazala su jaku antioksidativnu aktivnost prema ABTS radikalu, uporedivu sa aktivnošću askorbinske kiseline. Tokom ispitivanja akutne toksičnosti, jedinjenja su oralno davana miševima u pojedinačnim dozama i praćeni su klinički znaci, težina tela i mortalitet nakon 14 dana, a potom su životinje žrtvovane radi autopsije organa. Težina tela nije varirala nakon aplikacije. Generalno, jedinjenja su pokazala mali toksični efekat što i zahteva buduće in vivo terapeutsko ispitivanje

Comparative Study of the Antimicrobial Activity of Selenium Nanoparticles With Different Surface Chemistry and Structure

Although selenium nanoparticles (SeNPs) have gained attention in the scientific community mostly through investigation of their anticancer activity, a great potential of this nanomaterial was recognized recently regarding its antimicrobial activity. The particle form, size, and surface chemistry have been recognized as crucial parameters determining the interaction of nanomaterials with biological entities. Furthermore, considering a narrow boundary between beneficial and toxic effects for selenium per se, it is clear that investigations of biomedical applications of SeNPs are very demanding and must be done with great precautions. The goal of this work is to evaluate the effects of SeNPs surface chemistry and structure on antimicrobial activity against several common bacterial strains, including Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 29212), Bacillus subtilis (ATCC 6633), and Kocuria rhizophila (ATCC 9341), as well as Escherichia coli (ATCC 8739), Salmonella Abony (NCTC 6017), Klebsiella pneumoniae (NCIMB 9111) and Pseudomonas aeruginosa (ATCC 9027), and the standard yeast strain Candida albicans (ATCC 10231). Three types of SeNPs were synthesized by chemical reduction approach using different stabilizers and reducing agents: (i) bovine serum albumin (BSA) + ascorbic acid, (ii) chitosan + ascorbic acid, and (iii) with glucose. A thorough physicochemical characterization of the obtained SeNPs was performed to determine the effects of varying synthesis parameters on their morphology, size, structure, and surface chemistry. All SeNPs were amorphous, with spherical morphology and size in the range 70–300 nm. However, the SeNPs obtained under different synthesis conditions, i.e. by using different stabilizers as well as reducing agents, exhibited different antimicrobial activity as well as cytotoxicity which are crucial for their applications. In this paper, the antimicrobial screening of the selected systems is presented, which was determined by the broth microdilution method, and inhibitory influence on the production of monomicrobial and dual-species biofilm was evaluated. The potential mechanism of action of different systems is proposed. Additionally, the cytotoxicity of SeNPs was examined on the MRC-5 cell line, in the same concentration interval as for antimicrobial testing. It was shown that formulation SeNPs-BSA expressed a significantly lower cytotoxic effect than the other two formulations

Supplementary data for article: Filipović, N. R.; Borna, M.; Klisurić, O.; Pregelj, M.; Jagodić, M.; Anđelković, K. K.; Todorović, T. Synthesis, Characterization, and Thermal Behavior of Cu(II) and Zn(II) Complexes with (E)-2-[N-(1-Pyridin-2-Yl-Ethylidene)Hydrazino]Acetic Acid (AphaOH). Crystal Structure of [Zn-2(AphaO)(2)Cl-2]. Journal of Coordination Chemistry 2013, 66 (9), 1549–1560. https://doi.org/10.1080/00958972.2013.786052

Supplementary material for: [https://doi.org/10.1080/00958972.2013.786052]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1639

Comparative Study of the Antimicrobial Activity of Selenium Nanoparticles With Different Surface Chemistry and Structure

Although selenium nanoparticles (SeNPs) have gained attention in the scientific community mostly through investigation of their anticancer activity, a great potential of this nanomaterial was recognized recently regarding its antimicrobial activity. The particle form, size, and surface chemistry have been recognized as crucial parameters determining the interaction of nanomaterials with biological entities. Furthermore, considering a narrow boundary between beneficial and toxic effects for selenium per se, it is clear that investigations of biomedical applications of SeNPs are very demanding and must be done with great precautions. The goal of this work is to evaluate the effects of SeNPs surface chemistry and structure on antimicrobial activity against several common bacterial strains, including Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 29212), Bacillus subtilis (ATCC 6633), and Kocuria rhizophila (ATCC 9341), as well as Escherichia coli (ATCC 8739), Salmonella Abony (NCTC 6017), Klebsiella pneumoniae (NCIMB 9111) and Pseudomonas aeruginosa (ATCC 9027), and the standard yeast strain Candida albicans (ATCC 10231). Three types of SeNPs were synthesized by chemical reduction approach using different stabilizers and reducing agents: (i) bovine serum albumin (BSA) + ascorbic acid, (ii) chitosan + ascorbic acid, and (iii) with glucose. A thorough physicochemical characterization of the obtained SeNPs was performed to determine the effects of varying synthesis parameters on their morphology, size, structure, and surface chemistry. All SeNPs were amorphous, with spherical morphology and size in the range 70–300 nm. However, the SeNPs obtained under different synthesis conditions, i.e. by using different stabilizers as well as reducing agents, exhibited different antimicrobial activity as well as cytotoxicity which are crucial for their applications. In this paper, the antimicrobial screening of the selected systems is presented, which was determined by the broth microdilution method, and inhibitory influence on the production of monomicrobial and dual-species biofilm was evaluated. The potential mechanism of action of different systems is proposed. Additionally, the cytotoxicity of SeNPs was examined on the MRC-5 cell line, in the same concentration interval as for antimicrobial testing. It was shown that formulation SeNPs-BSA expressed a significantly lower cytotoxic effect than the other two formulations

Supplementary data for the article: Božić, A. R.; Bjelogrlić, S. K.; Novaković, I. T.; Filipović, N. R.; Petrović, P. M.; Marinković, A. D.; Todorović, T. R.; Cvijetić, I. N. Antimicrobial Activity of Thiocarbohydrazones: Experimental Studies and Alignment-Independent 3D QSAR Models. ChemistrySelect 2018, 3 (7), 2215–2221. https://doi.org/10.1002/slct.201702691

Supplementary material for: [https://doi.org/10.1002/slct.201702691]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2094

Supplementary data for the article: Božić, A.; Marinković, A.; Bjelogrlić, S.; Todorović, T. R.; Cvijetić, I. N.; Novaković, I.; Muller, C. D.; Filipović, N. R. Quinoline Based Mono- and Bis-(Thio)Carbohydrazones: Synthesis, Anticancer Activity in 2D and 3D Cancer and Cancer Stem Cell Models. RSC Advances 2016, 6 (106), 104763–104781. https://doi.org/10.1039/c6ra23940d

Supplementary material for: [https://doi.org/10.1039/c6ra23940d]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2352