TY - JOUR T1 - A biocompatible hybrid material with simultaneous calcium and strontium release capability for bone tissue repair JF - Materials Science and Engineering: C Y1 - 2016 A1 - Almeida, J. Carlos A1 - András Wacha A1 - Gomes, Pedro S. A1 - Alves, Luís C. A1 - Fernandes, M. Helena Vaz A1 - Salvado, Isabel M. Miranda A1 - Fernandes, M. Helena R. KW - Biocompatible KW - Hybrid materials KW - peer-reviewed KW - Strontium AB -

The increasing interest in the effect of strontium in bone tissue repair has promoted the development of bioactive materials with strontium release capability. According to literature, hybrid materials based on the system PDMS–{}SiO2 have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS–{}SiO2–{}CaO–{}SrO, was prepared with the incorporation of 0.05 mol of titanium per mol of SiO2. Calcium and strontium were added using the respective acetates as sources, following a sol–{}gel technique previously developed by the present authors. The obtained samples were characterized by FT-IR, solid-state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studies were performed by immersion of the samples in Kokubo's SBF for different periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed samples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity.

VL - 62 ER - TY - JOUR T1 - Amfifil polimer kotérhálók: egy újszerű nanoszerkezetű anyagcsoport JF - Magyar Kémiai Folyóirat - Kémiai Közlemények Y1 - 2015 A1 - Szabó, Ákos A1 - Mezey, Péter A1 - Fodor, Csaba A1 - Domján, Attila A1 - Kali, Gergely A1 - Stumphauser, Tímea A1 - Erdődi, Gábor A1 - Thomann, Ralf A1 - Németh, Péter A1 - Szanka, István A1 - Illés, Gergely A1 - Haraszti, Márton A1 - Pásztor, Szabolcs A1 - Bóta, Attila A1 - András Wacha A1 - Süvegh, Károly A1 - Iván, Béla KW - no-peer-review VL - 121 ER - TY - JOUR T1 - Inherently fluorescent and porous zirconia colloids: preparation, characterization and drug adsorption studies JF - J. Mater. Chem. B Y1 - 2015 A1 - Naszályi Nagy, Lívia A1 - Mihály, Judith A1 - Polyák, András A1 - Debreczeni, Balázs A1 - Császár, Barbara A1 - Szigyártó, Imola Csilla A1 - András Wacha A1 - Czégény, Zsuzsanna A1 - Jakab, Emma A1 - Klébert, Szilvia A1 - Drotár, Eszter A1 - Dabasi, G A1 - Bóta, Attila A1 - Balogh, Lajos A1 - Kiss, Éva KW - peer-reviewed AB - Porous, fluorescent zirconia particles of nearly 380 nm diameter were prepared without template molecules or labeling dyes. The porous structure is the result of aggregation-induced particle formation. The inherent fluorescence is assigned to coordinatively unsaturated Zr4+ ions at the sol–{}gel derived ZrO2 surface. After physico-chemical characterization of the native zirconia particles carboxyl and/or amine bearing drug molecules (D,L-\ensuremath{\alpha}-difluoromethylornithine –{} DFMO, ursolic acid –{} UA and doxorubicin –{} DOX) were adsorbed onto their surface, and the products were analyzed with Fourier-transform infrared spectroscopy (FTIR), thermogravimetry (TG), small-angle X-ray scattering (SAXS), fluorimetry and zeta potential vs. pH measurements. We have found that DOX complexes coordinatively unsaturated Zr4+ ions without dislocating them, while carboxyl-bearing drugs interact with basic surface Zr–{}OH sites eliminating some of the carbonate species. The adsorption of UA at the zirconia surface shifts considerably the isoelectric point of the surface and thus provides kinetic stability to the particles at physiological pH. An in vivo biodistribution study in two healthy dogs performed by SPECT/CT detection after 99mTc labeling of the nanocarriers has shown the possibility of drug delivery application. VL - 3 ER - TY - JOUR T1 - PDMS-SiO2 hybrid materials – A new insight into the role of Ti and Zr as additives JF - Polymer Y1 - 2015 A1 - Almeida, J. Carlos A1 - András Wacha A1 - Bóta, A. A1 - Almásy, L. A1 - Vaz Fernandes, M. Helena A1 - Margaça, Fernanda M. A. A1 - Miranda Salvado, Isabel M. KW - CREDO KW - Hybrid materials KW - Sol–gel KW - Structure AB - The last two decades have seen a remarkable growth in the design of new hybrid materials applied to different areas, from photonics to biomaterials, together with new coating materials with self-cleaning features. Among the various systems studied, the PDMS-SiO2 system remains as a good basis for further developments by adding other compounds such as transition metals. In this work, a detailed study of the influence of titanium or zirconium in the chemical structure and final microstructure of such hybrids was made. It was concluded that, due to the lower reactivity of the titanium alkoxide during the sol–gel preparation process, titanium is preferably located on the surface of secondary particles of silica, unlike the zirconium, which being more reactive, positions on the surface of the primary particles. This difference leads to xerogels with dissimilar characteristics and morphologies. VL - 72 SN - 0032-3861 UR - http://www.sciencedirect.com/science/article/pii/S0032386115300732 JO - Polymer ER - TY - JOUR T1 - Physicochemical characterization of artificial nanoerythrosomes derived from erythrocyte ghost membranes JF - Colloids and Surfaces B: Biointerfaces Y1 - 2015 A1 - Deák, Róbert A1 - Mihály, Judith A1 - Szigyártó, Imola Cs. A1 - András Wacha A1 - Lelkes, Gábor A1 - Bóta, Attila KW - CREDO KW - Erythrocyte KW - Freeze fracture TEM KW - Infrared spectroscopy KW - Nanoerythrosomes KW - Protein to lipid ratio KW - Small angle X-ray scattering (SAXS) KW - Vesicles AB - Colloidal stabile nanoerythrosomes with 200 nm average diameter were formed from hemoglobin-free erythrocyte ghost membrane via sonication and membrane extrusion. The incorporation of extra lipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC), added to the sonicated ghosts, caused significant changes in the thermotropic character of the original membranes. As a result of the increased DPPC ratio the chain melting of the hydrated DPPC system and the characteristic small angle X-ray scattering (SAXS) of the lipid bilayers appeared. Significant morphological changes were followed by transmission electron microscopy combined with freeze fracture method (FF-TEM). After the ultrasonic treatment the large entities of erythrocyte ghosts transformed into nearly spherical nanoerythrosomes with diameters between 100 and 300 nm and at the same time a great number of 10–30 nm large membrane proteins or protein clusters were dispersed in the aqueous medium. The infrared spectroscopy (FT-IR) pointed out, that the sonication did not cause changes in the secondary structures of the membrane proteins under our preparation conditions. About fivefold of extra lipid – compared to the lipid content of the original membrane – caused homogeneous dispersion of nanoerythrosomes however the shape of the vesicles was not uniform. After the addition of about tenfold of DPPC, monoform and monodisperse nanoerythrosomes became typical. The outer surfaces of these roughly spherical objects were frequently polygonal, consisting of a net of pentagons and hexagons. VL - 135 SN - 0927-7765 UR - http://www.sciencedirect.com/science/article/pii/S0927776515301004 JO - Colloids and Surfaces B: Biointerfaces ER - TY - JOUR T1 - The supramolecular chemistry of gold and l-cysteine: Formation of photoluminescent, orange-emitting assemblies with multilayer structure JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects Y1 - 2015 A1 - Söptei, Balázs A1 - Mihály, Judith A1 - Szigyártó, Imola Cs. A1 - András Wacha A1 - Németh, Csaba A1 - Bertóti, Imre A1 - May, Zoltán A1 - Baranyai, Péter A1 - Sajó, István E. A1 - Bóta, Attila KW - CREDO VL - 470 UR - http://linkinghub.elsevier.com/retrieve/pii/S092777571500076X ER - TY - JOUR T1 - Synthesis of Poly}(methyl methacrylate)-poly(poly(ethylene glycol) methacrylate)-polyisobutylene ABCBA Pentablock Copolymers} by Combining Quasiliving Carbocationic} and Atom Transfer Radical Polymerizations} and Characterization Thereof} JF - Journal of Macromolecular Science, Part A Y1 - 2015 A1 - Szabó, Ákos A1 - András Wacha A1 - Thomann, Ralf A1 - Szarka, Györgyi A1 - Bóta, Attila A1 - Iván, Béla KW - Kratky camera KW - peer-reviewed VL - 52 ER - TY - JOUR T1 - Szervetlen gyógyszerhordozó nanorészecskék el\H oáll{ítása és jellemzése JF - Magyar Kémiai Folyóirat - Kémiai Közlemények Y1 - 2015 A1 - Nagyné Naszályi, Lívia A1 - Pálmai, Marcell A1 - Peth\H o, Adrienn A1 - Császár, Barbara A1 - Polyák, András A1 - Szigyártó, Imola Csilla A1 - Mihály, Judith A1 - András Wacha A1 - L\H orincz, András KW - no-peer-review VL - 121 ER - TY - JOUR T1 - Effect of metal oxide on surface area and pore size of water-dispersible colloids from three German silt loam topsoils JF - Geoderma Y1 - 2014 A1 - Jiang, Canlan A1 - Séquaris, Jean-Marie A1 - András Wacha A1 - Bóta, Attila A1 - Vereecken, Harry A1 - Klumpp, Erwin KW - CREDO VL - 235-236 UR - http://linkinghub.elsevier.com/retrieve/pii/S0016706114002882 ER - TY - JOUR T1 - Intercalation of Bovine Serum Albumin Coated Gold Clusters Between Phospholipid Bilayers: Temperature-Dependent Behavior of Lipid-AuQC@BSA Assemblies with Red Emission and Superlattice Structure JF - The Journal of Physical Chemistry B Y1 - 2014 A1 - Söptei, Balázs A1 - Mihály, Judith A1 - Visy, Júlia A1 - András Wacha A1 - Bóta, Attila AB -

A method has been developed to encapsulate bovine serum albumin (BSA)-coated gold quantum clusters (AuQC@BSA) in a multilamellar system of dipalmitoylphosphatidylcholine (DPPC). Results have shown that intercalation of AuQC@BSA particles into lipid bilayers occurs in the presence of CaCl2. Intense red photoluminescence emission was observed after encapsulation of the clusters. A well-defined structure was found with periodic distances drastically larger than that in the pure DPPC/water system. Although Ca2+ ions can change the dipole characteristics of the lipid bilayer surface, leading to unbinding between the bilayers of multilamellar DPPC/water system, the repulsion is shielded in the presence of AuQC@BSA particles. A coherent superlattice structure evolves due to mixed Ca2+-DPPC and Ca2+-AuQC@BSA interactions. Studies at different temperatures have suggested a correlation between the luminescence properties of the clusters and phase transition of the lipid layers. The temperature-dependent behavior assumes the connection between the coating and the lipid bilayer surface. Temperature-dependent features of lipid intercalated Au clusters provide new opportunities in their application.

VL - 118 SN - 1520-6106 UR - http://dx.doi.org/10.1021/jp4124138 IS - 14 JO - Intercalation of Bovine Serum Albumin Coated Gold Clusters Between Phospholipid BilayersJ. Phys. Chem. B ER - TY - JOUR T1 - Mechanical Stability and Fibrinolytic Resistance of Clots Containing Fibrin, DNA, and Histones JF - Journal of Biological ChemistryJournal of Biological Chemistry Y1 - 2013 A1 - Longstaff, Colin A1 - Varjú, Imre A1 - Sótonyi, Péter A1 - Szabó, László A1 - Krumrey, Michael A1 - Hoell, Armin A1 - Bóta, Attila A1 - Varga, Zoltán A1 - Komorowicz, Erzsébet A1 - Kolev, Krasimir KW - DNA KW - Fibrinolysis KW - Histones KW - Neutrophil KW - Neutrophil Extracellular Trap KW - Tissue Plasminogen Activator (tPA) AB -

Neutrophil extracellular traps are networks of DNA and associated proteins produced by nucleosome release from activated neutrophils in response to infection stimuli and have recently been identified as key mediators between innate immunity, inflammation, and hemostasis. The interaction of DNA and histones with a number of hemostatic factors has been shown to promote clotting and is associated with increased thrombosis, but little is known about the effects of DNA and histones on the regulation of fibrin stability and fibrinolysis. Here we demonstrate that the addition of histone-DNA complexes to fibrin results in thicker fibers (increase in median diameter from 84 to 123 nm according to scanning electron microscopy data) accompanied by improved stability and rigidity (the critical shear stress causing loss of fibrin viscosity increases from 150 to 376 Pa whereas the storage modulus of the gel increases from 62 to 82 pascals according to oscillation rheometric data). The effects of DNA and histones alone are subtle and suggest that histones affect clot structure whereas DNA changes the way clots are lysed. The combination of histones + DNA significantly prolongs clot lysis. Isothermal titration and confocal microscopy studies suggest that histones and DNA bind large fibrin degradation products with 191 and 136 nm dissociation constants, respectively, interactions that inhibit clot lysis. Heparin, which is known to interfere with the formation of neutrophil extracellular traps, appears to prolong lysis time at a concentration favoring ternary histone-DNA-heparin complex formation, and DNase effectively promotes clot lysis in combination with tissue plasminogen activator.

VL - 288 SN - 0021-9258, 1083-351X UR - http://www.jbc.org/content/288/10/6946 IS - 10 JO - J. Biol. Chem. ER - TY - JOUR T1 - A Closer Look at the Structure of Sterically Stabilized Liposomes: A Small-Angle X-ray Scattering Study JF - The Journal of Physical Chemistry BThe Journal of Physical Chemistry B Y1 - 2010 A1 - Varga, Zoltán A1 - Berényi, Szilvia A1 - Szokol, Bálint A1 - Őrfi, László A1 - Kéri, György A1 - Peták, István A1 - Hoell, Armin A1 - Bóta, Attila VL - 114 SN - 1520-6106, 1520-5207 UR - http://pubs.acs.org/doi/abs/10.1021/jp9109207 IS - 20 JO - A Closer Look at the Structure of Sterically Stabilized Liposomes ER - TY - BOOK T1 - X-ray Data Booklet Y1 - 2009 A1 - Attwood, David A1 - Gullikson, Eric A1 - Howells, Malcolm A1 - Kim, Kwang-Je A1 - Kirz, Janos A1 - Kortright, Jeffrey A1 - Lindau, Ingolf A1 - Liu, Yanwei A1 - Pianetta, Piero A1 - Robinson, Arthur A1 - Scofield, James A1 - Underwood, James A1 - Williams, Gwyn A1 - Winick, Herman PB - Lawrence Berkeley National Laboratory, University of California CY - Berkeley, CA UR - http://xdb.lbl.gov ER - TY - BOOK T1 - Az anyagvizsgálat diffrakciós módszerei Y1 - 1987 A1 - Schultz, Jerold M PB - Műszaki Könyvkiadó CY - Budapest SN - 9631068544 UR - http://link.oszk.hu/libriurl.php?LN=hu&DB=any&SRY=an&SRE=000000604970 ER - TY - BOOK T1 - Structure Analysis by Small-Angle X-Ray and Neutron Scattering Y1 - 1987 A1 - Feigin, L. A. A1 - Svergun, D. I. PB - Plenum Press CY - New York SN - 0306426293 UR - http://www.embl-hamburg.de/biosaxs/reprints/feigin_svergun_1987.pdf ER -