TY - JOUR T1 - Effects of ursolic acid on the structural and morphological behaviours of dipalmitoyl lecithin vesicles JF - Biochimica et Biophysica Acta (BBA) - Biomembranes Y1 - 2015 A1 - Lőrincz, András A1 - Mihály, Judith A1 - Németh, Csaba A1 - András Wacha A1 - Bóta, Attila KW - DPPC KW - Freeze-fractured transmission electron-microscopy (FF-TEM) KW - Kratky camera KW - Non-bilayer lipid structure KW - peer-reviewed KW - Small- and wide-angle X-ray scattering (SWAXS) KW - Ursolic acid AB -

Effects of ursolic acid on the structural and morphological characteristics of dipalmitoyl lecithin(DPPC)-water system was studied by using differential scanning calorimetry (DSC), small- and wide-angle X-ray scattering (SWAXS), freeze-fracture method combined with transmission electron-microscopy (FF-TEM) and infrared spectroscopy (FT-IR). The surface of the uncorrelated lipid system is rippled or grained and a huge number of small, presumably unilamellar vesicles are present if the UA/DPPC molar ratio is 0.1 mol/mol or higher. Besides the destroyed layer packing of regular multilamellar vesicles, non-bilayer (e.g. cubic or hexagonal) local structures are evidenced by SAXS and FF-TEM methods. The ability of UA to induce non-bilayer structures in hydrated DPPC system originates from the actual geometry form of associated lipid and UA molecules as concluded from the FT-IR measurements and theoretical calculations. Beside numerous beneficial e.g. chemopreventive and chemotherapeutic effect of ursolic acid against cancer, their impact to modify the lipid bilayers can be utilized in liposomal formulations.

VL - 1848 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 - 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 - 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 - 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 -