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Feraru A, Tóth ZR, Mureșan-Pop M, Baia M, Gyulavári T, Páll E, Turcu RVF, Magyari K, Baia L. Anionic Polysaccharide Cryogels: Interaction and In Vitro Behavior of Alginate-Gum Arabic Composites. Polymers (Basel) 2023; 15:polym15081844. [PMID: 37111992 PMCID: PMC10146865 DOI: 10.3390/polym15081844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/31/2023] [Accepted: 04/09/2023] [Indexed: 04/29/2023] Open
Abstract
In the present study, polysaccharide-based cryogels demonstrate their potential to mimic a synthetic extracellular matrix. Alginate-based cryogel composites with different gum arabic ratios were synthesized by an external ionic cross-linking protocol, and the interaction between the anionic polysaccharides was investigated. The structural features provided by FT-IR, Raman, and MAS NMR spectra analysis indicated that a chelation mechanism is the main process linking the two biopolymers. In addition, SEM investigations revealed a porous, interconnected, and well-defined structure suitable as a scaffold in tissue engineering. The in vitro tests confirmed the bioactive character of the cryogels through the development of the apatite layer on the surface of the samples after immersion in simulated body fluid, identifying the formation of a stable phase of calcium phosphate and a small amount of calcium oxalate. Cytotoxicity tests performed on fibroblast cells demonstrated the non-toxic effect of alginate-gum arabic cryogel composites. In addition, an increase in flexibility was noted for samples with a high gum arabic content, which determines an appropriate environment to promote tissue regeneration. The newly obtained biomaterials that exhibit all these properties can be successfully involved in the regeneration of soft tissues, wound management, or controlled drug release systems.
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Affiliation(s)
- Alexandra Feraru
- Doctoral School of Physics, Babes-Bolyai University, M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, T. Laurian 42, 400271 Cluj-Napoca, Romania
| | - Zsejke-Réka Tóth
- Doctoral School of Physics, Babes-Bolyai University, M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, T. Laurian 42, 400271 Cluj-Napoca, Romania
| | - Marieta Mureșan-Pop
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, T. Laurian 42, 400271 Cluj-Napoca, Romania
| | - Monica Baia
- Faculty of Physics, Babes-Bolyai University, M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania
- Institute for Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, Fântânele 30, 400294 Cluj-Napoca, Romania
| | - Tamás Gyulavári
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich B. Sqr. 1, 6720 Szeged, Hungary
| | - Emőke Páll
- Faculty of Veterinary Medicine, University of Agricultural Science and Veterinary Medicine, Manastur 3-5, 400372 Cluj-Napoca, Romania
| | - Romulus V F Turcu
- Faculty of Physics, Babes-Bolyai University, M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania
- National Institute for Research and Development of Isotopic and Molecular Technologies, Donath 67-103, 400293 Cluj-Napoca, Romania
| | - Klára Magyari
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, T. Laurian 42, 400271 Cluj-Napoca, Romania
| | - Lucian Baia
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, T. Laurian 42, 400271 Cluj-Napoca, Romania
- Faculty of Physics, Babes-Bolyai University, M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania
- Institute for Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, Fântânele 30, 400294 Cluj-Napoca, Romania
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Kovács Z, Molnár C, Gyulavári T, Magyari K, Tóth ZR, Baia L, Pap Z, Hernádi K. Solvothermal synthesis of ZnO spheres: tuning the structure and morphology from nano- to micro-meter range and its impact on their photocatalytic activity. Catal Today 2022. [DOI: 10.1016/j.cattod.2022.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Tóth ZR, Kiss J, Todea M, Kovács G, Gyulavári T, Sesarman A, Negrea G, Vodnar DC, Szabó A, Baia L, Magyari K. Bioactive Properties of Composites Based on Silicate Glasses and Different Silver and Gold Structures. Materials (Basel) 2022; 15:ma15051655. [PMID: 35268885 PMCID: PMC8911207 DOI: 10.3390/ma15051655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 02/01/2023]
Abstract
Using an ideal biomaterial to treat injured bones can accelerate the healing process and simultaneously exhibit antibacterial properties; thus protecting the patient from bacterial infections. Therefore, the aim of this work was to synthesize composites containing silicate-based bioactive glasses and different types of noble metal structures (i.e., AgI pyramids, AgIAu composites, Au nanocages, Au nanocages with added AgI). Bioactive glass was used as an osteoconductive bone substitute and Ag was used for its antibacterial character, while Au was included to accelerate the formation of new bone. To investigate the synergistic effects in these composites, two syntheses were carried out in two ways: AgIAu composites were added in either one step or AgI pyramids and Au nanocages were added separately. All composites showed good in vitro bioactivity. Transformation of AgI in bioactive glasses into Ag nanoparticles and other silver species resulted in good antibacterial behavior. It was observed that the Ag nanoparticles remained in the Au nanocages, which was also beneficial in terms of antibacterial properties. The presence of Au nanoparticles contributed to the composites achieving high cell viability. The most outstanding result was obtained by the consecutive addition of noble metals into the bioactive glasses, resulting in both a high antibacterial effect and good cell viability.
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Affiliation(s)
- Zsejke-Réka Tóth
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400271 Cluj-Napoca, Romania; (Z.-R.T.); (M.T.)
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Hungary; (J.K.); (G.K.); (T.G.); (A.S.)
| | - János Kiss
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Hungary; (J.K.); (G.K.); (T.G.); (A.S.)
| | - Milica Todea
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400271 Cluj-Napoca, Romania; (Z.-R.T.); (M.T.)
- Faculty of Medicine, Iuliu Hațieganu University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Gábor Kovács
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Hungary; (J.K.); (G.K.); (T.G.); (A.S.)
- Department of Horticulture, Faculty of Technical and Human Sciences, Sapientia Hungarian University of Transylvania, 530104 Târgu-Mureș, Romania
| | - Tamás Gyulavári
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Hungary; (J.K.); (G.K.); (T.G.); (A.S.)
| | - Alina Sesarman
- Department of Molecular Biology and Biotechnology, Center of Systems Biology, Biodiversity and Bioresources, Faculty of Biology and Geology, Babes-Bolyai University, 400006 Cluj-Napoca, Romania;
| | - Giorgiana Negrea
- Doctoral School in Integrative Biology, Faculty of Biology and Geology, Babes-Bolyai University, 400006 Cluj-Napoca, Romania;
| | - Dan C. Vodnar
- Faculty of Food Science and Technology, University of Agricultural Science and Veterinary Medicine, 400372 Cluj-Napoca, Romania;
| | - Anna Szabó
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Hungary; (J.K.); (G.K.); (T.G.); (A.S.)
| | - Lucian Baia
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400271 Cluj-Napoca, Romania; (Z.-R.T.); (M.T.)
- Faculty of Physics, Babes-Bolyai University, 400084 Cluj-Napoca, Romania
- Institute for Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, 400294 Cluj-Napoca, Romania
- Correspondence: (L.B.); (K.M.); Tel.: +40-264-405300 (L.B. & K.M.)
| | - Klára Magyari
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400271 Cluj-Napoca, Romania; (Z.-R.T.); (M.T.)
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Hungary; (J.K.); (G.K.); (T.G.); (A.S.)
- Correspondence: (L.B.); (K.M.); Tel.: +40-264-405300 (L.B. & K.M.)
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Rusu E, Magyari K, Baia L, Baia M. Vibrational analysis of α-lipoic acid and its adsorption behavior study by SERS. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Cadar C, Fort CI, Mihis A, Kedves Z, Magyari K, Baia L, Baia M, Dudescu MC, Olteanu I, Cotet LC, Danciu V. 3-Aminopropyl-Triethoxysilane Functionalized Graphene Oxide for Silane-Based Consolidation Treatments to Increase Mortar Performances. J Nanosci Nanotechnol 2021; 21:2351-2359. [PMID: 33500051 DOI: 10.1166/jnn.2021.18958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The influence of chemically converted GO (graphene oxide) functionalized with APTES (3-aminopropyl-triethoxysilane) and unfunctionalized GO, dispersed in ethanolic solution of TEOS (tetraethyl orthosilicate), on the performances of the mortar samples, such as capillary water absorption and compressive strength was evaluated. The effect of the GO based nanomaterials (GO and GO functionalized with APTES) on the mortar microstructure was investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The multifunctionality of the mortar brushed with GO based nanomaterials consolidation suspension was proved by the results (i) of the mechanical tests which show an improvement of the compressive strength and (ii) the capillary water absorption results which indicate the decreasing of the water penetration speed. For the mortar samples brushed with GO consolidation suspension, an increase value for the compressive strength of approximately twice compared to the untreated control samples and a decreased value for the capillary absorption water coefficient with one order of magnitude in comparison with the untreated control samples were obtained.
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Affiliation(s)
- C Cadar
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca, Romania
| | - C I Fort
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca, Romania
| | - A Mihis
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca, Romania
| | - Zs Kedves
- Faculty of Physics, Babes-Bolyai University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania
| | - K Magyari
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, Treboniu Laurian 42, RO-400271 Cluj-Napoca, Romania
| | - L Baia
- Institute of Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, Fantanele 30, RO-400294, Cluj-Napoca, Romania
| | - M Baia
- Faculty of Physics, Babes-Bolyai University, M. Kogalniceanu 1, RO-400084 Cluj-Napoca, Romania
| | - M C Dudescu
- Department of Mechanical Engineering, Faculty of Mechanics, Technical University of Cluj-Napoca, Muncii Bd. 103-105, RO-400641, Cluj-Napoca, Romania
| | - I Olteanu
- S.C.Duct SRL, Feroviarilor 55, Sector 1, RO-012206, Bucuresti, Romania
| | - L C Cotet
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca, Romania
| | - V Danciu
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, RO-400028, Cluj-Napoca, Romania
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Cotet LC, Cadar C, Mihis A, Magyari K, Muresan-Pop M, Pop LC, Mihaila A, Szekely I, Dragan S, Dudescu M, Zgura I, Matei E, Baia M, Baibarac M, Anghel I, Baia L. Mixture of Graphene Oxide/Phosphoric Acid/Melamine as Coating for Improved Fire Protective Performance and Enhancement of Surface Electrical Properties on Wood Chipboard. J Nanosci Nanotechnol 2021; 21:2312-2322. [PMID: 33500047 DOI: 10.1166/jnn.2021.18959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Looking for multifunctional materials, an assessment of the performances both as fire retardant and generator of electrically conductive surfaces for a three component mixture of graphene oxide, phosphoric acid and melamine applied on wood chipboard was performed. A simple approach was used to investigate the intumescent char formation and quantify the loss mass during vertical burning tests, in which the prepared samples were exposed for a certain time interval to a flame generated by an ethanol lamp in ambient conditions. Moreover, mass loss evolution and structural changes that occur during the burning process were more comprehensive investigated by differential thermal and thermogravimetric (DTA/TGA) techniques. By comparing the performances between the wood chipboard samples without any coverage and those covered with one or multiple component mixture, an increase of protection against the fire action was noticed when the three component mixture was used. Also, an improvement of the electrical properties was observed, after flame exposure of the samples covered with multiple layers (i.e., two and three), when the three component mixture was used. Morphological and structural investigations by microscopy (optical and electronic-SEMEDX), X-ray diffraction (XRD) and spectral (Raman, FTIR) methods are described. An assessment of market potential is also discussed.
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Affiliation(s)
- L C Cotet
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, RO-400028, Cluj-Napoca, 077125, Romania
- Institute of Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, RO-400294, Cluj-Napoca, Romania
| | - C Cadar
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, RO-400028, Cluj-Napoca, 077125, Romania
- Institute of Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, RO-400294, Cluj-Napoca, Romania
- Department of Physics and Chemistry, Faculty of Materials and Environmental Engineering, Technical University of Cluj-Napoca,Muncii Bulevardul 103-105, RO-400641, Cluj-Napoca, Romania
| | - A Mihis
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, RO-400028, Cluj-Napoca, 077125, Romania
- Institute of Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, RO-400294, Cluj-Napoca, Romania
| | - K Magyari
- Faculty of Physics, Babes-Bolyai University, RO-400084, Cluj-Napoca, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271, Cluj-Napoca, Romania
| | - M Muresan-Pop
- Faculty of Physics, Babes-Bolyai University, RO-400084, Cluj-Napoca, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271, Cluj-Napoca, Romania
| | - L C Pop
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, RO-400028, Cluj-Napoca, 077125, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271, Cluj-Napoca, Romania
| | - A Mihaila
- Faculty of Economics and Business Administration, Babes-Bolyai University, RO-400591, Cluj-Napoca, Romania
| | - I Szekely
- Faculty of Physics, Babes-Bolyai University, RO-400084, Cluj-Napoca, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271, Cluj-Napoca, Romania
| | - S Dragan
- Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, RO-400028, Cluj-Napoca, 077125, Romania
| | - M Dudescu
- Department of Mechanical Engineering, Faculty of Mechanics, Technical University of Cluj-Napoca, Muncii Bulevardul 103-105, RO-400641, Cluj-Napoca, Romania
| | - I Zgura
- Lab. Optical Process in Nanostructured Materials (LOPNM), National Institute of Materials Physics, Atomistilor str. 405 A, Bucharest-Magurele, 077125, Romania
| | - E Matei
- Lab. Optical Process in Nanostructured Materials (LOPNM), National Institute of Materials Physics, Atomistilor str. 405 A, Bucharest-Magurele, 077125, Romania
| | - M Baia
- Faculty of Physics, Babes-Bolyai University, RO-400084, Cluj-Napoca, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271, Cluj-Napoca, Romania
| | - M Baibarac
- Lab. Optical Process in Nanostructured Materials (LOPNM), National Institute of Materials Physics, Bucharest-Magurele, 077125, Romania
| | - I Anghel
- Fire Officers Faculty, "Alexandru Ioan Cuza" Police Academy, Bucharest, 022451, Romania
| | - L Baia
- Institute of Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University, RO-400294, Cluj-Napoca, Romania
- Faculty of Physics, Babes-Bolyai University, RO-400084, Cluj-Napoca, Romania
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271, Cluj-Napoca, Romania
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Tóth ZR, Pap Z, Kiss J, Baia L, Gyulavári T, Czekes Z, Todea M, Magyari K, Kovács G, Hernadi K. Shape tailoring of AgBr microstructures: effect of the cations of different bromide sources and applied surfactants. RSC Adv 2021; 11:9709-9720. [PMID: 35423471 PMCID: PMC8695391 DOI: 10.1039/d0ra09144h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/01/2021] [Indexed: 11/21/2022] Open
Abstract
Investigations regarding AgBr-based photocatalysts came to the center of attention due to their high photosensitivity. The present research focuses on the systematic investigation regarding the effect of different alkali metal cation radii and surfactants/capping agents applied during the synthesis of silver-halides. Their morpho-structural and optical properties were determined via X-ray diffractometry, diffuse reflectance spectroscopy, scanning electron microscopy, infrared spectroscopy, and contact angle measurements. The semiconductors' photocatalytic activities were investigated using methyl orange as the model contaminant under visible light irradiation. The correlation between the photocatalytic activity and the obtained optical and morpho-structural properties was analyzed using generalized linear models. Moreover, since the (photo)stability of Ag-based photoactive materials is a crucial issue, the stability of catalysts was also investigated after the degradation process. It was concluded that (i) the photoactivity of the samples could be fine-tuned using different precursors and surfactants, (ii) the as-obtained AgBr microcrystals were transformed into other Ag-containing composites during/after the degradation, and (iii) elemental bromide did not form during the degradation process. Thus, the proposed mechanisms in the literature (for the degradation of MO using AgBr) must be reconsidered. Systematic investigation of the effect of different alkali metal cation radii and shape-tailoring agents applied during the synthesis of AgBr-based photocatalysts.![]()
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Affiliation(s)
- Zsejke-Réka Tóth
- Department of Applied and Environmental Chemistry, University of Szeged Rerrich Béla tér 1 HU-6720 Szeged Hungary .,Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Treboniu Laurian 42 RO-400271 Cluj-Napoca Romania
| | - Zsolt Pap
- Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Treboniu Laurian 42 RO-400271 Cluj-Napoca Romania .,Institute of Environmental Science and Technology, University of Szeged Tisza Lajos krt. 103 HU-6720 Szeged Hungary.,Institute of Research-Development-Innovation in Applied Natural Sciences, Babes-Bolyai University Fântânele 30 RO-400294 Cluj-Napoca Romania
| | - János Kiss
- Department of Applied and Environmental Chemistry, University of Szeged Rerrich Béla tér 1 HU-6720 Szeged Hungary
| | - Lucian Baia
- Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Treboniu Laurian 42 RO-400271 Cluj-Napoca Romania .,Faculty of Physics, Babeş-Bolyai University M. Kogălniceanu 1 RO-400084 Cluj-Napoca Romania
| | - Tamás Gyulavári
- Department of Applied and Environmental Chemistry, University of Szeged Rerrich Béla tér 1 HU-6720 Szeged Hungary
| | - Zsolt Czekes
- Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Treboniu Laurian 42 RO-400271 Cluj-Napoca Romania .,Hungarian Department of Biology and Ecology, Babeş-Bolyai University Clinicilor 5-7 RO-400006 Cluj-Napoca Romania
| | - Milica Todea
- Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Treboniu Laurian 42 RO-400271 Cluj-Napoca Romania .,Iuliu Hatieganu University of Medicine and Pharmacy, Faculty of Medicine Victor Babeş 8 RO-400012 Cluj-Napoca Romania
| | - Klára Magyari
- Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Treboniu Laurian 42 RO-400271 Cluj-Napoca Romania .,Institute of Environmental Science and Technology, University of Szeged Tisza Lajos krt. 103 HU-6720 Szeged Hungary
| | - Gábor Kovács
- Department of Applied and Environmental Chemistry, University of Szeged Rerrich Béla tér 1 HU-6720 Szeged Hungary .,Nanostructured Materials and Bio-Nano-Interfaces Center, Institute for Interdisciplinary Research on Bio-Nano-Sciences, Babeş-Bolyai University Treboniu Laurian 42 RO-400271 Cluj-Napoca Romania .,Institute of Environmental Science and Technology, University of Szeged Tisza Lajos krt. 103 HU-6720 Szeged Hungary
| | - Klara Hernadi
- Department of Applied and Environmental Chemistry, University of Szeged Rerrich Béla tér 1 HU-6720 Szeged Hungary .,Institute of Physical Metallurgy, Metal Forming and Nanotechnology, University of Miskolc 3515 Miskolc-Egyetemváros Hungary
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Kása Z, Orbán E, Pap Z, Ábrahám I, Magyari K, Garg S, Hernadi K. Innovative and Cost-Efficient BiOI Immobilization Technique on Ceramic Paper-Total Coverage and High Photocatalytic Activity. Nanomaterials (Basel) 2020; 10:E1959. [PMID: 33019625 PMCID: PMC7599943 DOI: 10.3390/nano10101959] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 11/17/2022]
Abstract
In the present work, visible light active bismuth oxyiodide (BiOI) was immobilized on a commercial, non-conductive support (an Al2O3 based ceramic paper) using a novel two-step spray coating technique and investigated with different characterization methods (e.g., SEM, Raman, XPS). Our main goal was to eliminate the separation costs after the photocatalytic measurement and investigate the chemical relevance and opportunity to use this technique in the industry. Our as-prepared uniform BiOI layer had similar properties to the well-known reference BiOI powder. The Raman and XPS measurements confirmed that the enriched amount of the surface iodine defined the color and as well the band gap of the BiOI layer. The durable BiOI layers have prominent photocatalytic activity under UV and visible light irradiation as well. The scale-up procedure proved that the designed BiOI coated paper was reusable and potentially applicable in the industry by straightforward scale-up, which is due to the elaborated non-conventional BiOI coverage estimation method. This immobilization technique could open several opportunities for immobilizing many other visible light active photocatalysts with simple materials and low cost.
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Affiliation(s)
- Zsolt Kása
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Rerrich Béla sqr. 1, 6720 Szeged, Hungary
| | - Eszter Orbán
- Department of Organic Chemistry, University of Szeged, Dóm sqr. 8, 6720 Szeged, Hungary;
| | - Zsolt Pap
- Institute of Environmental Science and Technology, University of Szeged, Tisza Lajos blvd. 103, 6720 Szeged, Hungary; (Z.P.); (K.M.)
- Nanostructured Materials and Bio-Nano-Interfaces Center Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, Treboniu Laurian Str. 42, 400271 Cluj-Napoca, Romania
| | - Imre Ábrahám
- UniChem Ltd., Department of Development, T. 491, Kőiskola str. 3., 6760 Kistelek, Hungary;
| | - Klára Magyari
- Institute of Environmental Science and Technology, University of Szeged, Tisza Lajos blvd. 103, 6720 Szeged, Hungary; (Z.P.); (K.M.)
- Nanostructured Materials and Bio-Nano-Interfaces Center Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, Treboniu Laurian Str. 42, 400271 Cluj-Napoca, Romania
| | - Seema Garg
- Amity Institute of Applied Sciences, Amity University, Sector 125, Noida, Uttar Pradesh 201313, India;
| | - Klara Hernadi
- Department of Applied and Environmental Chemistry, University of Szeged, 6720 Szeged, Rerrich Béla sqr. 1, 6720 Szeged, Hungary
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Chuquitarqui A, Cotet LC, Baia M, György E, Magyari K, Barbu-Tudoran L, Baia L, Díaz-González M, Fernández-Sánchez C, Pérez Del Pino A. New fabrication method for producing reduced graphene oxide flexible electrodes by using a low-power visible laser diode engraving system. Nanotechnology 2020; 31:325402. [PMID: 32340003 DOI: 10.1088/1361-6528/ab8d67] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The fabrication of bendable electronic devices is a scientific-technological area of very rapid advance in which new materials and fabrication techniques are being continuously developed. In these kinds of devices, the fabrication of flexible conductive electrodes adherent to the substrate is a key factor. Further, eco-friendliness, low cost and fast production are essential requirements for the successful progress of new technologies. In this work, a novel method for obtaining graphene-based flexible electrodes is presented. Conductive films were obtained by means of the visible laser irradiation of graphene oxide layers deposited on polyethylene terephthalate substrates and self-standing membranes sandwiched between glass slides. Despite the low power of the laser system, the numerical simulations indicate the development of temperatures over 1000 K throughout the irradiated material. The laser-induced spatially confined heating leads to the reduction of the graphene oxide material, whereas the glass-based sandwich assembly avoids reoxidation from the surrounding air. By scanning and pixelated modes, reduced graphene oxide electrodes, up to 100 μm in thickness, and with a resistivity as low as 6 × 10-4 Ωm, were obtained in an easy and versatile way. Proof-of-concept microsupercapacitors and electrochemical sensors were fabricated with this technique, showing promising performance.
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Affiliation(s)
- A Chuquitarqui
- Instituto de Ciencia de Materiales de Barcelona, Consejo Superior de Investigaciones Científicas (ICMAB-CSIC), Campus UAB 08193, Bellaterra, Spain
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10
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Gyulavári T, Veréb G, Pap Z, Réti B, Baan K, Todea M, Magyari K, Szilágyi IM, Hernadi K. Utilization of Carbon Nanospheres in Photocatalyst Production: From Composites to Highly Active Hollow Structures. Materials (Basel) 2019; 12:ma12162537. [PMID: 31395835 PMCID: PMC6720943 DOI: 10.3390/ma12162537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 07/26/2019] [Accepted: 08/07/2019] [Indexed: 01/17/2023]
Abstract
Titanium dioxide–carbon sphere (TiO2–CS) composites were constructed via using prefabricated carbon spheres as templates. By the removal of template from the TiO2–CS, TiO2 hollow structures (HS) were synthesized. The CS templates were prepared by the hydrothermal treatment of ordinary table sugar (sucrose). TiO2–HSs were obtained by removing CSs with calcination. Our own sensitized TiO2 was used for coating the CSs. The structure of the CSs, TiO2–CS composites, and TiO2–HSs were characterized by scanning electron microscopy (SEM), infrared spectroscopy (IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS). The effect of various synthesis parameters (purification method of CSs, precursor quantity, and applied furnace) on the morphology was investigated. The photocatalytic activity was investigated by phenol model pollutant degradation under visible light irradiation (λ > 400 nm). It was established that the composite samples possess lower crystallinity and photocatalytic activity compared to TiO2 hollow structures. Based on XPS measurements, the carbon content on the surface of the TiO2–HS exerts an adverse effect on the photocatalytic performance. The synthesis parameters were optimized and the TiO2–HS specimen having the best absolute and surface normalized photocatalytic efficiency was identified. The superior properties were explained in terms of its unique morphology and surface properties. The stability of this TiO2–HS was investigated via XRD and SEM measurements after three consecutive phenol degradation tests, and it was found to be highly stable as it entirely retained its crystal phase composition, morphology and photocatalytic activity.
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Affiliation(s)
- Tamás Gyulavári
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
| | - Gábor Veréb
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary.
- Institute of Process Engineering, Faculty of Engineering, University of Szeged, H-6725 Szeged, Moszkvai krt. 9, Hungary.
| | - Zsolt Pap
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary.
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271 Cluj-Napoca, Treboniu Laurian 42, Romania.
- Institute of Environmental Science and Technology, University of Szeged, H-6720, Szeged, Tisza Lajos krt. 103, Hungary.
| | - Balázs Réti
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
| | - Kornelia Baan
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
| | - Milica Todea
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271 Cluj-Napoca, Treboniu Laurian 42, Romania
- Department of Molecular Sciences, Faculty of Medicine, Iuliu Haţieganu University of Medicine and Pharmacy, RO-400012 Cluj-Napoca, Romania
| | - Klára Magyari
- Nanostructured Materials and Bio-Nano-Interfaces Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, RO-400271 Cluj-Napoca, Treboniu Laurian 42, Romania
| | - Imre Miklós Szilágyi
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1111 Budapest, Hungary
| | - Klara Hernadi
- Research Group of Environmental Chemistry, Institute of Chemistry, University of Szeged, H-6720 Szeged, Tisza Lajos krt. 103, Hungary
- Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged, Rerrich tér 1, Hungary
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11
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Mârza SM, Magyari K, Bogdan S, Moldovan M, Peştean C, Nagy A, Tăbăran F, Licarete E, Suarasan S, Dreanca A, Baia L, Papuc I. Skin wound regeneration with bioactive glass-gold nanoparticles ointment. ACTA ACUST UNITED AC 2019; 14:025011. [PMID: 30630137 DOI: 10.1088/1748-605x/aafd7d] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The bioactive glasses can lead to the promotion of growth of granulation tissue, while the gold nanoparticles (AuNPs) can induce the acceleration of wound healing including tissue regeneration, connective tissue formation, and angiogenesis. The aim of this study was to evaluate the impact of using the bioactive glass (BG) and BG-AuNPs composites on skin wound healing in experimental rat models for 14 days. Sol-gel derived BGs and BG-AuNPs composites mixed with Vaseline at 6, 12 and 18 wt% were used to evaluate the repair response of the skin. During the process of healing, granulomatous reaction was observed in the wound treated with 12 and 18 wt% BG-Vaseline ointments. Furthermore, a strong vascular proliferation and complete wound regeneration were found in 18%BG-AuNPs-Vaseline treated groups. The results derived from the performed investigations revealed that the 18% BG-AuNPs-Vaseline ointment is a promising candidate for wound healing applications.
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Affiliation(s)
- S M Mârza
- Faculty of Veterinary Medicine, University of Agricultural Science and Veterinary Medicine, 400372 Cluj-Napoca, Romania. Faculty of Physics, Babeș-Bolyai University, 400084 Cluj-Napoca, Romania
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12
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Kása Z, Baia L, Magyari K, Hernádi K, Pap Z. Innovative visualization of the effects of crystal morphology on semiconductor photocatalysts. Tuning the Hückel polarity of the shape-tailoring agents: the case of Bi 2WO 6. CrystEngComm 2019. [DOI: 10.1039/c8ce01744a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Morphology was quantified for the first time; the rose-shape measured in “rosality-RSDC” was found to be directly related with the activity and structural properties.
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Affiliation(s)
- Zsolt Kása
- Institute of Environmental Science and Technology
- University of Szeged
- Szeged
- Hungary
- Department of Applied and Environmental Chemistry
| | - Lucian Baia
- Nanostructured Materials and Bio-Nano-Interfaces Centre
- Interdisciplinary Research Institute on Bio-Nano-Sciences
- Babeş-Bolyai University
- Cluj-Napoca
- Romania
| | - Klára Magyari
- Faculty of Physics
- Babeş-Bolyai University
- RO-400084 Cluj-Napoca
- Romania
| | - Klára Hernádi
- Department of Applied and Environmental Chemistry
- University of Szeged
- Szeged
- Hungary
| | - Zsolt Pap
- Institute of Environmental Science and Technology
- University of Szeged
- Szeged
- Hungary
- Faculty of Physics
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13
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Magyari K, Nagy-Simon T, Vulpoi A, Popescu R, Licarete E, Stefan R, Hernádi K, Papuc I, Baia L. Novel bioactive glass-AuNP composites for biomedical applications. Materials Science and Engineering: C 2017; 76:752-759. [DOI: 10.1016/j.msec.2017.03.138] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/30/2016] [Accepted: 03/13/2017] [Indexed: 10/19/2022]
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14
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Affiliation(s)
- K. Magyari
- Faculty of Physics & Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400084 Cluj-Napoca, Romania
| | - E. Vanea
- Faculty of Physics & Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400084 Cluj-Napoca, Romania
| | - L. Baia
- Faculty of Physics & Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400084 Cluj-Napoca, Romania
| | - V. Simon
- Faculty of Physics & Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai University, 400084 Cluj-Napoca, Romania
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15
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Craciun AM, Diac A, Focsan M, Socaci C, Magyari K, Maniu D, Mihalache I, Veca LM, Astilean S, Terec A. Surface passivation of carbon nanoparticles with p-phenylenediamine towards photoluminescent carbon dots. RSC Adv 2016. [DOI: 10.1039/c6ra10127e] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
New photoluminescent carbon dots with intriguing photoluminescent properties were prepared from carboxylated carbon nanoparticles via covalent bonding of p-phenylenediamine oligomers.
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16
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Popescu RA, Magyari K, Vulpoi A, Trandafir DL, Licarete E, Todea M, Ştefan R, Voica C, Vodnar DC, Simon S, Papuc I, Baia L. Bioactive and biocompatible copper containing glass-ceramics with remarkable antibacterial properties and high cell viability designed for future in vivo trials. Biomater Sci 2016; 4:1252-65. [DOI: 10.1039/c6bm00270f] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The efficiency of 60SiO2·(32 − x) CaO·8P2O5·xCuO (mol%) glass-ceramics were proved, and was determined the most appropriate composition for further in vivo trials.
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17
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Magyari K, Gruian C, Varga B, Ciceo-Lucacel R, Radu T, Steinhoff HJ, Váró G, Simon V, Baia L. Addressing the optimal silver content in bioactive glass systems in terms of BSA adsorption. J Mater Chem B 2014; 2:5799-5808. [PMID: 32262023 DOI: 10.1039/c4tb00733f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bioactive glasses doped with silver are aimed to minimize the risk of microbial contamination; therefore, the influence of silver on the bioactive properties is intensely investigated. However, information related to the role played by silver, when added to the bioactive glass composition, on biocompatibility properties is scarce. This aspect is essential as long as the silver content can influence blood protein adsorption onto the surface of the glass, thus affecting the material's biocompatibility. Therefore, from the perspective of the biocompatibility standpoint, the finding of an optimal silver content in a bioactive glass is an extremely important issue. In this study, silver-doped bioactive glasses were prepared by a melt-derived technique, which eliminates the pores' influence in the protein adsorption process. The obtained glasses were characterized by X-ray diffraction, UV-vis, X-ray photoelectron (XPS) and Fourier transform infrared (FT-IR) spectroscopy; afterwards, they were investigated in terms of protein adsorption. Both UV-vis and XPS spectroscopy revealed the presence of Ag+ ions in all silver containing samples. By increasing the silver content, metallic Ag0 appears, the highest amount being observed for the sample with 1 mol% AgO2. Electron paramagnetic resonance measurements evidenced that the amount of spin-labeled serum albumin attached to the surface increases with the silver content. The results obtained by analyzing the information derived from atomic force microscopy and FT-IR measurements indicate that the occurrence of metallic Ag0 in the samples' structure influences the secondary structure of the adsorbed protein. Based on the results derived from the protein response upon interaction with the investigated glass calcium-phosphate based system, the optimal silver oxide concentration was determined for which the secondary structure of the adsorbed protein is similar with that of the free one. This concentration was found to be 0.5 mol%.
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Affiliation(s)
- Klára Magyari
- Babes-Bolyai University, Faculty of Physics & Institute of Interdisciplinary Research in Bio-Nano-Sciences, 400084 Cluj-Napoca, Romania.
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18
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Magyari K, Baia L, Vulpoi A, Simon S, Popescu O, Simon V. Bioactivity evolution of the surface functionalized bioactive glasses. J Biomed Mater Res B Appl Biomater 2014; 103:261-72. [DOI: 10.1002/jbm.b.33203] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 04/04/2014] [Accepted: 04/24/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Klára Magyari
- Faculty of Physics and Institute of Interdisciplinary Research in Bio-Nano-Sciences; Babes-Bolyai University; 400084 Cluj-Napoca Romania
| | - Lucian Baia
- Faculty of Physics and Institute of Interdisciplinary Research in Bio-Nano-Sciences; Babes-Bolyai University; 400084 Cluj-Napoca Romania
| | - Adriana Vulpoi
- Faculty of Physics and Institute of Interdisciplinary Research in Bio-Nano-Sciences; Babes-Bolyai University; 400084 Cluj-Napoca Romania
| | - Simion Simon
- Faculty of Physics and Institute of Interdisciplinary Research in Bio-Nano-Sciences; Babes-Bolyai University; 400084 Cluj-Napoca Romania
| | - Octavian Popescu
- Molecular Biology Center of Institute of Interdisciplinary Research in Bio-Nano-Sciences, Babes-Bolyai University; 400271 Cluj-Napoca Romania
- Romanian Academy; Institute of Biology; 060031 Bucharest Romania
| | - Viorica Simon
- Faculty of Physics and Institute of Interdisciplinary Research in Bio-Nano-Sciences; Babes-Bolyai University; 400084 Cluj-Napoca Romania
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Magyari K, Popescu O, Simon V. Interface processes between iron containing aluminosilicate systems and simulated body fluid enriched with protein. J Mater Sci Mater Med 2010; 21:1913-1920. [PMID: 20224936 DOI: 10.1007/s10856-010-4041-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 03/01/2010] [Indexed: 05/28/2023]
Abstract
The behaviour of iron containing aluminosilicate samples in Kokubo's simulated body fluid (SBF) and in SBF enriched with bovine serum albumin (BSA) has been investigated. Crystalline samples of (80-x)SiO2 X 20Al2O3 X Fe2O3 system, with x = 5, 10 or 15 mol%, obtained by sol-gel method and heat treated at 1200 degrees C in air for 24 h. Data on electrical conductivity, calcium, phosphorous and potassium concentrations in simulated body fluids after samples soaking in static regime at 37 degrees C, for several periods up to 14 days, were used to estimate the dynamics of these cations on the interface of aluminosilicate samples with SBF, and with SBF containing BSA. The UV-visible and fluorescence spectra recorded from the simulated body fluids after immersion of the investigated aluminosilicate samples evidence changes function on immersion time and Fe2O3 content.
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Affiliation(s)
- K Magyari
- Faculty of Physics and Institute for Interdisciplinary Experimental Research, Babes-Bolyai University, Cluj-Napoca, Romania
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20
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Magyari K, Bálint Z, Simon V, Váró G. The photochemical reaction cycle of retinal reconstituted bacteriorhodopsin. J Photochem Photobiol B 2006; 85:140-4. [PMID: 16904334 DOI: 10.1016/j.jphotobiol.2006.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 05/08/2006] [Accepted: 05/20/2006] [Indexed: 11/20/2022]
Abstract
The function of three types of bacteriorhodopsins was compared: the wild-type, the bleached and retinal reconstituted and retinal deficient bacteriorhodopsin after retinal addition. The apparent pK(a) of the proton acceptor group for the bleached BR and retinal deficient BR shifted toward higher pH values compared to the wild-type BR. Fitting the photocycle model to the absorption kinetic signals for all three proteins showed the existence of the same intermediates, but the time-dependent concentration of the intermediates was different. Although measurements were made at pH 7, the absorption kinetics and photoelectric signals in both retinal reconstituted samples acted as wild-type bacteriorhodopsin at significantly higher pH. Below pH 3 the retinal deficient and reconstituted sample bleached. These results suggested that the added retinal was not able to rebind in the same position in the protein as in native bacteriorhodopsin. This points out that care should be taken, when bleached bacteriorhodopsin is reconstituted with different retinal analogs.
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Affiliation(s)
- Klára Magyari
- Department of Physics, University "Babes-Bolyai" Cluj-Napoca, Romania
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21
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Magyari K, Simon V, Váró G. The influence of the halide ions on the photochemical reaction cycle of pharaonis halorhodopsin. Journal of Photochemistry and Photobiology B: Biology 2006; 82:16-20. [PMID: 16219469 DOI: 10.1016/j.jphotobiol.2005.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Revised: 08/04/2005] [Accepted: 08/08/2005] [Indexed: 11/27/2022]
Abstract
Sodium salt of chloride, bromide and iodide were used to elucidate the effect of the size of the anion on the binding to pharaonis halorhodopsin and its transport during the photocycle of this retinal protein. Spectroscopic titration revealed an apparent strong binding constant of 2 mM for chloride, 0.23 mM for bromide and 5 mM for iodide. In the case of iodide a second, week binding constant of about 10 M could be estimated. This second binding constant was similar to that observed earlier for nitrate. By changing the halide ions, only the transitions in the second half of the photocycle were affected, which contained intermediates N, O, and HR'. The O to HR' transition becomes faster with increasing ion volume, meaning that the ion uptake is accelerated. This effect shows a direct correlation with the ion radius. With increasing ion concentration the N-O-HR' equilibrium changed in such a way that the accumulated O tended to decrease. This tendency was overruled in iodide, by the appearance of the second binding constant. The increasing iodide concentration, up to 100mM decreases the accumulation of the intermediate O, due to kinetic reasons, but at higher ion concentration the amount of O increases, although its decay becomes faster. This effect correlates with the appearance of the second iodide bound to the protein.
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Affiliation(s)
- Klára Magyari
- Department of Physics, University "Babes-Bolyai" Cluj-Napoca, Romania
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