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The synthesis of the copper-poor and aluminum-rich layered double hydroxides (LDHs) of the CuAl4 type was optimized in detail in this work, by applying an intense mechanochemical treatment to activate the gibbsite starting reagent. The phase-pure forms of these LDHs were prepared for the first time; using copper nitrate and perchlorate salts during the syntheses turned out to be the key to avoiding the formation of copper hydroxide sideproducts. Based on the use of the optimized syntheses parameters, the preparation of layered triple and multiple hydroxides was also attempted using Ni(II), Co(II), Zn(II) and even Mg(II) ions. These studies let us identify the relative positions of the incorporating cations in the well-known selectivity series as Ni2+ >> Cu2+ >> Zn2+ > Co2+ >> Mg2+. The solids formed were characterized by using powder X-ray diffractometry, UV–Vis diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The catalytic potential of the samples was investigated in carbon monoxide oxidation reactions at atmospheric pressure, supported by an in situ diffuse reflectance infrared spectroscopy probe. All solids proved to be active and the combination of the nickel and cobalt incorporation (which resulted in a NiCoAl8 layered triple hydroxide) brought outstanding benefits regarding low-temperature oxidation and increased carbon monoxide conversion values.
Márton Szabados; Adél Anna Ádám; Zsolt Kása; Kornélia Baán; Róbert Mucsi; András Sápi; Zoltán Kónya; Ákos Kukovecz; Pál Sipos. M(II)Al4 Type Layered Double Hydroxides—Preparation Using Mechanochemical Route, Structural Characterization and Catalytic Application. Materials 2021, 14, 4880 .
AMA StyleMárton Szabados, Adél Anna Ádám, Zsolt Kása, Kornélia Baán, Róbert Mucsi, András Sápi, Zoltán Kónya, Ákos Kukovecz, Pál Sipos. M(II)Al4 Type Layered Double Hydroxides—Preparation Using Mechanochemical Route, Structural Characterization and Catalytic Application. Materials. 2021; 14 (17):4880.
Chicago/Turabian StyleMárton Szabados; Adél Anna Ádám; Zsolt Kása; Kornélia Baán; Róbert Mucsi; András Sápi; Zoltán Kónya; Ákos Kukovecz; Pál Sipos. 2021. "M(II)Al4 Type Layered Double Hydroxides—Preparation Using Mechanochemical Route, Structural Characterization and Catalytic Application." Materials 14, no. 17: 4880.
(1) Background: Several properties of silver nanoparticles (AgNPs), such as cytotoxic, anticancer, and antimicrobial activities, have been subjects of intense research; however, important aspects such as nanoparticle aggregation are generally neglected, although a decline in colloidal stability leads to a loss of the desired biological activities. Colloidal stability is affected by pH, ionic strength, or a plethora of biomolecules that interact with AgNPs under biorelevant conditions. (2) Methods: As only a few studies have focused on the relationship between aggregation behavior and the biological properties of AgNPs, here, we have systematically evaluated this issue by completing a thorough analysis of sterically (via polyvinyl-pyrrolidone (PVP)) stabilized AgNPs that were subjected to different circumstances. We assessed ultraviolet–visible light absorption, dynamic light scattering, zeta potential measurements, in vitro cell viability, and microdilution assays to screen both colloidal stability as well as bioactivity. (3) Results: The results revealed that although PVP provided outstanding biorelevant colloidal stability, the chemical stability of AgNPs could not be maintained completely with this capping material. (4) Conclusion: These unexpected findings led to the realization that stabilizing materials have more profound importance in association with biorelevant applications of nanomaterials than just being simple colloidal stabilizers.
Andrea Rónavári; Péter Bélteky; Eszter Boka; Dalma Zakupszky; Nóra Igaz; Bettina Szerencsés; Ilona Pfeiffer; Zoltán Kónya; Mónika Kiricsi. Polyvinyl-Pyrrolidone-Coated Silver Nanoparticles—The Colloidal, Chemical, and Biological Consequences of Steric Stabilization under Biorelevant Conditions. International Journal of Molecular Sciences 2021, 22, 8673 .
AMA StyleAndrea Rónavári, Péter Bélteky, Eszter Boka, Dalma Zakupszky, Nóra Igaz, Bettina Szerencsés, Ilona Pfeiffer, Zoltán Kónya, Mónika Kiricsi. Polyvinyl-Pyrrolidone-Coated Silver Nanoparticles—The Colloidal, Chemical, and Biological Consequences of Steric Stabilization under Biorelevant Conditions. International Journal of Molecular Sciences. 2021; 22 (16):8673.
Chicago/Turabian StyleAndrea Rónavári; Péter Bélteky; Eszter Boka; Dalma Zakupszky; Nóra Igaz; Bettina Szerencsés; Ilona Pfeiffer; Zoltán Kónya; Mónika Kiricsi. 2021. "Polyvinyl-Pyrrolidone-Coated Silver Nanoparticles—The Colloidal, Chemical, and Biological Consequences of Steric Stabilization under Biorelevant Conditions." International Journal of Molecular Sciences 22, no. 16: 8673.
Our study aimed to formulate a novel dexamethasone (DXM)-loaded, mixed polymeric micelle-based drug delivery system, focusing on the auspicious nose-to-brain pathway, as a key delivery route to treat central nervous system (CNS) associated diseases. Polymeric micelles might be a solution to deliver drugs to the place of action compared to conventional formulations. Due to low Z-average (89.92 ± 2.7 nm), a polydispersity index of 0.216 ± 0.014 and high surface polarity (52.23%), a significant increase in water solubility (14-fold) was experienced. This increase resulted in favourable dissolution profile at nasal and axonal conditions with high in vitro permeability value (14.6×10−6 cm/s) on polar brain (porcine) lipid extract. Modified Side-bi-side® type diffusion study confirmed rapid and efficient passive diffusion through the nasal mucosa contributed by strong mucoadhesive properties. The final formulation met all the requirements of a nasal drug delivery system with rapid onset of action, meaning DXM can reach the CNS and there it can exert its beneficial effects in pathological conditions.
Bence Sipos; Ildikó Csóka; Mária Budai-Szűcs; Gábor Kozma; Dániel Berkesi; Zoltán Kónya; György Tibor Balogh; Gábor Katona. Development of Dexamethasone-loaded mixed polymeric micelles for nasal delivery. European Journal of Pharmaceutical Sciences 2021, 105960 .
AMA StyleBence Sipos, Ildikó Csóka, Mária Budai-Szűcs, Gábor Kozma, Dániel Berkesi, Zoltán Kónya, György Tibor Balogh, Gábor Katona. Development of Dexamethasone-loaded mixed polymeric micelles for nasal delivery. European Journal of Pharmaceutical Sciences. 2021; ():105960.
Chicago/Turabian StyleBence Sipos; Ildikó Csóka; Mária Budai-Szűcs; Gábor Kozma; Dániel Berkesi; Zoltán Kónya; György Tibor Balogh; Gábor Katona. 2021. "Development of Dexamethasone-loaded mixed polymeric micelles for nasal delivery." European Journal of Pharmaceutical Sciences , no. : 105960.
Liposomal formulation development is a challenging process. Certain factors have a critical influence on the characteristics of the liposomes, and even the relevant properties can vary based on the predefined interests of the research. In this paper, a Quality by Design-guided and Risk Assessment (RA)-based study was performed to determine the Critical Material Attributes and the Critical Process Parameters of an “intermediate” active pharmaceutical ingredient-free liposome formulation prepared via the thin-film hydration method, collect the Critical Quality Attributes of the future carrier system and show the process of narrowing a general initial RA for a specific case. The theoretical liposome design was proved through experimental models. The investigated critical factors covered the working temperature, the ratio between the wall-forming agents (phosphatidylcholine and cholesterol), the PEGylated phospholipid content (DPPE-PEG2000), the type of the hydration media (saline or phosphate-buffered saline solutions) and the cryoprotectants (glucose, sorbitol or trehalose). The characterisation results (size, surface charge, thermodynamic behaviours, formed structure and bonds) of the prepared liposomes supported the outcomes of the updated RA. The findings can be used as a basis for a particular study with specified circumstances.
Zsófia Németh; Edina Pallagi; Dorina Dobó; Gábor Kozma; Zoltán Kónya; Ildikó Csóka. An Updated Risk Assessment as Part of the QbD-Based Liposome Design and Development. Pharmaceutics 2021, 13, 1071 .
AMA StyleZsófia Németh, Edina Pallagi, Dorina Dobó, Gábor Kozma, Zoltán Kónya, Ildikó Csóka. An Updated Risk Assessment as Part of the QbD-Based Liposome Design and Development. Pharmaceutics. 2021; 13 (7):1071.
Chicago/Turabian StyleZsófia Németh; Edina Pallagi; Dorina Dobó; Gábor Kozma; Zoltán Kónya; Ildikó Csóka. 2021. "An Updated Risk Assessment as Part of the QbD-Based Liposome Design and Development." Pharmaceutics 13, no. 7: 1071.
Ceramic materials, despite their high strength and modulus, are limited in many structural applications due to inherent brittleness and low toughness. Nevertheless, ceramic-based structures, in nature, overcome this limitation using bottom-up complex hierarchical assembly of hard ceramic and soft polymer, where ceramics are packaged with tiny fraction of polymers in an internalized fashion. Here, we propose a far simpler approach of entirely externalizing the soft phase via conformal polymer coating over architected ceramic structures, leading to damage tolerance. Architected structures are printed using silica-filled preceramic polymer, pyrolyzed to stabilize the ceramic scaffolds, and then dip-coated conformally with a thin, flexible epoxy polymer. The polymer-coated architected structures show multifold improvement in compressive strength and toughness while resisting catastrophic failure through a considerable delay of the damage propagation. This surface modification approach allows a simple strategy to build complex ceramic parts that are far more damage-tolerant than their traditional counterparts.
Seyed Mohammad Sajadi; Lívia Vásárhelyi; Reza Mousavi; Amir Hossein Rahmati; Zoltán Kónya; Ákos Kukovecz; Taib Arif; Tobin Filleter; Robert Vajtai; Peter Boul; Zhenqian Pang; Teng Li; Chandra Sekhar Tiwary; Muhammad M. Rahman; Pulickel M. Ajayan. Damage-tolerant 3D-printed ceramics via conformal coating. Science Advances 2021, 7, eabc5028 .
AMA StyleSeyed Mohammad Sajadi, Lívia Vásárhelyi, Reza Mousavi, Amir Hossein Rahmati, Zoltán Kónya, Ákos Kukovecz, Taib Arif, Tobin Filleter, Robert Vajtai, Peter Boul, Zhenqian Pang, Teng Li, Chandra Sekhar Tiwary, Muhammad M. Rahman, Pulickel M. Ajayan. Damage-tolerant 3D-printed ceramics via conformal coating. Science Advances. 2021; 7 (28):eabc5028.
Chicago/Turabian StyleSeyed Mohammad Sajadi; Lívia Vásárhelyi; Reza Mousavi; Amir Hossein Rahmati; Zoltán Kónya; Ákos Kukovecz; Taib Arif; Tobin Filleter; Robert Vajtai; Peter Boul; Zhenqian Pang; Teng Li; Chandra Sekhar Tiwary; Muhammad M. Rahman; Pulickel M. Ajayan. 2021. "Damage-tolerant 3D-printed ceramics via conformal coating." Science Advances 7, no. 28: eabc5028.
Background: The drug release of antiparkinsonian drugs is an important issue during the formulation process because proper release kinetics can help to reduce the off periods of Parkinson’s disease. A 2-factor, 3-level (32) full-factorial design was conducted to evaluate statistically the influence of the hydrophobicity of mesoporous silica on drug release. Methods: Hydrophobization was evaluated by different methods, such as contact angle measurement, infrared spectroscopy and charge titration. After loading the drug (levodopa methyl ester hydrochloride, melevodopa hydrochloride, LDME) into the mesopores, drug content, particle size, specific surface area and homogeneity of the products were also analyzed. The amorphous state of LDME was verified by X-ray diffractometry and differential scanning calorimetry. Results: Drug release was characterized by a model-independent method using the so-called initial release rate parameter, as detailed in the article. The adaptability of this method was verified; the model fitted closely to the actual release results according to the similarity factor, independently of the release kinetics. Conclusions: The API was successfully loaded into the silica, resulting in a reduced surface area. The release studies indicated that the release rate significantly decreased (p< 0.05) with increasing hydrophobicity. The products with controlled release can reduce the off period frequency.
Tamás Kiss; Gábor Katona; László Mérai; László Janovák; Ágota Deák; Gábor Kozma; Zoltán Kónya; Rita Ambrus. Development of a Hydrophobicity-Controlled Delivery System Containing Levodopa Methyl Ester Hydrochloride Loaded into a Mesoporous Silica. Pharmaceutics 2021, 13, 1039 .
AMA StyleTamás Kiss, Gábor Katona, László Mérai, László Janovák, Ágota Deák, Gábor Kozma, Zoltán Kónya, Rita Ambrus. Development of a Hydrophobicity-Controlled Delivery System Containing Levodopa Methyl Ester Hydrochloride Loaded into a Mesoporous Silica. Pharmaceutics. 2021; 13 (7):1039.
Chicago/Turabian StyleTamás Kiss; Gábor Katona; László Mérai; László Janovák; Ágota Deák; Gábor Kozma; Zoltán Kónya; Rita Ambrus. 2021. "Development of a Hydrophobicity-Controlled Delivery System Containing Levodopa Methyl Ester Hydrochloride Loaded into a Mesoporous Silica." Pharmaceutics 13, no. 7: 1039.
A silver-containing hybrid material is reported as a heterogeneous noble metal catalyst for protodecarboxylations and decarboxylative deuterations of carboxylic acids.
Rebeka Mészáros; András Márton; Márton Szabados; Gábor Varga; Zoltán Kónya; Ákos Kukovecz; Ferenc Fülöp; István Pálinkó; Sándor B. Ötvös. Exploiting a silver–bismuth hybrid material as heterogeneous noble metal catalyst for decarboxylations and decarboxylative deuterations of carboxylic acids under batch and continuous flow conditions. Green Chemistry 2021, 1 .
AMA StyleRebeka Mészáros, András Márton, Márton Szabados, Gábor Varga, Zoltán Kónya, Ákos Kukovecz, Ferenc Fülöp, István Pálinkó, Sándor B. Ötvös. Exploiting a silver–bismuth hybrid material as heterogeneous noble metal catalyst for decarboxylations and decarboxylative deuterations of carboxylic acids under batch and continuous flow conditions. Green Chemistry. 2021; ():1.
Chicago/Turabian StyleRebeka Mészáros; András Márton; Márton Szabados; Gábor Varga; Zoltán Kónya; Ákos Kukovecz; Ferenc Fülöp; István Pálinkó; Sándor B. Ötvös. 2021. "Exploiting a silver–bismuth hybrid material as heterogeneous noble metal catalyst for decarboxylations and decarboxylative deuterations of carboxylic acids under batch and continuous flow conditions." Green Chemistry , no. : 1.
Boron nitride nanospheres (BNNSs) were functionalized with polyelectrolytes. The effect of the polyelectrolyte dose and ionic strength on the charging and aggregation properties was investigated. At appropriate polyelectrolyte doses, charge neutralization occurred, whereas by increasing the dose, charge reversal was observed. The complete coating of the particles was indicated by a plateau in the ζ-potential values, which do not change significantly beyond the dose corresponding to the onset of such a plateau. The dispersions were highly aggregated around the charge neutralization point, while at lower or higher doses, the particles were stable. The salt-induced aggregation experiments revealed that the polyelectrolyte coatings contribute to the colloidal stability of the particles, namely, the critical coagulation concentrations deviated from the one determined for bare BNNSs. The presence of electrostatic and steric interparticle forces induced by the adsorbed polyelectrolyte chains was assumed. The obtained results confirm that the comprehensive investigation of the colloidal stability of BNNS particles is crucial to design stable or unstable dispersions and that polyelectrolytes are suitable agents for both stabilization and destabilization of BNNS dispersions, depending on the purpose of their application.
Lívia Vásárhelyi; Tímea Hegedűs; Szilárd Sáringer; Gergő Ballai; István Szilágyi; Zoltán Kónya. Stability of Boron Nitride Nanosphere Dispersions in the Presence of Polyelectrolytes. Langmuir 2021, 37, 5399 -5407.
AMA StyleLívia Vásárhelyi, Tímea Hegedűs, Szilárd Sáringer, Gergő Ballai, István Szilágyi, Zoltán Kónya. Stability of Boron Nitride Nanosphere Dispersions in the Presence of Polyelectrolytes. Langmuir. 2021; 37 (17):5399-5407.
Chicago/Turabian StyleLívia Vásárhelyi; Tímea Hegedűs; Szilárd Sáringer; Gergő Ballai; István Szilágyi; Zoltán Kónya. 2021. "Stability of Boron Nitride Nanosphere Dispersions in the Presence of Polyelectrolytes." Langmuir 37, no. 17: 5399-5407.
A hierarchically porous polymer (HPP) consisting of micropores (∼1 nm) within a 3D continuous mesoporous wall (∼15 nm) was used to support well-defined Pt nanoparticles (2 nm in diameter) as a heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction in the liquid phase. The ligand-capped nanoparticles were loaded into the polymer and treated with plasma to expose the active surface. The dual porosity was essential: the block polymer-templated mesopores provided the reactants facile access to the nanoparticle center, which was firmly immobilized by the microporous surface. Compared to inorganic mesoporous silica supports, which are intrinsically susceptible to basic hydrolysis, the Pt-HPP featured higher activity for all halide leaving groups, even in green solvents, as well as excellent recyclability. Only 5% decrease in activity was observed after 10 cycles. Pt-HPP was one of the most active heterogeneous catalysts for aryl chloride substrates compared to literature Pt or Pd examples.
Soobin Kim; Gábor Varga; Myungeun Seo; András Sápi; Viktória Rácz; Juan F. Gómez-Pérez; Dániel Sebők; Jeonghyeon Lee; Ákos Kukovecz; Zoltán Kónya. Nesting Well-Defined Pt Nanoparticles within a Hierarchically Porous Polymer as a Heterogeneous Suzuki–Miyaura Catalyst. ACS Applied Nano Materials 2021, 4, 4070 -4076.
AMA StyleSoobin Kim, Gábor Varga, Myungeun Seo, András Sápi, Viktória Rácz, Juan F. Gómez-Pérez, Dániel Sebők, Jeonghyeon Lee, Ákos Kukovecz, Zoltán Kónya. Nesting Well-Defined Pt Nanoparticles within a Hierarchically Porous Polymer as a Heterogeneous Suzuki–Miyaura Catalyst. ACS Applied Nano Materials. 2021; 4 (4):4070-4076.
Chicago/Turabian StyleSoobin Kim; Gábor Varga; Myungeun Seo; András Sápi; Viktória Rácz; Juan F. Gómez-Pérez; Dániel Sebők; Jeonghyeon Lee; Ákos Kukovecz; Zoltán Kónya. 2021. "Nesting Well-Defined Pt Nanoparticles within a Hierarchically Porous Polymer as a Heterogeneous Suzuki–Miyaura Catalyst." ACS Applied Nano Materials 4, no. 4: 4070-4076.
Purpose: Silver nanoparticles (AgNPs) are one of the most commonly investigated nanomaterials, especially due to their biomedical applications. However, their excellent cytotoxic and antimicrobial activity is often compromised in biological media due to nanoparticle aggregation. In this work, the aggregation behavior and the related biological activity of three different samples of citrate capped silver nanoparticles, with mean diameters of 10, 20, and 50 nm, respectively, were examined. Methods: Following nanoparticle synthesis and characterization with transmission electron microscopy, their aggregation behavior under various pH values, NaCl, glucose, and glutamine concentrations, furthermore in cell culture medium components such as Dulbecco’s Modified Eagle’s Medium and fetal bovine serum, was assessed through dynamic light scattering and ultraviolet-visible spectroscopy. Results: The results indicated that acidic pH and physiological electrolyte content universally induce micron-scale aggregation, which can be mediated by biomolecular corona formation. Remarkably, larger particles demonstrated higher resistance against external influences than smaller counterparts. In vitro cytotoxicity and antimicrobial assays were performed by treating cells with nanoparticulate aggregates in differing stages of aggregation. Conclusion: Our results revealed a profound association between colloidal stability and toxicity of AgNPs, as extreme aggregation led to the complete loss of biological activity. The higher degree of aggregation resistance observed for larger particles had a significant impact on the in vitro toxicity, since such samples retained more of their activity against microbes and mammalian cells. These findings lead to the conclusion that aiming for the smallest possible nanoparticles might not be the best course of action, despite the general standpoint of the relevant literature.
Péter Bélteky; Andrea Rónavári; Dalma Zakupszky; Eszter Boka; Nóra Igaz; Bettina Szerencsés; Ilona Pfeiffer; Csaba Vágvölgyi; Mónika Kiricsi; Zoltán Kónya. Are Smaller Nanoparticles Always Better? Understanding the Biological Effect of Size-Dependent Silver Nanoparticle Aggregation Under Biorelevant Conditions. International Journal of Nanomedicine 2021, ume 16, 3021 -3040.
AMA StylePéter Bélteky, Andrea Rónavári, Dalma Zakupszky, Eszter Boka, Nóra Igaz, Bettina Szerencsés, Ilona Pfeiffer, Csaba Vágvölgyi, Mónika Kiricsi, Zoltán Kónya. Are Smaller Nanoparticles Always Better? Understanding the Biological Effect of Size-Dependent Silver Nanoparticle Aggregation Under Biorelevant Conditions. International Journal of Nanomedicine. 2021; ume 16 ():3021-3040.
Chicago/Turabian StylePéter Bélteky; Andrea Rónavári; Dalma Zakupszky; Eszter Boka; Nóra Igaz; Bettina Szerencsés; Ilona Pfeiffer; Csaba Vágvölgyi; Mónika Kiricsi; Zoltán Kónya. 2021. "Are Smaller Nanoparticles Always Better? Understanding the Biological Effect of Size-Dependent Silver Nanoparticle Aggregation Under Biorelevant Conditions." International Journal of Nanomedicine ume 16, no. : 3021-3040.
This work investigates the possibility of applying two types of oxidized multiwalled carbon nanotubes (oxMWCNTs) as effective adsorbents for removing low concentrations of Cd(II) and Pb(II) (≤ 5 mg L-1) from aqueous media, as well as the influence of the functionalization process duration (3 h (oxMWCNT3h) or 6 h (oxMWCNT6h)) on the performance of the materials tested. Both oxMWCNTs were thoroughly characterized by SEM/EDS, TEM, FTIR, N2 adsorption/desorption and pHpzc techniques. An extensive study of Cd(II) and Pb(II) adsorption and the mechanisms responsible was conducted by evaluating the effects of contact time, initial Cd(II) and Pb(II) concentration, pH and ionic strength. Adsorption kinetic data show that the two materials can be considered extremely effective, as less than 20 min was required to reach a state of equilibrium. Freundlich, Langmuir, Dubinin-Radushkevic and Temkin adsorption isotherm models fit the data well and suggest that the investigated adsorption processes are favourable, mainly electrostatically driven and exothermic. The maximum adsorption capacities obtained by the Langmuir model were 10.5 and 13.5 mg g-1 for Cd(II) and 23.4 and 27.9 mg g -1 for Pb(II) (thus: oxMWCNT6h > oxMWCNT3h and Pb(II) > Cd(II)). The adsorption of Cd(II) and Pb(II) is strongly and positively influenced by increasing the pH and negatively affected by increasing the ionic strength of the solutions. In general, the obtained results are very promising, with the application of oxMWCNTs proving effective for the purification of aqueous media contaminated with low concentrations of Cd(II) and Pb(II), regardless of the duration of the functionalization process.
Marko Šolić; Snežana Maletić; Marijana Kragulj Isakovski; Jasmina Nikić; Malcolm Watson; Zoltan Kónya; Srđan Rončević. Removing low levels of Cd(II) and Pb(II) by adsorption on two types of oxidized multiwalled carbon nanotubes. Journal of Environmental Chemical Engineering 2021, 9, 105402 .
AMA StyleMarko Šolić, Snežana Maletić, Marijana Kragulj Isakovski, Jasmina Nikić, Malcolm Watson, Zoltan Kónya, Srđan Rončević. Removing low levels of Cd(II) and Pb(II) by adsorption on two types of oxidized multiwalled carbon nanotubes. Journal of Environmental Chemical Engineering. 2021; 9 (4):105402.
Chicago/Turabian StyleMarko Šolić; Snežana Maletić; Marijana Kragulj Isakovski; Jasmina Nikić; Malcolm Watson; Zoltan Kónya; Srđan Rončević. 2021. "Removing low levels of Cd(II) and Pb(II) by adsorption on two types of oxidized multiwalled carbon nanotubes." Journal of Environmental Chemical Engineering 9, no. 4: 105402.
Investigating the molecular composition of small extracellular vesicles (sEVs) for tumor diagnostic purposes is becoming increasingly popular, especially for diseases for which diagnosis is challenging, such as central nervous system (CNS) malignancies. Thorough examination of the molecular content of sEVs by Raman spectroscopy is a promising but hitherto barely explored approach for these tumor types. We attempt to reveal the potential role of serum-derived sEVs in diagnosing CNS tumors through Raman spectroscopic analyses using a relevant number of clinical samples. A total of 138 serum samples were obtained from four patient groups (glioblastoma multiforme, non-small-cell lung cancer brain metastasis, meningioma and lumbar disc herniation as control). After isolation, characterization and Raman spectroscopic assessment of sEVs, the Principal Component Analysis–Support Vector Machine (PCA–SVM) algorithm was performed on the Raman spectra for pairwise classifications. Classification accuracy (CA), sensitivity, specificity and the Area Under the Curve (AUC) value derived from Receiver Operating Characteristic (ROC) analyses were used to evaluate the performance of classification. The groups compared were distinguishable with 82.9–92.5% CA, 80–95% sensitivity and 80–90% specificity. AUC scores in the range of 0.82–0.9 suggest excellent and outstanding classification performance. Our results support that Raman spectroscopic analysis of sEV-enriched isolates from serum is a promising method that could be further developed in order to be applicable in the diagnosis of CNS tumors.
Matyas Bukva; Gabriella Dobra; Juan Gomez-Perez; Krisztian Koos; Maria Harmati; Edina Gyukity-Sebestyen; Tamas Biro; Adrienn Jenei; Sandor Kormondi; Peter Horvath; Zoltan Konya; Almos Klekner; Krisztina Buzas. Raman Spectral Signatures of Serum-Derived Extracellular Vesicle-Enriched Isolates May Support the Diagnosis of CNS Tumors. Cancers 2021, 13, 1407 .
AMA StyleMatyas Bukva, Gabriella Dobra, Juan Gomez-Perez, Krisztian Koos, Maria Harmati, Edina Gyukity-Sebestyen, Tamas Biro, Adrienn Jenei, Sandor Kormondi, Peter Horvath, Zoltan Konya, Almos Klekner, Krisztina Buzas. Raman Spectral Signatures of Serum-Derived Extracellular Vesicle-Enriched Isolates May Support the Diagnosis of CNS Tumors. Cancers. 2021; 13 (6):1407.
Chicago/Turabian StyleMatyas Bukva; Gabriella Dobra; Juan Gomez-Perez; Krisztian Koos; Maria Harmati; Edina Gyukity-Sebestyen; Tamas Biro; Adrienn Jenei; Sandor Kormondi; Peter Horvath; Zoltan Konya; Almos Klekner; Krisztina Buzas. 2021. "Raman Spectral Signatures of Serum-Derived Extracellular Vesicle-Enriched Isolates May Support the Diagnosis of CNS Tumors." Cancers 13, no. 6: 1407.
The present study aimed to develop n-propyl gallate (PG)-encapsulated liposomes through a novel direct pouring method using the quality-by-design (QbD) approach. A further aim was to coat liposomes with hyaluronic acid (HA) to improve the stability of the formulation in nasal mucosa. The QbD method was used for the determination of critical quality attributes in the formulation of PG-loaded liposomes coated with HA. The optimized formulation was determined by applying the Box–Behnken design to investigate the effect of composition and process variables on particle size, polydispersity index (PDI), and zeta potential. Physiochemical characterization, in vitro release, and permeability tests, as well as accelerated stability studies, were performed with the optimized liposomal formulation. The optimized formulation resulted in 90 ± 3.6% encapsulation efficiency, 167.9 ± 3.5 nm average hydrodynamic diameter, 0.129 ± 0.002 PDI, and −33.9 ± 4.5 zeta potential. Coated liposomes showed significantly improved properties in 24 h in an in vitro release test (>60%), in vitro permeability measurement (420 μg/cm2) within 60 min, and also in accelerated stability studies compared to uncoated liposomes. A hydrogen-peroxide-scavenging assay showed improved stability of PG-containing liposomes. It can be concluded that the optimization of PG-encapsulated liposomes coated with HA has great potential for targeting several brain diseases.
Fakhara Sabir; Gábor Katona; Edina Pallagi; Dorina Dobó; Hussein Akel; Dániel Berkesi; Zoltán Kónya; Ildikó Csóka. Quality-by-Design-Based Development of n-Propyl-Gallate-Loaded Hyaluronic-Acid-Coated Liposomes for Intranasal Administration. Molecules 2021, 26, 1429 .
AMA StyleFakhara Sabir, Gábor Katona, Edina Pallagi, Dorina Dobó, Hussein Akel, Dániel Berkesi, Zoltán Kónya, Ildikó Csóka. Quality-by-Design-Based Development of n-Propyl-Gallate-Loaded Hyaluronic-Acid-Coated Liposomes for Intranasal Administration. Molecules. 2021; 26 (5):1429.
Chicago/Turabian StyleFakhara Sabir; Gábor Katona; Edina Pallagi; Dorina Dobó; Hussein Akel; Dániel Berkesi; Zoltán Kónya; Ildikó Csóka. 2021. "Quality-by-Design-Based Development of n-Propyl-Gallate-Loaded Hyaluronic-Acid-Coated Liposomes for Intranasal Administration." Molecules 26, no. 5: 1429.
L-Cysteinate-intercalated CaAl-layered double hydroxide (LDH) was prepared by the co-precipitation method producing highly crystalline hydrocalumite phase with a well-pillared interlayer gallery. The obtained materials were characterized by X-ray diffractometry, IR as well as Raman spectroscopies. By performing interlamellar oxidation reactions with peracetic acid as oxidant, oxidation of cysteinate to cystinate in aqueous and cysteinate sulfenic acid in acetonic suspensions occurred. The oxidations could be performed under mild conditions, at room temperature, under neutral pH and in air. It has been shown that the transformation pathways are due to the presence of the layered structure, that is, the confined space of the LDH behaved as molecular reactor.
Zita Timár; Truong Hung; Cora Pravda; Zoltán Kónya; Ákos Kukovecz; Pál Sipos; Gábor Varga; István Pálinkó. Oxidation of Cysteinate Anions Immobilized in the Interlamellar Space of CaAl-Layered Double Hydroxide. Materials 2021, 14, 1202 .
AMA StyleZita Timár, Truong Hung, Cora Pravda, Zoltán Kónya, Ákos Kukovecz, Pál Sipos, Gábor Varga, István Pálinkó. Oxidation of Cysteinate Anions Immobilized in the Interlamellar Space of CaAl-Layered Double Hydroxide. Materials. 2021; 14 (5):1202.
Chicago/Turabian StyleZita Timár; Truong Hung; Cora Pravda; Zoltán Kónya; Ákos Kukovecz; Pál Sipos; Gábor Varga; István Pálinkó. 2021. "Oxidation of Cysteinate Anions Immobilized in the Interlamellar Space of CaAl-Layered Double Hydroxide." Materials 14, no. 5: 1202.
Several different methods are established for the analysis of gases, including optical spectroscopy, photoacoustic spectroscopy as well as colorimetric and resistive sensing, the measurements systems are either too complex or have limited sensitivity. In particular, when the goal is to apply a large number of sensors in networks, it is highly desirable to have devices that are simple, have low cost and energy consumption, yet sensitive and selective to monitor analytes even in traces. Herein, we propose a new type of resistive sensor device based on a composite of single-wall carbon nanotubes and an ion-in-conjugation polymer, poly(1,5-diaminonaphthalene-squaraine), capable of detecting H2S and NH3 in air even at room temperature with a theoretical concentration limit of ∼1 ppb and ∼7 ppb, respectively. Density functional theory calculations revealed that H atoms of the analytes and O atoms of the polymer chain interact and form hydrogen bonds, and the electron withdrawal from the gas molecules by the polymer chain results in the change of its electrical conductivity. To demonstrate the feasibility of the new nanocomposites in sensing, we show the devices for monitoring food safety with good sensor stability of operation for at least 3 months of period of time.
Jin Zhou; Topias Järvinen; Olli Pitkänen; Zoltán Kónya; Akos Kukovecz; Krisztian Kordas. Composites of ion-in-conjugation polysquaraine and SWCNTs for the detection of H2S and NH3 at ppb concentrations. Nanotechnology 2021, 32, 185502 .
AMA StyleJin Zhou, Topias Järvinen, Olli Pitkänen, Zoltán Kónya, Akos Kukovecz, Krisztian Kordas. Composites of ion-in-conjugation polysquaraine and SWCNTs for the detection of H2S and NH3 at ppb concentrations. Nanotechnology. 2021; 32 (18):185502.
Chicago/Turabian StyleJin Zhou; Topias Järvinen; Olli Pitkänen; Zoltán Kónya; Akos Kukovecz; Krisztian Kordas. 2021. "Composites of ion-in-conjugation polysquaraine and SWCNTs for the detection of H2S and NH3 at ppb concentrations." Nanotechnology 32, no. 18: 185502.
Although using supported noble-metal catalysts for CO2 hydrogenation is an effective solution due to their excellent catalytic properties, metal oxide supports themselves can exhibit good activity being more economically feasible. This work focuses on investigating the complexity of the Co3O4 system during the CO2 methanation reaction, which is usually accompanied by the formation of unstable dispersions of cobalt oxide and metallic Co. Herein, we have tested different types of Co3O4: synthetically prepared mesoporous m-Co3O4 (BET surface area, 95 m2/g) and commercial c-Co3O4 (BET surface area, 15 m2/g; purchased from Merck) in the CO2 methanation reaction under different reduction temperatures (273–673 K). The reduction temperature was adjusted to 573 K for both the catalysts to reach the optimal Co/cobalt oxide ratio and consequently the best catalytic performance. m-Co3O4 is more active (CO2 conversion 95%) and stable at higher temperatures compared to c-Co3O4 (CO2 conversion 63%) due to its morphology-induced ∼66 times higher surface basicity. DRIFTS results showed differences in the detected surface species: formate was observed on m-Co3O4 and was proven to contribute to the total methane formation. It was revealed that in CO2 methanation reaction, both bulk and surface properties such as morphology, cobalt oxidation states, acid–base properties, and presence of defect sites directly affect the catalytic performance and reaction mechanism. Furthermore, 1% 5 nm Pt nanoparticles were loaded onto the Co3O4s to check the competitiveness of the catalysts. This study evidences on a cheap noble-metal-free catalyst for CO2 methanation consisting of m-Co3O4 with competitive activity and ∼100% CH4 selectivity.
Anastasiia Efremova; T. Rajkumar; Ákos Szamosvölgyi; András Sápi; Kornélia Baán; Imre Szenti; Juan Gómez-Pérez; Gábor Varga; János Kiss; Gyula Halasi; Ákos Kukovecz; Zoltán Kónya. Complexity of a Co3O4 System under Ambient-Pressure CO2 Methanation: Influence of Bulk and Surface Properties on the Catalytic Performance. The Journal of Physical Chemistry C 2021, 125, 7130 -7141.
AMA StyleAnastasiia Efremova, T. Rajkumar, Ákos Szamosvölgyi, András Sápi, Kornélia Baán, Imre Szenti, Juan Gómez-Pérez, Gábor Varga, János Kiss, Gyula Halasi, Ákos Kukovecz, Zoltán Kónya. Complexity of a Co3O4 System under Ambient-Pressure CO2 Methanation: Influence of Bulk and Surface Properties on the Catalytic Performance. The Journal of Physical Chemistry C. 2021; 125 (13):7130-7141.
Chicago/Turabian StyleAnastasiia Efremova; T. Rajkumar; Ákos Szamosvölgyi; András Sápi; Kornélia Baán; Imre Szenti; Juan Gómez-Pérez; Gábor Varga; János Kiss; Gyula Halasi; Ákos Kukovecz; Zoltán Kónya. 2021. "Complexity of a Co3O4 System under Ambient-Pressure CO2 Methanation: Influence of Bulk and Surface Properties on the Catalytic Performance." The Journal of Physical Chemistry C 125, no. 13: 7130-7141.
The charging and aggregation properties of boron nitride nanospheres (BNNSs) were investigated in the presence of electrolytes of different compositions and valences in aqueous suspensions. The influence of mono- and multivalent cations (counterions) and anions (coions) on the colloidal stability of the negatively charged particles was studied over a wide range of salt concentrations. For monovalent ions, similar trends were determined in the stability and charging of the particles irrespective of the salt composition, i.e., no ion-specific effects were observed. Once multivalent counterions were involved, the critical coagulation concentrations (CCCs) decreased with the valence in line with the direct Schulze–Hardy rule. The dependence indicated an intermediate charge density for BNNSs. The influence of the coions on the CCCs was weaker and the destabilization ability followed the inverse Schulze–Hardy rule. The predominant interparticle forces were identified as electrical double-layer repulsion and van der Waals attraction. These findings offer useful information to design stable BNNS dispersions in various applications, where mono- and multivalent electrolytes or their mixtures are present in the samples.
Tímea Hegedűs; Dóra Takács; Lívia Vásárhelyi; István Szilágyi; Zoltán Kónya. Specific Ion Effects on Aggregation and Charging Properties of Boron Nitride Nanospheres. Langmuir 2021, 37, 2466 -2475.
AMA StyleTímea Hegedűs, Dóra Takács, Lívia Vásárhelyi, István Szilágyi, Zoltán Kónya. Specific Ion Effects on Aggregation and Charging Properties of Boron Nitride Nanospheres. Langmuir. 2021; 37 (7):2466-2475.
Chicago/Turabian StyleTímea Hegedűs; Dóra Takács; Lívia Vásárhelyi; István Szilágyi; Zoltán Kónya. 2021. "Specific Ion Effects on Aggregation and Charging Properties of Boron Nitride Nanospheres." Langmuir 37, no. 7: 2466-2475.
The nanomaterial industry generates gigantic quantities of metal-based nanomaterials for various technological and biomedical applications; however, concomitantly, it places a massive burden on the environment by utilizing toxic chemicals for the production process and leaving hazardous waste materials behind. Moreover, the employed, often unpleasant chemicals can affect the biocompatibility of the generated particles and severely restrict their application possibilities. On these grounds, green synthetic approaches have emerged, offering eco-friendly, sustainable, nature-derived alternative production methods, thus attenuating the ecological footprint of the nanomaterial industry. In the last decade, a plethora of biological materials has been tested to probe their suitability for nanomaterial synthesis. Although most of these approaches were successful, a large body of evidence indicates that the green material or entity used for the production would substantially define the physical and chemical properties and as a consequence, the biological activities of the obtained nanomaterials. The present review provides a comprehensive collection of the most recent green methodologies, surveys the major nanoparticle characterization techniques and screens the effects triggered by the obtained nanomaterials in various living systems to give an impression on the biomedical potential of green synthesized silver and gold nanoparticles.
Andrea Rónavári; Nóra Igaz; Dóra Adamecz; Bettina Szerencsés; Csaba Molnar; Zoltán Kónya; Ilona Pfeiffer; Monika Kiricsi. Green Silver and Gold Nanoparticles: Biological Synthesis Approaches and Potentials for Biomedical Applications. Molecules 2021, 26, 844 .
AMA StyleAndrea Rónavári, Nóra Igaz, Dóra Adamecz, Bettina Szerencsés, Csaba Molnar, Zoltán Kónya, Ilona Pfeiffer, Monika Kiricsi. Green Silver and Gold Nanoparticles: Biological Synthesis Approaches and Potentials for Biomedical Applications. Molecules. 2021; 26 (4):844.
Chicago/Turabian StyleAndrea Rónavári; Nóra Igaz; Dóra Adamecz; Bettina Szerencsés; Csaba Molnar; Zoltán Kónya; Ilona Pfeiffer; Monika Kiricsi. 2021. "Green Silver and Gold Nanoparticles: Biological Synthesis Approaches and Potentials for Biomedical Applications." Molecules 26, no. 4: 844.
Extending the absorption range of TiO2 nanofibers to visible light is a great improvement of the photocatalytic property of TiO2. In this study, TiO2/WO3/C/N nanofibers were prepared by electrospinning using precursors soluble in water then annealing in argon. Titanium(IV) bis(ammonium lactato)dihydroxide (TiBALDH) and ammonium metatungstate (AMT) were used as the precursor for TiO2 and WO3 respectively. Different volume ratios of the precursors were added to a solution of PVP before electrospinning. The fibers were studied by XPS, SEM-EDX, TEM, FTIR, XRD, Raman spectroscopy and UV–VIS diffuse reflectance spectroscopy (DRS). The photocatalytic degradation of methylene blue by the fibers in visible light was investigated. The fibers had anatase TiO2 and monoclinic WO3. Based on UV–VIS DRS and Kubelka-Munk function the fibers could absorb visible light. Moreover, 100% TiBALDH had an indirect band gap of 2.9 eV, and the band gap decreased with increase in AMT, i.e., for 0% TiBALDH, band gap was 2.4 eV. The fibers degraded methylene blue dye in visible light, and 90% TiBALDH had the highest photocatalytic activity, i.e., it degraded 40% of the dye after 240 min.
Vincent Odhiambo; Chra Mustafa; Le Thong; Zoltán Kónya; Csaba Cserháti; Zoltán Erdélyi; István Lukác; Imre Szilágyi. Preparation of TiO2/WO3/C/N Composite Nanofibers by Electrospinning Using Precursors Soluble in Water and Their Photocatalytic Activity in Visible Light. Nanomaterials 2021, 11, 351 .
AMA StyleVincent Odhiambo, Chra Mustafa, Le Thong, Zoltán Kónya, Csaba Cserháti, Zoltán Erdélyi, István Lukác, Imre Szilágyi. Preparation of TiO2/WO3/C/N Composite Nanofibers by Electrospinning Using Precursors Soluble in Water and Their Photocatalytic Activity in Visible Light. Nanomaterials. 2021; 11 (2):351.
Chicago/Turabian StyleVincent Odhiambo; Chra Mustafa; Le Thong; Zoltán Kónya; Csaba Cserháti; Zoltán Erdélyi; István Lukác; Imre Szilágyi. 2021. "Preparation of TiO2/WO3/C/N Composite Nanofibers by Electrospinning Using Precursors Soluble in Water and Their Photocatalytic Activity in Visible Light." Nanomaterials 11, no. 2: 351.