Edit Csapó

University of Szeged · Department of Physical Chemistry and Materials Science

Hydrophobic ion pairing (HIP) complexation was found to be an efficient approach in modulating the release and enhancing the stability and encapsulation of hydrophilic macromolecules such as proteins in hydrophobic nano/microcarriers. The present work strives to develop and optimize the preparation of the HIP complex of the antimicrobial enzyme lys...

Sub-nanometer-sized gold nanoclusters (Au NCs) were prepared via the spontaneous reduction of [AuCl4]−- ions with a hydroxamate derivative of L-tryptophan (Trp) natural amino acid (TrpHA). The prepared TrpHA-Au NCs possess intense blue emission (λem = 470 nm; λex = 380 nm) with a 2.13% absolute quantum yield and 1.47 ns average lifetime. The Trp-st...

Fluorescent gold nanoclusters have been successfully used as fluorescent markers for imaging of cells and tissues, and their potential role in drug delivery monitoring is coming to the fore. In addition, the development of biosensors using structure-tunable fluorescent nanoclusters is also a prominent research field. In the case of these sensor app...

Encapsulation possibilities of an extensively investigated neuroprotective drug (kynurenic acid, KYNA) are studied via lipid-based nanocarriers to increase the blood–brain barrier (BBB) specific permeability. The outcomes of various preparation conditions such as stirring and sonication time, concentration of the lipid carriers and the drug, and th...

Role of amino acids like L‐phenylalanine (Phe), L‐glutamine (Gln) and L‐arginine (Arg) is described and interpreted in terms of their potential for preparation of fluorescent molecular‐like gold and silver nanostructures. We are among the first to demonstrate the effect of syntheses conditions as well as the molecular characteristics of Phe, Gln an...

The assembly of colloidal hyaluronic acid (HyA, as a polysaccharide) based hydrogel particles in an aqueous medium is characterized in the present paper, with an emphasis on the particular case of nanohydrogels formed by surfactant-neutralized polysaccharide networks. The structural changes and particle formation process of polysaccharide- and cati...

Carbon dots (CDs) are zero-dimensional nanomaterials composed of carbon and surface groups attached to their surface. CDs have a size smaller than 10 nm and have potential applications in different fields such as metal ion detection, photodegradation of pollutants, and bio-imaging, in this review, the capabilities of CDs in metal ion detection will...

The paper presents the research results on synthesizing silver nanoparticles in aqueous solutions and their extraction into the organic phase. Studies have shown that it is best to perform the extraction process using n-hexane > cyclohexane > toluene > chloroform > ethyl acetate. The results show a correlation between the dielectric constant of the...

The non-steroid anti-inflammatory drug ketoprofen (KP) as a model molecule is encapsulated in different poly(lactide-co-glycolide) (PLGA) nanostructured particles, using Tween20 (TWEEN) and Pluronic F127 (PLUR) as stabilizers to demonstrate the design of a biocompatible colloidal carrier particles with highly controllable drug release feature. Base...

In the current work, we first present a simple synthesis method for the preparation of novel Vitamin-B1-stabilized few-atomic gold nanoclusters with few atomic layers. The formed nanostructure contains ca. eight Au atoms and shows intensive blue emissions at 450 nm. The absolute quantum yield is 3%. The average lifetime is in the nanosecond range a...

This publication presents the synthesis of core–shell nanoparticles, where the core was Ni, and the shell was a Ag–Ni nano alloy. The synthesis was based on the reduction of Ni and Ag ions with sodium borohydride in the presence of trisodium citrate as a stabilizer. In order to determine the phase composition of the obtained nanoparticles, an XRD s...

Liquid phase delamination of layered materials into single- or few-layer nanosheets leads to stable nanoscale dispersions of 2D materials. The delamination of layered double hydroxide (LDH) to double hydroxide nanosheets was studied in two ionic liquids (ILs): ethylammonium nitrate (EAN) and 1-butyl-3-methylimidazolium thiocyanate (BMIMSCN). The as...

Carbon dots (CDs) are carbon-based zero-dimensional nanomaterials that can be prepared from a number of organic precursors. In this research, they are prepared using fat-free UHT cow milk through the hydrothermal method. FTIR analysis shows C=O and C-H bond presence, as well as nitrogen-based bond like C-N, C=N and –NH2 presence in CDs, while the a...

Fabrication protocol of bovine serum albumin-(BSA) and lysozyme-(LYZ) stabilized gold/silver bimetallic nanoclusters (Au/Ag NCs) have been reported via optimization of the protein/metal ion ratios, metal concentration, pH and incubation time. No other reducing and stabilizing compounds were used to produce these nanoclusters at room temperature. In...

Encapsulation possibilities of two neuroprotective drugs of slightly different structures, kynurenic acid (KYNA) and its more hydrophilic analogue (SzR72), are studied in bovine serum albumin (BSA) nanoparticles (NPs) to increase their permeability through the blood-brain barrier (BBB). The effect of various preparation conditions such as protein c...

Encapsulation possibilities of two neuroprotective drugs of slightly different structures, kynurenic acid (KYNA) and its more hydrophilic analogue (SzR72), are studied in bovine serum albumin (BSA) nanoparticles (NPs) to increase their permeability through the blood-brain barrier (BBB). The effect of various preparation conditions such as protein c...

In actual work we clearly highlight in the first time the experimental factors (dominantly the concentration of the macromolecule components) influencing the formation of human serum albumin/hyaluronic acid (HSA/HyA) complex carrier particles which is not available in the literature despite the several published articles. We have shown that the cha...

A new synthesis method is described for the first time to produce silver nanoclusters (AgNCs) by using the tyrosine (Tyr) amino acid. Several important parameters (e.g., molar ratios, initial pH, reaction time etc.) were optimized to reach the highest yield. The formed Tyr-AgNCs show characteristic blue emission at λem = 410 nm, and two dominant fl...

The selective determination of metals in waste solutions is a very important aspect of the industry and environmental protection. Knowledge of the contents and composition of the waste can contribute to design an efficient process separation and recovery of valuable metals. The problematic issue is primarily the correct determination of metals with...

In this paper, we firstly demonstrate a simple and reproducible synthesis protocol to produce nicotinamide-stabilized gold nanoclusters (NAM-Au NCs) under mild conditions. The dominant role of the pH and the ligand to metal ion molar ratio on the formation of these few atomic fluorescent NCs were proven. The prepared NCs show intensive blue-emissio...

In this review, we clearly highlight the importance of the detailed study of the interactions between noble metal colloids (nanoparticles (NPs) and nanoclusters (NCs)) with serum albumins (SAs) due to their rapidly growing presence in biomedical research. Besides the changes in the structure and optical property of SA, we demonstrate that the chara...

Effective applicability of serum albumin-hyaluronic acid (HyA) conjugates as potential drug delivery colloidal particles having d ∼ 220 – 260 nm average size has been presented for encapsulation of ibuprofen (IBU). Increased IBU content with drug loading of 30 % can be achieved via combination of the serum albumin proteins with biodegradable HyA po...

This paper reports a novel approach to the use of carbon, in the form of reduced graphene oxide, as a reducing agent for Au(III) chloride complex ions. This approach allows fabrication of a composite material [email protected]r in a single-step process. The reduction of Au(III) complex ions was performed using high pressure, 50 bar, and high temper...

In our study, core-shell nanoparticles containing lysozyme were formulated with precipitation and layering self-assembly. Factorial design (DoE) was applied by setting the process parameters during the preparation with Quality by Design (QbD) approach. The factors were the concentration of lysozyme and sodium alginate, and pH. Our aim was to unders...

While numerous papers have been published according to the binary surfactant mixtures, only a few articles provide deeper information on the composition dependence of the micellization, and even less work attempts to apply the enhanced feature of the mixed micelles. The most important parameter of the self-assembled surfactants is the critical mice...

Introduction: The present work describes a calorimetry-founded characterization and design of a potential surfactant based colloidal drug delivery system. However, numerous research groups have published their outcomes according to the thermodynamic characterization of mixed micelle formation but only a few articles provide deeper information on th...

In this work, we firstly presented a simple encapsulation method to prepare thiamine hydrochloride (vitamin B1)-loaded asolectin-based liposomes with average hydrodynamic diameter of ca. 225 and 245 nm under physiological and acidic conditions, respectively. In addition to the optimization of the sonication and magnetic stirring times used for size...

In the paper, the mechanism of the process of the Rh(III) ions adsorption on activated carbon ORGANOSORB 10—AA was investigated. It was shown, that the process is reversible, i.e., stripping of Rh(III) ions from activated carbon to the solution is also possible. This opens the possibility of industrial recovery of Rh (III) ions from highly dilute a...

In this work, sodium borohydride was used as a strong reductant of traces of platinum complex ions. The investigations of the kinetics of redox reaction between platinum(IV) chloride complex ions and sodium borohydride were carried out. For the first time, the kinetic experiments were carried out in a basic medium (pH~13), which prevents NaBH4 from...

In this work, a simple one-pot preparation protocol is presented for synthesis of adenosine monophosphate-stabilized bimetallic gold/silver nanoclusters (AMP-Au/Ag NCs). These yellow-emitting NCs (λem= 560 nm) with quantum yield of 7.3% show great kinetic stability and photostability as well. Besides the detailed size, composition, and structural c...

In this paper, the comprehensive toxicity mechanism of four well-defined protein-stabilized gold nanoclusters (Au NCs) is firstly highlighted against promyelocytic leukaemia cells (HL-60). For this purpose, bovine serum albumins (BSA) and human serum albumins (HSA), as well as lysozyme (LYZ) and gamma globulin (γG) immunoproteins were applied as re...

Introduction: The present work describes a calorimetry-founded characterization and design of a potential surfactant-based colloidal drug delivery system. However, numerous research groups have published their outcomes according to the thermodynamic characterization of mixed micelle formation but only a few articles provide deeper information on th...

In this paper, a novel method for the synthesis of Pt nanoparticles (PtNPs) using a microwave autoclave reactor is proposed. For benchmarking, the obtained results are compared with the traditional, batch method. A novel process window is proposed, which is the application of high-temperature and high-pressure. The main finding is that this only br...

The objective of this work was to study the kinetics of phosphomolybdenum blue formation onto the surface of intermetallic Al2Cu in orthophosphoric acid solution. This was performed using UV-Vis spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical methods. The latter included measurement of open circuit...

In this work, we clearly focus on the comparative cytotoxicity investigations of several protein-stabilized gold nanoclusters (Au NCs) towards lymphocytes B (COLO-720 L) and lymphocytes T (HUT-78) cells. For synthesis, the one-pot template-assisted method was carried out using lysozyme (LYZ), human (HSA) and bovine (BSA) serum albumins, and gamma g...

Analysis of in vitro dissolution profiles of encapsulated drugs usually involves the linearization of the applied mathematical model and sometimes transformation of the measured data. In this work, we demonstrate that a spreadsheet routine could provide a universal and reproducible data analysis strategy without the need for linearization. To test...

In medical research the visualization of drug carrier accumulation and release of the loaded drugs in vivo is an important field. In this work, two protein-stabilized gold nanoclusters (Au NCs) as effective fluorescent reporters (FRs) were investigated for labeling of biocompatible chitosan-modified hyaluronic acid based nanocarriers having two dif...

Charging and aggregation processes were studied in aqueous dispersions of halloysite nanotubes (HNTs) in the presence of monovalent inorganic electrolytes and ionic liquid (IL) constituents. The same type of co-ion (same sign of charge as HNT) was used in all systems, while the type of counterions (opposite sign of charge as HNT) was systematically...

A protein-polysaccharide-based potential nanocarrier system have been developed via a simple, one-step preparation protocol without the use of long-term heating and the utilization of hardly removable crosslinking agents, surfactants, and toxic organic solvents. To the best of our knowledge, this article is the first which summarizes in detail the...

Plasmonically enhanced fluorescence is a widely studied and applied phenomenon, however, only a comparative theoretical and experimental analysis of coupled fluorophores and plasmonic nanoresonators makes it possible to uncover how this phenomenon can be controlled. A numerical optimization method was applied to design configurations that are capab...

Over the past decade, search for novel materials for nucleic acid delivery has prompted a special interest in polymeric nanoparticles (NPs). In this study, the biological applicability of a water‐soluble cationic lipopolymer (WSLP) obtained by the modification of high molecular weight branched poly(ethylenimine) (PEI) with cholesteryl chloroformate...

Bimetallic nanoparticles (NPs) offer great flexibility to tailor the activity and selectivity in electrocatalytic conversion of carbon dioxide (CO 2 ) to valuable chemicals. Here, we report on the electrocatalytic behavior of Au-Sn, Au-Ag and Au-Pb NPs, to highlight the effect of the intermetallic phase formation and the bimetallic composition in C...

Plasmonically enhanced fluorescence is a widely studied and applied phenomenon, however only a comparative theoretical and experimental analyses of coupled fluorophores and plasmonic nanoresonators makes it possible to uncover, how this phenomenon can be controlled. A numerical optimization method was applied to design configurations that are capab...

The electrochemical conversion of carbon dioxide (CO2) to high-value chemicals is an attractive approach to create an artificial carbon cycle. Tuning the activity and product selectivity while maintaining long-term stability, however, remains a significant challenge. Here, we study a series of Au–Pb bimetallic electrocatalysts with different Au/Pb...

We first demonstrate a simple and rapid fabrication protocol of bovine serum albumin (BSA) nanoparticles (NPs), as potential drug carriers using a microchannel flow technique with the successful encapsulation of a water-soluble kynurenic acid (KYNA) having neuroactive property has also been performed. By comparison, the preparation of a hydrophobic...

A new porosity determination method for nano- and sub-micron particles is proposed, which is based on single particle inductively coupled plasma mass spectrometry (spICP-MS) measurements. The performance of the new method was tested on core-shell Ag-Au, hollow Au and mesoporous SiO2 nanoparticles of different size and porosity and it was found that...

The interaction of neuroactive kynurenic acid (KYNA) with human serum albumin (HSA) was studied from both thermodynamic and structural point of view. This protein-drug interaction has high relevance in neuroscience, because the serum albumin-based KYNA-containing composites may act as a potential drug delivery system. Reversible binding of KYNA on...

Fabrication possibilities, detailed size and structural characterization of biodegradable chitosan (Chit) polysaccharide-modified hyaluronic acid (HyA)-based colloidal carriers are demonstrated. The negatively charged and highly hydrophilic HyA polymer chains have been ionically modified by positively charged pure Chit and crosslinked Chit macromol...

This poster demonstrates the preparation and characterization of size-controlled liposomes in the diameter range of 50-250 nm for encapsulation of the fluorescent Rhodamin-B (RhoB) as a model drug molecule. During the experimental work three different encapsulation techniques have been studied and the dominant effect of the size, the structure and...

In this review, the presentation of the synthetic routes of plasmonic gold nanoparticles (Au NPs), fluorescent gold nanoclusters (Au NCs), as well as self-assembled Au-containing thiolated coordination polymers (Au CPs) was highlighted. We exclusively emphasize the gold products that are synthesized by the spontaneous interaction of tetrachloroaura...

The (±)-α-Tocopherol (TP) with vitamin E activity has been encapsulated into biocompatible poly(lactic acid) (PLA) and poly(lactide-co-glycolide) (PLGA) carriers, which results in the formation of well-defined nanosized (d ~200–220 nm) core-shell structured particles (NPs) with 15–19% of drug loading (DL%). The optimal ratios of the polymer carrier...

Target and appiled model: The studied system is specifically relevant in the neuroscience. Glutamate is the main excitatory neurotransmitter in the CNS. Kynurenic acid (KYNA) is the only known endogenous antagonist of ionotropic glutamate-receptors (GluR), and an increasing evidence suggests its neuroprotective capacity. At a higher, micromolar con...

The electrocatalytic reduction of carbon dioxide (CO 2 )on Au–Ag bimetallic alloy nanoparticles was scrutinized. This system provides a good model to investigate the correlation between the electrocatalytic activity and the composition of the nanoparticles. The CO Faradaic efficiency (and thus the forming CO:H 2 ratio)was changed linearly by contro...

Three drugs with different hydrophilicity are encapsulated in poly-lactide (PLA) and Poly(lactide-co-glycolide) (PLGA) drug delivery systems prepared by ring-opening polymerization (ROP). Formation of well-defined core-shell type nanoparticles (NPs) is observed for α-tocopherol (TP) and by systematically altering the hydrophilicity of the drug carr...

The pH- induced intelligent drug release ability of poly(styrene-co-maleic acid) copolymer nanoparticles (SMA NPs; d = 22.4 ± 3.1 nm) is presented using poorly water soluble ketoprofen (KETO) and α-Tocopherol (TP) model drugs. Increasing styrene content of the copolymer led to lower surface charge (from −28.4 to −15.0 meq/100 g) and the different s...

This work presents a detailed description of a commonly used and low-cost evaluation process that is simply based on the nonlinear fitting of concentration-, time- and temperature-dependent surface plasmon resonance (SPR) sensorgrams in order to provide kinetic and thermodynamic characterization of a biologically relevant interaction. Regardless of...

In this work, we first present a simple “green” preparation procedure of red-emitting (λemission = 645 nm, d = 1.5 ± 0.3 nm) fluorescent gold nanoclusters (Au NCs) using only γ-globulin (γG) immunoprotein as reducing and stabilizing agent. The γG-Au NCs are potent candidate for rapid detection of L-kynurenine (Kyn) which is a dominant molecule of t...

A Szegedi Tudományegyetem Természettudományi és Informatikai Karának, Fizikai Kémiai és Anyagtudományi Tanszékén mûködõ Kolloidok és Nanoszerkezetû Anyagok Kutatócsoportunk kutatási profilja a csoport közel 25 éves fennállása óta számos területet érintett. A rétegszilikátok és réteges kettõs hidroxidok (LDH) által stabilizált félvezetõ nanorészecsk...

Photoreactive composite thin layers with tunable wetting properties from superhydrophilic to superhydrophobic nature were prepared. To achieve extreme wetting properties, the adequate surface roughness is a crucial factor, which was achieved by the incorporation of plasmonic Ag-TiO2 particles, as polymer filler, into the smooth polymer film with ad...

Bimetallic electrocatalysts offer great flexibility to tailor the activity and selectivity in electrochemical carbon dioxide (CO2) reduction. Here, we report on the electrocatalytic behavior of Au–Sn bimetallic nanoparticles with different intermetallic phases towards CO2 electroreduction. Two high-value products formed with reasonable current dens...

This paper presents some findings from the rheological and drug dissolution characterizations of hyaluronic acid (HyA)-based colloidal drug delivery systems. During this investigations the widely applied, non-steroidal, anti-inflammatory ketoprofen (KP) has been used as model drug. For the moderation of the hydrophilic character of HyA and encapsul...

In the last years, the nanosized noble metal (gold, silver) became increasingly in the focus of interest in the sensor and medical researches thanks to their unique properties. During the biocompatible syntheses the applied biomolecule (e.g. peptide, dendrimer, amino acid) has two roles at the same time: both reducing and stabilizing agent. Small l...

The experiments in the present work describe, the synthesis and preparation, rheological, conductometric and titration calorimetry based characterization, and drug dissolution of different hyaluronic acid (HyA)-based colloidal drug delivery systems. During this investigations the hydrophobic ketoprofen (KP), one of the most used non-steroidal anti-...

Introduction: Detailed kinetic and thermodynamic characterization of physiological relevant receptor-ligand interactions provides several important data on the mechanisms of the drug binding and release process. Surface plasmon resonance (SPR) spectroscopy is capable of real-time monitoring of these interactions without use of labels via immobiliza...

The noble metal-based nanohybrid systems are in particularly focus due to their size-, shape-, composition-, aggregation- and surface roughnessdependent optical properties. Different nanostructures can be synthesized and they were characterized by several techniques. The optical properties were identified based UV-Vis and Fluorescence spectrophotom...

This work demonstrates the preparation, characterization, and drug dissolution of different hyaluronic acid (HyA)-based colloidal drug delivery systems containing hydrophobic ketoprofen (KP), a non-steroidal anti-inflammatory drug (NSAID), as the model drug molecule. Because of the highly hydrophilic character of HyA the cross-linked derivatives at...

The pH-responsive intelligent drug release facility of hydrophobically modified chitosan nanoparticles (Chit NPs) (d = 5.2 ± 1.1 nm) was presented in the case of poorly water soluble Ca2+ channel blocker nimodipine (NIMO) drug molecules. The adequate pH-sensitivity, i.e. the suitable drug carrier properties of the initial hydrophilic Chit were achi...