The use of giant vesicles as microreactors presents a novel approach to control biochemical reactions in confined spaces, offering advantages such as compartmentalization, tunable permeability, and potential for biomimetic applications. These constructs can serve as versatile platforms for catalysis, drug delivery, and synthetic biology by providing confined environments that mimic natural cellular compartments. We have successfully produced microvesicles (also referred to as giant vesicles) by means of the simple double emulsification method using five amphiphilic block copolymers comprising poly(ethylene oxide) (PEO) as hydrophilic segment and five disparate hydrophobic blocks: poly(caprolactone) (PCL), poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA), poly[2-(diisopropylamino)ethyl methacrylate] (PDPA), and poly[2-(heptamethyleneimino)ethyl methacrylate] (PHIA). The last two blocks are pH-responsive (PDPA, PHIA), while the first ones are not (PCL, PMMA, PLA). The resulting vesicles have average size ranging from 2.9 to 9.3 μm, with the pH-responsive vesicles exhibiting larger diameters, likely due to partial protonation of the hydrophobic blocks. The formation of the giant vesicles was confirmed via optical and fluorescence microscopy using Nile red as a hydrophobic marker. The ability of the vesicles to encapsulate larger molecules was demonstrated by loading Alexa-labeled bovine serum albumin (BSA-Alexa). Furthermore, the potential of these vesicles as microreactors was explored by encapsulating horseradish peroxidase enzyme (HRP) and evaluating the catalytic oxidation of o-dianisidine in the presence of hydrogen peroxide (H₂O₂), a reaction catalyzed by the HRP enzyme. The experimental data confirm that the pH-responsive vesicles are permeable to the reactants, as evidenced by colored product formation, whereas the permeability of the nonresponsive assemblies is negligible. The non-responsive vesicles exhibited particularly low permeability, even at the pH where the catalytic activity of the enzyme is optimum. These findings highlight the potential of pH-responsive vesicles for controlled molecular transport and catalytic applications, paving the way for their use in biocatalysis as microreactors.

• Klíčová slova
• Block copolymers, Giant polymer vesicles, Microreactors, Self-assembly,
• MeSH
• hydrofobní a hydrofilní interakce MeSH
• koncentrace vodíkových iontů MeSH
• křenová peroxidasa chemie   metabolismus   MeSH
• permeabilita MeSH
• polyestery chemie   MeSH
• polymery * chemie   MeSH
• povrchové vlastnosti MeSH
• velikost částic MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• křenová peroxidasa MeSH
• polyestery MeSH
• polymery * MeSH

The scale-down of reaction processes by microreactors enables significant benefits over the applications of conventional reactors due to the intensification of reaction which become an emerging prospect in the environmental engineering. In the last decades, there has been a rapid pollution increase connected with various industries, in particular due to the dye and textile industries, which generate huge amounts of wastewater containing organic dyes. The abatement of dyes in wastewater using microreactors therefore has great potential. This paper reviews a rapidly emerging area of microreactors applications in the removal of dyes from polluted water and describes a survey on recent advances in the development of microreactors in this area. With respect to the nature of the treatment technique, the scope of the literature was divided into several categories - Fenton reaction, ozonation, photocatalytic degradation, reductive degradation, biotreatment, and separative sequestration. This review focusses on summarizing different configurations of reaction conditions of the respective treatment techniques, their efficiency, and, mainly, the characteristics including design, construction materials, and fabrication of microreactors applied. The evaluation and evolution of treatment techniques have also been critically analyzed, and future perspectives are proposed in this work. From the present study, it can be concluded that several treatment methods can be applied for removal of organic dyes in a wide range of microreactor designs. Furthermore, this work showcases how microreactor technology may improve mass transfer as well as treatment efficiency. A novelty of the this review article lies in (i) data analysis with emphasis on reaction conditions as well as microreactor designs, and, based on this, in (ii) the proposition of decision-making algorithm which can facilitate a designing of the dyes removal in microreactors.

• Klíčová slova
• Advanced oxidation processes, Dye, Microfluidic, Microreactor, Textile wastewater, Treatment,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

In this work, the combination of an immobilized enzyme microreactor (IMER) based on the clinically important isoform cytochrome P450 2C9 (CYP2C9) with capillary electrophoresis (CE) is presented. The CYP2C9 was attached to magnetic SiMAG-carboxyl microparticles using the carbodiimide method. The formation of an IMER in the inlet part of the separation capillary was ensured by two permanent magnets fixed in a cassette from the CE apparatus in the repulsive arrangement. The resulting on-line system provides an integration of enzyme reaction mixing and incubation, reaction products separation, detection and quantification into a single fully automated procedure with the possibility of repetitive use of the enzyme and minuscule amounts of reactant consumption. The on-line kinetic and inhibition studies of CYP2C9's reaction with diclofenac as a model substrate and sulfaphenazole as a model inhibitor were conducted in order to demonstrate its practical applicability. Values of the apparent Michalis-Menten constant, apparent maximum reaction velocity, Hill coefficient, apparent inhibition constant and half-maximal inhibition concentration were determined on the basis of the calculation of the effective substrate and inhibitor concentrations inside the capillary IMER using a model described by the Hagen-Poisseulle law and a novel enhanced model that reflects the influence of the reactants' diffusion during the injection process.

• Klíčová slova
• Capillary electrophoresis, Cytochrome P450, Drug metabolism, Immobilized enzyme reactor,
• MeSH
• bioreaktory MeSH
• difuze MeSH
• diklofenak chemie   MeSH
• elektroforéza kapilární * MeSH
• enzymy imobilizované metabolismus   MeSH
• kinetika MeSH
• objevování léků přístrojové vybavení   metody   MeSH
• systém (enzymů) cytochromů P-450 chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• diklofenak MeSH
• enzymy imobilizované MeSH
• systém (enzymů) cytochromů P-450 MeSH

The preparation and characterization of a miniaturized trypsin reactor using on-line coupling with an ESI-TOF mass spectrometer are described. L-1-Tosylamido-2-phenylethyl chloromethyl ketone-trypsin was covalently immobilized on poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith prepared in a 75 microm ID fused silica capillary resulting in a bioreactor with high local concentration of the proteolytic enzyme. Covalent immobilization of trypsin on this support was performed using the epoxide functional groups in either a one- or a multistep reaction. For on-line protein digestion-MS analysis the bioreactor was coupled with the mass spectrometer using a liquid junction microelectrospray interface. The performance of the reactor was tested using an on-line flow through the system with flow rates of 50-300 nL/min. The resulting protein consumption was in the atto- to low femtomole range. Proteolytic activity was characterized in a wide range of conditions with respect to the flow rate, pH, and temperature. Complete protein digestion was achieved in less than 30 s at 25 degrees C with the sequence coverage of 80% (cytochrome c), which is comparable to 3 h digestion in solution at 37 degrees C. Besides the good performance at laboratory temperature, the immobilized trypsin in the bioreactor also performed well at lower pH compared to the standard in-solution protocols.

• MeSH
• enzymy imobilizované chemie   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• indikátory a reagencie MeSH
• kapilární jevy MeSH
• oxid křemičitý MeSH
• tosylfenylalanylchlormethylketon MeSH
• trypsin chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• enzymy imobilizované MeSH
• indikátory a reagencie MeSH
• oxid křemičitý MeSH
• tosylfenylalanylchlormethylketon MeSH
• trypsin MeSH

Droplet microfluidics may soon change the paradigm of performing chemical analyses and related instrumentation. It can improve not only the analysis scale, possibility for sensitivity improvement, and reduced consumption of chemical and biological reagents, but also the speed of performing a variety of unit operations. At present, microfluidic platforms can reproducibly generate monodisperse droplet populations at kHz or higher rates with droplet sizes suitable for high-throughput experiments, single-cell detection or even single molecule analysis. In addition to being used as microreactors with volume in the micro- to femtoliter range, droplet based systems have also been used to directly synthesize particles and encapsulate biological entities for biomedicine and biotechnology applications. This minireview summarizes various droplet microfluidics operations and applications for (bio)chemical assays described in the literature during the past few years.

• MeSH
• mikrofluidika * MeSH
• povrchové vlastnosti MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

In this paper, we report on a novel oriented peptide-N-glycosidase F (PNGase F) immobilization approach onto methacrylate based monolithic support for rapid, reproducible and efficient release of the N-linked carbohydrate moieties from glycoproteins. The glutathione-S-transferase-fusion PNGase F (PNGase F-GST) was expressed in Escherichia coli using regular vector technology. The monolithic pore surface was functionalized with glutathione via a succinimidyl-6-(iodoacetyl-amino)-hexanoate linker and the specific affinity of GST toward glutathione was utilized for the oriented coupling. This novel immobilization procedure was compared with reductive amination technique commonly used for non-oriented enzyme immobilization via primary amine functionalities. Both coupling approaches were compared using enzymatic treatment of several glycoproteins, such as ribonuclease B, fetuin and immunoglobulin G followed by MALDI/MS and CE-LIF analysis of the released glycans. Orientedly immobilized PNGase F via GST-glutathione coupling showed significantly higher activity, remained stable for several months, and allowed rapid release of various types of glycans (high-mannose, core fucosylated, sialylated, etc.) from glycoproteins. Complete protein deglycosylation was obtained as fast as in several seconds when using flow-through immobilized microreactors.

• Klíčová slova
• Deglycosylation, Enzyme microreactor, Monolith, Oriented immobilization, PNGase F,
• MeSH
• elektroforéza kapilární metody   MeSH
• enzymy imobilizované chemie   metabolismus   MeSH
• Escherichia coli genetika   metabolismus   MeSH
• glykosylace MeSH
• imunoglobulin G chemie   MeSH
• lidé MeSH
• mannosyl-glykoprotein endo-beta-N-acetylglukosaminidasa chemie   metabolismus   MeSH
• polysacharidy analýza   chemie   MeSH
• poréznost MeSH
• skot MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• enzymy imobilizované MeSH
• imunoglobulin G MeSH
• mannosyl-glykoprotein endo-beta-N-acetylglukosaminidasa MeSH
• polysacharidy MeSH

The ever-growing field of microfluidics requires precise and flexible control over fluid flows at reduced scales. Current constraints demand a variety of controllable components to carry out several operations inside microchambers and microreactors. In this context, brand-new nanophotonic approaches can significantly enhance existing capabilities providing unique functionalities via finely tuned light-matter interactions. A concept is proposed, featuring dual on-chip functionality: boosted optically driven diffusion and nanoparticle sorting. High-index dielectric nanoantennae is specially designed to ensure strongly enhanced spin-orbit angular momentum transfer from a laser beam to the scattered field. Hence, subwavelength optical nanovortices emerge driving spiral motion of plasmonic nanoparticles via the interplay between curl-spin optical forces and radiation pressure. The nanovortex size is an order of magnitude smaller than that provided by conventional beam-based approaches. The nanoparticles mediate nanoconfined fluid motion enabling moving-part-free nanomixing inside a microchamber. Moreover, exploiting the nontrivial size dependence of the curled optical forces makes it possible to achieve precise nanoscale sorting of gold nanoparticles, demanded for on-chip separation and filtering. Altogether, a versatile platform is introduced for further miniaturization of moving-part-free, optically driven microfluidic chips for fast chemical analysis, emulsion preparation, or chemical gradient generation with light-controlled navigation of nanoparticles, viruses or biomolecules.

• Klíčová slova
• all‐dielectric nanophotonics, lab‐on‐a‐chip platforms, nanofluidics, optomechanical manipulations, spin‐orbit couplings,
• Publikační typ
• časopisecké články MeSH

A mathematical model of an enzymatic separating microreactor with the electro-osmotic control of reaction component transport rates is analysed. The micro-reactor is considered in a form of a thin channel filled with a gel containing an immobilised enzyme and an adsorbent where the enzyme reaction, the molecular diffusion, the electro-osmotic flux and the adsorption take place. The substrate inhibited enzyme reaction splitting a non-ionic substrate to two non-ionic products is considered. The reactor operates in a periodic regime, when the channel entry is exposed to the periodic substrate concentration pulses. A chromatographic separation of reaction components, therefore, proceeds in the channel. Effects of principal operational parameters of the reactor system-the reaction channel length, the electric current density, the substrate inlet concentration, the rate of adsorption, and the enzyme activity--on resolution of the products at reactor outlet are analysed. The existence of optimum parameter values (maximising the resolution of reaction products) is shown and a multiparametric optimisation of the reactor performance is accomplished.

• MeSH
• biologické modely * MeSH
• bioreaktory * MeSH
• enzymy imobilizované metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• enzymy imobilizované MeSH

A new sol-gel synthesis route for rare earth (Ce and Pr) alumina hybrid aero- and xerogels is presented which is based on the so-called epoxide addition method. The resulting materials are characterized by TEM, XRD and nitrogen adsorption. The results reveal a different crystallization behavior for the praseodymia/alumina and the ceria/alumina gel. Whereas the first remains amorphous until 875°C, small ceria domains form already after preparation in the second case which grow with increasing calcination temperature. The use of the calcined gels as CO oxidation catalysts was studied in a quartz tube (lab) reactor and in a (slit) microreactor and compared to reference catalysts consisting of the pure rare earth oxides. The Ce/Al hybrid gels exhibit a good catalytic activity and a thermal stability against sintering which was superior to the investigated reference catalyst. In contrast, the Pr/Al hybrid gels show lower CO oxidation activity which, due to the formation of PrAlO3, decreased with increasing calcination temperature.

• Klíčová slova
• Aerogels, CO oxidation, Rare earth oxides, Sol–gel chemistry, Xerogels,
• Publikační typ
• časopisecké články MeSH

Cost-effective and efficient photoelectrochemical (PEC) water splitting stands out as one of the most promising strategies to address sustainable energy supply in the form of green H2. Large-area photoelectrodes featuring precise chemical and morphological control are key components for a practical solar-to-hydrogen conversion. Herein, we report the continuous flow synthesis of BiVO4 nanoparticles (NPs) by using a simple microreactor configuration. The solution containing the as-prepared NPs enables the deposition of BiVO4 photoanodes with areas up to 52 cm2 through a simple and scalable chemical bath deposition method. On the other hand, surface protection by an ultrathin Al2O3 overlayer grown by atomic layer deposition (ALD) increases the performance of the 1 cm2 BiVO4 photoanodes ~30 %, exhibiting a photocurrent density of ~2.0 mA⋅cm-2 at 1.23 V vs. the Reversible Hydrogen Electrode in the presence of a sacrificial hole scavenger. The optimized continuous flow synthesis provides an affordable methodology for the fabrication of cost-effective, large-scale photoanodes, which could potentially be applied for different photoelectrochemical reactions.

• Klíčová slova
• Bismuth vanadate, Flow synthesis, Photoanode, Solar hydrogen, Upscaling,
• Publikační typ
• časopisecké články MeSH