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The separation of layered MFI into unilamellar nanosheets in solution confirms the general validity of soft-chemical exfoliation for zeolites and allows top-down production of films with potential applications in separation and catalysis.

DNA origami is a widely used DNA nanotechnology that allows construction of two-dimensional and three-dimensional nanometric shapes. The designability and rigidity of DNA origami make it an ideal material for construction of topologically linked molecules such as catenanes, which are attractive for their potential as motors and molecular machines. However, a general method for production of topologically linked DNA origami has been lacking. Here, we show that catenated single-stranded DNA circles can be produced and used as a universal scaffold for the production of topologically linked (catenated) DNA origami structures where the individual linked structures can be of any arbitrary design. Assembly of these topologically linked DNA origami structures is achieved via a simple one-pot annealing protocol.

The selection of grass mixtures with appropriate visual and functional parameters for sowing football fields is a key element in shaping the sports infrastructure, ensuring the spectacularity of a match and comfort for players. The aim of the research was to investigate the properties of lawn grass mixtures and their suitability for football pitches. The experiment was conducted at the Toya Golf & Country Club (51° 20′ E, 17° 07′ N), Wrocław, Poland, between 2007 and 2009. 12 grass mixtures were selected, mainly based on red fescue, Kentucky bluegrass, and perennial ryegrass. The assessment was carried out using a nine-point scale, according to the Plant Variety Office methodology for crops and turf grass. Six features of sports turf were studied: appearance, density, colour, leaf fineness, overwintering, and susceptibility to disease and they significantly varied, depending on the grass mixture and the year of research. Our study showed that mixtures based on the dominance of meadow grass were characterized by higher values of the general visual aspect, colour and slenderness of the leaf blade and these based on the dominance of perennial ryegrass and co-dominance of perennial ryegrass and meadow grass were the most useful in terms of wintering, resistance to diseases and sodding.

Leydig cell tumors (LCT) are the most common type of testicular stromal tumor. Herein, we investigate the G protein-coupled estrogen receptor (GPER) and peroxisome proliferator–activated receptor (PPAR) implication in regulation of lipid homeostasis including the expression of steroidogenesis-controlling molecules in clinical specimens of LCTs and tumor Leydig cells (MA-10). We showed the general structure and morphology of LCTs by scanning electron and light microscopy. In LCTs, mRNA and protein analyses revealed increased expression of GPER and decreased expression of PPARα, β, and γ. Concomitantly, changes in expression pattern of the lutropin receptor (LHR), protein kinase A (PKA), perilipin (PLIN), hormone sensitive lipase (HSL), steroidogenic acute regulatory protein (StAR), translocator protein (TSPO), HMG-CoA synthase, and reductase (HMGCS, HMGCR) were observed. Using MA-10 cells treated with GPER and PPAR antagonists (alone and in combination), we demonstrated GPER-PPAR–mediated control of estradiol secretion via GPER-PPARα and cyclic guanosine monophosphate (cGMP) concentration via GPER-PPARγ. It is assumed that GPER and PPAR can crosstalk, and this can be altered in LCT, resulting in a perturbed lipid balance and steroidogenesis. In LCTs, the phosphatidylinositol-3-kinase (PI3K)-Akt-mTOR pathway was disturbed. Thus, PI3K-Akt-mTOR with cGMP can play a role in LCT outcome and biology including lipid metabolism.

Decoration of inorganic substrates with surface-grafted and perpendicularly oriented conjugated polymers has gained substantial attention spurred by the development of new facile synthetic methodologies. We have recently shown that conjugated polymer brushes with interesting optoelectrical properties and presupposed ladder-like architecture could be obtained by a self-templating surface-initiated polymerization (ST-SIP). In this report, nanomechanical properties of ladder-like brushes composed of alkyl backbones supported by conjugated polyacetylene chains are investigated by means of AFM nanoindentation, quantitative nanomechanical mapping (QNM), and lateral force microscopy (LFM) in air and organic solvents. It is shown that conversion of deprotected linear poly(3-trimethylsilyl-2-propynyl methacrylate) (PTPM) brushes into ladder-type brushes using ST-SIP leads to pronounced changes in the structure and mechanical properties of the formed films. Ladder-type brushes possess an open (porous) structure and enhanced stiffness compared to the parent brushes. In contrast to linear brushes, the Young's modulus of ladder-like brushes is shown to be independent of solvent quality, due to the low conformational freedom of the grafted chains. The LFM measurements reveal slightly enhanced lubricating properties of linear brushes. However, the differences between linear and ladder-like brushes are much smaller than those reported for typical isotropically crosslinked films. Degrafting experiments reveal the predominantly intramolecular mechanism of ST-SIP and hence efficient generation of ladder-type conjugated polymers. The observation of structure-dependent changes of mechanical properties revealed in this study indicates new opportunities to fine-tune interface properties by exploiting stretched polymer chains in advanced architectures leading to low conformational freedom.

The high stability and conductivity of 3,4-disubstituted polythiophenes such as poly(3,4-ethylenedioxythiophene) (PEDOT) make them attractive candidates for commercial applications. However, next-generation nanoelectronic devices require novel macromolecular strategies for the precise synthesis of advanced polymer structures as well as their arrangement. In this report, we present a synthetic route to make ladder-like polymer brushes with poly(3,4-propylenedioxythiophene) (PProDOT)-conjugated chains. The brushes were prepared via a self-templating surface-initiated technique (ST-SIP) that combines the surface-initiated atom transfer radical polymerization (SI-ATRP) of bifunctional ProDOT-based monomers and subsequent oxidative polymerization of the pendant ProDOT groups in the parent brushes. The brushes prepared in this way were characterized by grazing-angle FTIR, XPS spectroscopy, and AFM. Steady-state and time-resolved photoluminescence measurements were used to extract the information about the structure and effective conjugation length of PProDOT-based chains. Stability tests performed in ambient conditions and under exposure to standardized solar light revealed the remarkable stability of the obtained materials. ispartof: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES vol:23 issue:11 ispartof: location:Switzerland status: published

Layered zeolites, especially MWW, have been used to synthesize pillared micro/mesoporous hybrids with the goal to enhance catalytic activity towards larger molecules. The critical preparation step is expansion of the interlayer space by swelling with cationic surfactants at high pH. Recently reported solutions of MWW monolayers, obtained by exfoliation of the zeolite MCM-56, can be used to prepare analogous materials by flocculation (precipitation) with surfactant solutions. This previously unavailable approach is studied in this work with both high pH (0.2 M, pH > 13.3) and lower pH (0.01 M, pH~12) solutions, and resulted in finding conditions for preparation of catalysts that can be more active than pure microporous layers (zeolite) despite large content of unreactive silica pillars. Both the high and low pH conditions afforded similar expanded surfactant-MWW composites, but their behavior differed during pillaring with TEOS. Well-defined expanded interlayer distances indicated by a low angle reflection in XRD above 3 nm d-spacing was observed only with the high alkalinity preparations. An additional benefit was observed with TEOS treatment in the presence of isopropyl alcohol leading to a product showing high catalytic activity in model alkylation reaction (mesitylene with benzyl alcohol) proceeding faster than with the pure zeolite. The products obtained under different conditions were characterized by textural methods, nitrogen adsorption and QE-TPDA, and FT-IR to investigate acid site parameters. Notably, the MCM-56 used in this work was prepared with addition of aniline as the structure-promoting agent and is the second formulation affording exfoliable MWW materials.

As plant growth stimulants, Ti and amino acids affect physiological processes of plants, promoting their vegetative and generative development and improving their yield and its quality. An experiment was carried out at the Experimental Station of the University of Agriculture in Krakow on degraded black earth soil formed from loess. Its aim was to determine the effect of two products, one containing amino acids and the other with Ti, on the Poa pratensis yield and its quality. Foliar application of amino acids and Ti, used on their own and together, constituted the main factor of the experiment. It was found that the treatment with both stimulants applied together significantly affected plant parameters. Compared to control, plants treated with those growth stimulants produced higher dry matter yields and contained significantly more phosphorus, potassium, calcium, magnesium, and sodium in dry matter. The highest effect was recorded on plots where combined application of amino acids and Ti was used. Almost as good results were recorded when amino acids were applied on their own. Regarding the cuts, higher effects were noted in the first and second ones than in the third. The growth stimulants used in the present experiment had a positive effect on the chemical composition of Poa pratensis meadow plants. The results indicated that the treatment significantly increased macronutrient content, compared to control plants. The most favourable effects were recorded for plants on the plot with combined application of amino acids and Ti. Similar results were also obtained on plots where only amino acids were used. Regarding the harvests, better results were noted in the first and second ones than in the third. In view of the potential benefits, it would be advisable to extend and update research on the effects of these stimulants on other common varieties of forage grasses.

Leydig cell tumours are the most common sex cord-stromal tumours. In the last years, apparent increased incidence is noted while aetiology of the tumour is still unknown. Therefore, here, we focused on the genetics of Leydig cell tumours using the next-generation sequencing. Leydig cell micronodules were revealed in patients with azoospermia who were qualified for testicular biopsy. Complete gene set of Leydig cell tumours was compared with transcriptome of healthy Leydig cells obtained from donors. Bioinformatic analysis of the obtained sequencing data revealed alterations in expression of 219 transcripts. We showed, for the first time, that a significant proportion of differentially expressed genes is directly involved in regulation of apoptotic process, which downregulation might be important to Leydig cell tumour development. Additionally, we found a significant upregulation of heat shock protein genes that might be a unique feature of Leydig cell tumours when compared to other tumour types. Our study offers fundamental transcriptomic data for future studies on human Leydig cell tumour that are crucial to determine its causes. Moreover, presented here the in-depth analysis and discussion of alterations observed in tumour transcriptome may be important for the diagnosis and therapy of this pathology.

Direct exfoliation of layered zeolites into solutions of monolayers has remained unresolved since the 1990s. Recently, zeolite MCM-56 with the MWW topology (layers denoted mww) has been exfoliated directly in high yield by soft-chemical treatment with tetrabutylammonium hydroxide (TBAOH). This has enabled preparation of zeolite-based hierarchical materials and intimate composites with other active species that are unimaginable via the conventional solid-state routes. The extension to other frameworks, which provides broader benefits, diversified activity, and functionality, is not routine and requires finding suitable synthesis formulations, viz. compositions and conditions, of the layered zeolites themselves. This article reports exfoliation and characterization of layers with ferrierite-related structure, denoted bifer, having rectangular lattice constants like those of the FER and CDO zeolites, and thickness of approximately 2 nm, which is twice that of the so-called fer layer. Several techniques were combined to prove the exfoliation, supported by simulations: AFM; in-plane, in situ, and powder X-ray diffraction; TEM; and SAED. The results confirmed (i) the structure and crystallinity of the layers without unequivocal differentiation between the FER and CDO topologies and (ii) uniform thickness in solution (monodispersity), ruling out significant multilayered particles and other impurities. The bifer layers are zeolitic with Bronsted acid sites, demonstrated catalytic activity in the alkylation of mesitylene with benzyl alcohol, and intralayer pores visible in TEM. The practical benefits are demonstrated by the preparation of unprecedented intimately mixed zeolite composites with the mww, with activity greater than the sum of the components despite high content of inert silica as pillars.

Lactobacillus rhamnosus GG is an environmentally and human-friendly bacteria that can be found in probiotics. However, it is incapable of forming a biofilm on metal surfaces, what limits the possibility of using it in bioelectrochemical systems (BESs) as promising and green alternatives. Hence, we propose a simple and cost-effective modification of metal surface with cationic dextran derivative (DEX-G) by using the electrostatically driven self-assembly procedure resulting in the formation of a polymeric monolayer. Modification of metal electrodes was confirmed by using infrared spectroscopy (IR) and atomic force microscopy (AFM). Synthesized metal/polycation electrodes provided a bioactive environment for L. rhamnosus GG enhancing its proliferation and formation of the biofilm as confirmed by SEM imaging. Moreover, using cyclic voltammetry (CV) and chronoamperometry measurements, it was proven that metal/polycation/L. rhamnosus bioelectrodes are electrochemically active in the glucose-rich medium. The electrochemical activity of fabricated bioanodes allows to consider them for their potential use in the bioelectrochemical systems.

The DNA origami technique allows the facile design and production of three-dimensional shapes from single template strands of DNA. These can act as functional devices with multiple potential applications but are constrained by practical limitations on size. Multi-functionality could be achieved by connecting together distinct DNA origami modules in an ordered manner. Arraying of non-identical, three-dimensional DNA origamis in an ordered manner is challenging due for example, to a lack of compatible rotational symmetries. Here we show that we can design and build ordered DNA structures using non-identical 3D building blocks by using DNA origami snub-cubes in left-handed and right-handed forms. These can be modified such that one form only binds to the opposite-handed form allowing regular arrays wherein building blocks demonstrate alternating chirality.

Electronic energy transfer and the migration of electrons generated via photoinduced electron transfer are key processes for the conversion of solar energy in natural photosynthetic systems. The proper arrangement of chromophores, electron donors and acceptors, or molecular wires on the scale of nanometers is a prerequisite for creating synthetic systems capable of achieving the high energy conversion efficiencies seen in nature. Ordered polymer layers that are adsorbed-to, or grafted-from, surfaces can serve as systems for harvesting of light and directional transfer of energy and electrons in confined environments. Moreover, ordered layers can act as templates for the desired ordering of different photoactive nanoobjects necessary for the development of optoelectronic devices, molecular electronics, and nanosensors. Herein, various macromolecular strategies are reviewed for synthesizing and arranging polymer chains on surfaces to improve the transport of electrons and excitation energy at interfaces. Specifically, the versatile layer-by-layer assembly method for forming thin films from polyelectrolytes and other charged nanoobjects, and the formation of surface-tethered polymer brushes, especially conjugated ones, with various chain architectures are presented together with their applications. The impact of various macromolecular architectures and compositions are discussed in relation to the performance of the polymer and polymer-templated films. Further development of the field could focus on precise engineering of macromolecules with complex architectures, precise positioning of active groups along the chains, towards mimicking the natural systems and their performance.

The synthesis of surface-grafted polymers with variable functionality requires the careful selection of polymerization methods that also enable spatially controlled grafting, which is crucial for the fabrication of, e.g., nano (micro) sensor or nanoelectronic devices. The development of versatile, simple, economical, and eco-friendly synthetic strategies is important for scaling up the production of such polymer brushes. We have recently shown that poly (3-methylthienyl methacrylate) (PMTM) and poly (3-trimethylsilyl-2-propynyl methacrylate) (PTPM) brushes with pendant thiophene and acetylene groups, respectively, could be used for the production of ladder-like conjugated brushes that are potentially useful in the mentioned applications. However, the previously developed syntheses of such brushes required the use of high volumes of reagents, elevated temperature, or high energy UV-B light. Therefore, we present here visible light-promoted metal-free surface-initiated ATRP (metal-free SI-ATRP) that allows the economical synthesis of PMTM and PTPM brushes utilizing only microliter volumes of reaction mixtures. The versatility of this approach was shown by the formation of homopolymers but also the block copolymer conjugated brushes (PMTM and PTPM blocks in both sequences) and patterned films using TEM grids serving as photomasks. A simple reaction setup with only a monomer, solvent, commercially available organic photocatalyst, and initiator decorated substrate makes the synthesis of these complex polymer structures achievable for non-experts and ready for scaling up.

Wood-polymer hybrid material was prepared using an easily scalable supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) concept with low ppm catalyst concentration. Polymers with hydrophobic characteristics – poly (n-butyl acrylate) (PnBA), poly (tert-butyl acrylate) (PtBA) and poly (methyl methacrylate) (PMMA) were grafted from the fir wood surface in a controlled manner, proved by linear first-order kinetics of polymerization in solution and low dispersity (Mw/Mn = 1.12) of the polymers formed in the reaction mixture. Moreover, the thickness of the polymer brushes grafted from the wood surface was estimated based on the measurements performed for brush decorated silicon wafers that were placed in the reaction mixture. Scanning electron microscopy (SEM) proved successful coverage of the wood by a covalently attached polymer layer, going from sharp-edged untreated wood surface with clearly visible wood cell wall structural elements, to full coverage rough texture with no visible structural components. Water contact angle (Θ) measurements indicated excellent hydrophobic properties of the prepared biohybrid material (Θ ~138°) without notable changes after 120 s of water droplet exposure. Water and acid solution uptake tests confirmed a significant improvement in resistance for absorption of wood samples after modification with polymers.

The main focus of this work was to establish a correlation between surface topography and chemistry and surface colonization by lactic acid bacteria. For this reason, we chose gold substrates with different surface architectures (i.e., smooth and nanorough) that were characterized by atomic force microscopy (AFM), electron scanning microscopy (SEM), and X-ray diffractometry (XRD). Moreover, to enhance biocompatibility, we modified gold substrates with polymeric monolayers, namely cationic dextran derivatives with different molar masses. The presence of those layers was confirmed by AFM, infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS). In order to determine the adhesion abilities of non-modified and modified gold surfaces, we tested three lactic acid bacteria (LAB) strains (i.e., Lactobacillus rhamnosus GG, Lactobacillus acidophilus, and Lactobacillus plantarum 299v). We have shown that surface roughness influences the surface colonization of bacteria, and the most significant impact on the growth was observed for the Lactobacillus rhamnosus GG strain. What is more, covering the gold surface with a molecular polymeric film by using the layer-by-layer (LbL) method allows additional changes in the bacterial growth, independently on the used strain. The well-being of the bacteria cells on tested surfaces was confirmed by using selective staining and fluorescence microscopy. Finally, we have determined the bacterial metabolic activity by measuring the amount of produced lactic acid regarding the growth conditions. The obtained results proved that the adhesion of bacteria to the metallic surface depends on the chemistry and topography of the surface, as well as the specific bacteria strain.

The aim of this research was to determine the effect of micronutrients and a fungicide on the germination of perennial ryegrass seeds. The experiment was conducted between 2016 and 2018 in Blizocin (51&deg, 22&prime, N, 17&deg, 09&prime, E), Poland. The first experimental factor was InnoFert Mikro, a micronutrient fertilizer used at doses of 0.5 and 1 L∙ha&minus, 1, while the second factor was the Soprano 125 S.C. fungicide used at the same doses. From each of the plots, 100 seeds were collected and placed on a Petri dish. Then, every day for 14 days, the plant germination was observed. The highest germination capacity of 95.3% was recorded for seeds from plots where combined full doses of the experimental factors were applied. This figure was 2% higher than for the control sample. The germination speed of the seeds from the above plot, determined by Maguire&rsquo, s index, was the highest out of the other seed groups, although the seeds from the above plot had the longest average germination time. It was also noted that by increasing the dose of micronutrient fertilizer, the germination speed also increased. In the case of the fungicide, half a dose had a positive effect on germination, but increasing the dose to 1 L∙ha&minus, 1 resulted in fewer germinated plants when compared to the control sample.

Field trials were conducted in the years 2017&ndash, 2019 at the Małopolska Plant Breeding in the Plant Breeding Stations in Polanowice, Nieznanice and Palikije. The trials were designed to determine the yield of some timothy genotypes in the context of chemical composition under different habitat conditions. The present evaluation of the strain quality shows a high potential for breeding. The analyzed genotypes produced high dry matter yields, which differed by as much as 53%. The experimental plots also differed in the crude protein content, which varied from 104.5 to 230.1 g kg&minus, 1 d.m., depending on the crop and year of harvest. For crude fiber, these values ranged from 173.9 to 274.8 g kg&minus, 1 d.m., depending on the crop and harvest year. The analysis of the mineral composition also revealed significant large variation.

The purpose of this research was to assess the functional value of the &ldquo, Super Trawnik&rdquo, lawn mixture. The studies were carried out between 2017 and 2019 at the Experimental Station of the University of Agriculture in Krakow (50&deg, 07&prime, N, 20&deg, 05&prime, E), and the experimental factor was the AGRO-SORB&reg, Folium, a biostimulant containing amino acids and applied at three doses: 1, 2, and 3 L&middot, ha&minus, 1. Lawn visual quality was assessed on a 9-point scale, with 10&ndash, 11 mowings at 4 cm during the growing period. An increase in the concentration of the stimulant applied as a spray resulted in a significant increase in its effectiveness, plants in plots with the highest dose of amino acid solution (Variant III) had the highest aesthetic and functional values. The AGRO-SORB&reg, Folium reduced the occurrence of fungal diseases, compared to control plants, there was a 16% reduction of Fusarium patch (Microdochium nivale) infection and a 20% reduction of Dreschlera leaf spot (Drechslera siccans). Satisfactory effects were also recorded on plots where the product was applied at a dose of 2 L&middot, 1 (Variant II). Those plots had more favourably rated turf, with higher resistance of plants to Fusarium patch by 12% and to Dreschlera leaf spot by 20% compared to control.

Silicon wafers as semiconductors are essential components of integrated circuits in electronic devices. For this reason, modification of the silicon surface is an important factor in the manufacturing of new hybrid materials applied in micro- and nanoelectronics. Herein, copolymer brushes of hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) and hydrophobic poly(tert-butyl acrylate) (PtBA) were grafted from silicon wafers via simplified electrochemically mediated atom transfer radical polymerization (seATRP) according to a surface-initiated approach. The syntheses of PHEA-b-PtBA copolymers were carried out with diminished catalytic complex concentration (successively 25 and 6 ppm of Cu). In order to optimize the reaction condition, the effect of the addition of a supporting electrolyte was investigated. A controlled increase in PHEA brush thickness was confirmed by atomic force microscopy (AFM). Various other parameters including contact angles and free surface energy (FSE) for the modified silicon wafer were presented. Furthermore, the effect of the presence of a sacrificial initiator in solution on the thickness of the grafted brushes was reported. Successfully fabricated inorganic&ndash, organic hybrid nanomaterials show potential application in biomedicine and microelectronics devices, e.g., biosensors.

The first direct exfoliation of zeolites in high yield expands potential for catalysts, membranes, and tailored composites., The most effective approach to practical exploitation of the layered solids that often have unique valuable properties—such as graphene, clays, and other compounds—is by dispersion into colloidal suspensions of monolayers, called liquid exfoliation. This fundamentally expected behavior can be used to deposit monolayers on supports or to reassemble into hierarchical materials to produce, by design, catalysts, nanodevices, films, drug delivery systems, and other products. Zeolites have been known as extraordinary catalysts and sorbents with three-dimensional structures but emerged as an unexpected new class of layered solids contributing previously unknown valuable features: catalytically active layers with pores inside or across. The self-evident question of layered zeolite exfoliation has remained unresolved for three decades. Here, we report the first direct exfoliation of zeolites into suspension of monolayers as proof of the concept, which enables diverse applications including membranes and hierarchical catalysts with improved access.

Although epidemiological studies from the last years report an increase in the incidences of Leydig cell tumors (previously thought to be a rare disease), the biochemical characteristics of that tumor important for understanding its etiology, diagnosis, and therapy still remains not completely characterized. Our prior studies reported G-protein coupled estrogen receptor signaling and estrogen level disturbances in Leydig cell tumors. In addition, we found that expressions of multi-level-acting lipid balance- and steroidogenesis&ndash, controlling proteins including peroxisome proliferator-activated receptor are altered in this tumor. In order to get deeper into the other molecular mechanisms that regulate lipid homeostasis in the Leydig cell tumor, here we investigate the presence and expression of newly-described hormones responsible for lipid homeostasis balancing (leptin and adiponectin), together with expression of estrogen synthase (aromatase). Samples of Leydig cell tumors (n = 20) were obtained from patients (31&ndash, 45 years old) and used for light and transmission electron microscopic, western blotting, and immunohistochemical analyses. In addition, body mass index (BMI) was calculated. In tumor mass, abundant lipid accumulation in Leydig cells and various alterations of Leydig cell shape, as well as the presence of adipocyte-like cells, were observed. Marked lipid content and various lipid droplet size, especially in obese patients, may indicate alterations in lipid homeostasis, lipid processing, and steroidogenic organelle function in response to interstitial tissue pathological changes. We revealed significantly increased expression of leptin, adiponectin and their receptors, as well as aromatase in Leydig cell tumors in comparison to control. The majority of patients (n = 13) were overweight as indicated by their BMI. Moreover, a significant increase in expression of phospholipase C (PLC), and kinases Raf, ERK which are part of adipokine transductional pathways, was demonstrated. These data expand our previous findings suggesting that in human Leydig cell tumors, estrogen level and signaling, together with lipid status, are related to each other. Increased BMI may contribute to certain biochemical characteristics and function of the Leydig cell in infertile patients with a tumor. In addition, altered adipokine-estrogen microenvironment can have an effect on proliferation, growth, and metastasis of tumor cells. We report here various targets (receptors, enzymes, hormones) controlling lipid balance and estrogen action in Leydig cell tumors indicating their possible usefulness for diagnostics and therapy.

Metal-free ATRP approach was improved by eliminating undesirable organic photocatalyst from the reaction medium by an application of a fully-biocompatible riboflavin (vitamin B2)-based molecule playing two crucial roles in photoinduced polymerization – as an ATRP initiator and photoinitiator simultaneously. The brominated ribitol tail constituted an ATRP initiator, while the unmodified isoalloxazine ring was excited to a highly reactive triplet excited state under blue light irradiation, and thus induced the photopolymerization of (meth)acrylates from the ribitol tail. The double initiation functionality of riboflavin provides brush-like polymers with side chains composed of poly(ethylene glycol) methyl ether methacrylate (OEGMA500) with narrow molecular weight distribution (Mw/Mn = 1.36) and preserved chain-end functionality proved by successfully conducted chain extension experiment with the final product characterized by low dispersity (Mw/Mn = 1.35). The riboflavin-induced polymerization of OEGMA500 was temporally controlled by switching on–off blue light irradiation without the loss of chain-end functionality after restarting the synthesis, resulting in well-defined polymer materials (Mw/Mn = 1.37). The results indicate precisely established reversible redox cycle of the riboflavin photosensitizer during polymerization, providing equilibrium between the active and dormant species, and thus controlled polymer products. The double-functional riboflavin molecule makes metal-free ATRP approach an efficient and green chemistry solution for the preparation of functional polymer materials. The prepared riboflavin-based brush-like polymers were visualized by atomic force microscopy (AFM).

Pioglitazone, a popular antidiabetic drug, which was recently shown to be effective in the treatment of skin ulcers, was successfully encapsulated in polysaccharide nanoparticles and used as a bioactive component of the wound-dressing material based on modified bacterial nanocellulose. Alginate and hydroxypropyl cellulose were used as a matrix for the nanoparticulate drug-delivery system. The matrix composition and particles&rsquo, size, as well as drug encapsulation efficiency and loading, were optimized. Pioglitazone hydrochloride (PIO) loaded particles were coated with chitosan introduced into the crosslinking medium, and covalently attached to the surface of bacterial nanocellulose functionalized with carboxyl groups. PIO was released from the surface of the hybrid material in a controlled manner for 5 days. Preliminary cytotoxicity studies confirmed safety of the system at PIO concentrations as high as 20 mg/mL. The obtained hybrid system may have potential application in the treatment of skin ulcers e.g., in diabetic foot.