Magneto-Responsive Textiles for Non-Invasive Heating.

Magneto-responsive textiles have emerged lately as an important carrier in various fields, including biomedical engineering. To date, most research has been performed on single magnetic fibers and focused mainly on the physical characterization of magnetic textiles. Herein, from simple woven and non-woven textiles we engineered materials with magnetic properties that can become potential candidates for a smart magnetic platform for heating treatments. Experiments were performed on tissue-mimicking materials to test the textiles' heating efficiency in the site of interest. When the heat was induced with magneto-responsive textiles, the temperature increase in tissue-mimicking phantoms depended on several factors, such as the type of basic textile material, the concentration of magnetic nanoparticles deposited on the textile's surface, and the number of layers covering the phantom. The values of temperature elevation, achieved with the use of magnetic textiles, are sufficient for potential application in magnetic hyperthermia therapies and as heating patches or bandages.

Semiquantitative color catcher and smartphone-based analysis of synthetic food dyes in alcohol containing beverages.

Solid phase extraction, based on the use of color catcher sheets, was successfully employed for the preconcentration of food dyes from alcohol containing beverages. The photos of color catcher sheets with the adsorbed dyes were taken with a mobile phone. The smartphone-based image analysis of the photos was performed using Color Picker application. The values of several color spaces were collected. Specific values from RGB, CMY, RYB and LAB color spaces were proportional to the dye concentration in the analyzed samples. The described inexpensive, simple and elution free assay enables analysis of dyes concentration in various solutions.

Cotton Textile/Iron Oxide Nanozyme Composites with Peroxidase-like Activity: Preparation, Characterization, and Application.

At present, both native and immobilized nanoparticles are of great importance in many areas of science and technology. In this paper, we have studied magnetic iron oxide nanoparticles and their aggregates bound on woven cotton textiles employing two simple modification procedures. One modification was based on the treatment of textiles with perchloric-acid-stabilized magnetic fluid diluted with methanol followed by drying. The second procedure was based on the microwave-assisted conversion of ferrous sulfate at high pH followed by drying. The structure and functional properties of these modified textiles were analyzed in detail. Scanning electron microscopy of native and modified textiles clearly showed the presence of iron oxide nanoparticles on the surface of the modified cotton fibers. All of the modified textile materials exhibited light to dark brown color depending on the amount of the bound iron oxide particles. Magnetic measurements showed that the saturation magnetization values reflect the amount of magnetic nanoparticles present in the modified textiles. Small-angle X-ray and neutron scattering measurements were conducted for the detailed structural characterization at the nanoscale of both the native and magnetically modified textiles, and different structural organization of nanoparticles in the two kinds of textile samples were concluded. The textile-bound iron oxide particles exhibited peroxidase-like activity when the N,N-diethyl-p-phenylenediamine sulfate salt was used as a substrate; this nanozyme activity enabled rapid decolorization of crystal violet in the presence of hydrogen peroxide. The deposition of a sufficient amount of iron oxide particles on textiles enabled their simple magnetic separation from large volumes of solutions; if necessary, the magnetic response of the modified textiles can be simply increased by incorporation of a piece of magnetic iron wire. The simplicity of the immobilized nanozyme preparation and the low cost of all the precursors enable its widespread application, such as decolorization and degradation of selected organic dyes and other important pollutants. Other types of textile-bound nanozymes can be prepared and used as low-cost catalysts for a variety of applications.

Peroxidase-like activity of magnetic poly(glycidyl methacrylate-co-ethylene dimethacrylate) particles.

Poly(glycidyl methacrylate) (PGMA) is prone to modifications with different functional groups, magnetic fluids or direct coupling with biological molecules. The purpose of this research was to synthesize new magnetically responsive particles with peroxidase-like activity. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) [P(GMA-EDMA)] particles containing carboxyl groups were obtained by emulsifier-free emulsion polymerization and hydrolysis and oxidation of PGMA with KMnO4, resulting in poly(carboxymethyl methacrylate-co-ethylene dimethacrylate) [P(CMMA-EDMA)] particles. Thionine (Th) was also attached to the particles [(P(CMMA-EDMA)-Th] via EDC/NHS chemistry to observe its effect on electron transfer during the oxidation reaction. Finally, the particles were coated with a nitric acid-stabilized ferrofluid in methanol. The resulting magnetic particles were characterized by several methods, including scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. The effect of EDMA on the P(CMMA-EDMA) particle size and size distribution was investigated; the particle size changed from 300 to 340 nm, and the particles were monodispersed with a saturation magnetization of 11 Am2/kg. Finally, the effects of temperature and pH on the peroxidase-like activity of the magnetic P(CMMA-EDMA) and P(CMMA-EDMA)-Th particles were investigated. The particles, which exhibited a high activity at pH 4-6 and at ∼37 °C, represent a highly sensitive sensor component potentially useful in enzyme-based immunoassays.

Smartphone-based image analysis for evaluation of magnetic textile solid phase extraction of colored compounds.

Novel modern easily feasible methods for direct evaluation of a new, simple preconcentration analytical procedure have been developed. Two types of smartphone image analysis applications (ON Color Measure and Color Lab) were evaluated to obtain RGB and HSV color spaces data for the quantification of Magnetic textile solid phase extraction of colored compounds (e.g. water-soluble organic dyes). Both direct measurement of color spaces values via the smartphone camera and image analysis of the photograph can be used successfully. The obtained data were similar to those obtained by previously examined professional ImageJ software. The saturation (S) values of the HSV color space are directly proportional to the concentrations of the analyzed dye.

Magnetically Modified Agricultural and Food Waste: Preparation and Application.

The annual food and agricultural waste production reaches enormous numbers. Therefore, an increasing need to valorize produced wastes arises. Waste materials originating from the food and agricultural industry can be considered as functional materials with interesting properties and broad application potential. Moreover, using an appropriate magnetic modification, smart materials exhibiting a rapid response to an external magnetic field can be obtained. Such materials can be easily and selectively separated from desired environments. Magnetically responsive waste derivatives of biological origins have already been prepared and used as efficient biosorbents for the isolation and removal of both biologically active compounds and organic and inorganic pollutants and radionuclides, as biocompatible carriers for the immobilization of diverse types of (bio)molecules, cells, nano- and microparticles, or (bio)catalysts. Potential bactericidal, algicidal, or anti-biofilm properties of magnetic waste composites have also been tested. Furthermore, low cost and availability of waste biomaterials in larger amounts predetermine their utilization in large-scale processes.

Suppression of protein inactivation during freezing by minimizing pH changes using ionic cryoprotectants.

Freezing and lyophilization are often used for stabilization of biomolecules; however, this sometimes results in partial degradation and loss of biological function in these molecules. In this study we examined the effect of freezing-induced acidity changes on denaturation of the model enzyme haloalkane dehalogenase under various experimental conditions. The effective local pH of frozen solutions is shown to be the key causal factor in protein stability. To preserve the activity of frozen-thawed enzymes, acidity changes were prevented by the addition of an ionic cryoprotectant, a compound which counteracts pH changes during freezing due to selective incorporation of its ions into the ice. This approach resulted in complete recovery of enzyme activity after multiple freeze-thaw cycles. We propose the utilization of ionic cryoprotectants as a new and effective cryopreservation method in research laboratories as well as in industrial processes.

Biological and molecular analysis of the pathogenic variant C3 of potato spindle tuber viroid (PSTVd) evolved during adaptation to chamomile (Matricaria chamomilla).

Viroid-caused pathogenesis is a specific process dependent on viroid and host genotype(s), and may involve viroid-specific small RNAs (vsRNAs). We describe a new PSTVd variant C3, evolved through sequence adaptation to the host chamomile (Matricaria chamomilla) after biolistic inoculation with PSTVd-KF440-2, which causes extraordinary strong ('lethal') symptoms. The deletion of a single adenine A in the oligoA stretch of the pathogenicity (P) domain appears characteristic of PSTVd-C3. The pathogenicity and the vsRNA pool of PSTVd-C3 were compared to those of lethal variant PSTVd-AS1, from which PSTVd-C3 differs by five mutations located in the P domain. Both lethal viroid variants showed higher stability and lower variation in analyzed vsRNA pools than the mild PSTVd-QFA. PSTVd-C3 and -AS1 caused similar symptoms on chamomile, tomato, and Nicotiana benthamiana, and exhibited similar but species-specific distributions of selected vsRNAs as quantified using TaqMan probes. Both lethal PSTVd variants block biosynthesis of lignin in roots of cultured chamomile and tomato. Four 'expression markers' (TCP3, CIPK, VSF-1, and VPE) were selected from a tomato EST library to quantify their expression upon viroid infection; these markers were strongly downregulated in tomato leaf blades infected by PSTVd-C3- and -AS1 but not by PSTVd-QFA.

Combinatorial analysis of lupulin gland transcription factors from R2R3Myb, bHLH and WDR families indicates a complex regulation of chs_H1 genes essential for prenylflavonoid biosynthesis in hop (Humulus Lupulus L.).

BACKGROUND: Lupulin glands of hop produce a specific metabolome including hop bitter acids valuable for the brewing process and prenylflavonoids with promising health-beneficial activities. The detailed analysis of the transcription factor (TF)-mediated regulation of the oligofamily of one of the key enzymes, i.e., chalcone synthase CHS_H1 that efficiently catalyzes the production of naringenin chalcone, a direct precursor of prenylflavonoids in hop, constitutes an important part of the dissection of the biosynthetic pathways leading to the accumulation of these compounds. RESULTS: Homologues of flavonoid-regulating TFs HlMyb2 (M2), HlbHLH2 (B2) and HlWDR1 (W1) from hop were cloned using a lupulin gland-specific cDNA library from the hop variety Osvald's 72. Using a "combinatorial" transient GUS expression system it was shown that these unique lupulin-gland-associated TFs significantly activated the promoter (P) of chs_H1 in ternary combinations of B2, W1 and either M2 or the previously characterized HlMyb3 (M3). The promoter activation was strongly dependent on the Myb-P binding box TCCTACC having a core sequence CCWACC positioned on its 5' end region and it seems that the complexity of the promoter plays an important role. M2B2W1-mediated activation significantly exceeded the strength of expression of native chs_H1 gene driven by the 35S promoter of CaMV, while M3B2W1 resulted in 30% of the 35S:chs_H1 expression level, as quantified by real-time PCR. Another newly cloned hop TF, HlMyb7, containing a transcriptional repressor-like motif pdLNLD/ELxiG/S (PDLNLELRIS), was identified as an efficient inhibitor of chs_H1-activating TFs. Comparative analyses of hop and A. thaliana TFs revealed a complex activation of Pchs_H1 and Pchs4 in combinatorial or independent manners. CONCLUSIONS: This study on the sequences and functions of various lupulin gland-specific transcription factors provides insight into the complex character of the regulation of the chs_H1 gene that depends on variable activation by combinations of R2R3Myb, bHLH and WDR TF homologues and inhibition by a Myb repressor.