Browsing by Author "Kubovcikova, Martina"

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Dynamic morphogenesis of dendritic structures formation in hen egg white lysozyme fibrils doped with magnetic nanoparticles
(2018-01-01)
Tomasovicova, Natalia
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Hu, Po-Sheng
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Zeng, Cyun-Lun
;
Hurakova, Maria
;
Csach, Kornel
In this research, the dynamic process of aggregation that forms microflower morphology in solution of lysozyme amyloid fibrils doped with spherical or spindle-like magnetic nanoparticles during the process of drying as well as their final microstructures were investigated. The prepared lysozyme amyloid fibrils as well as their mixtures with in-lab synthesized magnetic particles, which were prepared by adding the nanoparticles to the fibrils solution after the process of fibrillation was done, were characterized using brightfield trans-illumination-mode optical microscope, atomic force microscopy (AFM) and scanning electron microscope (SEM). Brightfield optical imaging bases upon photoabsorptive property of the fibrils-nanoparticle composites clearly reveals the morphological features in microscale, and additionally, for the in vivo, live action of the time-dependent process of self-assembly of such composites composed of fibrillary structure incorporated with magnetic particles was optically elucidated at ambient temperature. Moreover, while results of AFM reveal delicate and peculiar association of fibrils with magnetic nanoparticles of different shapes, SEM images illustrate a stark difference in fine detailed final morphology of microstructures associated with spherical and spindle-like nanoparticles. Our results indicated that the interaction between fibrils solution and the nanoparticles commence right after mixing, the dynamic process of forming dendritic structure resembling microflower morphology is on the order of minutes, and its final structure is highly dependent on the shape of magnetic nanoparticles. (C) 2017 Elsevier B.V. All rights reserved.
Effect of the concentration of protein and nanoparticles on the structure of biohybrid nanocomposites
(1970-01-01)
Majorosova, Jozefina
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Schroer, Martin A.
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Tomasovicova, Natalia
;
Batkova, Marianna
;
Hu, Po-Sheng
We present colloidal nanocomposites formed by incorporating magnetite Fe3O4 nanoparticles (MNPs) with lysozyme amyloid fibrils (LAFs). Preparation of two types of solutions, with and without addition of salt, was carried out to elucidate the structure of MNPs-incorporated fibrillary nanocomposites and to study the effect of the presence of salt on the stability of the nanocomposites. The structural morphology of the LAFs and their interaction with MNPs were analyzed by atomic force microscopy and small-angle x-ray scattering measurements. The results indicate that conformational properties of the fibrils are dependent on the concentration of protein, and the precise ratio of the concentration of the protein and MNPs is crucially important for the stability of the fibrillary nanocomposites. Our results confirm that despite the change in fibrillary morphology induced by the varying concentration of the protein, the adsorption of MNPs on the surface of LAF is morphologically independent. Moreover, most importantly, the samples containing salt have excellent stability for up to 1 year of shelf-life.