Nanoparticles are implemented in different biotechnological fields, and there is interest in their use in plant biology. Nanotechnology can help overcome the persistent limitations of using conventional fungicides in the management of plant diseases, contributing to a safer environment. Hence, this study is focused on evaluating the behavior of nanoparticles on two different strains of Fusarium oxysporum, which have a wide-ranging occurrence in tomato production and account for important economic losses. Fusarium oxysporum is an ascomycetous fungus that is well-known as a soilborne plant pathogen, adapted to any soil type, and it lives in different forms on organic materials. Gold–chitosan and carbon nanoparticles were suspended in potato dextrose agar growth media, and their antifungal activity was evaluated at 1, 3, 5, and 7 days after incubation by measuring the diameter of fungal colonies. The results showed that the nanoparticles have antifungal properties against F. oxysporum, the fungal colony growth diameter being reduced. Likewise, it was observed that the colony diameter was smaller when the nanoparticle concentration increased. However, in the case of one F. oxysporum strain, the highest nanoparticle concentration applied during the experiment’s execution was not able to completely inhibit fungal growth.
Silver nanoparticles synthesized using plant extracts as reducing and capping agents showed various biological activities. In the present study, colloidal silver nanoparticle solutions were produced from the aqueous extracts of Picea abies and Pinus nigra bark. The phenolic profile of bark extracts was analyzed by liquid chromatography coupled to mass spectrometry. The synthesis of silver nanoparticles was monitored using UV-Vis spectroscopy by measuring the Surface Plasmon Resonance band. Silver nanoparticles were characterized by attenuated total reflection Fourier transform infrared spectroscopy, Raman spectroscopy, dynamic light scattering, scanning electron microscopy, energy dispersive X-ray and transmission electron microscopy analyses. The antimicrobial and cytogenotoxic effects of silver nanoparticles were evaluated by disk diffusion and Allium cepa assays, respectively. Picea abies and Pinus nigra bark extract derived silver nanoparticles were spherical (mean hydrodynamic diameters of 78.48 and 77.66 nm, respectively) and well dispersed, having a narrow particle size distribution (polydispersity index values of 0.334 and 0.224, respectively) and good stability (zeta potential values of −10.8 and −14.6 mV, respectively). Silver nanoparticles showed stronger antibacterial, antifungal, and antimitotic effects than the bark extracts used for their synthesis. Silver nanoparticles obtained in the present study are promising candidates for the development of novel formulations with various therapeutic applications.
Non-thermal plasma activated water (PAW) has recently emerged as a powerful antimicrobial agent. Despite numerous potential bio-medical applications, studies concerning toxicity in live animals, especially after long-term exposure, are scarce. Our study aimed to assess the effects of long-term watering with PAW on the health of CD1 mice. PAW was prepared from distilled water with a GlidArc reactor according to a previously published protocol. The pH was 2.78. The mice received PAW (experimental group) or tap water (control group) daily for 90 days as the sole water source. After 90 days, the following investigations were performed on the euthanatized animals: gross necropsy, teeth mineral composition, histopathology, immunohistochemistry, hematology, blood biochemistry, methemoglobin level and cytokine profile. Mice tolerated PAW very well and no adverse effects were observed during the entire period of the experiment. Histopathological examination of the organs and tissues did not reveal any structural changes. Moreover, the expression of proliferation markers PCNA and Ki67 has not been identified in the epithelium of the upper digestive tract, indicating the absence of any pre- or neoplastic transformations. The results of our study demonstrated that long-term exposure to PAW caused no toxic effects and could be used as oral antiseptic solution in dental medicine.
Aromatic polyimides containing side azo-naphthalene groups have been investigated regarding their capacity of generating surface relief gratings (SRGs) under pulsed UV laser irradiation through phase masks, using different fluencies and pulse numbers. The process of the material photo-fluidization and the supramolecular re-organization of the surface were investigated using atomic force microscopy (AFM). At first, an AFM nanoscale topographical analysis of the induced SRGs was performed in terms of morphology and tridimensional amplitude, spatial, hybrid, and functional parameters. Afterward, a nanomechanical characterization of SRGs using an advanced method, namely, AFM PinPoint mode, was performed, where the quantitative nanomechanical properties (i.e., modulus, adhesion, deformation) of the nanostructured azo-polyimide surfaces were acquired with a highly correlated topographic registration. This method proved to be very effective in understanding the formation mechanism of the surface modulations during pulsed UV laser irradiation. Additionally to AFM investigations, confocal Raman measurements and molecular simulations were performed to provide information about structured azo-polyimide chemical composition and macromolecular conformation induced by laser irradiation.
Dielectric, magnetic and Raman measurements of cerium oxide nanoparticles obtained by the precipitation method are discussed. Morphological study was performed by scanning electron microscopy, confirming the formation of nanoparticles of 5–27 nm. The Raman spectra exhibited a strong band around 465 cm−1, corresponding to the symmetrical stretching mode of the Ce-O8 vibrational unit. The nature of the room temperature ferromagnetism of cerium oxide nanoparticles was analyzed, taking into account the oxygen defects at the surface or interface of the nanoparticles. The evolution of dielectric constant, ε′, and dielectric loss, ε″ was studied as a function of frequency at different temperatures. Additionally, the variation of the electric conductivity versus temperature was investigated. Finally, complex impedance study of the cerium oxide nanoparticles was performed.
When studying polyethylenimine derivatives as nonviral vectors for gene delivery, among the important issues to be addressed are high toxicity, low transfection efficiency, and nucleic acid polyplex condensation. The molecular weight of polyethylenimine, PEGylation, biocompatibility and, also, supramolecular structure of potential carrier can all influence the nucleic acid condensation behavior, polyplex size, and transfection efficiency. The main challenge in building an efficient carrier is to find a correlation between the constituent components, as well as the synergy between them, to transport and to release, in a specific manner, different molecules of interest. In the present study, we investigated the synergy between components in dynamic combinatorial frameworks formed by connecting PEGylated squalene, poly-(ethyleneglycol)-bis(3-aminopropyl) and low molecular weight polyethylenimine components to 1,3,5-benzenetrialdehyde, via reversible imine bond, applying a dynamic combinatorial chemistry approach. We report comparative structural and morphological data, DNA binding affinity, toxicity and transfection efficiency concerning the ratio of polyethylenimine and presence or absence of poly-(ethyleneglycol)-bis(3-aminopropyl) in composition of dynamic combinatorial frameworks. In vitro biological assessments have revealed the fact that nonviral vectors containing poly-(ethyleneglycol)-bis(3-aminopropyl) and the lowest amount of polyethylenimine have significant transfection efficiency at N/P 50 ratio and display insignificant cytotoxicity on the HeLa cell line.