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Nanoformulation of the Broad-Spectrum Hydrophobic Antiviral Vacuolar ATPase Inhibitor Diphyllin in Human Recombinant H-ferritin
(Dove Press, 2024-04-30) Vojníková, Michaela; Súkupová, Martina; Štefánik, Michal; Straková, Petra; Haviernik, Jan; Kapolková, Kateřina; Gruberová, Eliška; Rašková, Klára; Michálková, Hana; Švec, Pavel; Pešková, Marie; Huvarová, Ivana; Růžek, Daniel; Salát, Jiří; Pekařík, Vladimír; Eyer, Luděk; Heger, Zbyněk
As highlighted by recent pandemic outbreaks, antiviral drugs are crucial resources in the global battle against viral diseases. Unfortunately, most antiviral drugs are characterized by a plethora of side effects and low efficiency/poor bioavailability owing to their insolubility. This also applies to the arylnaphthalide lignin family member, diphyllin (Diph). Diph acts as a vacuolar ATPase inhibitor and has been previously identified as a promising candidate with broad-spectrum antiviral activity. However, its physicochemical properties preclude its efficient administration in vivo, complicating preclinical testing.
The planar anodic Al2O3-ZrO2 nanocomposite capacitor dielectrics for advanced passive device integration
(Taylor & Francis, 2023-12-31) Kamnev, Kirill; Pytlíček, Zdeněk; Bendová, Mária; Prášek, Jan; Gispert-Guirado, Francesc; Llobet, Eduard; Mozalev, Alexander
The need for integrated passive devices (IPDs) emerges from the increasing consumer demand for electronic product miniaturization. Metal-insulator-metal (MIM) capacitors are vital components of IPD systems. Developing new materials and technologies is essential for advancing capacitor characteristics and co-integrating with other electronic passives. Here we present an innovative electrochemical technology joined with the sputter-deposition of Al and Zr layers to synthesize novel planar nanocomposite metal-oxide dielectrics consisting of ZrO2 nanorods self-embedded into the nanoporous Al2O3 matrix such that its pores are entirely filled with zirconium oxide. The technology is utilized in MIM capacitors characterized by modern surface and interface analysis techniques and electrical measurements. In the 95-480 nm thickness range, the best-achieved MIM device characteristics are the one-layer capacitance density of 112 nF center dot cm(-2), the loss tangent of 4 center dot 10(-3) at frequencies up to 1 MHz, the leakage current density of 40 pA center dot cm(-2), the breakdown field strength of up to 10 MV center dot cm(-1), the energy density of 100 J center dot cm(-3), the quadratic voltage coefficient of capacitance of 4 ppm center dot V-2, and the temperature coefficient of capacitance of 480 ppm center dot K-1 at 293-423 K at 1 MHz. The outstanding performance, stability, and tunable capacitors' characteristics allow for their application in low-pass filters, coupling/decoupling/bypass circuits, RC oscillators, energy-storage devices, ultrafast charge/discharge units, or high-precision analog-to-digital converters. The capacitor technology based on the non-porous planar anodic-oxide dielectrics complements the electrochemical conception of IPDs that combined, until now, the anodized aluminum interconnection, microresistors, and microinductors, all co-related in one system for use in portable electronic devices.
Silver Nanoparticle-Decorated Reduced Graphene Oxide Nanomaterials Exert Membrane Stress and Induce Immune Response to Inhibit the Early Phase of HIV-1 Infection
(WILEY, 2023-02-01) Mukherjee, Soumajit; Bytešníková, Zuzana; Martin, Sophie; Švec, Pavel; Ridošková, Andrea; Pekárková, Jana; Seguin, Cendrine; Weickert, Jean-Luc; Mesaddeq, Nadia; Mély, Yves; Richtera, Lukáš; Anton, Halina; Adam, Vojtěch
Graphene-based 2D nanomaterials exhibit unique physicochemical, electric, and optical properties that facilitate applications in a wide range of fields including material science, electronics, and biotechnology. Recent studies have shown that graphene oxide (GO) and reduced graphene oxide (rGO) exhibit antimicrobial effects on bacteria and viruses. While the bactericidal activity of graphene-based nanomaterials is related to mechanical and oxidative damage to bacterial membranes, their antiviral activity has been less explored. Currently available experimental data are limited and suggest mechanical disruption of viral particles prior to infection. In this study, the antiviral properties of reduced GO-based nanocomposites decorated with Ag nanoparticles (rGO-Ag) are evidenced against human immunodeficiency virus-1 pseudovirus used as an enveloped virus model. By combining biochemical and original single virus imaging approaches, it is shown that rGO-Ag induces peroxidation of pseudoviral lipid membrane and that consequent alteration of membrane properties leads to a reduction in cell entry. In addition, rGO-Ag is found to be efficiently internalized in the host cell leading to the elevated expression of pro-inflammatory cytokines. Altogether, the presented results shed new light on the mechanisms of rGO-Ag antiviral properties and confirm the high potential of graphene derivatives as an antimicrobial material for biomedical applications.
SPEED: an integrated, smartphone-operated, handheld digital PCR Device for point-of-care testing
(Springer Nature, 2024-05-20) Zhang, Haoqing; Liu, Xiaocheng; Wang, Xinlu; Yan, Zhiqiang; Xu, Ying; Gaňová, Martina; Řezníček, Tomáš; Korabečná, Marie; Neužil, Pavel
This study elaborates on the design, fabrication, and data analysis details of SPEED, a recently proposed smartphone-based digital polymerase chain reaction (dPCR) device. The dPCR chips incorporate partition diameters ranging from 50 mu m to 5 mu m, and these partitions are organized into six distinct blocks to facilitate image processing. Due to the superior thermal conductivity of Si and its potential for mass production, the dPCR chips were fabricated on a Si substrate. A temperature control system based on a high-power density Peltier element and a preheating/cooling PCR protocol user interface shortening the thermal cycle time. The optical design employs four 470 nm light-emitting diodes as light sources, with filters and mirrors effectively managing the light emitted during PCR. An algorithm is utilized for image processing and illumination nonuniformity correction including conversion to a monochromatic format, partition identification, skew correction, and the generation of an image correction mask. We validated the device using a range of deoxyribonucleic acid targets, demonstrating its potential applicability across multiple fields. Therefore, we provide guidance and verification of the design and testing of the recently proposed SPEED device.
Smart bactericide based on reduced graphene oxide decorated with copper and zinc nanoparticles
(Springer Nature, 2023-10-24) Bytešníková, Zuzana; Pečenka, Jakub; Tekielska, Dorota; Pekárková, Jana; Ridošková, Andrea; Bezdička, Petr; Kiss, Tomáš; Eichmeier, Aleš; Adam, Vojtěch; Lukas, Richtera
Graphene oxide (GO) synthesised by modified Tour's method was decorated with copper and zinc nanoparticles (NPs) and simultaneously reduced by sodium borohydride to obtain a nanocomposite of reduced GO with copper and zinc NPs (rGO-Cu-Zn). The nanocomposite rGO-Cu-Zn was characterised by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The rGO-Cu-Zn was tested against Xanthomonas euvesicatoria (X. euvesicatoria), which attacks tomatoes and causes bacterial spots (BSs), and compared with the commercial product Champion 50 WG. Total bacterial growth inhibition was observed for the 1% rGO-Cu-Zn, whereas Champion 50 WG at the same concentration inhibited but did not eradicate all the bacterial colonies. To evaluate the negative effect of the rGO-Cu-Zn on the molecular level, the expression of the genes associated with the action of abiotic and biotic stress factors was analysed. Gene expression in the plants treated with 10% rGO-Cu-Zn did not exhibit a noticeable increase.

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