This manuscript presents a comprehensive study on the quantification of modifier molecules adsorbed on gold nanoparticles (AuNPs) using two complementary techniques Ellman's method (UV-vis spectroscopy) and isothermal titration calorimetry (ITC). In this paper, we compare the feasibility of using the ITC technique and Ellman's method to study the interactions of mercaptosulfonate compounds (sodium mercaptoethanesulfonate, MES, and sodium mercaptoundecanesulfonate, MUS) with the surface of AuNPs of various sizes. The thermodynamic functions of the attachment of mercaptosulfonates to AuNPs were determined, revealing a linear relationship between the number of adsorbed molecules and the surface area of the nanoparticles. The amount of MES and MUS determined by Ellman's method (7 and 11 molecules per square nm, respectively) is more than twice that measured by the ITC technique (3 and 4 molecules per square nm, respectively). The slight differences in the adsorption of MES and MUS on the gold surface are due to differences in the carbon chain length of the ligand molecules. In the case of MES, the formation of the Au-S bond is the dominant stage of the adsorption process, whereas for MUS, the ordering process and self-assembly of molecules on the gold surface are dominant.

• Publikační typ
• časopisecké články MeSH

Stability and cytotoxicity of PEGylated Au NPs is crucial for biomedical application. In this study, we have focused on thermal stability of PEGylated Au NPs at 4 and 37 °C and after sterilization in autoclave. Gold nanoparticles were prepared by direct sputtering of gold into PEG and PEG-NH2. Transmission electron microscopy revealed that NPs exhibit a spherical shape with average dimensions 3.8 nm for both AuNP_PEG and AuNP_PEG-NH2. The single LSPR band at wavelength of 509 nm also confirmed presence of spherical Au NPs in both cases. Moreover, according to UV-Vis spectra, the Au NPs were overall stable during aging or thermal stressing and even after sterilization in autoclave. Based on gel electrophoresis results, the higher density of functionalizing ligands and the higher stability is assumed on AuNP_PEG-NH2. Changes in concentration of gold did not occur after thermal stress or with aging. pH values have to be adjusted to be suitable for bioapplications - original pH values are either too alkaline (AuNP_PEG-NH2, pH 10) or too acidic (AuNP_PEG, pH 5). Cytotoxicity was tested on human osteoblasts and fibroblasts. Overall, both Au NPs have shown good cytocompatibility either freshly prepared or even after Au NPs' sterilization in the autoclave. Prepared Au NP dispersions were also examined for their antiviral activity, however no significant effect was observed. We have synthesized highly stable, non-cytotoxic PEGylated Au NPs, which are ready for preclinical testing.

• Klíčová slova
• Antiviral activity, Cytotoxicity, Gold, Nanoparticle, Polyethylene glycol, Stability,
• Publikační typ
• časopisecké články MeSH

We designed and synthesized a set of four 2'-deoxyribonucleoside 5'-O-triphosphates (dNTPs) derived from 5-substituted pyrimidines and 7-substituted 7-deazapurines bearing anionic substituents (carboxylate, sulfonate, phosphonate, and phosphate). The anion-linked dNTPs were used for enzymatic synthesis of modified and hypermodified DNA using KOD XL DNA polymerase containing one, two, three, or four modified nucleotides. The polymerase was able to synthesize even long sequences of >100 modified nucleotides in a row by primer extension (PEX). We also successfully combined two anionic and two hydrophobic dNTPs bearing phenyl and indole moieties. In PCR, the combinations of one or two modified dNTPs gave exponential amplification, while most of the combinations of three or four modified dNTPs gave only linear amplification in asymmetric PCR. The hypermodified ONs were successfully re-PCRed and sequenced by Sanger sequencing. Biophysical studies including hybridization, denaturation, CD spectroscopy and molecular modelling and dynamics suggest that the presence of anionic modifications in one strand decreases the stability of duplexes while still preserving the B-DNA conformation, whilst the DNA hypermodified in both strands adopts a different secondary structure.

• MeSH
• DNA-dependentní DNA-polymerasy metabolismus   MeSH
• DNA * chemie   MeSH
• nukleotidy * chemie   MeSH
• pyrimidiny MeSH
• sekvence nukleotidů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA-dependentní DNA-polymerasy MeSH
• DNA * MeSH
• nukleotidy * MeSH
• pyrimidiny MeSH

The Czech Republic, a part of the former Czechoslovakia, has been at the forefront of several research directions in virology, genetics and physiology [...].

• MeSH
• virologie * MeSH
• Publikační typ
• práce podpořená grantem MeSH
• úvodníky MeSH
• Geografické názvy
• Česká republika MeSH

Recent experience with the COVID-19 pandemic should be a lesson learnt with respect to the effort we have to invest in the development of new strategies for the treatment of viral diseases, along with their cheap, easy, sensitive, and selective detection. Since we live in a globalized world where just hours can play a crucial role in the spread of a virus, its detection must be as quick as possible. Thanks to their chemical stability, photostability, and superior biocompatibility, carbon dots are a kind of nanomaterial showing great potential in both the detection of various virus strains and a broad-spectrum antiviral therapy. The biosensing and antiviral properties of carbon dots can be tuned by the selection of synthesis precursors as well as by easy post-synthetic functionalization. In this review, we will first summarize current options of virus detection utilizing carbon dots by either electrochemical or optical biosensing approaches. Secondly, we will cover and share the up-to-date knowledge of carbon dots' antiviral properties, which showed promising activity against various types of viruses including SARS-CoV-2. The mechanisms of their antiviral actions will be further adressed as well. Finally, we will discuss the advantages and distadvantages of the use of carbon dots in the tangled battle against viral infections in order to provide valuable informations for further research and development of new virus biosensors and antiviral therapeutics.

• Klíčová slova
• Antiviral, Biosensors, COVID-19, Carbon dots, Coronavirus, Functionalization of carbon dots, Virus detection,
• MeSH
• antivirové látky farmakologie   MeSH
• biokompatibilní materiály MeSH
• biosenzitivní techniky MeSH
• cílená molekulární terapie MeSH
• COVID-19 diagnóza   terapie   MeSH
• elektrochemie MeSH
• farmakoterapie COVID-19 * MeSH
• fototerapie MeSH
• kvantové tečky * MeSH
• lidé MeSH
• nanostruktury MeSH
• polymery MeSH
• SARS-CoV-2 MeSH
• testování na COVID-19 metody   MeSH
• uhlík chemie   MeSH
• virové nemoci MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antivirové látky MeSH
• biokompatibilní materiály MeSH
• polymery MeSH
• uhlík MeSH

Dengue virus (DENV) causes 390 million infections per year. Infections can be asymptomatic or range from mild fever to severe haemorrhagic fever and shock syndrome. Currently, no effective antivirals or safe universal vaccine is available. In the present work we tested different gold nanoparticles (AuNP) coated with ligands ω-terminated with sugars bearing multiple sulfonate groups. We aimed to identify compounds with antiviral properties due to irreversible (virucidal) rather than reversible (virustatic) inhibition. The ligands varied in length, in number of sulfonated groups as well as their spatial orientation induced by the sugar head groups. We identified two candidates, a glucose- and a lactose-based ligand showing a low EC50 (effective concentration that inhibit 50% of the viral activity) for DENV-2 inhibition, moderate toxicity and a virucidal effect in hepatocytes with titre reduction of Median Tissue Culture Infectious Dose log10TCID50 2.5 and 3.1. Molecular docking simulations complemented the experimental findings suggesting a molecular rationale behind the binding between sulfonated head groups and DENV-2 envelope protein.

• MeSH
• antivirové látky chemie   farmakologie   MeSH
• buněčné linie MeSH
• buňky Hep G2 MeSH
• Cercopithecus aethiops MeSH
• dengue farmakoterapie   MeSH
• hepatocyty virologie   MeSH
• kovové nanočástice chemie   MeSH
• lidé MeSH
• ligandy MeSH
• nádorové buněčné linie MeSH
• simulace molekulového dockingu MeSH
• Vero buňky MeSH
• virus dengue účinky léků   MeSH
• zlato chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antivirové látky MeSH
• ligandy MeSH
• zlato MeSH