SARS-CoV-2 Virus-like Particles with Plasmonic Au Cores and S1-Spike Protein Coronas.

The COVID-19 pandemic has stimulated the scientific world to intensify virus-related studies aimed at the development of quick and safe ways of detecting viruses in the human body, studying the virus-antibody and virus-cell interactions, and designing nanocarriers for targeted antiviral therapies. However, research on dangerous viruses can only be performed in certified laboratories that follow strict safety procedures. Thus, developing deactivated virus constructs or safe-to-use virus-like objects, which imitate real viruses and allow performing virus-related studies in any research laboratory, constitutes an important scientific challenge. Such species, called virus-like particles (VLPs), contain instead of capsids with viral DNA/RNA empty or synthetic cores with real virus proteins attached to them. We have developed a method for the preparation of VLPs imitating the virus responsible for the COVID-19 disease: the SARS-CoV-2. The particles have Au cores surrounded by "coronas" of S1 domains of the virus's spike protein. Importantly, they are safe to use and specifically interact with SARS-CoV-2 antibodies. Moreover, Au cores exhibit localized surface plasmon resonance (LSPR), which makes the synthesized VLPs suitable for biosensing applications. During the studies, the effect allowed us to visualize the interaction between the VLPs and the antibodies and identify the characteristic vibrational signals. What is more, additional functionalization of the particles with a fluorescent label revealed their potential in studying specific virus-related interactions. Notably, the universal character of the developed synthesis method makes it potentially applicable for fabricating VLPs imitating other life-threatening viruses.

Molecular Dynamics and Structure of Poly(Methyl Methacrylate) Chains Grafted from Barium Titanate Nanoparticles.

Core-shell nanocomposites comprising barium titanate, BaTiO3 (BTO), and poly(methyl methacrylate) (PMMA) chains grafted from its surface with varied grafting densities were prepared. BTO nanocrystals are high-k inorganic materials, and the obtained nanocomposites exhibit enhanced dielectric permittivity, as compared to neat PMMA, and a relatively low level of loss tangent in a wide range of frequencies. The impact of the molecular dynamics, structure, and interactions of the BTO surface on the polymer chains was investigated. The nanocomposites were characterized by broadband dielectric and vibrational spectroscopies (IR and Raman), transmission electron microscopy, differential scanning calorimetry, and nuclear magnetic resonance. The presence of ceramic nanoparticles in core-shell composites slowed down the segmental dynamic of PMMA chains, increased glass transition temperature, and concurrently increased the thermal stability of the organic part. It was also evidenced that, in addition to segmental dynamics, local ß relaxation was affected. The grafting density influenced the self-organization and interactions within the PMMA phase, affecting the organization on a smaller size scale of polymeric chains. This was explained by the interaction of the exposed surface of nanoparticles with polymer chains.

An Investigation of the Sol-Gel Transition of Chitosan Lactate and Chitosan Chloride Solutions via Rheological and NMR Studies.

In recent years, intensive research has been carried out on the use of hydrogels obtained from natural polymers, mainly chitosan. These products are increasingly replacing solutions based on synthetic materials in medicine. This publication presents the results of studies on the sol-gel transition of chitosan solutions as the base material for the preparation of thermosensitive hydrogels for potential applications in tissue engineering. The measurements were carried out for systems consisting of chitosan lactate and chitosan chloride solutions using ß-glycerol phosphate disodium salt pentahydrate and uridine 5'-monophosphate disodium salt as the cross-linking agents. The sol-gel transition point of the solutions was determined based on the rheological measurements in the cone-plate configuration of the rotational rheometer and experiments performed using the method of nuclear magnetic resonance. The obtained results showed a significant influence of the cross-linking agent on the course of the sol-gel transition of chitosan salt solutions, and the systems that consisted of chitosan lactate seemed to be especially interesting for biomedical applications.

Novel Short PEG Chain-Substituted Porphyrins: Synthesis, Photochemistry, and In Vitro Photodynamic Activity against Cancer Cells.

This work presents the synthesis and characterization of metal-free, zinc (II), and cobalt (II) porphyrins substituted with short PEG chains. The synthesized compounds were characterized by UV-Vis, 1H and 13C NMR spectroscopy, and MALDI-TOF mass spectrometry. The origin of the absorption bands for tested compounds in the UV-Vis range was determined using a computational model based on the electron density functional theory (DFT) and its time-dependent variant (TD-DFT). The photosensitizing activity was evaluated by measuring the ability to generate singlet oxygen (ΦΔ), which reached values up to 0.54. The photodynamic activity was tested using bladder (5637), prostate (LNCaP), and melanoma (A375) cancer cell lines. In vitro experiments clearly showed the structure-activity relationship regarding types of substituents, their positions in the phenyl ring, and the variety of central metal ions on the porphyrin core. Notably, the metal-free derivative 3 and its zinc derivative 6 exerted strong cytotoxic activity toward 5637 cells, with IC50 values of 8 and 15 nM, respectively. None of the tested compounds induced a cytotoxic effect without irradiation. In conclusion, these results highlight the potential value of the tested compounds for PDT application.

Zinc(II), Palladium(II), and Metal-Free Phthalocyanines Bearing Nipagin-Functionalized Substituents against Candida auris and Selected Multidrug-Resistant Microbes.

Due to the rapidly increasing problem of antibiotic resistance in recent years, the use of phthalocyanines as photosensitizers with their superior properties in photodynamic antimicrobial therapy (PACT) applications has become important. In this study, magnesium(II) 1,4,8,11,15,18,22,25-octakis(4-[4-butoxycarbonylphenoxy]butyloxy)phthalocyanine was used in the demetalation reaction in trifluoroacetic acid, and subsequently subjected to metalation reaction in dimethylformamide with zinc(II) acetate and bis(benzonitrile)palladium(II) chloride towards zinc(II) and palladium(II) derivatives. Three phthalocyanines, including a demetalated one as well as two metalated, in the core with zinc(II) and palladium(II) were characterized using 1D and 2D NMR spectroscopy and mass spectrometry. In addition, all macrocycles were subjected to absorption and emission studies as well as photostability tests. In a photochemical study, zinc(II) and palladium(II) phthalocyanine complexes appeared to be efficient singlet oxygen generators. There were noted quantum yields of singlet oxygen generation for zinc(II) phthalocyanine derivative in DMF and DMSO at 0.55 and 0.72, whereas for palladium(II) complex at 0.73 and 0.77, respectively. Liposomal formulations of phthalocyanine derivatives were prepared, and their activity was evaluated against a broad spectrum of antibiotic-resistant microorganisms, such as methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (ESBL+), Candida albicans resistant to fluconazole, C. auris, and against dermatophytes. Phthalocyanine palladium(II) complex showed the highest bactericidal activity against all antibiotic-resistant microorganisms, including reducing C. auris growth at 3.54 log.

Epigenetic on Earth and in Space / Epigenetyka na Ziemi i w kosmosie.

The year 1961 went down in history with exceptional scientific achievements. On May 13, the journal Nature published two articles on the first isolation of messenger ribonucleic acid (mRNA), which is an intermediate product between a gene and a protein. Just two weeks later, on May 27, the first letter of the genetic code, phenylalanine, was discovered. These discoveries made it possible to understand how genetic information is encoded and processed, thus causing the dynamic development of molecular biology. The breakthroughs of 1961 concerned not only nucleic acids. On April 12, the first human, Yuri Gagarin, entered space. Eight years later, in 1969, Neil Armstrong made his first walk on the moon, uttering the famous phrase: It is a small step for man, but a great leap for humanity. The era of conquering and learning about the cosmos has begun, mainly motivated by the natural curiosity of man and the desire to learn about the surrounding reality. The environmental factors in space are very different from terrestrial conditions, which raises questions about their effects on living organisms. In search of answers, a variety of scientific research has been carried out at the International Space Station (ISS) for over twenty years. As space travel is set to become more common in the near future, detailed studies of the effects of long-term space missions on the human body are required. These studies are currently carried out, among others using molecular biology techniques that enable detailed analysis of nucleic acids and proteins, but not only. The breakthrough achievements of 1961 initiated the development both in the field of molecular biology and the science of space, thanks to which today, 60 years after those events, we can combine knowledge and technological achievements from both fields to analyze and understand changes at the molecular level that occur as a result of being in organisms in outer space.

Relative Cation-Anion Diffusion in Alkyltriethylammonium-Based Ionic Liquids.

19F Nuclear Magnetic Resonance spin-lattice relaxation experiments have been performed for a series of ionic liquids including the same anion, bis(trifluoromethanesulfonyl)imide, and cations with alkyl chains of different lengths: triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, dodecyltriethylammonium, decyltriethylammonium, and hexadecyltriethylammonium. The experiments have been carried out in a frequency range of 10 kHz to 10 MHz versus temperature. A thorough analysis of the relaxation data has led to the determination of the cation-anion as a relative translation diffusion coefficient. The diffusion coefficients have been compared with the corresponding cation-cation and anion-anion diffusion coefficients, revealing a correlation in the relative translation movement of the anion and the triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, and dodecyltriethylammonium cations, whereas the relative translation diffusion between the anion and the cations with the longer alkyl chains, decyltriethylammonium and hexadecyltriethylammonium, remains rather uncorrelated (correlated to a much lesser extent).

ZnO size and shape effect on antibacterial activity and cytotoxicity profile.

The aim of our work was the synthesis of ZnO nano- and microparticles and to study the effect of shapes and sizes on cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of bacteria. We fabricated ZnO nano- and microparticles through facile chemical and physical routes. The crystal structure, morphology, textural properties, and photoluminescent properties were characterized by powder X-ray diffraction, electron microscopies, nitrogen adsorption/desorption measurements, and photoluminescence spectroscopy. The obtained ZnO structures were highly crystalline and monodispersed with intensive green emission. ZnO NPs and NRs showed the strongest antibacterial activity against Escherichia coli and Staphylococcus aureus compared to microparticles due to their high specific surface area. However, the ZnO HSs at higher concentrations also strongly inhibited bacterial growth. S. aureus strain was more sensitive to ZnO particles than the E. coli. ZnO NPs and NRs were more harmful to cancer cell lines than to normal ones at the same concentration.

Water Dynamics in Starch Based Confectionery Products including Different Types of Sugar.

Starch-based confectionery products were prepared using different types of sugar. In addition to using different sugar, starch was replaced with soy protein isolate (SPI) in some of the products. 1H NMR spin-lattice relaxation experiments were performed for the collection of products in a broad frequency range from 4 KHz to 30 MHz to get insight into the influence of different sugar types and SPI on the dynamics of water in composite gel systems. The relaxation data have been decomposed into relaxation contributions associated with two different pools of water molecules characterized by different mobility. The translation dynamics of water molecules has been quantitatively described in terms of a dedicated relaxation model. The influence of the sample composition (the type of sugar and/or the presence of SPI) on the water mobility was thoroughly discussed. The results indicate that the addition of soy protein does not affect water dynamics for samples including sucrose. In addition, as the complementary measurements, physical properties of the products, such as the moisture content, water activity and texture, were investigated in terms of X-ray diffraction and thermogravimetric analysis.

Relationship between Translational and Rotational Dynamics of Alkyltriethylammonium-Based Ionic Liquids.

1H spin-lattice relaxation experiments have been performed for a series of ionic liquids including bis(trifluoromethanesulfonyl)imide anion and cations of a varying alkyl chain length: triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, dodecyltriethylammonium, triethyltetradecylammonium, and hexadecyltriethylammonium. The relaxation studies were carried out in abroad frequency range covering three orders of magnitude, from 10 kHz to 10 MHz, versus temperature. On the basis of a thorough, quantitative analysis of this reach data set, parameters characterizing the relative, cation-cation, translation diffusion (relative diffusion coefficients and translational correlation times), and rotational motion of the cation (rotational correlation times) were determined. Relationships between these quantities and their dependence on the alkyl chain length were discussed in comparison to analogous properties of molecular liquids. It was shown, among other findings, that the ratio between the translational and rotational correlation times is smaller than for molecular liquids and considerably dependent on temperature. Moreover, a comparison of relative and self-diffusion coefficients indicate correlated translational dynamics of the cations.

Nanomolar Nitric Oxide Concentrations in Living Cells Measured by Means of Fluorescence Correlation Spectroscopy.

Measurement of the nitric oxide (NO) concentration in living cells in the physiological nanomolar range is crucial in understanding NO biochemical functions, as well as in characterizing the efficiency and kinetics of NO delivery by NO-releasing drugs. Here, we show that fluorescence correlation spectroscopy (FCS) is perfectly suited for these purposes, due to its sensitivity, selectivity, and spatial resolution. Using the fluorescent indicators, diaminofluoresceins (DAFs), and FCS, we measured the NO concentrations in NO-producing living human primary endothelial cells, as well as NO delivery kinetics, by an external NO donor to the immortal human epithelial living cells. Due to the high spatial resolution of FCS, the NO concentration in different parts of the cells were also measured. The detection of nitric oxide by means of diaminofluoresceins is much more efficient and faster in living cells than in PBS solutions, even though the conversion to the fluorescent form is a multi-step reaction.

A new molecular mechanism of RNA circularization and the microRNA sponge formation.

A new mechanism of RNA circularization driven by specific binding of miRNAs is described. We identified the 71 CUUCC pentanucleotide motifs distributed regularly throughout the entire molecule of CDR1as RNA that bind to 71 miRNAs through their seed sequence GGAAG. The sequential binding of miR-7 RNAs (71 molecules) brings both ends of CDR1as RNA (1 molecule) together and stimulate phosphodiester bond formation between nucleotides C1 and A1299 at the 5' and 3' end, respectively. The binding of miRNAs to CDR1as RNA results in the unique complex formation, which shows three specific structural domains: (i) two short helixes with an internal loop, (ii) the hinge, and (iii) the triple-helix. The proposed mechanism explains specific RNA circularization and its function as a miRNAs sponge. Furthermore, the existing wet experimental data on the interaction of CDR1as RNA with miR-7 fully supports our observation. Although miR-671 shows the same seed sequence as miR-7, it forms an almost perfect double helix with CDR1as RNA and induces the cleavage of CDR1as, but does not stimulate circularization. To check how common is the proposed mechanism among circular RNAs, we analyzed the most recent circAtlas database counting almost 1.1 million sequences. It turned out that there are a huge number of circRNAs, which showed miRNAs seed binding sequences distributed through the whole circRNA sequences and prove that circularization of linear transcript is miRNA dependent.Communicated by Ramaswamy H. Sarma.

100 years of RNA. The Diamond Jubilee of Information RNA / 100 lat RNA. Diamentowy jubileusz informacyjnego RNA.

The year 2021 marks not only 60 years since the discovery of messenger RNA and the genetic code. Already 100 yaers passed since RNA was discovered. On the occasion of this special anniversary, we would like to recall the most important events in the history of nucleic acids that led to the above discoveries. We remind the beginning of a new era in science caused by the isolation of nuclein and then nucleic acid, whose components and properties were gradually learned, often by little-known researchers. The distinction of RNA and DNA and the analysis of their occurrence in cells made it possible to formulate the first conclusions about the functions of these compounds. Conclusions on the ratio of nitrogenous bases in DNA led to the knowledge of the structure of the double helix, triggering an avalanche of questions about the essence of transmission of genetic information. Answers began to emerge with the discovery of mRNA, and knowledge of the first three nucleotides encoding an amino acid caused a race to decipher the genetic code. The above discoveries are the foundation of molecular biology. The diamond jubilee coincided with the development of an mRNA-based vaccine against the SARS-CoV-2.

Correlated Dynamics in Ionic Liquids by Means of NMR Relaxometry: Butyltriethylammonium bis(Trifluoromethanesulfonyl)imide as an Example.

1H and 19F spin-lattice relaxation experiments have been performed for butyltriethylammonium bis(trifluoromethanesulfonyl)imide in the temperature range from 258 to 298 K and the frequency range from 10 kHz to 10 MHz. The results have thoroughly been analysed in terms of a relaxation model taking into account relaxation pathways associated with 1H-1H, 19F-19F and 1H-19F dipole-dipole interactions, rendering relative translational diffusion coefficients for the pairs of ions: cation-cation, anion-anion and cation-anion, as well as the rotational correlation time of the cation. The relevance of the 1H-19F relaxation contribution to the 1H and 19F relaxation has been demonstrated. A comparison of the diffusion coefficients has revealed correlation effects in the relative cation-anion translational movement. It has also turned out that the translational movement of the anions is faster than of cations, especially at high temperatures. Moreover, the relative cation-cation diffusion coefficients have been compared with self-diffusion coefficients obtained by means of NMR (Nuclear Magnetic Resonance) gradient diffusometry. The comparison indicates correlation effects in the relative cation-cation translational dynamics-the effects become more pronounced with decreasing temperature.

Mothers' cafeteria diet induced sex-specific changes in fat content, metabolic profiles, and inflammation outcomes in rat offspring.

"Western diet" containing high concentrations of sugar and fat consumed during pregnancy contributes to development of obesity and diabetes type 2 in offspring. To mimic effects of this diet in animals, a cafeteria (CAF) diet is used. We hypothesized that CAF diet given to rats before, and during pregnancy and lactation differently influences fat content, metabolic and inflammation profiles in offspring. Females were exposed to CAF or control diets before pregnancy, during pregnancy and lactation. At postnatal day 25 (PND 25), body composition, fat contents were measured, and blood was collected for assessment of metabolic and inflammation profiles. We have found that CAF diet lead to sex-specific alterations in offspring. At PND25, CAF offspring had: (1) higher percentage of fat content, and were lighter; (2) sex-specific differences in levels of glucose; (3) higher levels of interleukin 6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor (TNF-α); (4) sex-specific differences in concentration of IL-6 and TNF-α, with an increase in CAF females; (5) higher level of IL-10 in both sexes, with a more pronounced increase in females. We concluded that maternal CAF diet affects fat content, metabolic profiles, and inflammation parameters in offspring. Above effects are sex-specific, with female offspring being more susceptible to the diet.

Assessment of Immunological Potential of Glial Restricted Progenitor Graft In Vivo-Is Immunosuppression Mandatory?

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease, causing motor neuron and skeletal muscle loss and death. One of the promising therapeutic approaches is stem cell graft application into the brain; however, an immune reaction against it creates serious limitations. This study aimed to research the efficiency of glial restricted progenitors (GRPs) grafted into murine CNS (central nervous system) in healthy models and the SOD1G93A ALS disease model. The cellular grafts were administered in semiallogenic and allogeneic settings. To investigate the models of immune reaction against grafted GRPs, we applied three immunosuppressive/immunomodulatory regimens: preimplantation factor (PiF); Tacrolimus; and CTLA-4, MR1 co-stimulatory blockade. We tracked the cells with bioluminescence imaging (BLI) in vivo to study their survival. The immune response character was evaluated with brain tissue assays and multiplex ELISA in serum and cerebrospinal fluid (CSF). The application of immunosuppressive drugs is disputable when considering cellular transplants into the immune-privileged site/brain. However, our data revealed that semiallogenic GRP graft might survive inside murine CNS without the necessity to apply any immunomodulation or immunosuppression, whereas, in the situation of allogeneic mouse setting, the combination of CTLA-4, MR1 blockade can be considered as the best immunosuppressive option.

Structure and Oligonucleotide Binding Efficiency of Differently Prepared Click Chemistry-Type DNA Microarray Slides Based on 3-Azidopropyltrimethoxysilane.

The structural characterization of glass slides surface-modified with 3-azidopropyltrimethoxysilane and used for anchoring nucleic acids, resulting in the so-called DNA microarrays, is presented. Depending on the silanization conditions, the slides were found to show different oligonucleotide binding efficiency, thus, an attempt was made to correlate this efficiency with the structural characteristics of the silane layers. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray reflectometry (XRR) measurements provided information on the surface topography, chemical composition and thickness of the silane films, respectively. The surface for which the best oligonucleotides binding efficiency is observed, has been found to consist of a densely-packed silane layer, decorated with a high-number of additional clusters that are believed to host exposed azide groups.

Influence of Alkyl Chain Length on Thermal Properties, Structure, and Self-Diffusion Coefficients of Alkyltriethylammonium-Based Ionic Liquids.

The application of ionic liquids (ILs) has grown enormously, from their use as simple solvents, catalysts, media in separation science, or electrolytes to that as task-specific, tunable molecular machines with appropriate properties. A thorough understanding of these properties and structure-property relationships is needed to fully exploit their potential, open new directions in IL-based research and, finally, properly implement the appropriate applications. In this work, we investigated the structure-properties relationships of a series of alkyltriethylammonium bis(trifluoromethanesulfonyl)imide [TEA-R][TFSI] ionic liquids in relation to their thermal behavior, structure organization, and self-diffusion coefficients in the bulk state using DSC, FT-IR, SAXS, and NMR diffusometry techniques. The phase transition temperatures were determined, indicating alkyl chain dependency. Fourier-transformed infrared spectroscopy studies revealed the structuration of the ionic liquids along with alkyl chain elongation. SAXS experiments clearly demonstrated the existence of polar/non-polar domains. The alkyl chain length influenced the expansion of the non-polar domains, leading to the expansion between cation heads in polar regions of the structured IL. 1H NMR self-diffusion coefficients indicated that alkyl chain elongation generally caused the lowering of the self-diffusion coefficients. Moreover, we show that the diffusion of anions and cations of ILs is similar, even though they vary in their size.

Comprehensive and comparative studies on nanocytotoxicity of glyceryl monooleate- and phytantriol-based lipid liquid crystalline nanoparticles.

BACKGROUND: Lipid liquid crystalline nanoparticles (LLCNPs) emerge as a suitable system for drug and contrast agent delivery. In this regard due to their unique properties, they offer a solubility of a variety of active pharmaceutics with different polarities increasing their stability and the possibility of controlled delivery. Nevertheless, the most crucial aspect underlying the application of LLCNPs for drug or contrast agent delivery is the unequivocal assessment of their biocompatibility, including cytotoxicity, genotoxicity, and related aspects. Although studies regarding the cytotoxicity of LLCNPs prepared from various lipids and surfactants were conducted, the actual mechanism and its impact on the cells (both cancer and normal) are not entirely comprehended. Therefore, in this study, LLCNPs colloidal formulations were prepared from two most popular structure-forming lipids, i.e., glyceryl monooleate (GMO) and phytantriol (PHT) with different lipid content of 2 and 20 w/w%, and the surfactant Pluronic F-127 using the top-down approach for further comparison of their properties. Prepared formulations were subjected to physicochemical characterization and followed with in-depth biological characterization, which included cyto- and genotoxicity towards cervical cancer cells (HeLa) and human fibroblast cells (MSU 1.1), the evaluation of cytoskeleton integrity, intracellular reactive oxygen species (ROS) generation upon treatment with prepared LLCNPs and finally the identification of internalization pathways. RESULTS: Results denote the higher cytotoxicity of PHT-based nanoparticles on both cell lines on monolayers as well as cellular spheroids, what is in accordance with evaluation of ROS activity level and cytoskeleton integrity. Detected level of ROS in cells upon the treatment with LLCNPs indicates their insignificant contribution to the cellular redox balance for most concentrations, however distinct for GMO- and PHT-based LLCNPs. The disintegration of cytoskeleton after administration of LLCNPs implies the relation between LLCNPs and F-actin filaments. Additionally, the expression of four genes involved in DNA damage and important metabolic processes was analyzed, indicating concentration-dependent differences between PHT- and GMO-based LLCNPs. CONCLUSIONS: Overall, GMO-based LLCNPs emerge as potentially more viable candidates for drug delivery systems as their impact on cells is not as deleterious as PHT-based as well as they were efficiently internalized by cell monolayers and 3D spheroids.