Size Matters in Conjugated Polymer Chirality-Selective SWCNT Extraction.

Carbon-based nanomaterials have catalyzed breakthroughs across various scientific and engineering disciplines. The key to unlocking a new generation of tailor-made nanomaterials based on single-walled carbon nanotubes (SWCNTs) lies in the precise sorting of raw material into individual chiralities, each possessing unique properties. This can be achieved using conjugated polymer extraction (CPE), but to a very limited extent since the process generates only a few chirality-enriched suspensions. Therefore, it is imperative to comprehend the mechanism of the wrapping of SWCNTs by polymers to unleash CPE's full potential. However, the lack of a diverse palette of chirality-selective polymers with varying macromolecular parameters has hindered a comprehensive understanding of how the nature of the polymer affects the performance and selectivity of SWCNT isolation. To address this gap, multiple batches of such polymers are synthesized to elucidate the impact of molecular weight and dispersity on the purity and concentrations of the generated SWCNT suspensions. The obtained results explain the inconsistent outcomes reported in the literature, greatly improving the application potential of this promising SWCNT sorting approach. Concomitantly, the discovered significant influence of the macromolecular characteristics of conjugated polymers on the SWCNT isolation efficacy sheds considerable insight into the unresolved mechanism of this sorting technique.

Tuning the Structure of Pd@Ni-Co Nanowires and Their Electrochemical Properties.

One-dimensional transition metal materials are promising supports for precious metals used in energy production processes. Due to their electrochemical properties, 3d-group metals (such as Ni, Co, and Fe) can actively interact with catalysts by a strong metal-support interaction. This study shows that changing the Ni:Co ratio makes it possible to modulate the structure of the catalyst supports, which, in turn, provides a tool for designing their electrical and electrochemical properties. For example, Ni1-Co9 shows the highest electrical conductivity (5.8-10-4 S/cm) among all of the materials examined. On the contrary, the Pd@Ni7-Co3 system presents the highest mass activity (>2000 mA mg-1) at 0.7 V, exceeding by several times that of commercial Pt/C (>300 mA mg-1) at the same potential. Our study opens the gateway for applications of bimetallic transition metal nanowires in catalytic conversion and energy production processes.

PdNPs/NiNWs as a welding tool for the synthesis of polyfluorene derivatives by Suzuki polycondensation under microwave radiation.

Conjugated polymers are promising tools to differentiate various types of semiconducting single-walled carbon nanotubes (s-SWCNTs). However, their synthesis is challenging. Insufficient control over molecular weights, and unpredictive/unrepeatable batches hinder possible applications and scale-up. Furthermore, commercial homogeneous catalysts often require inert conditions and are almost impossible to recycle. To overcome these problems, we present a nanocatalyst consisting of magnetic nickel nanowires decorated with highly active palladium nanoparticles. A two-step wet chemical reduction protocol with the assistance of sonochemistry was employed to obtain a heterogeneous catalyst capable of conducting step-growth Suzuki polycondensation of a fluorene-based monomer. Additionally, we enhanced the performance of our catalytic system via controlled microwave irradiation, which significantly shortened the reaction time from 3 d to only 1 h. We studied the influence of the main process parameters on the yield and polymer chain length to gain insight into phenomena occurring in the presence of metallic species under microwave irradiation. Finally, the produced polymers were used to extract specific s-SWCNTs by conjugated polymer extraction to validate their utility.

Suggested mechanism of CCR5Δ32, CCR2-64I and SDF 1-3'A allele frequency change in Polish and Lithuanian gene pools from the perspective of passing time.

The study aimed to determine the frequency of the alleles associated with hereditary immune response in 16 historical populations and assess which evolutionary forces may have contributed to the observed frequency fluctuation. The analysed polymorphic sites are located in three genes - CCR5, CCR2 and SDF 1 (CXCL12). Protein products are involved in the innate immune response and are also involved in various types of infections, autoimmune diseases and tumours. The frequency of the alleles found in the DNA of the studied individuals was determined by the Sanger methodology and was compared with the data obtained for modern populations. To confirm the authenticity of the obtained results, mtDNA HVRI haplotypes of all the studied samples were obtained and compared with the genetic database of the laboratory personnel who came into contact with the studied material. Based on the variability of allele frequency, advanced biostatistical analysis was used to distinguish the effect of natural selection from genetic drift, i.e. the forces operating on the polymorphic sites studied. All procedures were performed according to the guidelines for working with ancient DNA to avoid contamination with modern DNA molecules. 681 samples from 39 archaeological sites in Poland and Lithuania dated to the 40th century BC and the 19th century were studied. The biostatistical analysis showed that the fluctuations in the frequency of CCR5Δ32 in the analysed time interval could be mainly the effect of genetic drift. Nevertheless, for CCR2-64I and SDF 1-3'A, the results confirm the suggestion of negative selection as the mechanism involved. Since all the polymorphic sites encode the elements of innate immune response that are indirectly associated with the process of an HPV infection and the development of cervical cancer, the human papillomavirus may be a good candidate for a selection coefficient affecting the frequency of CCR2-64I and SDF 1-3'A. However, for CCR5Δ32, selection was not detected despite its proven role in the molecular mechanism involved in the response to an HPV infection. The presented work seems to be the first in which the problem of the pattern of CCR5Δ32, CCR2-64I and SDF 1-3'A frequency fluctuations in a temporal perspective was discussed, proposing HPV as a factor influencing the occurrence of the CCR2 and SDF1 alleles.

Immunohistochemical detection of EGFRvIII in glioblastoma - Anti-EGFRvIII antibody validation for diagnostic and CAR-T purposes.

The emergence of therapies such as CAR-T has created a need for reliable, validated methods for detecting EGFRvIII in patient tumor cells. Particularly so since previous studies have already suggested that some anti-EGFRvIII antibodies may be non-specific. The present paper evaluates the use of the L8A4 antibody in the immunohistochemical (IHC) and immunocytochemical (ICC) detection of EGFRvIII in 30 glioblastoma specimens, and compares it with other methods such as RT-PCR, MLPA, and FISH. The results indicate that Real-time PCR appears to be a very specific and sensitive method of EGFRvIII detection. ICC analysis with L8A4 also appears specific but requires cell culture. IHC analyses of EGFRvIII returned a number of false positives when using L8A4. Due to the growing need for an effective diagnostic tool before starting immunotherapy methods, such as the CAR-T anti-EGFRvIII or SynNotch CAR-T recognizing EGFRvIII, it is necessary to identify a more reliable and simple method of EGFRvIII detection or improve the specificity of the anti-EGFRvIII antibody, until then, immunocytochemistry may temporarily replace immunohistochemistry.

Compositional differences between gut microbiota of adult patients with asthma and healthy controls.

Introduction: Asthma is a complex and multifactorial disorder, with severe public health implications. Over the last several years, our knowledge in the field of human gut microbiota has expanded and allowed us to understand its crucial role in the development of many diseases. Aim: To analyse the nature of human gut microbiota patterns among patients with asthma compared to healthy controls. Material and methods: Composition of the complex gut microbiota was analysed in faecal samples from 13 asthma patients and 7 healthy volunteers using Next-Generation Sequencing technology (NGS). The Kruskal-Wallis Analysis of Variance (ANOVA) and Mann-Whitney tests were used to compare the above two groups of subjects. Results: The composition of the gut microbiota of asthma patients differed from that of healthy volunteers at each of the analysed levels (p < 0.05). Compared to healthy individuals, bacterial diversity was significantly lowered among the asthma group, which is the evidence of gut microbiota depletion in asthma patients. The analysis of beta diversity showed that the gut community compositions of asthma are widely dispersed in contrast to the tight clustering observed in the control group. Finally, the similarity index was found to be lower in the inter-group comparison than in the intra-group comparison, which confirmed changes in the gut microbial composition in the asthmatic group. Conclusions: The study revealed significant differences in the human gut microbiome composition between asthma patients and the healthy control group.

The Genetic Diversity of Proteasome Genes in the T1DM Polish Population.

Autoimmune metabolic diseases generate numerous healthy and social problems. The possible association of SNPs in the ubiquitin-proteasome system (UPS) with human pathology is under intensive study. OBJECTIVE: In the present study, the genetic variations in PSMB5 (rs11543947), PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) UPS gene cluster was investigated in type 1 diabetes and healthy donors in the Polish population. METHODS: The study comprised 105 patients with type 1 diabetes mellitus (T1DM) and 214 controls. All were genotyped by PCR and restriction digestion analysis or Sanger sequencing. RESULTS: Rs1048990 and rs2348071 were found to be neutral to T1DM (p-value: 0.499 and 0.656, respectively). According to the multiple loci genotype (MLG) analysis, the major homozygote of the tested polymorphisms had a protective effect. The most common MLG in the T1DM group was characterised by simultaneous risk factors at rs11543947, rs2277460, rs2295826 and rs2295827 (pvalue: <0.0001 vs. MGL1). Multiple locus haplotype analysis revealed a similar dependence, with common alleles at all tested loci demonstrating a protective effect, and the rare alleles increasing T1DM risk (p-value: <0.0001 vs. MLH1). CONCLUSION: Our study suggests that the proteasome gene polymorphisms rs11543947, rs2277460, rs2295826, and rs2295827 could be potential markers for T1DM susceptibility in the Polish population.

Phenotypical Flexibility of the EGFRvIII-Positive Glioblastoma Cell Line and the Multidirectional Influence of TGFß and EGF on These Cells-EGFRvIII Appears as a Weak Oncogene.

BACKGROUND: The biological role of EGFRvIII (epidermal growth factor receptor variant three) remains unclear. METHODS: Three glioblastoma DK-MG sublines were tested with EGF (epidermal growth factor) and TGFß (transforming growth factor ß). Sublines were characterized by an increased percentage of EGFRvIII-positive cells and doubling time (DK-MGlow to DK-MGextra-high), number of amplicons, and EGFRvIII mRNA expression. The influence of the growth factors on primary EGFRvIII positive glioblastomas was assessed. RESULTS: The overexpression of exoEGFRvIII in DK-MGhigh did not convert them into DK-MGextra-high, and this overexpression did not change DK-MGlow to DK-MGhigh; however, the overexpression of RASG12V increased the proliferation of DK-MGlow. Moreover, the highest EGFRvIII phosphorylation in DK-MGextra-high did not cause relevant AKT (known as protein kinase B) and ERK (extracellular signal-regulated kinase) activation. Further analyses indicate that TGFß is able to induce apoptosis of DK-MGhigh cells. This subline was able to convert to DK-MGextra-high, which appeared resistant to this proapoptotic effect. EGF acted as a pro-survival factor and stimulated proliferation; however, simultaneous senescence induction in DK-MGextra-high cells was ambiguous. Primary EGFRvIII positive (and SOX2 (SRY-Box Transcription Factor 2) positive or SOX2 negative) glioblastoma cells differentially responded to EGF and TGFß. CONCLUSIONS: The roles of TGFß and EGF in the EGFRvIII context remain unclear. EGFRvIII appears as a weak oncogene and not a marker of GSC (glioma stem cells). Hence, it may not be a proper target for CAR-T (chimeric antigen receptor T cells).

Carbon Nanotube-Based Thermoelectric Modules Enhanced by ZnO Nanowires.

Carbon nanotubes (CNTs) have a wide range of unique properties, which have kept them at the forefront of research in recent decades. Due to their electrical and thermal characteristics, they are often evaluated as key components of thermogenerators. One can create thermogenerators exclusively from CNTs, without any metal counterpart, by properly selecting dopants to obtain n- and p-doped CNTs. However, the performance of CNT thermogenerators remains insufficient to reach wide commercial implementation. This study shows that molecular doping and the inclusion of ZnO nanowires (NWs) can greatly increase their application potential. Moreover, prototype modules, based on single-walled CNTs (SWCNTs), ZnO NWs, polyethyleneimine, and triazole, reveal notable capabilities for generating electrical energy, while ensuring fully scalable performance. Upon doping and the addition of ZnO nanowires, the electrical conductivity of pure SWCNTs (211 S/cm) was increased by a factor of three. Moreover, the proposed strategy enhanced the Power Factor values from 18.99 (unmodified SWCNTs) to 34.9 and 42.91 µW/m∙K2 for CNTs triazole and polyethyleneimine + ZnO NWs inclusion, respectively.

Transformation of industrial wastewater into copper-nickel nanowire composites: straightforward recycling of heavy metals to obtain products of high added value.

Large amounts of industrial metal containing process and waste solutions are a growing issue. In this work, we demonstrated that they could be transformed into materials of high added values such as copper-nickel nanowires (CuNi NWs) by simple chemical reduction. A thorough investigation of the parameter space was conducted. The microstructure of the obtained material was found tunable depending on the employed concentration of precursor, reducing agent, capping agent, pH, temperature, and reaction time. Moreover, the obtained product had a strong magnetic character, which enabled us to separate it from the reaction medium with ease. The results open new perspectives for materials science by proposing a new type of nanostructure: composite NWs of very promising properties, with metallic elements originating directly from industrial process solution.

Simple Method to Improve Electrical Conductivity of Films Made from Single-Walled Carbon Nanotubes.

Despite the widespread use of sonication for individualization of nanomaterials, its destructive nature is rarely acknowledged. In this study, we demonstrated how exposure of the material to a hostile sound wave environment can be limited by the application of another preprocessing step. Single-walled carbon nanotubes (CNTs) were initially ground in a household coffee grinder, which enabled facile deagglomeration thereof. Such a simple approach enabled us to obtain high-quality CNT dispersion at reduced sonication time. Most importantly, electrical conductivity of free-standing films prepared from these dispersion was improved almost fourfold as compared with unground material eventually reaching 1067 ± 34 S/cm. This work presents a new approach as to how electrical properties of nanocarbon ensembles may be enhanced without the application of doping agents, the presence of which is often ephemeral.

Simultaneous transcriptome and proteome analysis of EA.hy926 cells under stress conditions induced by nanomaterials.

Today, the extensive and constantly growing number of applications in the field of nanotechnology poses a lot of questions about the potential toxicity of nanomaterials (NMs) toward cells of different origins. In our work we employed the tools of molecular biology to evaluate changes that occur in human endothelial cells at the transcriptomic and proteomic level, following 24 h of exposure to three different classes of NMs. Using microarray technology, we demonstrated that 24 h of exposure to silver nanoparticles (SNPs), multiwalled carbon nanotubes (MWCNTs) and polyamidoamine dendrimers (PAMAMs) leads to changes in 299, 1271, and 431 genes, respectively, influencing specific molecular pathways. The 2D-DIGE and mass spectrometry analysis revealed that differentially expressed proteins were involved in numerous cellular processes, for example, cytoskeletal reorganization, cell growth and proliferation, or response to stress. Both, transcriptome and proteome alterations indicate reorganization of mechanism regulating cell functioning. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1024-1034, 2019.

Probing the mechanics of aqueous two-phase extraction using large diameter single-walled carbon nanotubes.

We have demonstrated that large diameter (1.8 ± 0.4 nm) carbon nanotubes (CNTs) can be separated by means of the aqueous two-phase extraction (ATPE). This rapid and convenient tool has enabled us to isolate fractions of particular CNT diameter distribution. We have shown how a range of parameters can be used to fine tune the characteristics of the isolated material. Interestingly, by varying the pH of the medium, we have suppressed the extraction of low diameter CNTs and only large diameter CNTs were obtained. A number of other factors such as selected surfactant concentration steps, temperature or amount of starting CNT material have been found to have a significant effect on the end result of the CNT differentiation. The findings have provided us with more insight regarding the underlying mechanics of ATPE for processing polydisperse CNT mixtures.

Sensing of silver nanoparticles on/in endothelial cells using atomic force spectroscopy.

Endothelial cells, due to their location, are interesting objects for atomic force spectroscopy study. They constitute a barrier between blood and vessel tissues located deeper, and therefore they are the first line of contact with various substances present in blood, eg, drugs or nanoparticles. This work intends to verify whether the mechanical response of immortalized human umbilical vein endothelial cells (EA.hy926), when exposed to silver nanoparticles, as measured using force spectroscopy, could be effectively used as a bio-indicator of the physiological state of the cells. Silver nanoparticles were characterized with transmission electron microscopy and dynamic light scattering techniques. Tetrazolium salt reduction test was used to determine cell viability after treatment with silver nanoparticles. An elasticity of native cells was examined in the Hanks' buffer whereas fixed cells were softly fixed with formaldehyde. Additional aspect of the work is the comparative force spectroscopy utilizing AFM probes of ball-shape and conical geometries, in order to understand what changes in cell elasticity, caused by SNPs, were detectable with each probe. As a supplement to elasticity studies, cell morphology observation by atomic force microscopy and detection of silver nanoparticles inside cells using transmission electron microscopy were also performed. Cells exposed to silver nanoparticles at the highest selected concentrations (3.6 µg/mL, 16 µg/mL) are less elastic. It may be associated with the reorganization of the cellular cytoskeleton and the "strengthening" of the cell cortex caused by presence of silver nanoparticles. This observation does not depend on cell fixation. Agglomerates of silver nanoparticles were observed on the cell membrane as well as inside the cells.

Toxicity of silver nanoparticles, multiwalled carbon nanotubes, and dendrimers assessed with multicellular organism Caenorhabditis elegans.

Nematode Caenorhabditis elegans (C. elegans) was used to investigate the impact of silver nanoparticles (SNP), multiwalled carbon nanotubes (MWCNT), and polyamidoamine dendrimers (PAMAM) used in concentration of 1010 particle/mL. Population-based observations and gene expression analysis were employed in this study. SNP and PAMAM caused decrease in the number of live nematodes and their body length, but MWCNT did not affect the population of nematodes. Gene expression analysis revealed significant changes caused by the presence of all studied nanomaterials, and the results strongly suggest a specific metabolic response of the nematode organism to exposure to various nanomaterials. It was shown that C. elegans is a very sensitive organism capable to respond specifically to the exposure to some nanomaterials and therefore could be considered as a possible biosensor for early warning of presence of some nanoparticles.

Dendrimers reduce toxicity of Aß 1-28 peptide during aggregation and accelerate fibril formation.

The influence of a GATG (gallic acid-triethylene glycol) dendrimer decorated with 27 terminal morpholine groups ([G3]-Mor) on the aggregation process of Alzheimer's peptide has been investigated. Amyloid fibrils were formed from the Aß 1-28 peptide and the process was monitored by a ThT assay, changes in CD spectra, and transmission electron microscopy. In the presence of [G3]-Mor, more fibrils were built and the process significantly accelerated compared with a control. The cytotoxicity of (1) Aß and (2) the system [G3]-Mor/Aß was monitored at different stages of the aggregation process. Prefibrillar species were more toxic than mature fibrils. [G3]-Mor significantly reduced the toxicity of Aß, probably because of lowering the amount of prefibrillar forms in the system by speeding up the process of fibril formation. FROM THE CLINICAL EDITOR: In this study, GATG dendrimer decorated with 27 terminal morpholine groups was able to reduce beta-amyloid fibril formation, which might represent a new method to address the key pathology in Alzheimer's disease.

Phosphorus dendrimers affect Alzheimer's (Aß1-28) peptide and MAP-Tau protein aggregation.

Alzheimer's disease (AD) is characterized by pathological aggregation of ß-amyloid peptides and MAP-Tau protein. ß-Amyloid (Aß) is a peptide responsible for extracellular Alzheimer's plaque formation. Intracellular MAP-Tau aggregates appear as a result of hyperphosphorylation of this cytoskeletal protein. Small, oligomeric forms of Aß are intermediate products that appear before the amyloid plaques are formed. These forms are believed to be most neurotoxic. Dendrimers are highly branched polymers, which may find an application in regulation of amyloid fibril formation. Several biophysical and biochemical methods, like circular dichroism (CD), fluorescence intensity of thioflavin T and thioflavin S, transmission electron microscopy, spectrofluorimetry (measuring quenching of intrinsic peptide fluorescence) and MTT-cytotoxicity assay, were applied to characterize interactions of cationic phosphorus-containing dendrimers of generation 3 and generation 4 (CPDG3, CPDG4) with the fragment of amyloid peptide (Aß(1-28)) and MAP-Tau protein. We have demonstrated that CPDs are able to affect ß-amyloid and MAP-Tau aggregation processes. A neuro-2a cell line (N2a) was used to test cytotoxicity of formed fibrils and intermediate products during the Aß(1-28) aggregation. It has been shown that CPDs might have a beneficial effect by reducing the system toxicity. Presented results suggest that phosphorus dendrimers may be used in the future as agents regulating the fibrilization processes in Alzheimer's disease.