Carbon-Based Nanomaterials 4.0.

Research on carbon-based nanomaterials, such as carbon nanotubes and graphene and its derivatives, has experienced exponential development in recent years [...].

Dispersive Solid Phase Extraction of Melatonin with Graphene/Clay Mixtures and Fluorescence Analysis in Surfactant Aqueous Solutions.

In this work, the dispersive solid phase extraction (dSPE) of melatonin using graphene (G) mixtures with sepiolite (SEP) and bentonite (BEN) clays as sorbents combined with fluorescence detection has been investigated. The retention was found to be quantitative for both G/SEP and G/BEN 4/96 and 10/90 w/w mixtures. G/clay 4/96 w/w mixtures were selected to study the desorption process since the retention was weaker, thus leading to easier desorption. MeOH and aqueous solutions of the nonionic surfactant Brij L23 were tested as desorbents. For both clays and an initial sample volume of 25 mL, a percentage of melatonin recovery close to 100% was obtained using 10 or 25 mL of MeOH as desorbent. Further, using a G/SEP mixture, 25 mL as the initial sample volume and 5 mL of MeOH or 60 mM Brij L23 solution as the desorbent, recoveries of 98.3% and 90% were attained, respectively. The whole method was applied to herbal tea samples containing melatonin, and the percentage of agreement with the labeled value was 86.5%. It was also applied to herbal samples without melatonin by spiking them with two concentrations of this compound, leading to recoveries of 100 and 102%.

Biopolymer Composites 2022.

Recently, sustainable, biodegradable, and nontoxic materials, especially from renewable resources, have gained a lot of attention, and an important effort has been put into the research of biodegradable and biocompatible polymers as an alternative to petroleum-based commodity plastics [...].

Infiltrative and drug-resistant slow-cycling cells support metabolic heterogeneity in glioblastoma.

Metabolic reprogramming has been described in rapidly growing tumors, which are thought to mostly contain fast-cycling cells (FCCs) that have impaired mitochondrial function and rely on aerobic glycolysis. Here, we characterize the metabolic landscape of glioblastoma (GBM) and explore metabolic specificities as targetable vulnerabilities. Our studies highlight the metabolic heterogeneity in GBM, in which FCCs harness aerobic glycolysis, and slow-cycling cells (SCCs) preferentially utilize mitochondrial oxidative phosphorylation for their functions. SCCs display enhanced invasion and chemoresistance, suggesting their important role in tumor recurrence. SCCs also demonstrate increased lipid contents that are specifically metabolized under glucose-deprived conditions. Fatty acid transport in SCCs is targetable by pharmacological inhibition or genomic deletion of FABP7, both of which sensitize SCCs to metabolic stress. Furthermore, FABP7 inhibition, whether alone or in combination with glycolysis inhibition, leads to overall increased survival. Our studies reveal the existence of GBM cell subpopulations with distinct metabolic requirements and suggest that FABP7 is central to lipid metabolism in SCCs and that targeting FABP7-related metabolic pathways is a viable therapeutic strategy.

Human macrophage C-type lectin forms a heteromeric receptor complex with Mincle but not Dectin-2.

MCL, Mincle and Dectin-2 are C-type lectin receptors expressed by subsets of myeloid cells, and their genes cluster together in the APLEC/Dectin-2 gene complex. We have previously shown that MCL and Mincle form a heterodimer in the rat, and others have shown that MCL and Dectin-2 form a heterodimer in the mouse. In the rat, Dectin-2 is a pseudogene, but here, we examine the association of the three receptors in human. In co-transfection experiments analyzed with flow cytometry and immunoprecipitation, we here show that human MCL and Mincle form a disulphide-linked heterodimer that associates with the signalling adaptor molecule FcεRIγ, in accordance with our previous findings in the rat. In contrast to previous findings in the rat, data in this paper indicate a direct association of MCL with FcεRIγ, as previously shown for mouse MCL. We were unable to demonstrate the formation of a heterodimer between human MCL and Dectin-2. Thus, despite similarities, there may be important differences in the conformation of these receptors between rat, mouse and human, and this may have functional consequences.

siRNA-based nanotherapeutics as emerging modalities for immune-mediated diseases: A preliminary review.

Immune-mediated diseases (IMDs) are chronic conditions that have an immune-mediated etiology. Clinically, these diseases appear to be unrelated, but pathogenic pathways have been shown to connect them. While inflammation is a common occurrence in the body, it may either stimulate a favorable immune response to protect against harmful signals or cause illness by damaging cells and tissues. Nanomedicine has tremendous promise for regulating inflammation and treating IMIDs. Various nanoparticles coated with nanotherapeutics have been recently fabricated for effective targeted delivery to inflammatory tissues. RNA interference (RNAi) offers a tremendous genetic approach, particularly if traditional treatments are ineffective against IMDs. In cells, several signaling pathways can be suppressed by using RNAi, which blocks the expression of particular messenger RNAs. Using this molecular approach, the undesirable effects of anti-inflammatory medications can be reduced. Still, there are many problems with using short-interfering RNAs (siRNAs) to treat IMDs, including poor localization of the siRNAs in target tissues, unstable gene expression, and quick removal from the blood. Nanotherapeutics have been widely used in designing siRNA-based carriers because of the restricted therapy options for IMIDs. In this review, we have discussed recent trends in the fabrication of siRNA nanodelivery systems, including lipid-based siRNA nanocarriers, liposomes, and cationic lipids, stable nucleic acid-lipid particles, polymeric-based siRNA nanocarriers, polyethylenimine (PEI)-based nanosystems, chitosan-based nanoformulations, inorganic material-based siRNA nanocarriers, and hybrid-based delivery systems. We have also introduced novel siRNA-based nanocarriers to control IMIDs, such as pulmonary inflammation, psoriasis, inflammatory bowel disease, ulcerative colitis, rheumatoid arthritis, etc. This study will pave the way for new avenues of research into the diagnosis and treatment of IMDs.

Biopolymer Composites: Synthesis, Properties, and Applications.

Petroleum-based plastics can be found everywhere in our habitual life in diverse applications such as automobiles, aerospace, and medical science [...].

Carbon-Based Nanomaterials 3.0.

Carbon-based nanomaterials are currently attracting a lot of interest in many fields, ranging from medicine and biotechnology to electronics, energy storage, and sensing applications [...].

PMMA-Based Nanocomposites for Odontology Applications: A State-of-the-Art.

Polymethyl methacrylate (PMMA), a well-known polymer of the methacrylate family, is extensively used in biomedicine, particularly in odontological applications including artificial teeth, dentures and denture bases, obturators, provisional or permanent crowns, and so forth. The exceptional PMMA properties, including aesthetics, inexpensiveness, simple manipulation, low density, and adjustable mechanical properties, make it a perfect candidate in the field of dentistry. However, it presents some deficiencies, including weakness regarding hydrolytic degradation, poor fracture toughness, and a lack of antibacterial activity. To further enhance its properties and solve these drawbacks, different approaches can be performed, including the incorporation of nanofillers. In this regard, different types of metallic nanoparticles, metal oxide nanofillers, and carbon-based nanomaterials have been recently integrated into PMMA matrices with the aim to reduce water absorption and improve their performance, namely their thermal and flexural properties. In this review, recent studies regarding the development of PMMA-based nanocomposites for odontology applications are summarized and future perspectives are highlighted.

Machine Learning for Property Prediction and Optimization of Polymeric Nanocomposites: A State-of-the-Art.

Recently, the field of polymer nanocomposites has been an area of high scientific and industrial attention due to noteworthy improvements attained in these materials, arising from the synergetic combination of properties of a polymeric matrix and an organic or inorganic nanomaterial. The enhanced performance of those materials typically involves superior mechanical strength, toughness and stiffness, electrical and thermal conductivity, better flame retardancy and a higher barrier to moisture and gases. Nanocomposites can also display unique design possibilities, which provide exceptional advantages in developing multifunctional materials with desired properties for specific applications. On the other hand, machine learning (ML) has been recognized as a powerful predictive tool for data-driven multi-physical modelling, leading to unprecedented insights and an exploration of the system's properties beyond the capability of traditional computational and experimental analyses. This article aims to provide a brief overview of the most important findings related to the application of ML for the rational design of polymeric nanocomposites. Prediction, optimization, feature identification and uncertainty quantification are presented along with different ML algorithms used in the field of polymeric nanocomposites for property prediction, and selected examples are discussed. Finally, conclusions and future perspectives are highlighted.

Universal programs to prevent eating disorders in children and adolescents: A scoping review of ethical, legal, organizational and social impacts.

BACKGROUND: Appropriate and timely consideration of ethical, legal, organizational, and social issues in universal preventive programs for eating disorders (UPPED) are relevant for the approval, funding and implementation of health-policy decision making. OBJECTIVE: To identify and analyse the ethical, legal, organizational, and social aspects involved in interventions aimed at the universal prevention of eating disorders (ED) in children, pre-adolescents and adolescents in the school settings. METHOD: A scoping review of the literature was carried out. MEDLINE, EMBASE, CENTRAL, PsycINFO, and Social Science Citation Index were searched for studies published in English or Spanish. The quality of the studies was assessed using specific scales for each study design. RESULTS: Fourteen studies were included: one scoping review; four narrative reviews, six observational studies, two qualitative studies, and one mixed methods study. Results were narratively synthesised according to: (1) equity; (2) gender perspective; (3) potential harm; (4) participants and facilitators profile; (5) feasibility; and (6) acceptability. CONCLUSIONS: Interactive programs with relevant contents for participants have greater acceptability. Programs focussed on developing competencies can reduce the risk of potential harm. Incorporating a gender perspective contributes to improving equity. Teachers with prior training in ED are well suited as facilitators of these programs.

Chitosan/Gamma-Alumina/Fe3O4@5-FU Nanostructures as Promising Nanocarriers: Physiochemical Characterization and Toxicity Activity.

Today, cancer treatment is an important issue in the medical world due to the challenges and side effects of ongoing treatment procedures. Current methods can be replaced with targeted nano-drug delivery systems to overcome such side effects. In the present work, an intelligent nano-system consisting of Chitosan (Ch)/Gamma alumina (γAl)/Fe3O4 and 5-Fluorouracil (5-FU) was synthesized and designed for the first time in order to influence the Michigan Cancer Foundation-7 (MCF-7) cell line in the treatment of breast cancer. Physico-chemical characterization of the nanocarriers was carried out using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), and scanning electron microscopy (SEM). SEM analysis revealed smooth and homogeneous spherical nanoparticles. The high stability of the nanoparticles and their narrow size distribution was confirmed by DLS. The results of the loading study demonstrated that these nano-systems cause controlled, stable, and pH-sensitive release in cancerous environments with an inactive targeting mechanism. Finally, the results of MTT and flow cytometry tests indicated that this nano-system increased the rate of apoptosis induction on cancerous masses and could be an effective alternative to current treatments.

Remote Teaching of Chemistry Laboratory Courses during COVID-19.

This paper describes the transfer from face-to-face education to emergency remote teaching of chemistry laboratory courses in a bachelor's degree in Pharmacy during the COVID-19 pandemic. The virtualization was carried out using videos of each experimental practice and questionnaires containing the experimental data needed. The contents were integrated into the virtual platform Blackboard Collaborate, where tutorials and remote support from the teachers were provided to solve the issues raised. The didactic strategy was very positive: it turned the students into active learners, fostering knowledge sharing and promoting the self-management of their learning process. The teachers acted as guides, raising questions, and provided continuous feedback to the students that contributed to knowledge assimilation and competence acquisition. The teaching-learning process was evaluated through a rubric that graded the reports delivered by the students and a final online test. The impact of this teaching methodology was assessed by comparing the students' marks with those obtained in the conventional on-site education before the pandemic and feedback from the students via surveys. This study provides a unique experience on how a traditional instruction can be adapted to remote teaching in analytical chemistry laboratories, providing new tools that can be used in future pandemics or in other settings.

Identifying subpopulations in multicellular systems by quantitative chemical imaging using label-free hyperspectral CARS microscopy.

Quantitative hyperspectral coherent Raman scattering microscopy merges imaging with spectroscopy and utilises quantitative data analysis algorithms to extract physically meaningful chemical components, spectrally and spatially-resolved, with sub-cellular resolution. This label-free non-invasive method has the potential to significantly advance our understanding of the complexity of living multicellular systems. Here, we have applied an in-house developed hyperspectral coherent anti-Stokes Raman scattering (CARS) microscope, combined with a quantitative data analysis pipeline, to imaging living mouse liver organoids as well as fixed mouse brain tissue sections xenografted with glioblastoma cells. We show that the method is capable of discriminating different cellular sub-populations, on the basis of their chemical content which is obtained from an unsupervised analysis, i.e. without prior knowledge. Specifically, in the organoids, we identify sub-populations of cells at different phases in the cell cycle, while in the brain tissue, we distinguish normal tissue from cancer cells, and, notably, tumours derived from transplanted cancer stem cells versus non-stem glioblastoma cells. The ability of the method to identify different sub-populations was validated by correlative fluorescence microscopy using fluorescent protein markers. These examples expand the application portfolio of quantitative chemical imaging by hyperspectral CARS microscopy to multicellular systems of significant biomedical relevance, pointing the way to new opportunities in non-invasive disease diagnostics.

Unsupervised feature selection algorithm for multiclass cancer classification of gene expression RNA-Seq data.

This paper presents a Grouping Genetic Algorithm (GGA) to solve a maximally diverse grouping problem. It has been applied for the classification of an unbalanced database of 801 samples of gene expression RNA-Seq data in 5 types of cancer. The samples are composed by 20,531 genes. GGA extracts several groups of genes that achieve high accuracy in multiple classification. Accuracy has been evaluated by an Extreme Learning Machine algorithm and was found to be slightly higher in balanced databases than in unbalanced ones. The final classification decision has been made through a weighted majority vote system between the groups of features. The proposed algorithm finally selects 49 genes to classify samples with an average accuracy of 98.81% and a standard deviation of 0.0174.

State of the Art in the Antibacterial and Antiviral Applications of Carbon-Based Polymeric Nanocomposites.

The development of novel approaches to prevent bacterial infection is essential for enhancing everyday life. Carbon nanomaterials display exceptional optical, thermal, and mechanical properties combined with antibacterial ones, which make them suitable for diverse fields, including biomedical and food applications. Nonetheless, their practical applications as antimicrobial agents have not been fully explored yet, owing to their relatively poor dispersibility, expensiveness, and scalability changes. To solve these issues, they can be integrated within polymeric matrices, which also exhibit antimicrobial activity in some cases. This review describes the state of the art in the antibacterial applications of polymeric nanocomposites reinforced with 0D fullerenes, 1D carbon nanotubes (CNTs), and 2D graphene (G) and its derivatives such as graphene oxide (GO) and reduced graphene oxide (rGO). Given that a large number of such nanocomposites are available, only the most illustrative examples are described, and their mechanisms of antimicrobial activity are discussed. Finally, some applications of these antimicrobial polymeric nanocomposites are reviewed.

Carbon-Based Nanomaterials.

Research on carbon-based nanomaterials, such as carbon nanotubes, graphene and its derivatives, nanodiamonds, fullerenes, and other nanosized carbon allotropes, has experienced sharp exponential growth over recent years [...].

Active Targeted Nanoparticles for Delivery of Poly(ADP-ribose) Polymerase (PARP) Inhibitors: A Preliminary Review.

Nanotechnology has revolutionized novel drug delivery strategies through establishing nanoscale drug carriers, such as niosomes, liposomes, nanomicelles, dendrimers, polymeric micelles, and nanoparticles (NPs). Owing to their desirable cancer-targeting efficacy and controlled release, these nanotherapeutic modalities are broadly used in clinics to improve the efficacy of small-molecule inhibitors. Poly(ADP-ribose) polymerase (PARP) family members engage in various intracellular processes, including DNA repair, gene transcription, signal transduction, cell cycle regulation, cell division, and antioxidant response. PARP inhibitors are synthetic small-molecules that have emerged as one of the most successful innovative strategies for targeted therapy in cancer cells harboring mutations in DNA repair genes. Despite these advances, drug resistance and unwanted side effects are two significant drawbacks to using PARP inhibitors in the clinic. Recently, the development of practical nanotechnology-based drug delivery systems has tremendously improved the efficacy of PARP inhibitors. NPs can specifically accumulate in the leaky vasculature of the tumor and cancer cells and release the chemotherapeutic moiety in the tumor microenvironment. On the contrary, NPs are usually unable to permeate across the body's normal organs and tissues; hence the toxicity is zero to none. NPs can modify the release of encapsulated drugs based on the composition of the coating substance. Delivering PARP inhibitors without modulation often leads to the toxic effect; therefore, a delivery vehicle is essential to encapsulate them. Various nanocarriers have been exploited to deliver PARP inhibitors in different cancers. Through this review, we hope to cast light on the most innovative advances in applying PARP inhibitors for therapeutic purposes.

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review.

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.

Fluorescence Study of Riboflavin Interactions with Graphene Dispersed in Bioactive Tannic Acid.

The potential of tannic acid (TA) as a dispersing agent for graphene (G) in aqueous solutions and its interaction with riboflavin have been studied under different experimental conditions. TA induces quenching of riboflavin fluorescence, and the effect is stronger with increasing TA concentration, due to π-π interactions through the aromatic rings, and hydrogen bonding interactions between the hydroxyl moieties of both compounds. The influence of TA concentration, the pH, and the G/TA weight ratio on the quenching magnitude, have been studied. At a pH of 4.1, G dispersed in TA hardly influences the riboflavin fluorescence, while at a pH of 7.1, the nanomaterial interacts with riboflavin, causing an additional quenching to that produced by TA. When TA concentration is kept constant, quenching of G on riboflavin fluorescence depends on both the G/TA weight ratio and the TA concentration. The fluorescence attenuation is stronger for dispersions with the lowest G/TA ratios, since TA is the main contributor to the quenching effect. Data obey the Stern-Volmer relationship up to TA 2.0 g L-1 and G 20 mg L-1. Results demonstrate that TA is an effective dispersant for graphene-based nanomaterials in liquid medium and a green alternative to conventional surfactants and synthetic polymers for the determination of biomolecules.