Screen-Printed Carbon Electrodes with Cationic Cyclodextrin Carbon Nanotubes and Ferrocenyl-Carnosine for Electrochemical Sensing of Hg(II).

The study reports the use of nanoassembly based on cationic cyclodextrin carbon nanotubes (CNT-CDs) and ferrocenylcarnosine (FcCAR) for electrochemical sensing of Hg(II) in aqueous solution. ß-cyclodextrins (CDs) were grafted onto CNTs by a click chemistry reaction between heptakis-(6-azido-6-deoxy)-ß-cyclodextrin and alkyne-terminated CNTs. The cationic amine groups on the CD units were produced by the subsequent reduction of the residual nitrogen groups. The chemical composition and morphology of CNT-CDs were analyzed by X-ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetric analysis. A N,N-dimethylformamide dispersion of CNT-CDs was cast on the surface of screen-printed carbon electrodes (SPCEs), and the electrochemical response was evaluated by cyclic voltammetry (CV) using [Fe(CN)6]3- as the redox probe. The ability of SPCE/CNT-CD to significantly enhance the electroactive properties of the redox probe was combined with a suitable recognition element (FcCAR) for Hg(II). The electrochemical response of the CNT-CD/FcCAR nanoassembly was evaluated by CV and electrochemical impedance spectroscopy. The analytical performance of the Hg(II) sensor was evaluated by differential pulsed voltammetry and chronoamperometry. The oxidative peak current showed a linear concentration dependence in the range of 1-100 nM, with a sensitivity of 0.12 µA/nM, a limit of detection of 0.50 nM, and a limit of quantification of 1 nM.

Prevalence of Neuroradiological Abnormalities in First-Episode Psychosis: A Systematic Review and Meta-analysis.

Importance: Individuals presenting with first-episode psychosis (FEP) may have a secondary ("organic") etiology to their symptoms that can be identified using neuroimaging. Because failure to detect such cases at an early stage can have serious clinical consequences, it has been suggested that brain magnetic resonance imaging (MRI) should be mandatory for all patients presenting with FEP. However, this remains a controversial issue, partly because the prevalence of clinically relevant MRI abnormalities in this group is unclear. Objective: To derive a meta-analytic estimate of the prevalence of clinically relevant neuroradiological abnormalities in FEP. Data Sources: Electronic databases Ovid, MEDLINE, PubMed, Embase, PsychINFO, and Global Health were searched up to July 2021. References and citations of included articles and review articles were also searched. Study Selection: Magnetic resonance imaging studies of patients with FEP were included if they reported the frequency of intracranial radiological abnormalities. Data Extraction and Synthesis: Independent extraction was undertaken by 3 researchers and a random-effects meta-analysis of pooled proportions was calculated. Moderators were tested using subgroup and meta-regression analyses. Heterogeneity was evaluated using the I2 index. The robustness of results was evaluated using sensitivity analyses. Publication bias was assessed using funnel plots and Egger tests. Main Outcomes and Measures: Proportion of patients with a clinically relevant radiological abnormality (defined as a change in clinical management or diagnosis); number of patients needed to scan to detect 1 such abnormality (number needed to assess [NNA]). Results: Twelve independent studies (13 samples) comprising 1613 patients with FEP were included. Of these patients, 26.4% (95% CI, 16.3%-37.9%; NNA of 4) had an intracranial radiological abnormality, and 5.9% (95% CI, 3.2%-9.0%) had a clinically relevant abnormality, yielding an NNA of 18. There were high degrees of heterogeneity among the studies for these outcomes, 95% to 73%, respectively. The most common type of clinically relevant finding was white matter abnormalities, with a prevalence of 0.9% (95% CI, 0%-2.8%), followed by cysts, with a prevalence of 0.5% (95% CI, 0%-1.4%). Conclusions and Relevance: This systematic review and meta-analysis found that 5.9% of patients presenting with a first episode of psychosis had a clinically relevant finding on MRI. Because the consequences of not detecting these abnormalities can be serious, these findings support the use of MRI as part of the initial clinical assessment of all patients with FEP.

Superfluorinated Extracellular Vesicles for In Vivo Imaging by 19F-MRI.

Extracellular vesicles (EVs) play a crucial role in cell-to-cell communication and have great potential as efficient delivery vectors. However, a better understanding of EV in vivo behavior is hampered by the limitations of current imaging tools. In addition, chemical labels present the risk of altering the EV membrane features and, thus, in vivo behavior. 19F-MRI is a safe bioimaging technique providing selective images of exogenous probes. Here, we present the first example of fluorinated EVs containing PERFECTA, a branched molecule with 36 magnetically equivalent 19F atoms. A PERFECTA emulsion is given to the cells, and PERFECTA-containing EVs are naturally produced. PERFECTA-EVs maintain the physicochemical features, morphology, and biological fingerprint as native EVs but exhibit an intense 19F-NMR signal and excellent 19F relaxation times. In vivo 19F-MRI and tumor-targeting capabilities of stem cell-derived PERFECTA-EVs are also proved. We propose PERFECTA-EVs as promising biohybrids for imaging biodistribution and delivery of EVs throughout the body.

Optimization of superfluorinated PLGA nanoparticles for enhanced cell labelling and detection by 19F-MRI.

Fluorine-19 (19F) Magnetic Resonance Imaging (MRI) is an emergent imaging technique for molecular imaging and cell tracking. Lack of intrinsic 19F signals in tissues allows unambiguous in vivo detection of exogenous fluorinated probes, complementary to the anatomical and multiparametric information obtained by standard 1H-MRI. However, the intrinsic low sensitivity of MRI technique requires the need of designing increasingly effective fluorinated tracers. PERFECTA, with its 36 magnetically equivalent 19F atoms and a designed branched molecular structure, represents an excellent superfluorinated tracer. In this paper, we report the development of PERFECTA loaded PLGA NPs stabilized by different coatings as promising 19F-MRI probes. The results clearly show the optimal cellular uptake of the produced colloidally stable PERFECTA loaded PLGA NPs without impact on cells viability. Importantly, NPs stabilization with the anionic surfactant sodium cholate (NaC) clearly enhances NPs internalization within cells with respect to PVA-coated NPs. Moreover, the optimized NPs are characterized by shorter T1 relaxation times with respect to other PERFECTA formulations that would allow the increase of 19F-MRI sensitivity with fast imaging acquisitions.

Correction: Condorelli et al. Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity. Materials 2022, 15, 3701.

The authors wish to make the following correction to the published paper [...].

Nanoscale Technologies in the Fight against COVID-19: From Innovative Nanomaterials to Computer-Aided Discovery of Potential Antiviral Plant-Derived Drugs.

The last few years have increasingly emphasized the need to develop new active antiviral products obtained from artificial synthesis processes using nanomaterials, but also derived from natural matrices. At the same time, advanced computational approaches have found themselves fundamental in the repurposing of active therapeutics or for reducing the very long developing phases of new drugs discovery, which represents a real limitation, especially in the case of pandemics. The first part of the review is focused on the most innovative nanomaterials promising both in the field of therapeutic agents, as well as measures to control virus spread (i.e., innovative antiviral textiles). The second part of the review aims to show how computer-aided technologies can allow us to identify, in a rapid and therefore constantly updated way, plant-derived molecules (i.e., those included in terpenoids) potentially able to efficiently interact with SARS-CoV-2 cell penetration pathways.

Linezolid nanoAntiobiotics and SERS-nanoTags based on polymeric cyclodextrin bimetallic core-shell nanoarchitectures.

We describe a mild, ecofriendly, and straightforward two-step strategy for making core-shell Au@Ag bimetallic nanoparticles (BMNPs) for antibacterial nanomedicine and SERS imaging. The synthesis exploits the unique properties of the cationic polymeric cyclodextrin (PolyCD) as both reducing and stabilizing agent to obtain, monodispersed and stable Au@Ag BMNPs. PolyCD-driven protocol includes the synthesis of PolyCD-coated Au monometallic nanoparticles (MNPs) as a seed material for the subsequent growing of a silver shell. PolyCD was produced by polymerization of the azido modified ßCD monomers with epichlorohydrin and subsequent reduction of azido derivative. The amino groups, as hydrochloride salts (one for CD ring), are pivotal for the formation of BMNPs in mild conditions. Nanoantibiotics and SERS-nanoTag were prepared by complexation of Au@Ag BMNPs with Linezolid (Lz) and 4-mercaptophenyl boronic acid, respectively. Au@Ag@Lz complexes showed a good antibacterial activity against all tested microorganisms including the methicillin resistant Staphylococcus aureus (MRSA).

Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity.

Gold nanoparticles (Au NPs) have received great attention owing to their biocompatible nature, environmental, and widespread biomedical applications. Au NPs are known as capable to regulate inflammatory responses in several tissues and organs; interestingly, lower toxicity in conjunction with anti-inflammatory effects was reported to occur with Au NPs treatment. Several variables drive this benefit-risk balance, including Au NPs physicochemical properties such as their morphology, surface chemistry, and charge. In our research we prepared hybrid Au@LCC nanocolloids by the Pulsed Laser Ablation, which emerged as a suitable chemically clean technique to produce ligand-free or functionalized nanomaterials, with tight control on their properties (product purity, crystal structure selectivity, particle size distribution). Here, for the first time to our knowledge, we have investigated the bioproperties of Au@LCCs. When tested in vitro on intestinal epithelial cells exposed to TNF-α, Au@LCCs sample at the ratio of 2.6:1 showed a significantly reduced TNF gene expression and induced antioxidant heme oxygenase-1 gene expression better than the 1:1 dispersion. Although deeper investigations are needed, these findings indicate that the functionalization with LCCs allows a better interaction of Au NPs with targets involved in the cell redox status and inflammatory signaling.

State of the Art on Green Route Synthesis of Gold/Silver Bimetallic Nanoparticles.

Recently, bimetallic nanoparticles (BMNPs) blending the properties of two metals in one nanostructured system have generated enormous interest due to their potential applications in various fields including biosensing, imaging, nanomedicine, and catalysis. BMNPs have been developed later with respect to the monometallic nanoparticles (MNPs) and their physicochemical and biological properties have not yet been comprehensively explored. The manuscript aims at collecting the main design criteria used to synthetize BMNPs focusing on green route synthesis. The influence of experimental parameters such as temperature, time, reagent concentrations, capping agents on the particle growth and colloidal stability are examined. Finally, an overview of their nanotechnological applications and biological profile are presented.

Cancer-Related Intracellular Signalling Pathways Activated by DOXorubicin/Cyclodextrin-Graphene-Based Nanomaterials.

In the last decade, nanotechnological progress has generated new opportunities to improve the safety and efficacy of conventional anticancer therapies. Compared with other carriers, graphene nanoplatforms possess numerous tunable functionalities for the loading of multiple bioactive compounds, although their biocompatibility is still a debated concern. Recently, we have investigated the modulation of genes involved in cancer-associated canonical pathways induced by graphene engineered with cyclodextrins (GCD). Here, we investigated the GCD impact on cells safety, the HEp-2 responsiveness to Doxorubicin (DOX) and the cancer-related intracellular signalling pathways modulated by over time exposure to DOX loaded on GCD (GCD@DOX). Our studies evidenced that both DOX and GCD@DOX induced p53 and p21 signalling resulting in G0/G1 cell cycle arrest. A genotoxic behaviour of DOX was reported via detection of CDK (T14/Y15) activation and reduction of Wee-1 expression. Similarly, we found a cleavage of PARP by DOX within 72 h of exposure. Conversely, GCD@DOX induced a late cleavage of PARP, which could be indicative of less toxic effect due to controlled release of the drug from the GCD nanocarrier. Finally, the induction of the autophagy process supports the potential recycling of DOX with the consequent limitation of its toxic effects. Together, these findings demonstrate that GCD@DOX is a biocompatible drug delivery system able to evade chemoresistance and doxorubicin toxicity.

Weibull Modeling of Controlled Drug Release from Ag-PMA Nanosystems.

Traditional pharmacotherapy suffers from multiple drawbacks that hamper patient treatment such as antibiotic resistances or low drug selectivity and toxicity during systemic applications. Some functional hybrid nanomaterials are designed to handle the drug release process under remote-control. More attention has recently been paid to synthetic polyelectrolytes for their intrinsic properties which allow them to rearrange into compact structures, ideal to be used as drug carriers or probes influencing biochemical processes. The presence of Ag nanoparticles (NPs) in the Poly methyl acrylate (PMA) matrix leads to an enhancement of drug release efficiency, even using a low-power laser whose wavelength is far from the Ag Surface Plasmon Resonance (SPR) peak. Further, compared to the colloids, the nanofiber-based drug delivery system has shown shorter response time and more precise control over the release rate. The efficiency and timing of involved drug release mechanisms has been estimated by the Weibull distribution function, whose parameters indicate that the release mechanism of nanofibers obeys Fick's first law while a non-Fickian character controlled by diffusion and relaxation of polymer chains occurs in the colloidal phase.

Shedding Light on the Chemistry and the Properties of Münchnone Functionalized Graphene.

Münchnones are mesoionic oxazolium 5-oxides with azomethine ylide characteristics that provide pyrrole derivatives by a 1,3-dipolar cycloaddition (1,3-DC) reaction with acetylenic dipolarophiles. Their reactivity was widely exploited for the synthesis of small molecules, but it was not yet investigated for the functionalization of graphene-based materials. Herein, we report our results on the preparation of münchnone functionalized graphene via cycloaddition reactions, followed by the spontaneous loss of carbon dioxide and its further chemical modification to silver/nisin nanocomposites to confer biological properties. A direct functionalization of graphite flakes into few-layers graphene decorated with pyrrole rings on the layer edge was achieved. The success of functionalization was confirmed by micro-Raman and X-ray photoelectron spectroscopies, scanning transmission electron microscopy, and thermogravimetric analysis. The 1,3-DC reactions of münchnone dipole with graphene have been investigated using density functional theory to model graphene. Finally, we explored the reactivity and the processability of münchnone functionalized graphene to produce enriched nano biomaterials endowed with antimicrobial properties.

Metal-Oxide Based Nanomaterials: Synthesis, Characterization and Their Applications in Electrical and Electrochemical Sensors.

Pure, mixed and doped metal oxides (MOX) have attracted great interest for the development of electrical and electrochemical sensors since they are cheaper, faster, easier to operate and capable of online analysis and real-time identification. This review focuses on highly sensitive chemoresistive type sensors based on doped-SnO2, RhO, ZnO-Ca, Smx-CoFe2-xO4 semiconductors used to detect toxic gases (H2, CO, NO2) and volatile organic compounds (VOCs) (e.g., acetone, ethanol) in monitoring of gaseous markers in the breath of patients with specific pathologies and for environmental pollution control. Interesting results about the monitoring of biochemical substances as dopamine, epinephrine, serotonin and glucose have been also reported using electrochemical sensors based on hybrid MOX nanocomposite modified glassy carbon and screen-printed carbon electrodes. The fundamental sensing mechanisms and commercial limitations of the MOX-based electrical and electrochemical sensors are discussed providing research directions to bridge the existing gap between new sensing concepts and real-world analytical applications.

Antimicrobial Effect and Cytotoxic Evaluation of Mg-Doped Hydroxyapatite Functionalized with Au-Nano Rods.

Hydroxyapatite (HA) is the main inorganic mineral that constitutes bone matrix and represents the most used biomaterial for bone regeneration. Over the years, it has been demonstrated that HA exhibits good biocompatibility, osteoconductivity, and osteoinductivity both in vitro and in vivo, and can be prepared by synthetic and natural sources via easy fabrication strategies. However, its low antibacterial property and its fragile nature restricts its usage for bone graft applications. In this study we functionalized a MgHA scaffold with gold nanorods (AuNRs) and evaluated its antibacterial effect against S. aureus and E. coli in both suspension and adhesion and its cytotoxicity over time (1 to 24 days). Results show that the AuNRs nano-functionalization improves the antibacterial activity with 100% bacterial reduction after 24 h. The toxicity study, however, indicates a 4.38-fold cell number decrease at 24 days. Although further optimization on nano-functionalization process are needed for cytotoxicity, these data indicated that Au-NRs nano-functionalization is a very promising method for improving the antibacterial properties of HA.

Acrylate and Methacrylate Polymers' Applications: Second Life with Inexpensive and Sustainable Recycling Approaches.

Polymers are widely employed in several fields thanks to their wide versatility and the easy derivatization routes. However, a wide range of commercial polymers suffer from limited use on a large scale due to their inert nature. Nowadays, acrylate and methacrylate polymers, which are respectively derivatives of acrylic or methacrylic acid, are among the most proposed materials for their useful characteristics like good biocompatibility, capping ability toward metal clusters, low price, potentially recyclability and reusability. Here, we discuss the advantages and challenges of this class of smart polymers focusing our attention on their current technological applications in medical, electronic, food packaging and environmental remediation fields. Furthermore, we deal with the main issue of their recyclability, considering that the current commercial bioplastics are not yet able to meet the global needs as much as to totally replace fossil-fuel-based products. Finally, the most accredited strategies to reach recyclable composites based on acrylic polymers are described.

Recent Advances of Graphene-Based Strategies for Arsenic Remediation.

The decontamination of water containing toxic metals is a challenging problem, and in the last years many efforts have been undertaken to discover efficient, cost-effective, robust, and handy technology for the decontamination of downstream water without endangering human health. According to the World Health Organization (WHO), 180 million people in the world have been exposed to toxic levels of arsenic from potable water. To date, a variety of techniques has been developed to maintain the arsenic concentration in potable water below the limit recommended by WHO (10 µg/L). Recently, a series of technological advancements in water remediation has been obtained from the rapid development of nanotechnology-based strategies that provide a remarkable control over nanoparticle design, allowing the tailoring of their properties toward specific applications. Among the plethora of nanomaterials and nanostructures proposed in the remediation field, graphene-based materials (G), due to their unique physico-chemical properties, surface area, size, shape, ionic mobility, and mechanical flexibility, are proposed for the development of reliable tools for water decontamination treatments. Moreover, an emerging class of 3D carbon materials characterized by the intrinsic properties of G together with new interesting physicochemical properties, such as high porosity, low density, unique electrochemical performance, has been recently proposed for water decontamination. The main design criteria used to develop remediation nanotechnology-based strategies have been reviewed, and special attention has been reserved for the advances of magnetic G and for nanostructures employed in the fabrication of membrane filtration.

Intracellular Fate and Impact on Gene Expression of Doxorubicin/Cyclodextrin-Graphene Nanomaterials at Sub-Toxic Concentration.

The graphene road in nanomedicine still seems very long and winding because the current knowledge about graphene/cell interactions and the safety issues are not yet sufficiently clarified. Specifically, the impact of graphene exposure on gene expression is a largely unexplored concern. Herein, we investigated the intracellular fate of graphene (G) decorated with cyclodextrins (CD) and loaded with doxorubicin (DOX) and the modulation of genes involved in cancer-associated canonical pathways. Intracellular fate of GCD@DOX, tracked by FLIM, Raman mapping and fluorescence microscopy, evidenced the efficient cellular uptake of GCD@DOX and the presence of DOX in the nucleus, without graphene carrier. The NanoString nCounter™ platform provided evidence for 34 (out of 700) differentially expressed cancer-related genes in HEp-2 cells treated with GCD@DOX (25 µg/mL) compared with untreated cells. Cells treated with GCD alone (25 µg/mL) showed modification for 16 genes. Overall, 14 common genes were differentially expressed in both GCD and GCD@DOX treated cells and 4 of these genes with an opposite trend. The modification of cancer related genes also at sub-cytotoxic G concentration should be taken in consideration for the rational design of safe and effective G-based drug/gene delivery systems. The reliable advantages provided by NanoString® technology, such as sensibility and the direct RNA measurements, could be the cornerstone in this field.

Fluorinated PLGA Nanoparticles for Enhanced Drug Encapsulation and 19 F†NMR Detection.

In the continuous search for multimodal systems with combined diagnostic and therapeutic functions, several efforts have been made to develop multifunctional drug delivery systems. In this work, through a covalent approach, a new class of fluorinated poly(lactic-co-glycolic acid) co-polymers (F-PLGA) were designed that contain an increasing number of magnetically equivalent fluorine atoms. In particular, two novel compounds, F3 -PLGA and F9 -PLGA, were synthesized and their chemical structure and thermal stability were analyzed by solution NMR, DSC, and TGA. The obtained F-PLGA compounds were proven to form in aqueous solution colloidal stable nanoparticles (NPs) displaying a strong 19 F NMR signal. The fluorinated NPs also showed an enhanced ability to load hydrophobic drugs containing fluorine atoms compared to analogous pristine PLGA NPs. Preliminary in vitro studies showed high cell viability and the NP ability to intracellularly deliver and release a functioning drug.

Plasmon-Enhanced Controlled Drug Release from Ag-PMA Capsules.

Silver (Ag)-grafted PMA (poly-methacrylic acid, sodium salt) nanocomposite loaded with sorafenib tosylate (SFT), an anticancer drug, showed good capability as a drug carrier allowing on-demand control of the dose, timing and duration of the drug release by laser irradiation stimuli. In this study, the preparation of Ag-PMA capsules loaded with SFT by using sacrificial silica microparticles as templates was reported. A high drug loading (DL%) of ∼13% and encapsulation efficiency (EE%) of about 76% were obtained. The photo-release profiles were regulated via the adjustment of light wavelength and power intensity. A significant improvement of SFT release (14% vs. 21%) by comparing SFT-Ag-PMA capsules with Ag-PMA colloids under the same experimental conditions was observed. Moreover, an increase of drug release by up to 35% was reached by tuning the laser irradiation wavelength near to Ag nanoparticles' surface plasmon resonance (SPR). These experimental results together with more economical use of the active component suggest the potentiality of SFT-Ag-PMA capsules as a smart drug delivery system.

Graphene-Based Strategies in Liquid Biopsy and in Viral Diseases Diagnosis.

Graphene-based materials are intriguing nanomaterials with applications ranging from nanotechnology-related devices to drug delivery systems and biosensing. Multifunctional graphene platforms were proposed for the detection of several typical biomarkers (i.e., circulating tumor cells, exosomes, circulating nucleic acids, etc.) in liquid biopsy, and numerous methods, including optical, electrochemical, surface-enhanced Raman scattering (SERS), etc., have been developed for their detection. Due to the massive advancements in biology, material chemistry, and analytical technology, it is necessary to review the progress in this field from both medical and chemical sides. Liquid biopsy is considered a revolutionary technique that is opening unexpected perspectives in the early diagnosis and, in therapy monitoring, severe diseases, including cancer, metabolic syndrome, autoimmune, and neurodegenerative disorders. Although nanotechnology based on graphene has been poorly applied for the rapid diagnosis of viral diseases, the extraordinary properties of graphene (i.e., high electronic conductivity, large specific area, and surface functionalization) can be also exploited for the diagnosis of emerging viral diseases, such as the coronavirus disease 2019 (COVID-19). This review aimed to provide a comprehensive and in-depth summarization of the contribution of graphene-based nanomaterials in liquid biopsy, discussing the remaining challenges and the future trend; moreover, the paper gave the first look at the potentiality of graphene in COVID-19 diagnosis.