Advancing amyotrophic lateral sclerosis disease diagnosis: A lab-on-chip electrochemical immunosensor for ultra-sensitive TDP-43 protein detection and monitoring in serum patients'.

The global increase in population aging has led to a rise in neurodegenerative diseases (NDs), posing significant challenges to public health. Developing selective and specific biomarkers for early diagnosis and drug development is crucial addressing the growing burden of NDs. In this context, the RNA-binding protein TDP-43 has emerged as a promising biomarker for amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), and TDP-43-associated proteinopathies. However, existing detection methods suffer from limitations such as cost, complexity, and operator dependence. Here, we present a novel electrochemical biosensor integrated into a lab-on-chip (LoC) platform to detect TDP-43. The sensor utilizes electrosynthesized polypyrrole derivatives with carboxylic groups for transducer functionalization, enabling targeted immobilization of TDP-43 antibodies. Differential pulsed voltammetry (DPV) is used for the indirect detection and quantification of TDP-43. The chip exhibits rapid response, good reproducibility, a linear detection range, and sensitivity from 0.01 ng/mL to 25 ng/mL of TDP-43 protein concentration with a LOD = 10 pg/mL. Furthermore, successful TDP-43 detection in complex matrices like serum of ALS patients and healthy individuals demonstrates its potential as a point-of-care diagnostic device. This electrochemical biosensor integrated into a chip offers good sensitivity, rapid response, and robust performance, providing a promising avenue for advancing neurodegenerative disease diagnostics and therapeutic development.

Development of an MIP based electrochemical sensor for TGF-ß1 detection and its application in liquid biopsy.

Oral cancer is one of the most common types of cancer in Europe and its large diffusion requires, together with prevention, the development of low-cost and reliable portable platforms for its diagnosis, with features of high selectivity and sensitivity. In this study, the development and characterization of a molecularly imprinted polymer (MIP)-based electrochemical sensor for TGF-ß1 detection are reported. The optimized biosensor is a potential tool for the early screening of oral cancer. A biomimetic surface has been obtained by electropolymerization of o-phenylenediamine (o-PD) on platinum electrodes, in the presence of TGF-ß1 as a template molecule. MIP synthesis, template removal and TGF-ß1 rebinding have been monitored by Differential Pulse Voltammetry (DPV). Atomic Force Microscopy (AFM) has been performed to investigate and characterize the surface morphology and the influence of the washing step on MIP and NIP (non-imprinted polymer as the control) while the thickness of the polymer layer has been measured by Scanning Transmission Electron Microscopy (STEM) analysis. The MIP sensor performance has been tested in both buffer solution and saliva samples with TGF-ß1, showing a linear response in the considered range (from 20 ng ml-1 down to 0.5 ng ml-1), an outstanding LOD of 0.09 ng mL-1 and affinity and selectivity to TGF-ß1 also in the presence of interfering molecules. The sensor was used also for the detection of target molecules in spiked saliva samples with good recovery results suggesting the possibility of the use of the proposed system for large scale fast screening in oral cancer diagnosis.

Synthesis and Characterization of SPIONs Encapsulating Polydopamine Nanoparticles and Their Test for Aqueous Cu2+ Ion Removal.

The removal of pollutants, such as heavy metals, aromatic compounds, dyes, pesticides and pharmaceuticals, from water is still an open challenge. Many methods have been developed and exploited for the purification of water from contaminants, including photocatalytic degradation, biological treatment, adsorption and chemical precipitation. Absorption-based techniques are still considered among the most efficient and commonly used approaches thanks to their operational simplicity. In recent years, polydopamine-coated magnetic nanoparticles have emerged for the uptake of heavy metals in water treatment, since they combine specific affinity towards pollutants and magnetic separation capacity. In this context, this work focuses on the synthesis of polydopamine (PDA)-coated Super Paramagnetic Iron Oxide Nanoparticles (PDA@SPIONs) as adsorbents for Cu2+ ions, designed to serve as functional nanostructures for the removal of Cu2+ from water by applying a magnetic field. The synthetic parameters, including the amount of SPIONs and PDA, were thoroughly investigated to define their effects on the nanostructure features and properties. Subsequently, the ability of the magnetic nanostructures to bind metal ions was assessed on Cu2+-containing solutions. A systematic investigation of the prepared functional nanostructures was carried out by means of complementary spectroscopic, morphological and magnetic techniques. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements were performed in order to estimate the Cu2+ binding ability. The overall results indicate that these nanostructures hold great promise for future bioremediation applications.

Does Size Matter? The Case of Piezoresistive Properties of Carbon Nanotubes/Elastomer Nanocomposite Synthesized through Mechanochemistry.

The growing interest in piezoresistive sensors has favored the development of numerous approaches and materials for their fabrication. Within this framework, carbon nanotubes (CNTs) are often employed. However, CNTs are a heterogeneous material with different morphological characteristics in terms of length and diameter, and, so far, experimental studies have not usually considered the effect of these parameters on the final sensor performances. Here, we observe how, by simply changing the CNTs length in a solvent-free mechanochemistry fabrication method, different porous 3D elastomeric nanocomposites with different electrical and mechanical properties can be obtained. In particular, the use of longer carbon nanotubes allows the synthesis of porous nanocomposites with better mechanical stability and conductivity, and with a nine-times-lower limit of detection (namely 0.2 Pa) when used as a piezoresistive sensor. Moreover, the material prepared with longer carbon nanotubes evidenced a faster recovery of its shape and electrical properties during press/release cycles, thus allowing faster response at different pressures. These results provide evidence as to how CNTs length can be a key aspect in obtaining piezoresistive sensors with better properties.

Polydopamine-Coated Magnetic Iron Oxide Nanoparticles: From Design to Applications.

Magnetic iron oxide nanoparticles have been extensively investigated due to their applications in various fields such as biomedicine, sensing, and environmental remediation. However, they need to be coated with a suitable material in order to make them biocompatible and to add new functionalities on their surface. This review is intended to give a comprehensive overview of recent advantages and applications of iron oxide nanoparticles coated by polydopamine film. The synthesis method of magnetic nanoparticles, their functionalization with bioinspired materials and (in particular) with polydopamine are discussed. Finally, some interesting applications of polydopamine-coated magnetic iron oxide nanoparticles will be pointed out.

Nanoarchitectonics of highly sensitive and with large working range 3D piezoresistive microporous foam based on carbon nanotubes and elastomer.

HYPOTHESIS: Nanocarbon/polymeric 3D porous composites have been widely developed as piezoresistive sensors due to their improved performances. Functionalized nanocarbon is usually used to allow its adsorption on the surface of porous polymeric material. However, both the functionalization and the surface localized distribution of the nanomaterial can limit the nanocarbon effect on conductivity and mechanical stability of the material thus affecting piezoresistive performances. EXPERIMENTS: A novel nanoarchitectonics strategy to prepare an elastomeric/carbon nanotubes (CNTs) 3D porous piezoresistive nanocomposite is developed. The fabrication route does not require complex apparatus and CNTs chemical functionalization. Moreover, foams of any shape and dimensions can be produced with neither complex machinery and procedures nor wastes production. FINDINGS: The obtained material is characterized by the presence of well dispersed pristine CNTs on both surface and bulk of the polymeric matrix. The foam exhibited improved piezoresistive properties with excellent compressive stress (>150 kPa), sensitivity at low displacement (29 kPa-1) and limit of detection for both pressure (2 Pa) and extension (130 nm). These excellent features could allow the use of the as prepared nanocomposite in different applications ranging from wearable devices to robotic or infrastructure monitoring with outstanding flexibility.

An innovative and simple all electrochemical approach to functionalize electrodes with a carbon nanotubes/polypyrrole molecularly imprinted nanocomposite and its application for sulfamethoxazole analysis.

Sulfamethoxazole (SMX) is a commonly used antibiotic which accumulation can favor the development of antimicrobial resistance. Therefore, easy and cheap system to monitor the presence of SMX are needed for human health protection. Herein we present a straightforward all electrochemical approach to fabricate a sensor based on a nanocomposite molecularly imprinted polymer (nanoMIP) for the determination of SMX. Firstly, oxidized multiwalled carbon nanotubes (oxMWCNTs) were electrochemically deposited on a polarized electrode to increase electrodic surface area up to 350%. Then, ultrathin overoxidized polypyrrole MIP in presence of SMX was electropolymerized on oxMWCNTs surface (nanoMIP). Finally, antibiotic was electrochemically removed. The obtained nanoMIP was characterized by atomic force microscopy, X-ray photoelectron spectroscopy and electrochemical techniques. The nanoMIP was used for the electrochemical detection of SMX evidencing a lower limit of detection (413 nM) and a wider linear range (1.99-10.88 µM) with respect a non-nanostructured film. The nanoMIP evidenced also good affinity and a highly reproducible response (RSD = 1.2%). The sensor was able to determine SMX in milk samples evidencing good recovery values. The proposed approach can be also used in future to easily prepare different nanoMIP based sensors with improved performances for different target molecules thus overcoming current fabrication limits.

Efficacy and Safety of Non-Anesthesiologist Administration of Propofol Sedation in Endoscopic Ultrasound: A Propensity Score Analysis.

In spite of promising preliminary results, evidence supporting the use of non-anesthesiologist-administered propofol sedation (NAAP) in endoscopic ultrasound (EUS) procedures is still limited. The aim of this manuscript was to examine the safety and efficacy of NAAP as compared to anesthesiologist-administered propofol sedation in EUS procedures performed in a referral center. Out of 832 patients referred to our center between 2016 and 2019, after propensity score matching two groups were compared: 305 treated with NAAP and 305 controls who underwent anesthesiologist-administered propofol sedation. The primary outcome was the rate of major complications. The median age was 67 years and the proportion of patients with comorbidities was 31.8% in both groups. One patient in each group (0.3%) experienced a major complication, whereas minor complications were observed in 13 patients in the NAAP group (4.2%) and 10 patients in the control group (3.2%; p = 0.52). Overall pain during the procedure was 2.3 ± 1 in group 1 and 1.8 ± 1 in group 2 (p = 0.67), whereas pain/discomfort upon awakening was rated as 1 ± 0.5 in both groups (p = 0.72). NAAP is safe and effective even in advanced EUS procedures. Further randomized-controlled trials (RCTs) are warranted to confirm these findings.

Intracellular Antioxidant Activity of Biocompatible Citrate-Capped Palladium Nanozymes.

A method for the aqueous synthesis of stable and biocompatible citrate-coated palladium nanoparticles (PdNPs) in the size range comparable to natural enzymes (4-8 nm) has been developed. The toxicological profile of PdNPs was assessed by different assays on several cell lines demonstrating their safety in vitro also at high particle concentrations. To elucidate their cellular fate upon uptake, the localization of PdNPs was analyzed by Transmission Electron Microscopy (TEM). Moreover, crucial information about their intracellular stability and oxidation state was obtained by Sputtering-Enabled Intracellular X-ray Photoelectron Spectroscopy (SEI-XPS). TEM/XPS results showed significant stability of PdNPs in the cellular environment, an important feature for their biocompatibility and potential for biomedical applications. On the catalytic side, these PdNPs exhibited strong and broad antioxidant activities, being able to mimic the three main antioxidant cellular enzymes, i.e., peroxidase, catalase, and superoxide dismutase. Remarkably, using an experimental model of a human oxidative stress-related disease, we demonstrated the effectiveness of PdNPs as antioxidant nanozymes within the cellular environment, showing that they are able to completely re-establish the physiological Reactive Oxygen Species (ROS) levels in highly compromised intracellular redox conditions.

Antibiotics Do Not Decrease the Rate of Infection After Endoscopic Ultrasound Fine-Needle Aspiration of Pancreatic Cysts.

BACKGROUND: In spite of the weak evidence, antibiotic prophylaxis prior to endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions is routinely used in the clinical practice. AIMS: To compare a group of patients treated with antibiotics before fine-needle aspiration of pancreatic cystic lesions and a group who did not undergo antimicrobial prophylaxis. METHODS: Out of 335 patients with suspected pancreatic cystic lesions referred to our center between 2006 and 2018, after propensity score matching two groups were compared: 135 subjects who underwent endoscopic ultrasound fine-needle aspiration under antibiotic prophylaxis and 135 treated with no antimicrobial agents. Primary outcome was infection rate; secondary endpoints included other complications or antibiotic-related adverse events. RESULTS: Median age was 64 (interquartile range 61-68) and median cyst size was 24 mm (22-28), with no difference between groups. Overall, 10 adverse events (7.1%) of which 2 serious (1.4%) were observed in the antibiotic group and 8 (5.8%) of which 1 (0.7%) serious in the non-antibiotic group. Cyst infection was observed in 2 patients (1.4%) in the antibiotic group and 3 patients (2.2%) in the other cohort (p = 0.65). CONCLUSIONS: Prophylactic antibiotics do not seem to substantially reduce this risk of infection, and their routine use should be abandoned.

Easy fabrication of mussel inspired coated foam and its optimization for the facile removal of copper from aqueous solutions.

Herein we present a straightforward approach for the use of polydopamine (PDA) in adsorption of heavy metals from aqueous solutions. This is achieved by fabricating a healthy and environmentally friendly polydimethylsiloxane (PDMS) foam with a mussel inspired PDA layer deposited on the surface. Critical adsorption parameters (pH, temperature and PDA thickness) are optimized by the application of experimental design methodology. Adsorption kinetics and isotherms are studied in detail evidencing a good fitting with Langmuir isotherm and pseudo-second-order kinetics thus suggesting the occurrence of a chemical sorption process with monolayer nature between metals and PDMS/PDA foam. Intraparticle diffusion model evidences good accessibility and high affinity of binding sites on PDA surface. Once adsorbed, metals are reduced to a lower toxic form and can be then removed by a mild acidic treatment thus being easily collected and stocked.

Sputtering-Enabled Intracellular X-ray Photoelectron Spectroscopy: A Versatile Method To Analyze the Biological Fate of Metal Nanoparticles.

The investigation of the toxicological profile and biomedical potential of nanoparticles (NPs) requires a deep understanding of their intracellular fate. Various techniques are usually employed to characterize NPs upon cellular internalization, including high-resolution optical and electron microscopies. Here, we show a versatile method, named sputtering-enabled intracellular X-ray photoelectron spectroscopy, proving that it is able to provide valuable information about the behavior of metallic NPs in culture media as well as within cells, directly measuring their internalization, stability/degradation, and oxidation state, without any preparative steps. The technique can also provide nanoscale vertical resolution along with semiquantitative information about the cellular internalization of the metallic species. The proposed approach is easy-to-use and can become a standard technique in nanotoxicology/nanomedicine and in the rational design of metallic NPs. Two model cases were investigated: silver nanoparticles (AgNPs) and platinum nanoparticles (PtNPs) with the same size and coating. We observed that, after 48 h incubation, intracellular AgNPs were almost completely dissolved, forming nanoclusters as well as AgO, AgS, and AgCl complexes. On the other hand, PtNPs were resistant to the harsh endolysosomal environment, and only some surface oxidation was detected after 48 h.

An Innovative Porous Nanocomposite Material for the Removal of Phenolic Compounds from Aqueous Solutions.

Energy efficient, low-cost, user-friendly, and green methods for the removal of toxic phenolic compounds from aqueous solution are necessary for waste treatment in industrial applications. Herein we present an interesting approach for the utilization of oxidized carbon nanotubes (CNTs) in the removal of phenolic compounds from aqueous solution. Dried pristine CNTs were stably incorporated in a solid porous support of polydimethylsiloxane (PDMS) facilitating the handling during both oxidation process of the nanomaterial and uptake of phenolic compounds, and enabling their safe disposal, avoiding expensive post-treatment processes. The adsorption studies indicated that the materials can efficiently remove phenolic compounds from water with different affinities towards different phenolic compounds. Furthermore, the adsorption kinetics and isotherms were studied in detail. The experimental data of adsorption fitted well with Langmuir and Freundlich isotherms, and pseudo-second-order kinetics, and the results indicated that the adsorption process was controlled by a two-step intraparticle diffusion model. The incorporation of CNTs in polymeric matrices did not affect their functionality in phenol uptake. The material was also successfully used for the removal of phenolic compounds from agricultural waste, suggesting its possible application in the treatment of wastewater. Moreover, the surface of the material could be regenerated, decreasing treatment costs.

Long-term liver stiffness assessment in hepatitis C virus patients undergoing antiviral therapy: Results from a 5-year cohort study.

BACKGROUND AND AIM: Observational studies showed significant liver stiffness regression after sustained virological response, but long-term effects of antiviral therapy are still unknown. The aim of this study was to assess the magnitude of change in stiffness up to 5 years after therapy in hepatitis C patients undergoing antiviral treatment. METHODS: Data of 153 patients were retrieved. Stiffness was assessed by Fibroscan at baseline, end of treatment, 6 months after treatment, and every year hereafter up to 5 years. RESULTS: Seventy patients were treated with interferon-based regimens and 83 with direct antiviral agents. Baseline cirrhosis was diagnosed in 53 (34.6%) patients. Sustained virological response was achieved in 112 patients, whereas 41 were non-responders. In responders, stiffness decreased from 12.3 kPa (9-17.8) to 6.6 kPa (5.3-7.4) at 5 years. A sharper decline was observed immediately after treatment (-2.5 kPa at the end of treatment and -3.7 kPa at 6 months), while from 1 year onwards, the magnitude of stiffness decrease was progressively lower. In non-responders, stiffness showed a slight decrease at the end of treatment (from 19.2 to 18.1 kPa), then returned to baseline levels at 6 months (19.4 kPa), and finally increased over time up to 23.7 kPa (15-32.5) at 5 years. The proportion of cirrhotic patients decreased by 50% at 6 months and finally fell < 5% at 4 years after treatment. CONCLUSIONS: Stiffness declines significantly after achieving response, and the magnitude of decline is greater in the first year after treatment, while it tends to plateau from 1 year onwards.

From 2D to 3D: novel nanostructured scaffolds to investigate signalling in reconstructed neuronal networks.

To recreate in vitro 3D neuronal circuits will ultimately increase the relevance of results from cultured to whole-brain networks and will promote enabling technologies for neuro-engineering applications. Here we fabricate novel elastomeric scaffolds able to instruct 3D growth of living primary neurons. Such systems allow investigating the emerging activity, in terms of calcium signals, of small clusters of neurons as a function of the interplay between the 2D or 3D architectures and network dynamics. We report the ability of 3D geometry to improve functional organization and synchronization in small neuronal assemblies. We propose a mathematical modelling of network dynamics that supports such a result. Entrapping carbon nanotubes in the scaffolds remarkably boosted synaptic activity, thus allowing for the first time to exploit nanomaterial/cell interfacing in 3D growth support. Our 3D system represents a simple and reliable construct, able to improve the complexity of current tissue culture models.

Electrochemical sensor for sulfadimethoxine based on molecularly imprinted polypyrrole: study of imprinting parameters.

The present work describes the development of a simple and cost-effective electrochemical sensor for sulfadimethoxine (SDM) based on molecularly imprinted overoxidized polypyrrole (PPy). An all electrochemical approach is used for sensor fabrication and application consisting in molecularly imprinted polymer (MIP) galvanostatic deposition on a gold electrode and its overoxidation under different experimental conditions and in SDM amperometric detection. Several parameters influencing the imprinting effect are critically discussed and evaluated. A key role of the electrolyte used in electropolymerization (tetrabuthylammonium perchlorate and lithium perchlorate) has emerged demonstrating its effect on sensing performances of imprinted PPy and, related to this, on its morphology, as highlighted by atomic force microscopy (AFM). The effect of different overoxidation conditions in removing template is evaluated by analyzing MIP films before and after the treatment by X-ray photoelectron spectroscopy (XPS) also evidencing the correlation between MIP chemical structure and its rebinding ability. MIP-template interaction is verified also by Fourier Transform Infrared (FT-IR) spectroscopy. Under the selected optimal conditions, MIP sensor shows a linear range from 0.15 to 3.7 mM SDM, a limit of detection of 70 µM, a highly reproducible response (RSD 4.2%) and a good selectivity in the presence of structurally related molecules. SDM was determined in milk samples spiked at two concentration levels: 0.2 mM and 0.4 mM obtaining a satisfactory recovery of (97±3)% and (96±8)%, respectively.

Supramolecular assemblies of nucleoside functionalized carbon nanotubes: synthesis, film preparation, and properties.

Nucleoside-functionalized multi-walled carbon nanotubes (N-MWCNTs) were synthesized and characterized. A self-organization process using hydrogen bonding interactions was then used for the fabrication of self-assembled N-MWCNTs films free of stabilizing agents, polymers, or surfactants. Membranes were produced by using a simple water-dispersion-based vacuum-filtration method. Hydrogen-bond recognition was confirmed by analysis with IR spectroscopy and TEM images. Restoration of the electronic conduction properties in the N-MWCNTs membranes was performed by removing the organic portion by thermal treatment under an argon atmosphere to give d-N-MWCNTs. Electrical conductivity and thermal gravimetric analysis (TGA) measurements confirmed the efficiency of the annealing process. Finally, oxidative biodegradation of the films N-MWCNTs and d-N-MWCNTs was performed by using horseradish peroxidase (HRP) and low concentrations of H2 O2 . Our results confirm that functional groups play an important role in the biodegradation of CNT by HRP: N-MWCNTs films were completely biodegraded, whereas for d-N-MWCNTs films no degradation was observed, showing that the pristine CNT undergoes minimal enzyme-catalyzed oxidation This novel methodology offers a straightforward supramolecular strategy for the construction of conductive and biodegradable carbon nanotube films.

Carbon nanotube scaffolds instruct human dendritic cells: modulating immune responses by contacts at the nanoscale.

Nanomaterials interact with cells and modify their function and biology. Manufacturing this ability can provide tissue-engineering scaffolds with nanostructures able to influence tissue growth and performance. Carbon nanotube compatibility with biomolecules motivated ongoing interest in the development of biosensors and devices including such materials. More recently, carbon nanotubes have been applied in several areas of nerve tissue engineering to study cell behavior or to instruct the growth and organization of neural networks. To gather further knowledge on the true potential of future constructs, in particular to assess their immune-modulatory action, we evaluate carbon nanotubes interactions with human dendritic cells (DCs). DCs are professional antigen-presenting cells and their behavior can predict immune responses triggered by adhesion-dependent signaling. Here, we incorporate DC cultures to carbon nanotubes and we show by phenotype, microscopy, and transcriptional analysis that in vitro differentiated and activated DCs show when interfaced to carbon nanotubes a lower immunogenic profile.

Adhesion to carbon nanotube conductive scaffolds forces action-potential appearance in immature rat spinal neurons.

In the last decade, carbon nanotube growth substrates have been used to investigate neurons and neuronal networks formation in vitro when guided by artificial nano-scaled cues. Besides, nanotube-based interfaces are being developed, such as prosthesis for monitoring brain activity. We recently described how carbon nanotube substrates alter the electrophysiological and synaptic responses of hippocampal neurons in culture. This observation highlighted the exceptional ability of this material in interfering with nerve tissue growth. Here we test the hypothesis that carbon nanotube scaffolds promote the development of immature neurons isolated from the neonatal rat spinal cord, and maintained in vitro. To address this issue we performed electrophysiological studies associated to gene expression analysis. Our results indicate that spinal neurons plated on electro-conductive carbon nanotubes show a facilitated development. Spinal neurons anticipate the expression of functional markers of maturation, such as the generation of voltage dependent currents or action potentials. These changes are accompanied by a selective modulation of gene expression, involving neuronal and non-neuronal components. Our microarray experiments suggest that carbon nanotube platforms trigger reparative activities involving microglia, in the absence of reactive gliosis. Hence, future tissue scaffolds blended with conductive nanotubes may be exploited to promote cell differentiation and reparative pathways in neural regeneration strategies.