Biology subjects

Vitale, F.

Publications and source records attributed to Vitale, F..

11 recordsLinked to original sources

bioRxiv2026

Size Scaling of the Electrochemical Performance of Ti3C2Tx MXene Microelectrode Arrays for Electrophysiological Recording and Stimulation

Miniaturized neural interfaces for research, diagnostics, and neuromodulation therapies require electrode materials that maintain low impedance and high charge injection capacity as device dimensions shrink to ensure high-quality recordings and safe stimulation. Conventional interfaces rely on metals like platinum (Pt), which are limited by intrinsically high impedance and low charge transfer capacity, reducing their performance in sub-100 {micro}m applications. Ti3C2Tx MXene has emerged as a promising alternative for high-density recording and stimulation interfaces, though the fundamental charge transfer mechanisms governing its performance remain poorly understood. This study evaluates Ti3C2Tx MXene microelectrodes across a range of diameters (25 - 500 {micro}m) and systematically elucidates the mechanisms governing their recording and stimulation capabilities. Electrochemical impedance spectroscopy, cyclic voltammetry, and voltage transient measurements - supported by equivalent-circuit modeling - revealed enhanced recording and stimulation capabilities of the MXene microelectrodes over size-matched Pt microelectrodes, attributed to reduced charge-transfer resistance and increased double-layer capacitance. Finally, varying the volume and concentration of the spray-coated Ti3C2Tx films showed that increased MXene concentration and volume enhanced performance by creating thicker, rougher interfaces. Together, these results establish Ti3C2Tx MXene as a promising electrode material with exceptional performance at the microscale.

bioengineering↗

bioRxiv2026

Profiling co-occurrent morphological phenotypes and their degree of expression severity in vacuolated cells by holo-tomographic flow cytometry and fractal analysis

Cells are complex systems characterized by large phenotype heterogeneity. Conventional single cell classification approaches usually separate cells expressing a certain phenotype (e.g. associated to a disease condition) from the healthy control. However, multiple phenotypes typically coexist within the same cell as a result of complex intracellular interactions, machineries, functioning and external stimuli. Here we use label-free optical microscopy, powered by AI, to investigate how morphological phenotypes co-occur within vacuolated cells. Cytoplasmic vacuoles are important hallmarks of several pathological states (e.g. lysosomal storage diseases, viral infections, cancer). We rely on Holo-Tomographic Flow Cytometry (HTFC) to obtain 3D refractive index tomograms of vacuolated cells in continuous flow. Then, we propose a strategy to reduce the dimensionality of the tomogram using cross-sectioning and minimum intensity projection maps. We extract a set of morphological, refractive index-based, and fractal parameters demonstrating that the complex heterogeneity of vacuole patterns can be captured and can foster classification based on interpretable features. For training the AI, biologist domain-experts provided annotation of the different morphological phenotypes expressed and ranked them in terms of expression severity from the tomographic observations. Thus, we introduce a pipeline for morphometric phenotype profiling, in which each cell is associated with a 7-digits classification code representing the combination of coexisting phenotypes it expresses and their expression severity levels.

bioengineering↗

bioRxiv2025

Drug-Resistance Biomarkers in Leishmania infantum through Nanopore-Based Detection of Aneuploidy and Gene Copy Number Variations with LeishGenApp

BackgroundDrug-resistant strains of Leishmania infantum challenge the effectiveness of treatments for clinical leishmaniosis and may lead to more frequent relapses. Copy number variation (CNV) at specific genetic loci is associated with drug resistance and virulence, but information about its prevalence in endemic regions is limited. This study examines the drug resistance and virulence status of Leishmania strains in human and canine isolates from the Mediterranean region. MethodsForty-eight Leishmania infantum isolates were whole-genome sequenced with nanopore long reads, followed by de novo assembly. We analyzed chromosomal aneuploidies and gene copy number variation in loci linked to drug resistance and virulence in Leishmania, alongside the genomic structure and rearrangements responsible for these variations. ResultsComplete genomes were de novo assembled for 35 L. infantum isolates (22 from dogs and 13 from humans), revealing significant chromosomal variability. We assessed copy number variation for 22 potential biomarkers: 15 genes related to drug resistance to first-line drugs (METK for allopurinol; LdSMT for amphotericin B; AQP1 and H-locus for antimonials; LdMT, LdRos3, and MSL for miltefosine; PPM for paramomycin) and seven genes related to virulence (lipophosphoglycan and proteophosphoglycan biosynthesis, and the Lack protein). Drug-resistance biomarkers were identified in 80% of the isolates. Canine strains primarily showed resistance to allopurinol and antimonials, while human isolates exhibited a broader resistance spectrum, especially to antimonials and paromomycin. The co-occurrence of resistance biomarkers was common, especially for allopurinol and antimonial resistance. Distinct mechanisms underlie the observed copy number variations. Virulence-associated genes were less variable among isolates. ConclusionsThe prevalence of drug-resistance biomarkers in Leishmania infantum strains from the Mediterranean region, as revealed by this study, underscores the critical need for routine resistance surveillance in managing clinical leishmaniosis. These findings not only inform current clinical practice but also pave the way for more effective management strategies in the future.

genetics↗

bioRxiv2024

On-Demand Seizures Facilitate Rapid Screening of Therapeutics for Epilepsy

Animal models of epilepsy are critical in drug development and therapeutic testing, but dominant methods for pharmaceutical evaluation face a tradeoff between higher throughput and etiological relevance. For example, in temporal lobe epilepsy, a type of epilepsy where seizures originate from limbic structures like the hippocampus, the main screening models are either based on acutely induced seizures in wild type, naive animals or spontaneous seizures in chronically epileptic animals. Both types have their disadvantages - the acute convulsant or kindling induced seizures do not account for the myriad neuropathological changes in the diseased, epileptic brains, and spontaneous behavioral seizures are sparse in the chronically epileptic models, making it time-intensive to sufficiently power experiments. In this study, we took a mechanistic approach to precipitate seizures "on demand" in chronically epileptic mice. We briefly synchronized principal cells in the CA1 region of the diseased hippocampus to reliably induce stereotyped on-demand behavioral seizures. These induced seizures resembled naturally occurring spontaneous seizures in the epileptic animals and could be stopped by commonly prescribed anti-seizure medications such as levetiracetam and diazepam. Furthermore, we showed that seizures induced in chronically epileptic animals differed from those in naive animals, highlighting the importance of evaluating therapeutics in the diseased circuit. Taken together, we envision our model to advance the speed at which both pharmacological and closed loop interventions for temporal lobe epilepsy are evaluated.

neuroscience↗

bioRxiv2023

Genomic and epidemiological evidence for the emergence of a putative L. donovani/L. infantum hybrid with unusual epidemiology in Northern Italy

Leishmania (L.) infantum is the main causative agent of animal and human leishmaniasis in the Mediterranean basin. Despite its clinical significance, little is known on the genetic diversity of L. infantum parasites circulating in Italy. Here, we apply a comparative genomics approach on seven L. infantum isolates from different hosts (human, dog, cat, marten) and geographic regions (Emilia-Romagna, Sicily, Sardinia) as a first attempt to explore the breadth of parasite genetic heterogeneity in Italy. We revealed important genome instability at karyotype levels, with each isolate presenting a unique aneuploidy profile. Read depth analysis further identified strain-specific changes in gene dosage, which affected important virulence factors most of which are encoded by multi-copy gene arrays, such as amastins or surface antigen-like proteins. SNP-based clustering analysis of these genomes together with over 80 publicly available L. infantum and L. donovani genomes placed the Italian isolates into three geographically distinct clusters, with two isolates grouping with Spanish strains, two isolates grouping with Tunisian strains, and three isolates clustering with putative L. infantum/L. donovani hybrids isolated in Cyprus. As judged by microsatellite profiling of 73 isolates from dogs, sand flies and VL cases, these hybrid isolates are representative of a sub-population of parasites circulating in northeastern Italy that preferentially infects humans, but not dogs. In conclusion, our data uncover a remarkable heterogeneity of L. infantum isolates that indicates different geographic origin, including a novel hybrid-like genotype associated with an unusual infection pattern, placing Italy at the crossroad of Leishmania infection in the Mediterranean region.

genomics↗

bioRxiv2022

An Open-Source Rodent Chronic EEG Array System with High Density MXene-Based Skull Surface Electrodes

Electroencephalography (EEG) is an indispensable tool in epilepsy, sleep, and behavioral research. In rodents, EEG recordings are typically performed with metal electrodes that traverse the skull into the epidural space. In addition to requiring a major surgery, this intracranial EEG technique is difficult to perform for more than a few electrodes, is time-intensive, and confounds experiments studying traumatic brain injury. Here, we describe an open-source cost-effective refinement of this technique for chronic mouse EEG recording. Our alternative two channel (EEG2) and sixteen channel high-density EEG (HdEEG) arrays use electrodes made of the novel, flexible 2D nanomaterial titanium carbide (Ti3C2Tx) MXene. The MXene electrodes are placed on the surface of the intact skull and establish electrical connection without conductive gel or paste. Fabrication and implantation times of MXene EEG electrodes are significantly shorter than the standard approach and recorded resting baseline and epileptiform EEG waveforms are similar to those obtained with traditional epidural electrodes. Applying HdEEG to a mild traumatic brain injury (mTBI) model in mice of both sexes revealed that mTBI significantly altered awake resting state spectral density with a spatiospectral region of interest in the {beta} spectral band (12-30 Hz) in the central and posterior regions. These findings indicate that fabrication of MXene electrode arrays is a cost effective, efficient technology for multichannel EEG recording in rodents that obviates the need for skull-penetrating surgery. Moreover, increased {beta} spectral power may contribute to the development of early post-mTBI seizures. Significance StatementElectroencephalography (EEG) is a critical technique used to study neurological activity in rodents. Commonly used EEG procedures require time-consuming skull-penetrating surgeries that may confound the experiments. Here we provide a cost-effective solution for obtaining two channel (EEG2) and high-density EEG (HdEEG) recordings on the skull surface thus avoiding major surgery. We compared this HdEEG system to traditional EEG recordings and then used it to determine the effects of mild traumatic brain injury on awake resting state spectral density. This novel open-source EEG system will contribute the electrophysiological characterization of rodent behaviors and seizure activity.

neuroscience↗

bioRxiv2021

Design and validation of a multi-point injection technology for MR-guided convection enhanced delivery in the brain

Convection enhanced delivery (CED) allows direct intracranial administration of neuro-therapeutics. Success of CED relies on specific targeting and broad volume distributions (VD). However, to prevent off-target delivery and tissue damage, CED is typically conducted with small cannulas and at low flow rates, which critically limit the maximum achievable VD. Furthermore, in applications such as gene therapy requiring injections of large fluid volumes into broad subcortical regions, low flow rates translate into long infusion times and multiple surgical trajectories. The cannula design is a major limiting factor in achieving broad VD, while minimizing infusion time and backflow. Here we present and validate a novel multi-point cannula specifically designed to optimize distribution and delivery time in MR-guided intracranial CED of gene-based therapeutics. First, we evaluated the compatibility of our cannula with MRI and common viral vectors for gene therapy. Then, we conducted CED tests in agarose brain phantoms and benchmarked the results against single-needle delivery. 3T MRI in brain phantoms revealed minimal susceptibility-induced artifacts, comparable to the device dimensions. Benchtop CED of adeno-associated virus demonstrated no viral loss or inactivation. CED in agarose brain phantoms at 3, 6, and 9 L/min showed >3x increase in volume distribution and 60% time reduction compared to single-needle delivery. This study confirms the validity of a multi-point delivery approach for improving infusate distribution at clinically-compatible timescales and supports the feasibility of our novel cannula design for advancing safety and efficacy of MR-guided CED to the central nervous system.

bioengineering↗

bioRxiv2021

MXtrodes: MXene-infused bioelectronic interfaces for multiscale electrophysiology and stimulation

Soft bioelectronic interfaces for mapping and modulating excitable networks at high resolution and at large scale can enable paradigm-shifting diagnostics, monitoring, and treatment strategies. Yet, current technologies largely rely on materials and fabrication schemes that are expensive, do not scale, and critically limit the maximum attainable resolution and coverage. Solution processing is a cost-effective manufacturing alternative, but biocompatible conductive inks matching the performance of conventional metals are lacking. Here, we introduce MXtrodes, a novel class of soft, high-resolution, large-scale bioelectronic interfaces enabled by Ti3C2 MXene and scalable solution processing. We show that the electrochemical properties of MXtrodes exceed those of conventional materials, and do not require conductive gels when used in epidermal electronics. Furthermore, we validate MXtrodes in a number of applications ranging from mapping large scale neuromuscular networks in humans to delivering cortical microstimulation in small animal models. Finally, we demonstrate that MXtrodes are compatible with standard clinical neuroimaging modalities.

bioengineering↗

bioRxiv2021

Antiparasitic effect of stilbene and terphenyl compounds against Trypanosoma cruzi parasites

BackgroundChagas disease, also known as American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite Trypanosoma cruzi. No progress in the treatment of this pathology has been made since Nifurtimox was introduced more than fifty years ago and is considered very aggressive and may cause several adverse effects. Currently, this drug has severe limitations, including high frequency of undesirable side effects and limited efficacy and availability and the research to discover new drugs for the treatment of Chagas disease is imperative. Many drugs available in the market are natural products as found in nature or compounds designed based on the structure and activity of these natural products. Methodology/Principal FindingsThis study evaluated the in vitro antiparasitic activity in T. cruzi epimastigotes and intracellular amastigotes of a series of stilbene and terphenyl compounds previously synthesized. The action of the most selective compounds has been investigated by flow cytometry analysis to evaluate the mechanism of cell death. The ability to induce apoptosis or caspase-1 inflammasome were assayed in macrophages infected with T. cruzi after treatment comparing with Nifurtimox. Conclusions/SignificanceThe stilbene ST18 was the most potent compound of the series. It was slightly less active than Nifurtimox in epimastigotes but most active in intracellular amastigotes. Compared to Nifurtimox, it was markedly less cytotoxic when tested in vitro on normal cells. ST18 was able to induce a marked increase of parasites positive to Annexin V and monodansylcadaverine. Moreover, ST18 induced the activation in infected macrophages of caspase-1, a conserved enzyme which plays a main role in controlling parasitemia, host survival, and the onset of adaptive immune response in Trypanosoma infection. The antiparasitic activity of ST18 together to its ability to activate caspase-1 in infected macrophages and its low toxicity on normal cells makes this compound interesting for further clinical investigations. Author SummaryChagas disease is a pathology caused by the protozoan parasite Trypanosoma cruzi. No progress in the treatment of this pathology has been made since benznidazole and Nifurtimox were introduced more than fifty years ago. However, these drugs have severe limitations and the research to discover new drugs for the treatment of Chagas disease is imperative. We evaluated the in vitro antiparasitic activity in T. cruzi epimastigotes of a series of stilbene and terphenyl compounds previously synthesized. The stilbene ST18 was the most potent compound of the series. It was slightly less active than nifurtimox in epimastigotes but most active in intracellular amastigotes. Compared to Nifurtimox, it was markedly less cytotoxic when tested in vitro on normal cells. ST18 was able to induce a marked increase of parasites positive to Annexin V and monodansylcadaverine. Moreover, this compound induced the activation in infected macrophages of caspase-1, an evolutionarily conserved enzyme which plays a main role in controlling parasitemia, host survival, and the onset of adaptive immune response in T. cruzi infection. The antiparasitic activity of ST18 together to its ability to activate caspase-1 in infected macrophages and its low toxicity on normal cells makes this compound interesting for further clinical investigations.

microbiology↗

bioRxiv2020

Multimodal in vivo recording using transparent graphene microelectrodes illuminates spatiotemporal seizure dynamics at the microscale

Neurological disorders such as epilepsy arise from disrupted brain networks. Our capacity to treat these disorders is limited by our inability to map these networks at sufficient temporal and spatial scales to target interventions. Current best techniques either sample broad areas at low temporal resolution (e.g. calcium imaging) or record from discrete regions at high temporal resolution (e.g. electrophysiology). This limitation hampers our ability to understand and intervene in aberrations of network dynamics. Here we present a technique to map the onset and spatiotemporal spread of acute epileptic seizures in vivo by simultaneously recording high bandwidth microelectrocorticography and calcium fluorescence using transparent graphene microelectrode arrays. We integrate dynamic data features from both modalities using non-negative matrix factorization to identify sequential spatiotemporal patterns of seizure onset and evolution, revealing how the temporal progression of ictal electrophysiology is linked to the spatial evolution of the recruited seizure core. This integrated analysis of multimodal data reveals otherwise hidden state transitions in the spatial and temporal progression of acute seizures. The techniques demonstrated here may enable future targeted therapeutic interventions and novel spatially embedded models of local circuit dynamics during seizure onset and evolution.

neuroscience↗

bioRxiv2017

Fluidic Microactuation of Flexible Electrodes for Neural Recording

Ultra-flexible microelectrodes that can bend and flex with the natural movement of the brain reduce the inflammatory response and improve the stability of long-term neural recordings.1-5 However, current methods to implant these highly flexible electrodes rely on temporary stiffening agents that increase the electrode size6-10 thus aggravating neural damage during implantation, which leads to cell loss and glial activation that persists even after the stiffening agents are removed or dissolve.11-13 A method to deliver thin, ultra-flexible electrodes deep into neural tissue without increasing the stiffness or size of the electrodes will enable minimally invasive electrical recordings from within the brain. Here we show that specially designed microfluidic devices can apply a tension force to ultra-flexible electrodes that prevents buckling without increasing the thickness or stiffness of the electrode during implantation. Additionally, these \"fluidic microdrives\" allow us to precisely actuate the electrode position with micron-scale accuracy. To demonstrate the efficacy of our fluidic microdrives, we used them to actuate highly flexible carbon nanotube fiber (CNTf) microelectrodes11,14 for electrophysiology. We used this approach in three proof-of-concept experiments. First, we recorded compound action potentials in a soft model organism, the small cnidarian Hydra. Second, we targeted electrodes precisely to the thalamic reticular nucleus in brain slices and recorded spontaneous and optogenetically-evoked extracellular action potentials. Finally, we inserted electrodes more than 4 mm deep into the brain of rats and detected spontaneous individual unit activity in both cortical and subcortical regions. Compared to syringe injection, fluidic microdrives do not penetrate the brain and prevent changes in intracranial pressure by diverting fluid away from the injection site during insertion and actuation. Overall, the fluidic microdrive technology provides a robust new method to implant and actuate ultra-flexible neural electrodes.

neuroscience↗