Instituto Nacional de Ciência e Tecnologia em Nanomateriais de Carbono

Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60 are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60 exposure in brain acetylcholinesterase expression and activity, antioxidant responses, and oxidative damage using adult zebrafish as an animal model. None of the doses tested (7.5, 15, and 30 mg/kg) altered AChE activity, antioxidant responses, and oxidative damage when zebrafish were exposed to nonphotoexcited C60 nano/microparticles during 6 and 12 hours. However, adult zebrafish exposed to the 30 mg/kg dose for 24 hours have shown enhanced AChE activity and augmented lipid peroxidation (TBARS assays) in brain. In addition, the up-regulation of brain AChE activity was neither related to the transcriptional control (RT-qPCR analysis) nor to the direct action of nonphotoexcited C60 nano/microparticles on the protein (in vitro results) but probably involved a posttranscriptional or posttranslational modulation of this enzymatic activity. Taken together these findings provided further evidence of toxic effects on brain after C60 exposure.

Recently, it has been suggested that the mitochondrial oligomycin A-sensitive F0-ATPase subunit is an uncoupling channel linked to apoptotic cell death, and as such, the toxicological inhibition of mitochondrial F0-ATP hydrolase can be an interesting mitotoxicity-based therapy under pathological conditions. In addition, carbon nanotubes (CNTs) have been shown to offer higher selectivity like mitotoxic-targeting nanoparticles. In this work, linear and nonlinear classification algorithms on structure–toxicity relationships with artificial neural network (ANN) models were set up using the fractal dimensions calculated from CNTs as a source of supramolecular chemical information. The potential ability of CNT-family members to induce mitochondrial toxicity-based inhibition of the mitochondrial H+-F0F1-ATPase from in vitro assays was predicted. The attained experimental data suggest that CNTs have a strong ability to inhibit the F0-ATPase active-binding site following the order oxidized–CNT (CNT–COOH > CNT–OH) > pristine–CNT and mimicking the oligomycin A mitotoxicity behavior. Meanwhile, the performance of the ANN models was found to be improved by including different nonlinear combinations of the calculated fractal scanning electron microscopy (SEM) nanodescriptors, leading to models with excellent internal accuracy and predictivity on external data to classify correctly CNT-mitotoxic and nonmitotoxic with specificity (Sp > 98.9%) and sensitivity (Sn > 99.0%) from ANN models compared with linear approaches (LNN) with Sp ≈ Sn > 95.5%. Finally, the present study can contribute toward the rational design of carbon nanomaterials and opens new opportunities toward mitochondrial nanotoxicology-based in silico models.

Mitochondrial Permeability Transition Pore (MPTP) is involved in neurodegeneration, hepatotoxicity, cardiac necrosis, nervous and muscular dystrophies.

High Resolution Image Download MS PowerPoint Slide Understanding the mechanisms governing water transport in graphene oxide (GO) membranes remains a central challenge in the development of next-generation desalination materials. In this work, commercial polyamide reverse osmosis membranes were coated with GO using an in situ dynamic pressurization method, followed by a comprehensive characterization and performance evaluation. Experimentally, GO deposition altered surface morphology, reduced roughness, and increased hydraulic permeability by ∼25% while maintaining salt rejection above 90%. Raman spectroscopy confirmed the incorporation of GO, and AFM and SEM revealed smoothing of the ridge-and-valley structure characteristic of interfacially polymerized polyamide layers. To elucidate the molecular origins of these changes, we performed a systematic series of molecular dynamics (MD) simulations that isolate the effects of slit width, interlayer spacing, and commensurability in stacked GO galleries. The simulations demonstrate that enhanced permeability is linked to the formation of low-friction pathways, reduced hydrogen-bond (HB) structuring, and the emergence of preferential flow routes within GO nanochannels. High commensurability between adjacent slits increases dynamic coupling and suppresses bottlenecks, while geometric expansion of the channels accelerates water mobility without compromising ion exclusion. By integrating experimental observations with molecular-scale analysis, this study provides a unified mechanistic picture of water transport in GO-modified membranes. The synergy between surface smoothing, nanoscale alignment, and reduced interfacial friction explains the observed enhanced permeance and highlights how targeted control of GO morphology can be leveraged to optimize membrane performance. These findings establish a multiscale framework for the rational design of high-flux, high-selectivity desalination membranes based on graphene-derived materials.

on top of nanopillars at room temperature. Our results reveal two distinct localization regimes associated with leading theoretical models for single-photon activation and provide guidelines for deterministic nanoengineering of quantum light sources.