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1.
Int J Pharm ; 666: 124834, 2024 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-39414186

RESUMEN

The focus of current research work was to develop and validate size-exclusion chromatography method and develop and evaluate gel formulation of deferoxamine conjugated with PEGylated carbon nanoparticles (DEF-PEG-CNP) for topical delivery. Size-exclusion chromatography-based method was validated as per ICH guidelines. Effect of Carbopol® 974P and Transcutol® on the nanoparticles' permeation was studied by 3-level full factorial design of experiment. Gel formulations were characterized for viscosity, cohesive and adhesive force by texture analyzer, and drug permeation through pig ear and human skin. The analytical method was specific as no interference from solvent or excipients were observed and met preset criteria of validation with limit of quantification of 0.24 ± 0.00 µg/mL. The nanoparticles permeation, steady state flux, and retained drug were statistically (p < 0.05) affected by Carbopol® 974P and Transcutol® percentage in the gel formulations. The permeation, steady state flux, and retained nanoparticles from the gel formulations varied from 23.2 ± 2.5 % to 70.9 ± 113.3 %, 0.8 ± 0.3 to 6.6 ± 2.1 µg/cm2.h, and 5.6 ± 0.3 to 38.8 ± 8.8 µg/g, respectively. Permeation of the nanoparticles was 1.9 folds higher in pig skin compared to human skin. Immunofluorescence detected successful permeation of DEF-PEG-CNP particles into skin. In conclusion, the analytical method can quantify the nanoparticles from the gel formulation without interference, and gel formulation of the nanoparticles can permeate across the skin.

2.
Adv Healthc Mater ; : e2401629, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39329414

RESUMEN

Pro-energetic effects of functionalized, oxidized carbon nanozymes (OCNs) are reported. OCNs, derived from harsh acid oxidation of single-wall carbon nanotubes or activated charcoal are previously shown to possess multiple nanozymatic activities including mimicking superoxide dismutase and catalyzing the oxidation of reduced nicotinamide adenine dinucleotide (NADH) to NAD+. These actions are predicted to generate a glycolytic shift and enhance mitochondrial energetics under impaired conditions. Impaired mitochondrial energy metabolism is increasingly recognized as an important facet of traumatic brain injury (TBI) pathophysiology and decreases the efficiency of electron transport chain (ETC)-coupled adenosine triphosphate (ATP) and NAD+ regeneration. In vitro, OCNs promote a pro-aerobic shift in energy metabolism that persists through ETC inhibition and enhances glycolytic flux, glycolytic ATP production, and cellular generation of lactate, a crucial auxiliary substrate for energy metabolism. To address specific mechanisms of iron injury from hemorrhage, OCNs with the iron chelator, deferoxamine (DEF), covalently-linked were synthesized. DEF-linked OCNs induce a glycolytic shift in-vitro and in-vivo in tissue sections from a rat model of TBI complicated by hemorrhagic contusion. OCNs further reduced hemorrhage volumes 3 days following TBI. These results suggest OCNs are promising as pleiotropic mediators of cell and tissue resilience to injury.

3.
Nat Commun ; 15(1): 6250, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39048568

RESUMEN

Effective recycling of end-of-life Li-ion batteries (LIBs) is essential due to continuous accumulation of battery waste and gradual depletion of battery metal resources. The present closed-loop solutions include destructive conversion to metal compounds, by destroying the entire three-dimensional morphology of the cathode through continuous thermal treatment or harsh wet extraction methods, and direct regeneration by lithium replenishment. Here, we report a solvent- and water-free flash Joule heating (FJH) method combined with magnetic separation to restore fresh cathodes from waste cathodes, followed by solid-state relithiation. The entire process is called flash recycling. This FJH method exhibits the merits of milliseconds of duration and high battery metal recovery yields of ~98%. After FJH, the cathodes reveal intact core structures with hierarchical features, implying the feasibility of their reconstituting into new cathodes. Relithiated cathodes are further used in LIBs, and show good electrochemical performance, comparable to new commercial counterparts. Life-cycle-analysis highlights that flash recycling has higher environmental and economic benefits over traditional destructive recycling processes.

4.
Adv Mater ; 36(10): e2211239, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36940058

RESUMEN

Carbon-based superoxide dismutase (SOD) mimetic nanozymes have recently been employed as promising antioxidant nanotherapeutics due to their distinct properties. The structural features responsible for the efficacy of these nanomaterials as antioxidants are, however, poorly understood. Here, the process-structure-property-performance properties of coconut-derived oxidized activated charcoal (cOAC) nano-SOD mimetics are studied by analyzing how modifications to the nanomaterial's synthesis impact the size, as well as the elemental and electrochemical properties of the particles. These properties are then correlated to the in vitro antioxidant bioactivity of poly(ethylene glycol)-functionalized cOACs (PEG-cOAC). Chemical oxidative treatment methods that afford smaller, more homogeneous cOAC nanoparticles with higher levels of quinone functionalization show enhanced protection against oxidative damage in bEnd.3 murine endothelioma cells. In an in vivo rat model of mild traumatic brain injury (mTBI) and oxidative vascular injury, PEG-cOACs restore cerebral perfusion rapidly to the same extent as the former nanotube-derived PEG-hydrophilic carbon clusters (PEG-HCCs) with a single intravenous injection. These findings provide a deeper understanding of how carbon nanozyme syntheses can be tailored for improved antioxidant bioactivity, and set the stage for translation of medical applications.


Asunto(s)
Antioxidantes , Lesiones Traumáticas del Encéfalo , Clorambucilo/análogos & derivados , Ácidos Oléicos , Ratas , Ratones , Animales , Antioxidantes/farmacología , Antioxidantes/química , Carbón Orgánico/farmacología , Carbono/química , Superóxido Dismutasa/química , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico
5.
Adv Mater ; 36(10): e2211241, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37272655

RESUMEN

Hydrogen sulfide (H2 S) is a noxious, potentially poisonous, but necessary gas produced from sulfur metabolism in humans. In Down Syndrome (DS), the production of H2 S is elevated and associated with degraded mitochondrial function. Therefore, removing H2 S from the body as a stable oxide could be an approach to reducing the deleterious effects of H2 S in DS. In this report we describe the catalytic oxidation of hydrogen sulfide (H2 S) to polysulfides (HS2+n - ) and thiosulfate (S2 O3 2- ) by poly(ethylene glycol) hydrophilic carbon clusters (PEG-HCCs) and poly(ethylene glycol) oxidized activated charcoal (PEG-OACs), examples of oxidized carbon nanozymes (OCNs). We show that OCNs oxidize H2 S to polysulfides and S2 O3 2- in a dose-dependent manner. The reaction is dependent on O2 and the presence of quinone groups on the OCNs. In DS donor lymphocytes we found that OCNs increased polysulfide production, proliferation, and afforded protection against additional toxic levels of H2 S compared to untreated DS lymphocytes. Finally, in Dp16 and Ts65DN murine models of DS, we found that OCNs restored osteoclast differentiation. This new action suggests potential facile translation into the clinic for conditions involving excess H2 S exemplified by DS.


Asunto(s)
Síndrome de Down , Sulfuro de Hidrógeno , Humanos , Animales , Ratones , Tiosulfatos/metabolismo , Carbono , Síndrome de Down/tratamiento farmacológico , Sulfuros , Oxidación-Reducción , Polietilenglicoles/metabolismo
6.
Sci Adv ; 8(46): eabq0615, 2022 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-36383649

RESUMEN

Chronic exposure to airborne carbon black ultrafine (nCB) particles generated from incomplete combustion of organic matter drives IL-17A-dependent emphysema. However, whether and how they alter the immune responses to lung cancer remains unknown. Here, we show that exposure to nCB particles increased PD-L1+ PD-L2+ CD206+ antigen-presenting cells (APCs), exhausted T cells, and Treg cells. Lung macrophages that harbored nCB particles showed selective mitochondrial structure damage and decreased oxidative respiration. Lung macrophages sustained the HIF1α axis that increased glycolysis and lactate production, culminating in an immunosuppressive microenvironment in multiple mouse models of non-small cell lung cancers. Adoptive transfer of lung APCs from nCB-exposed wild type to susceptible mice increased tumor incidence and caused early metastasis. Our findings show that nCB exposure metabolically rewires lung macrophages to promote immunosuppression and accelerates the development of lung cancer.


Asunto(s)
Neoplasias Pulmonares , Hollín , Ratones , Animales , Hollín/metabolismo , Material Particulado/efectos adversos , Neoplasias Pulmonares/etiología , Neoplasias Pulmonares/metabolismo , Macrófagos , Pulmón/metabolismo , Carbono/metabolismo , Microambiente Tumoral
7.
Nat Commun ; 13(1): 5027, 2022 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-36028480

RESUMEN

High-surface-area α-Al2O3 nanoparticles are used in high-strength ceramics and stable catalyst supports. The production of α-Al2O3 by phase transformation from γ-Al2O3 is hampered by a high activation energy barrier, which usually requires extended high-temperature annealing (~1500 K, > 10 h) and suffers from aggregation. Here, we report the synthesis of dehydrated α-Al2O3 nanoparticles (phase purity ~100%, particle size ~23 nm, surface area ~65 m2 g-1) by a pulsed direct current Joule heating of γ-Al2O3. The phase transformation is completed at a reduced bulk temperature and duration (~573 K, < 1 s) via an intermediate δ'-Al2O3 phase. Numerical simulations reveal the resistive hotspot-induced local heating in the pulsed current process enables the rapid transformation. Theoretical calculations show the topotactic transition (from γ- to δ'- to α-Al2O3) is driven by their surface energy differences. The α-Al2O3 nanoparticles are sintered to nanograined ceramics with hardness superior to commercial alumina and approaching that of sapphire.

8.
Adv Mater ; 34(33): e2202666, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35748868

RESUMEN

Turbostratic layers in 2D materials have an interlayer misalignment. The lack of alignment expands the intrinsic interlayer distances and weakens the optical and electronic interactions between adjacent layers. This introduces properties distinct from those structures with well-aligned lattices and strong coupling interactions. However, direct and rapid synthesis of turbostratic materials remains a challenge owing to their thermodynamically metastable properties. Here, a flash Joule heating (FJH) method to achieve bulk synthesis of boron-carbon-nitrogen ternary compounds with turbostratic structures by a kinetically controlled ultrafast cooling process that takes place within milliseconds (103  to 104 K s-1 ) is reported. Theoretical calculations support the existence of turbostratic structures and provide estimates of the energy barriers with respect to conversion into the corresponding well-aligned counterparts. When using non-carbon conductive additives, a direct synthesis of boron nitride is possible. The turbostratic nature facilitates mechanical exfoliation and more stable dispersions. Accordingly, the addition of flash products to a poly(vinyl alcohol) nanocomposite film coating a copper surface greatly improves the copper's resistance to corrosion in 0.5 m sulfuric acid or 3.5 wt% saline solution. FJH allows the use of bulk materials as reactants and provides a rapid approach to large quantities of the hitherto hard-to-access turbostratic materials.

9.
Adv Mater ; 34(12): e2106506, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35064973

RESUMEN

Advances in nanoscience have enabled the synthesis of nanomaterials, such as graphene, from low-value or waste materials through flash Joule heating. Though this capability is promising, the complex and entangled variables that govern nanocrystal formation in the Joule heating process remain poorly understood. In this work, machine learning (ML) models are constructed to explore the factors that drive the transformation of amorphous carbon into graphene nanocrystals during flash Joule heating. An XGBoost regression model of crystallinity achieves an r2 score of 0.8051 ± 0.054. Feature importance assays and decision trees extracted from these models reveal key considerations in the selection of starting materials and the role of stochastic current fluctuations in flash Joule heating synthesis. Furthermore, partial dependence analyses demonstrate the importance of charge and current density as predictors of crystallinity, implying a progression from reaction-limited to diffusion-limited kinetics as flash Joule heating parameters change. Finally, a practical application of the ML models is shown by using Bayesian meta-learning algorithms to automatically improve bulk crystallinity over many Joule heating reactions. These results illustrate the power of ML as a tool to analyze complex nanomanufacturing processes and enable the synthesis of 2D crystals with desirable properties by flash Joule heating.

10.
Nat Commun ; 12(1): 5794, 2021 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-34608143

RESUMEN

Precious metal recovery from electronic waste, termed urban mining, is important for a circular economy. Present methods for urban mining, mainly smelting and leaching, suffer from lengthy purification processes and negative environmental impacts. Here, a solvent-free and sustainable process by flash Joule heating is disclosed to recover precious metals and remove hazardous heavy metals in electronic waste within one second. The sample temperature ramps to ~3400 K in milliseconds by the ultrafast electrical thermal process. Such a high temperature enables the evaporative separation of precious metals from the supporting matrices, with the recovery yields >80% for Rh, Pd, Ag, and >60% for Au. The heavy metals in electronic waste, some of which are highly toxic including Cr, As, Cd, Hg, and Pb, are also removed, leaving a final waste with minimal metal content, acceptable even for agriculture soil levels. Urban mining by flash Joule heating would be 80× to 500× less energy consumptive than using traditional smelting furnaces for metal-component recovery and more environmentally friendly.

11.
ACS Nano ; 15(7): 11158-11167, 2021 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-34138536

RESUMEN

Flash Joule heating (FJH), an advanced material synthesis technique, has been used for the production of high-quality carbon materials. Direct current discharge through the precursors by large capacitors has successfully converted carbon-based starting materials into bulk quantities of turbostratic graphene by the FJH process. However, the formation of other carbon allotropes, such as nanodiamonds and concentric carbon materials, as well as the covalent functionalization of different carbon allotropes by the FJH process, remains challenging. Here, we report the solvent-free FJH synthesis of three different fluorinated carbon allotropes: fluorinated nanodiamonds, fluorinated turbostratic graphene, and fluorinated concentric carbon. This is done by millisecond flashing of organic fluorine compounds and fluoride precursors. Spectroscopic analysis confirms the modification of the electronic states and the existence of various short-range and long-range orders in the different fluorinated carbon allotropes. The flash-time-dependent relationship is further demonstrated to control the phase evolution and product compositions.

12.
ACS Nano ; 15(5): 8976-8983, 2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-33900723

RESUMEN

The fabrication of patterned graphene electronics at high resolution is an important challenge for many applications in microelectronics. Here, we demonstrate the conversion of positive photoresist (PR), commonly employed in the commercial manufacture of consumer electronics, into laser-induced graphene (LIG). Sequential lasing converts the PR photopolymer first into amorphous carbon, then to photoresist-derived LIG (PR-LIG). The resulting material possesses good conductivity and is easily doped with metal or other additives for additional functionality. Furthermore, photolithographic exposure of PR prior to lasing enables the generation of PR-LIG patterns small enough to be invisible to the naked eye. By exploiting PR as a photopatternable LIG precursor, PR-LIG can be synthesized with a spatial resolution of ∼10 µm, up to 15 times smaller than conventional LIG patterning methods. The patterning of these small PR-LIG features could offer a powerful and broadly accessible strategy for the fabrication of microscale LIG-derived nanocomposites for on-chip devices.

13.
ACS Nano ; 15(1): 1282-1290, 2021 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-33412009

RESUMEN

Controllable phase engineering is vital for precisely tailoring material properties since different phase structures have various electronic states and atomic arrangements. Rapid synthesis of thermodynamically metastable materials, especially two-dimensional metastable materials, with high efficiency and low cost remains a large challenge. Here we report flash Joule heating (FJH) as an electrothermal method to achieve the bulk conversion of transition metal dichalcogenides, MoS2 and WS2, from 2H phases to 1T phases in milliseconds. The conversions can reach up to 76% of flash MoS2 using tungsten powder as conductive additive. Different degrees of phase conversion can be realized by controlling the FJH conditions, such as reaction duration and additives, which allows the study of ratio-dependent properties. First-principles calculations confirm that structural processes associated with the FJH, such as vacancy formation and charge accumulation, result in stabilization of the 1T phases. FJH offers rapid access to bulk quantities of the hitherto hard-to-access 1T phases, a promising method for further fundamental research and diverse applications of metastable phases.

14.
Elife ; 92020 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-32940602

RESUMEN

Similar to DNA replication, translation of the genetic code by the ribosome is hypothesized to be exceptionally sensitive to small chemical changes to its template mRNA. Here we show that the addition of common alkylating agents to growing cultures of Escherichia coli leads to the accumulation of several adducts within RNA, including N(1)-methyladenosine (m1A). As expected, the introduction of m1A to model mRNAs was found to reduce the rate of peptide bond formation by three orders of magnitude in a well-defined in vitro system. These observations suggest that alkylative stress is likely to stall translation in vivo and necessitates the activation of ribosome-rescue pathways. Indeed, the addition of alkylation agents was found to robustly activate the transfer-messenger RNA system, even when transcription was inhibited. Our findings suggest that bacteria carefully monitor the chemical integrity of their mRNA and they evolved rescue pathways to cope with its effect on translation.


Asunto(s)
Alquilantes/farmacología , Biosíntesis de Proteínas/efectos de los fármacos , ARN Bacteriano , ARN Mensajero , Ribosomas , Alquilación , Escherichia coli/efectos de los fármacos , Escherichia coli/fisiología , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Metilmetanosulfonato/farmacología , Metilnitronitrosoguanidina/farmacología , ARN Bacteriano/química , ARN Bacteriano/metabolismo , ARN Mensajero/química , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Ribosomas/química , Ribosomas/efectos de los fármacos , Ribosomas/metabolismo
15.
ACS Nano ; 14(10): 13691-13699, 2020 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-32909736

RESUMEN

Flash Joule heating (FJH) can convert almost any carbon-based precursor into bulk quantities of graphene. This work explores the morphologies and properties of flash graphene (FG) generated from carbon black. It is shown that FG is partially comprised of sheets of turbostratic FG (tFG) that have a rotational mismatch between neighboring layers. The remainder of the FG is wrinkled graphene sheets that resemble nongraphitizing carbon. To generate high quality tFG sheets, a FJH duration of 30-100 ms is employed. Beyond 100 ms, the turbostratic sheets have time to AB-stack and form bulk graphite. Atomistic simulations reveal that generic thermal annealing yields predominantly wrinkled graphene which displays minimal to no alignment of graphitic planes, as opposed to the high-quality tFG that might be formed under the direct influence of current conducted through the material. The tFG was easily exfoliated via shear, hence the FJH process has the potential for bulk production of tFG without the need for pre-exfoliation using chemicals or high energy mechanical shear.

16.
ACS Nano ; 14(3): 2827-2846, 2020 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-32049495

RESUMEN

Therapy for intracerebral hemorrhage (ICH) remains elusive, in part dependent on the severity of the hemorrhage itself as well as multiple deleterious effects of blood and its breakdown products such as hemin and free iron. While oxidative injury and genomic damage have been seen following ICH, the details of this injury and implications remain unclear. Here, we discovered that, while free iron produced mostly reactive oxygen species (ROS)-related single-strand DNA breaks, hemin unexpectedly induced rapid and persistent nuclear and mitochondrial double-strand breaks (DSBs) in neuronal and endothelial cell genomes and in mouse brains following experimental ICH comparable to that seen with γ radiation and DNA-complexing chemotherapies. Potentially as a result of persistent DSBs and the DNA damage response, hemin also resulted in senescence phenotype in cultured neurons and endothelial cells. Subsequent resistance to ferroptosis reported in other senescent cell types was also observed here in neurons. While antioxidant therapy prevented senescence, cells became sensitized to ferroptosis. To address both senescence and resistance to ferroptosis, we synthesized a modified, catalytic, and rapidly internalized carbon nanomaterial, poly(ethylene glycol)-conjugated hydrophilic carbon clusters (PEG-HCC) by covalently bonding the iron chelator, deferoxamine (DEF). This multifunctional nanoparticle, DEF-HCC-PEG, protected cells from both senescence and ferroptosis and restored nuclear and mitochondrial genome integrity in vitro and in vivo. We thus describe a potential molecular mechanism of hemin/iron-induced toxicity in ICH that involves a rapid induction of DSBs, senescence, and the consequent resistance to ferroptosis and provide a mechanistic-based combinatorial therapeutic strategy.


Asunto(s)
Carbono/farmacología , Hemorragia Cerebral/tratamiento farmacológico , Nanopartículas/química , Animales , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Senescencia Celular/efectos de los fármacos , Hemorragia Cerebral/genética , Hemorragia Cerebral/metabolismo , Roturas del ADN de Cadena Simple/efectos de los fármacos , Daño del ADN , Deferoxamina/farmacología , Hemina/antagonistas & inhibidores , Hemina/farmacología , Humanos , Hierro/farmacología , Ratones , Mitocondrias/efectos de los fármacos , Polietilenglicoles/farmacología , Especies Reactivas de Oxígeno/metabolismo
17.
Nature ; 577(7792): 647-651, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31988511

RESUMEN

Most bulk-scale graphene is produced by a top-down approach, exfoliating graphite, which often requires large amounts of solvent with high-energy mixing, shearing, sonication or electrochemical treatment1-3. Although chemical oxidation of graphite to graphene oxide promotes exfoliation, it requires harsh oxidants and leaves the graphene with a defective perforated structure after the subsequent reduction step3,4. Bottom-up synthesis of high-quality graphene is often restricted to ultrasmall amounts if performed by chemical vapour deposition or advanced synthetic organic methods, or it provides a defect-ridden structure if carried out in bulk solution4-6. Here we show that flash Joule heating of inexpensive carbon sources-such as coal, petroleum coke, biochar, carbon black, discarded food, rubber tyres and mixed plastic waste-can afford gram-scale quantities of graphene in less than one second. The product, named flash graphene (FG) after the process used to produce it, shows turbostratic arrangement (that is, little order) between the stacked graphene layers. FG synthesis uses no furnace and no solvents or reactive gases. Yields depend on the carbon content of the source; when using a high-carbon source, such as carbon black, anthracitic coal or calcined coke, yields can range from 80 to 90 per cent with carbon purity greater than 99 per cent. No purification steps are necessary. Raman spectroscopy analysis shows a low-intensity or absent D band for FG, indicating that FG has among the lowest defect concentrations reported so far for graphene, and confirms the turbostratic stacking of FG, which is clearly distinguished from turbostratic graphite. The disordered orientation of FG layers facilitates its rapid exfoliation upon mixing during composite formation. The electric energy cost for FG synthesis is only about 7.2 kilojoules per gram, which could render FG suitable for use in bulk composites of plastic, metals, plywood, concrete and other building materials.

18.
Front Mol Biosci ; 7: 592905, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33392255

RESUMEN

Mechanical injury to the articular cartilage is a key risk factor in joint damage and predisposition to osteoarthritis. Integrative multi-omics approaches provide a valuable tool to understand tissue behavior in response to mechanical injury insult and help to identify key pathways linking injury to tissue damage. Global or untargeted metabolomics provides a comprehensive characterization of the metabolite content of biological samples. In this study, we aimed to identify the metabolic signature of cartilage tissue post injury. We employed an integrative analysis of transcriptomics and global metabolomics of murine epiphyseal hip cartilage before and after injury. Transcriptomics analysis showed a significant enrichment of gene sets involved in regulation of metabolic processes including carbon metabolism, biosynthesis of amino acids, and steroid biosynthesis. Integrative analysis of enriched genes with putatively identified metabolite features post injury showed a significant enrichment for carbohydrate metabolism (glycolysis, galactose, and glycosylate metabolism and pentose phosphate pathway) and amino acid metabolism (arginine biosynthesis and tyrosine, glycine, serine, threonine, and arginine and proline metabolism). We then performed a cross analysis of global metabolomics profiles of murine and porcine ex vivo cartilage injury models. The top commonly modulated metabolic pathways post injury included arginine and proline metabolism, arginine biosynthesis, glycolysis/gluconeogenesis, and vitamin B6 metabolic pathways. These results highlight the significant modulation of metabolic responses following mechanical injury to articular cartilage. Further investigation of these pathways would provide new insights into the role of the early metabolic state of articular cartilage post injury in promoting tissue damage and its link to disease progression of osteoarthritis.

19.
ACS Nano ; 13(10): 11912-11920, 2019 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-31560513

RESUMEN

Nosocomial infections transmitted through airborne, droplet, aerosol, and particulate-transported modes pose substantial infection risks to patients and healthcare employees. In this study, we demonstrate a self-cleaning filter comprised of laser-induced graphene (LIG), a porous conductive graphene foam formed through photothermal conversion of a polyimide film by a commercial CO2 laser cutter. LIG was shown to capture particulates and bacteria. The bacteria cannot proliferate even when submerged in culture medium. Through a periodic Joule-heating mechanism, the filter readily reaches >300 °C. This destroys any microorganisms including bacteria, along with molecules that can cause adverse biological reactions and diseases. These molecules include pyrogens, allergens, exotoxins, endotoxins, mycotoxins, nucleic acids, and prions. Capitalizing on the high surface area and thermal stability of LIG, the utility of graphene for reduction of nosocomial infection in hospital settings is suggested.


Asunto(s)
Filtros de Aire , Grafito/química , Exotoxinas/química , Micotoxinas/química , Ácidos Nucleicos/química , Priones/química , Pirógenos/química
20.
Nanoscale ; 11(22): 10791-10807, 2019 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-31134256

RESUMEN

Previously, our group reported on the promising efficacy of poly(ethylene glycol)-hydrophilic carbon clusters (PEG-HCCs) to work as broadly active and high capacity antioxidants in brain ischemia and injury models including stroke and traumatic brain injury coupled with hemorrhagic shock. PEG-HCCs are a carbon nanomaterial derived from harsh oxidation of single wall carbon nanotubes and covalently modified with poly(ethylene glycol). They retain no tubular remnants and are composed of a highly oxidized carbon core functionalized with epoxy, peroxyl, quinone, ketone, carboxylate, and hydroxyl groups. HCCs are the redox active carbon core of PEG-HCCs, which have a broad reduction potential range starting at +200 mV and extending to -2 V. Here we describe a new property of these materials: the ability to catalytically transfer electrons between key surrogates and proteins of the mitochondrial electron transport complex in a catalytic fashion consistent with the concept of a nanozyme. The estimated reduction potential of PEG-HCCs is similar to that of ubiquinone and they enabled the catalytic transfer of electrons from low reduction potential species to higher reduction electron transport complex constituents. PEG-HCCs accelerated the reduction of resazurin (a test indicator of mitochondrial viability) and cytochrome c by NADH and ascorbic acid in solution. Kinetic experiments suggested a transient tertiary complex. Electron paramagnetic resonance demonstrated NADH increased the magnitude of PEG-HCCs' intrinsic radical, which then reduced upon subsequent addition of cytochrome c or resazurin. Deconvolution microscopy identified PEG-HCCs in close proximity to mitochondria after brief incubation with cultured SHSY-5Y human neuroblastoma cells. Compared to methylene blue (MB), considered a prototypical small molecule electron transport shuttle, PEG-HCCs were more protective against toxic effects of hydrogen peroxide in vitro and did not demonstrate impaired cell viability as did MB. PEG-HCCs were protective in vitro when cells were exposed to sodium cyanide, a mitochondrial complex IV poison. Because mitochondria are a major source of free radicals in pathology, we suggest that this newly described nanozyme action helps explain their in vivo efficacy in a range of injury models. These findings may also extend their use to mitochondrial disorders.


Asunto(s)
Citocromos c/metabolismo , Peróxido de Hidrógeno/metabolismo , Mitocondrias/metabolismo , NAD/metabolismo , Nanotubos de Carbono/química , Ácido Ascórbico/farmacología , Catálisis , Espectroscopía de Resonancia por Spin del Electrón , Transporte de Electrón/efectos de los fármacos , Humanos , Oxidación-Reducción/efectos de los fármacos , Polietilenglicoles/química , Polietilenglicoles/farmacología
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