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1.
Nature ; 630(8015): 91-95, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38778107

RESUMEN

The strength of materials depends on the rate at which they are tested, as defects, for example dislocations, that move in response to applied strains have intrinsic kinetic limitations1-4. As the deformation strain rate increases, more strengthening mechanisms become active and increase the strength4-7. However, the regime in which this transition happens has been difficult to access with traditional micromechanical strength measurements. Here, with microballistic impact testing at strain rates greater than 106 s-1, and without shock conflation, we show that the strength of copper increases by about 30% for a 157 °C increase in temperature, an effect also observed in pure titanium and gold. This effect is counterintuitive, as almost all materials soften when heated under normal conditions. This anomalous thermal strengthening across several pure metals is the result of a change in the controlling deformation mechanism from thermally activated strengthening to ballistic transport of dislocations, which experience drag through phonon interactions1,8-10. These results point to a pathway to better model and predict materials properties under various extreme strain rate conditions, from high-speed manufacturing operations11 to hypersonic transport12.


Asunto(s)
Cobre , Oro , Temperatura , Titanio , Oro/química , Titanio/química , Estrés Mecánico , Ensayo de Materiales , Fonones , Metales/química , Calor
2.
Nature ; 626(7999): 542-548, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38109940

RESUMEN

The success of colloidal semiconductor nanocrystals (NCs) in science and optoelectronics is inextricable from their surfaces. The functionalization of lead halide perovskite NCs1-5 poses a formidable challenge because of their structural lability, unlike the well-established covalent ligand capping of conventional semiconductor NCs6,7. We posited that the vast and facile molecular engineering of phospholipids as zwitterionic surfactants can deliver highly customized surface chemistries for metal halide NCs. Molecular dynamics simulations implied that ligand-NC surface affinity is primarily governed by the structure of the zwitterionic head group, particularly by the geometric fitness of the anionic and cationic moieties into the surface lattice sites, as corroborated by the nuclear magnetic resonance and Fourier-transform infrared spectroscopy data. Lattice-matched primary-ammonium phospholipids enhance the structural and colloidal integrity of hybrid organic-inorganic lead halide perovskites (FAPbBr3 and MAPbBr3 (FA, formamidinium; MA, methylammonium)) and lead-free metal halide NCs. The molecular structure of the organic ligand tail governs the long-term colloidal stability and compatibility with solvents of diverse polarity, from hydrocarbons to acetone and alcohols. These NCs exhibit photoluminescence quantum yield of more than 96% in solution and solids and minimal photoluminescence intermittency at the single particle level with an average ON fraction as high as 94%, as well as bright and high-purity (about 95%) single-photon emission.


Asunto(s)
Diseño de Fármacos , Ligandos , Nanopartículas del Metal , Puntos Cuánticos , Acetona/química , Alcoholes/química , Aniones , Compuestos de Calcio/química , Cationes , Coloides/química , Plomo , Mediciones Luminiscentes , Espectroscopía de Resonancia Magnética , Nanopartículas del Metal/química , Simulación de Dinámica Molecular , Óxidos/química , Fosfolípidos/química , Puntos Cuánticos/química , Solventes/química , Espectroscopía Infrarroja por Transformada de Fourier , Titanio/química
3.
Nature ; 604(7905): 280-286, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35418631

RESUMEN

Multijunction solar cells can overcome the fundamental efficiency limits of single-junction devices. The bandgap tunability of metal halide perovskite solar cells renders them attractive for multijunction architectures1. Combinations with silicon and copper indium gallium selenide (CIGS), as well as all-perovskite tandem cells, have been reported2-5. Meanwhile, narrow-gap non-fullerene acceptors have unlocked skyrocketing efficiencies for organic solar cells6,7. Organic and perovskite semiconductors are an attractive combination, sharing similar processing technologies. Currently, perovskite-organic tandems show subpar efficiencies and are limited by the low open-circuit voltage (Voc) of wide-gap perovskite cells8 and losses introduced by the interconnect between the subcells9,10. Here we demonstrate perovskite-organic tandem cells with an efficiency of 24.0 per cent (certified 23.1 per cent) and a high Voc of 2.15 volts. Optimized charge extraction layers afford perovskite subcells with an outstanding combination of high Voc and fill factor. The organic subcells provide a high external quantum efficiency in the near-infrared and, in contrast to paradigmatic concerns about limited photostability of non-fullerene cells11, show an outstanding operational stability if excitons are predominantly generated on the non-fullerene acceptor, which is the case in our tandems. The subcells are connected by an ultrathin (approximately 1.5 nanometres) metal-like indium oxide layer with unprecedented low optical/electrical losses. This work sets a milestone for perovskite-organic tandems, which outperform the best p-i-n perovskite single junctions12 and are on a par with perovskite-CIGS and all-perovskite multijunctions13.


Asunto(s)
Compuestos de Calcio , Indio , Cobre , Óxidos , Titanio
4.
Nature ; 581(7808): 278-282, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32433619

RESUMEN

Human eyes possess exceptional image-sensing characteristics such as an extremely wide field of view, high resolution and sensitivity with low aberration1. Biomimetic eyes with such characteristics are highly desirable, especially in robotics and visual prostheses. However, the spherical shape and the retina of the biological eye pose an enormous fabrication challenge for biomimetic devices2,3. Here we present an electrochemical eye with a hemispherical retina made of a high-density array of nanowires mimicking the photoreceptors on a human retina. The device design has a high degree of structural similarity to a human eye with the potential to achieve high imaging resolution when individual nanowires are electrically addressed. Additionally, we demonstrate the image-sensing function of our biomimetic device by reconstructing the optical patterns projected onto the device. This work may lead to biomimetic photosensing devices that could find use in a wide spectrum of technological applications.


Asunto(s)
Materiales Biomiméticos , Biomimética/instrumentación , Compuestos de Calcio , Nanocables , Óxidos , Retina , Titanio , Diseño de Equipo , Humanos , Robótica/instrumentación , Visión Ocular
5.
Proc Natl Acad Sci U S A ; 120(1): e2210211120, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36574649

RESUMEN

Controllable in situ formation of nanoclusters with discrete active sites is highly desirable in heterogeneous catalysis. Herein, a titanium oxide-based Fenton-like catalyst is constructed using exfoliated Ti3C2 MXene as a template. Theoretical calculations reveal that a redox reaction between the surface Ti-deficit vacancies of the exfoliated Ti3C2 MXene and H2O2 molecules facilitates the in situ conversion of surface defects into titanium oxide nanoclusters anchoring on amorphous carbon (TiOx@C). The presence of mixed-valence Tiδ+ (δ = 0, 2, 3, and 4) within TiOx@C is confirmed by X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) characterizations. The abundant surface defects within TiOx@C effectively promote the generation of reactive oxygen species (ROS) leading to superior and stable Fenton-like catalytic degradation of atrazine, a typical agricultural herbicide. Such an in situ construction of Fenton-like catalysts through defect engineering also applies to other MXene family materials, such as V2C and Nb2C.


Asunto(s)
Peróxido de Hidrógeno , Titanio , Peróxido de Hidrógeno/química , Titanio/química , Dominio Catalítico , Catálisis
6.
Proc Natl Acad Sci U S A ; 120(3): e2217148120, 2023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36630453

RESUMEN

Modulation of water activation is crucial to water-involved chemical reactions in heterogeneous catalysis. Organic sulfur (COS and CS2) hydrolysis is such a typical reaction involving water (H2O) molecule as a reactant. However, limited by the strong O-H bond in H2O, satisfactory CS2 hydrolysis performance is attained at high temperature above 310 °C, which is at the sacrifice of the Claus conversion, strongly hindering sulfur recovery efficiency improvement and pollution emissions control of the Claus process. Herein, we report a facile oxygen vacancy (VO) engineering on titanium-based perovskite to motivate H2O activation for enhanced COS and CS2 hydrolysis at lower temperature. Increased amount of VO contributed to improved degree of H2O dissociation to generate more active -OH, due to lower energy barrier for H2O dissociation over surface rich in VO, particularly VO clusters. Besides, low-coordinated Ti ions adjacent to VO were active sites for H2O activation. Consequently, complete conversion of COS and CS2 was achieved over SrTiO3 after H2 reduction treatment at 225 °C, a favorable temperature for the Claus conversion, at which both satisfying COS and CS2 hydrolysis performance and improved sulfur recovery efficiency can be obtained simultaneously. Additionally, the origin of enhanced hydrolysis activity from boosted H2O activation by VO was revealed via in-depth mechanism study. This provides more explicit direction for further design of efficacious catalysts for H2O-involved reactions.


Asunto(s)
Oxígeno , Titanio , Temperatura , Hidrólisis , Agua/química , Azufre
7.
Proc Natl Acad Sci U S A ; 120(2): e2212250120, 2023 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-36598953

RESUMEN

The interaction of water with TiO2 surfaces is of crucial importance in various scientific fields and applications, from photocatalysis for hydrogen production and the photooxidation of organic pollutants to self-cleaning surfaces and bio-medical devices. In particular, the equilibrium fraction of water dissociation at the TiO2-water interface has a critical role in the surface chemistry of TiO2, but is difficult to determine both experimentally and computationally. Among TiO2 surfaces, rutile TiO2(110) is of special interest as the most abundant surface of TiO2's stable rutile phase. While surface-science studies have provided detailed information on the interaction of rutile TiO2(110) with gas-phase water, much less is known about the TiO2(110)-water interface, which is more relevant to many applications. In this work, we characterize the structure of the aqueous TiO2(110) interface using nanosecond timescale molecular dynamics simulations with ab initio-based deep neural network potentials that accurately describe water/TiO2(110) interactions over a wide range of water coverages. Simulations on TiO2(110) slab models of increasing thickness provide insight into the dynamic equilibrium between molecular and dissociated adsorbed water at the interface and allow us to obtain a reliable estimate of the equilibrium fraction of water dissociation. We find a dissociation fraction of 22 ± 6% with an associated average hydroxyl lifetime of 7.6 ± 1.8 ns. These quantities are both much larger than corresponding estimates for the aqueous anatase TiO2(101) interface, consistent with the higher water photooxidation activity that is observed for rutile relative to anatase.


Asunto(s)
Simulación de Dinámica Molecular , Agua , Agua/química , Titanio/química
8.
Proc Natl Acad Sci U S A ; 120(29): e2305705120, 2023 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-37428922

RESUMEN

The assimilation of antibiotic resistance genes (ARGs) by pathogenic bacteria poses a severe threat to public health. Here, we reported a dual-reaction-site-modified CoSA/Ti3C2Tx (single cobalt atoms immobilized on Ti3C2Tx MXene) for effectively deactivating extracellular ARGs via peroxymonosulfate (PMS) activation. The enhanced removal of ARGs was attributed to the synergistic effect of adsorption (Ti sites) and degradation (Co-O3 sites). The Ti sites on CoSA/Ti3C2Tx nanosheets bound with PO43- on the phosphate skeletons of ARGs via Ti-O-P coordination interactions, achieving excellent adsorption capacity (10.21 × 1010 copies mg-1) for tetA, and the Co-O3 sites activated PMS into surface-bond hydroxyl radicals (•OHsurface), which can quickly attack the backbones and bases of the adsorbed ARGs, resulting in the efficient in situ degradation of ARGs into inactive small molecular organics and NO3. This dual-reaction-site Fenton-like system exhibited ultrahigh extracellular ARG degradation rate (k > 0.9 min-1) and showed the potential for practical wastewater treatment in a membrane filtration process, which provided insights for extracellular ARG removal via catalysts design.


Asunto(s)
Antibacterianos , Genes Bacterianos , Antibacterianos/farmacología , Cobalto , Titanio/farmacología , Adsorción , Aguas Residuales , Farmacorresistencia Microbiana/genética
9.
FASEB J ; 38(11): e23715, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38837260

RESUMEN

Impaired intestinal permeability induces systemic inflammation and metabolic disturbance. The effect of a leaky gut on metabolism in skeletal muscle, a major nutrient consumer, remains unclear. In this study, we aimed to investigate the glucose metabolic function of the whole body and skeletal muscles in a mouse model of diet-induced intestinal barrier dysfunction. At Week 2, we observed higher intestinal permeability in mice fed a titanium dioxide (TiO2)-containing diet than that of mice fed a normal control diet. Subsequently, systemic glucose and insulin tolerance were found to be impaired. In the skeletal muscle, glucose uptake and phosphorylation levels in insulin signaling were lower in the TiO2 group than those in the control group. Additionally, the levels of pro-inflammatory factors were higher in TiO2-fed mice than those in the control group. We observed higher carboxymethyl-lysin (CML) levels in the plasma and intestines of TiO2-fed mice and lower insulin-dependent glucose uptake in CML-treated cultured myotubes than those in the controls. Finally, soluble dietary fiber supplementation improved glucose and insulin intolerance, suppressed plasma CML, and improved intestinal barrier function. These results suggest that an impaired intestinal barrier leads to systemic glucose intolerance, which is associated with glucose metabolism dysfunction in the skeletal muscles due to circulating CML derived from the intestine. This study highlights that the intestinal condition regulates muscle and systemic metabolic health.


Asunto(s)
Lisina , Músculo Esquelético , Titanio , Animales , Ratones , Músculo Esquelético/metabolismo , Músculo Esquelético/efectos de los fármacos , Masculino , Lisina/análogos & derivados , Lisina/metabolismo , Ratones Endogámicos C57BL , Aditivos Alimentarios/farmacología , Insulina/sangre , Insulina/metabolismo , Glucosa/metabolismo , Intolerancia a la Glucosa/metabolismo , Mucosa Intestinal/metabolismo
10.
Methods ; 225: 74-88, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38493931

RESUMEN

Computational modeling and simulation (CM&S) is a key tool in medical device design, development, and regulatory approval. For example, finite element analysis (FEA) is widely used to understand the mechanical integrity and durability of orthopaedic implants. The ASME V&V 40 standard and supporting FDA guidance provide a framework for establishing model credibility, enabling deeper reliance on CM&S throughout the total product lifecycle. Examples of how to apply the principles outlined in the ASME V&V 40 standard are important to facilitating greater adoption by the medical device community, but few published examples are available that demonstrate best practices. Therefore, this paper outlines an end-to-end (E2E) example of the ASME V&V 40 standard applied to an orthopaedic implant. The objective of this study was to illustrate how to establish the credibility of a computational model intended for use as part of regulatory evaluation. In particular, this study focused on whether a design change to a spinal pedicle screw construct (specifically, the addition of a cannulation to an existing non-cannulated pedicle screw) would compromise the rod-screw construct mechanical performance. This question of interest (?OI) was addressed by establishing model credibility requirements according to the ASME V&V 40 standard. Experimental testing to support model validation was performed using spinal rods and non-cannulated pedicle screw constructs made with medical grade titanium (Ti-6Al-4V ELI). FEA replicating the experimental tests was performed by three independent modelers and validated through comparisons of common mechanical properties such as stiffness and yield force. The validated model was then used to simulate F1717 compression-bending testing on the new cannulated pedicle screw design to answer the ?OI, without performing any additional experimental testing. This E2E example provides a realistic scenario for the application of the ASME V&V 40 standard to orthopedic medical device applications.


Asunto(s)
Análisis de Elementos Finitos , Tornillos Pediculares , Tornillos Pediculares/normas , Humanos , Simulación por Computador , Ensayo de Materiales/métodos , Ensayo de Materiales/normas , Titanio/química , Fuerza Compresiva
11.
Nano Lett ; 24(26): 7821-7824, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38913950

RESUMEN

Liquid-transmission electron microscopy (liquid-TEM) provides exciting potential for capturing mineralization events at biomaterial interfaces, though it is largely unexplored. To address this, we established a unique approach to visualize calcium phosphate (CaP)-titanium (Ti) interfacial mineralization events by combining the nanofabrication of Ti lamellae by focused ion beam with in situ liquid-TEM. Multiphasic CaP particles were observed to nucleate, adhere, and form different assemblies onto and adjacent to Ti lamellae. Here, we discuss new approaches for exploring the interaction between biomaterials and liquids at the nanoscale. Driving this technology is crucial for understanding and controlling biomineralization to improve implant osseointegration and direct new pathways for mineralized tissue disease treatment in the future.


Asunto(s)
Materiales Biocompatibles , Fosfatos de Calcio , Microscopía Electrónica de Transmisión , Titanio , Titanio/química , Materiales Biocompatibles/química , Fosfatos de Calcio/química , Microscopía Electrónica de Transmisión/métodos , Propiedades de Superficie , Oseointegración , Humanos
12.
Nano Lett ; 24(30): 9155-9162, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-38917338

RESUMEN

Herein, we introduce a photobiocidal surface activated by white light. The photobiocidal surface was produced through thermocompressing a mixture of titanium dioxide (TiO2), ultra-high-molecular-weight polyethylene (UHMWPE), and reduced graphene oxide (rGO) powders. A photobiocidal activity was not observed on UHMWPE-TiO2. However, UHMWPE-TiO2@rGO exhibited potent photobiocidal activity (>3-log reduction) against Staphylococcus epidermidis and Escherichia coli bacteria after a 12 h exposure to white light. The activity was even more potent against the phage phi 6 virus, a SARS-CoV-2 surrogate, with a >5-log reduction after 6 h exposure to white light. Our mechanistic studies showed that the UHMWPE-TiO2@rGO was activated only by UV light, which accounts for 0.31% of the light emitted by the white LED lamp, producing reactive oxygen species that are lethal to microbes. This indicates that adding rGO to UHMWPE-TiO2 triggered intense photobiocidal activity even at shallow UV flux levels.


Asunto(s)
Escherichia coli , Grafito , Luz , Polietilenos , Staphylococcus epidermidis , Titanio , Grafito/química , Grafito/farmacología , Grafito/efectos de la radiación , Titanio/química , Titanio/farmacología , Polietilenos/química , Polietilenos/efectos de la radiación , Polietilenos/farmacología , Staphylococcus epidermidis/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Especies Reactivas de Oxígeno/metabolismo , Rayos Ultravioleta
13.
Nano Lett ; 24(20): 6069-6077, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38739779

RESUMEN

Nanoparticles (NPs) can be conjugated with diverse biomolecules and employed in biosensing to detect target analytes in biological samples. This proven concept was primarily used during the COVID-19 pandemic with gold-NP-based lateral flow assays (LFAs). Considering the gold price and its worldwide depletion, here we show that novel plasmonic NPs based on inexpensive metals, titanium nitride (TiN) and copper covered with a gold shell (Cu@Au), perform comparable to or even better than gold nanoparticles. After conjugation, these novel nanoparticles provided high figures of merit for LFA testing, such as high signals and specificity and robust naked-eye signal recognition. Since the main cost of Au NPs in commercial testing kits is the colloidal synthesis, our development with the Cu@Au and the laser-ablation-fabricated TiN NPs is exciting, offering potentially inexpensive plasmonic nanomaterials for various bioapplications. Moreover, our machine learning study showed that biodetection with TiN is more accurate than that with Au.


Asunto(s)
Cobre , Oro , Nanopartículas del Metal , Titanio , Nanopartículas del Metal/química , Titanio/química , Oro/química , Cobre/química , Técnicas Biosensibles/métodos , Técnicas Biosensibles/economía , Humanos , COVID-19/virología , COVID-19/diagnóstico , Oro Coloide/química , SARS-CoV-2/aislamiento & purificación
14.
Nano Lett ; 24(27): 8257-8267, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38920296

RESUMEN

Osseointegration is the most important factor determining implant success. The surface modification of TiO2 nanotubes prepared by anodic oxidation has remarkable advantages in promoting bone formation. However, the mechanism behind this phenomenon is still unintelligible. Here we show that the nanomorphology exhibited open and clean nanotube structure and strong hydrophilicity, and the nanomorphology significantly facilitated the adhesion, proliferation, and osteogenesis differentiation of stem cells. Exploring the mechanism, we found that the nanomorphology can enhance mitochondrial oxidative phosphorylation (OxPhos) by activating Piezo1 and increasing intracellular Ca2+. The increase in OxPhos can significantly uplift the level of acetyl-CoA in the cytoplasm but not significantly raise the level of acetyl-CoA in the nucleus, which was beneficial for the acetylation and stability of ß-catenin and ultimately promoted osteogenesis. This study provides a new interpretation for the regulatory mechanism of stem cell osteogenesis by nanomorphology.


Asunto(s)
Diferenciación Celular , Canales Iónicos , Osteogénesis , Propiedades de Superficie , Titanio , beta Catenina , Osteogénesis/efectos de los fármacos , Titanio/química , Titanio/farmacología , beta Catenina/metabolismo , Canales Iónicos/metabolismo , Diferenciación Celular/efectos de los fármacos , Animales , Proliferación Celular/efectos de los fármacos , Oseointegración/efectos de los fármacos , Ratones , Nanoporos , Nanotubos/química , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Fosforilación Oxidativa/efectos de los fármacos , Prótesis e Implantes , Adhesión Celular/efectos de los fármacos
15.
J Proteome Res ; 23(8): 3294-3309, 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39038167

RESUMEN

Compared to advancements in single-cell proteomics, phosphoproteomics sensitivity has lagged behind due to low abundance, complex sample preparation, and substantial sample input requirements. We present a simple and rapid one-pot phosphoproteomics workflow (SOP-Phos) integrated with data-independent acquisition mass spectrometry (DIA-MS) for microscale phosphoproteomic analysis. SOP-Phos adapts sodium deoxycholate based one-step lysis, reduction/alkylation, direct trypsinization, and phosphopeptide enrichment by TiO2 beads in a single-tube format. By reducing surface adsorptive losses via utilizing n-dodecyl ß-d-maltoside precoated tubes and shortening the digestion time, SOP-Phos is completed within 3-4 h with a 1.4-fold higher identification coverage. SOP-Phos coupled with DIA demonstrated >90% specificity, enhanced sensitivity, lower missing values (<1%), and improved reproducibility (8%-10% CV). With a sample size-comparable spectral library, SOP-Phos-DIA identified 33,787 ± 670 to 22,070 ± 861 phosphopeptides from 5 to 0.5 µg cell lysate and 30,433 ± 284 to 6,548 ± 21 phosphopeptides from 50,000 to 2,500 cells. Such sensitivity enabled mapping key lung cancer signaling sites, such as EGFR autophosphorylation sites Y1197/Y1172 and drug targets. The feasibility of SOP-Phos-DIA was demonstrated on EGFR-TKI sensitive and resistant cells, revealing the interplay of multipathway Hippo-EGFR-ERBB signaling cascades underlying the mechanistic insight into EGFR-TKI resistance. Overall, SOP-Phos-DIA is an efficient and robust protocol that can be easily adapted in the community for microscale phosphoproteomic analysis.


Asunto(s)
Fosfopéptidos , Fosfoproteínas , Proteómica , Flujo de Trabajo , Proteómica/métodos , Humanos , Fosfopéptidos/análisis , Fosfopéptidos/química , Fosfopéptidos/metabolismo , Fosfoproteínas/metabolismo , Fosfoproteínas/análisis , Fosfoproteínas/química , Reproducibilidad de los Resultados , Receptores ErbB/metabolismo , Línea Celular Tumoral , Fosforilación , Titanio/química , Neoplasias Pulmonares/metabolismo , Espectrometría de Masas/métodos
16.
J Cell Mol Med ; 28(7): e18157, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38494857

RESUMEN

Periprosthetic osteolysis (PPO) caused by wear particles is one of the leading causes of implant failure after arthroplasty. Macrophage polarization imbalance and subsequent osteogenic inhibition play a crucial role in PPO. Calycosin (CA) is a compound with anti-inflammatory and osteoprotective properties. This study aimed to evaluate the effects of CA on titanium (Ti) particle-induced osteolysis, Ti particle-induced macrophage polarization and subsequent osteogenic deficits, and explore the associated signalling pathways in a Ti particle-stimulated calvarial osteolysis mouse model using micro-CT, ELISA, qRT-PCR, immunofluorescence and western blot techniques. The results showed that CA alleviated inflammation, osteogenic inhibition and osteolysis in the Ti particle-induced calvarial osteolysis mouse model in vivo. In vitro experiments showed that CA suppressed Ti-induced M1 macrophage polarization, promoted M2 macrophage polarization and ultimately enhanced osteogenic differentiation of MC3T3-E1 cells. In addition, CA alleviated osteogenic deficits by regulating macrophage polarization homeostasis via the NF-κB signalling pathway both in vivo and in vitro. All these findings suggest that CA may prove to be an effective therapeutic agent for wear particle-induced osteolysis.


Asunto(s)
Isoflavonas , Osteogénesis , Osteólisis , Ratones , Animales , Osteólisis/inducido químicamente , Osteólisis/tratamiento farmacológico , Osteólisis/metabolismo , Titanio/toxicidad , Macrófagos/metabolismo
17.
J Cell Mol Med ; 28(6): e18050, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38400579

RESUMEN

Current treatment options available for prostate cancer (PCa) patients have many adverse side effects and hence, new alternative therapies need to be explored. Anticancer potential of various phytochemicals derived from Calotropis procera has been studied in many cancers but no study has investigated the effect of leaf extract of C. procera on PCa cells. Hence, we investigated the effect of C. procera leaf extract (CPE) on cellular properties of androgen-independent PC-3 and androgen-sensitive 22Rv1 cells. A hydroalcoholic extract of C. procera was prepared and MTT assay was performed to study the effect of CPE on viability of PCa cells. The effect of CPE on cell division ability, migration capability and reactive oxygen species (ROS) production was studied using colony formation assay, wound-healing assay and 2',7'-dichlorodihydrofluorescein diacetate assay, respectively. Caspase activity assay and LDH assay were performed to study the involvement of apoptosis and necrosis in CPE-mediated cell death. Protein levels of cell cycle, antioxidant, autophagy and apoptosis markers were measured by western blot. The composition of CPE was identified using untargeted LC-MS analysis. Results showed that CPE decreased the viability of both the PCa cells, PC-3 and 22Rv1, in a dose- and time-dependent manner. Also, CPE significantly inhibited the colony-forming ability, migration and endogenous ROS production in both the cell lines. Furthermore, CPE significantly decreased NF-κB protein levels and increased the protein levels of the cell cycle inhibitor p27. A significant increase in expression of autophagy markers was observed in CPE-treated PC-3 cells while autophagy markers were downregulated in 22Rv1 cells after CPE exposure. Hence, it can be concluded that CPE inhibits PCa cell viability possibly by regulating the autophagy pathway and/or altering the ROS levels. Thus, CPE can be explored as a possible alternative therapeutic agent for PCa.


Asunto(s)
Calotropis , Porcelana Dental , Aleaciones de Cerámica y Metal , Neoplasias de la Próstata , Titanio , Masculino , Humanos , Línea Celular Tumoral , Calotropis/química , Calotropis/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Andrógenos/farmacología , Neoplasias de la Próstata/tratamiento farmacológico , Apoptosis , Extractos Vegetales/farmacología , Extractos Vegetales/química , Autofagia , Proliferación Celular
18.
Anal Chem ; 96(21): 8560-8565, 2024 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-38720190

RESUMEN

In this work, we report a new generation of single microbead bioassay that employs a single BaTiO3 microbead as an optical booster for target biomarker enrichment and optical enhancement toward protein and nucleic acid analysis. The single BaTiO3 microbead can not only concentrate the target molecules by nearly 104-fold but also act as an optical booster to prominently enhance the target-induced fluorescence signal by the whispering gallery mode for improving the excitation efficiency and the microlens effect for promoting the signal collecting efficiency, respectively. Compared with using a conventional single microbead, this optical booster exhibits nearly 2 orders of magnitude higher sensitivity without the assistance of any signal amplification techniques or costly instruments. Moreover, this single microbead optical booster is capable of detecting different kinds of protein and nucleic acid biomarkers in a simple mix-and-read manner, holding great potential for early clinical diagnosis.


Asunto(s)
Compuestos de Bario , Técnicas Biosensibles , Titanio , Compuestos de Bario/química , Titanio/química , Fluorescencia , Humanos , Espectrometría de Fluorescencia
19.
Anal Chem ; 96(13): 5106-5114, 2024 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-38490960

RESUMEN

In this work, a novel MXene-Au nanoparticle (Ti3C2@Au) was synthesized with a high molar extinction coefficient, strong fluorescence quenching ability, ultrahigh antibody affinity, high stability, and good dispersibility, and it was used to develop a colorimetric-fluorescence dual-mode lateral flow immunoassay (LFIA). The detection limits of this method for the detection of dexamethasone in milk, beef, and pork were 0.0018, 0.12, and 0.084 µg/kg in the "turn-off" mode (colorimetric signal), and 0.0013, 0.080, and 0.070 µg/kg in the "turn-on" mode (fluorescent signal), respectively, which was up to 231-fold more sensitive compared with that of the reported LFIAs. The recovery rates ranged from 81.1-113.7%, and 89.2-115.4%, with the coefficients of variation ranging from 1.4-15.0%, and 1.9-14.8%, respectively. The results of the LC-MS/MS confirmation test on 30 real samples had a good correlation with that of our established method (R2 > 0.97). This work not only developed novel nanocarriers for antibody-based LFIA but also ensured high-performance detection.


Asunto(s)
Oro , Nanopartículas del Metal , Animales , Bovinos , Colorimetría , Cromatografía Liquida , Espectrometría de Masas en Tándem , Titanio , Inmunoensayo/métodos , Límite de Detección
20.
Anal Chem ; 96(9): 3914-3924, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-38387027

RESUMEN

Wearable, noninvasive sensors enable the continuous monitoring of metabolites in sweat and provide clinical information related to an individual's health and disease states. Uric acid (UA) is a key indicator highly associated with gout, hyperuricaemia, hypertension, kidney disease, and Lesch-Nyhan syndrome. However, the detection of UA levels typically relies on invasive blood tests. Therefore, developing a wearable device for noninvasive monitoring of UA concentrations in sweat could facilitate real-time personalized disease prevention. Here, we introduce 1,3,6,8-pyrene tetrasulfonic acid sodium salt (PyTS) as a bifunctional molecule functionalized with Ti3C2Tx via π-π conjugation to design nonenzymatic wearable sensors for sensitive and selective detection of UA concentration in human sweat. PyTS@Ti3C2Tx provides many oxidation-reduction active groups to enhance the electrocatalytic ability of the UA oxidation reaction. The PyTS@Ti3C2Tx-based electrochemical sensor demonstrates highly sensitive detection of UA in the concentration range of 5 µM-100 µM, exhibiting a lower detection limit of 0.48 µM compared to the uricase-based sensor (0.84 µM). In volunteers, the PyTS@Ti3C2Tx-based wearable sensor is integrated with flexible microfluidic sweat sampling and wireless electronics to enable real-time monitoring of UA levels during aerobic exercise. Simultaneously, it allows for comparison of blood UA levels via a commercial UA analyzer. Herein, this study provides a promising electrocatalyst strategy for nonenzymatic electrochemical UA sensor, enabling noninvasive real-time monitoring of UA levels in human sweat and personalized disease prevention.


Asunto(s)
Técnicas Biosensibles , Nitritos , Elementos de Transición , Dispositivos Electrónicos Vestibles , Humanos , Ácido Úrico/análisis , Titanio/análisis , Sudor/química
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