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1.
Nano Lett ; 24(14): 4091-4100, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38489158

RESUMO

Catalytic cancer therapy targets cancer cells by exploiting the specific characteristics of the tumor microenvironment (TME). TME-based catalytic strategies rely on the use of molecules already present in the TME. Amino groups seem to be a suitable target, given the abundance of proteins and peptides in biological environments. Here we show that catalytic CuFe2O4 nanoparticles are able to foster transaminations with different amino acids and pyruvate, another key molecule present in the TME. We observed a significant in cellulo decrease in glutamine and alanine levels up to 48 h after treatment. In addition, we found that di- and tripeptides also undergo catalytic transamination, thereby extending the range of the effects to other molecules such as glutathione disulfide (GSSG). Mechanistic calculations for GSSG transamination revealed the formation of an imine between the oxo group of pyruvate and the free -NH2 group of GSSG. Our results highlight transamination as alternative to the existing toolbox of catalytic therapies.


Assuntos
Aminoácidos , Neoplasias , Aminoácidos/química , Dissulfeto de Glutationa , Microambiente Tumoral , Aminas , Ácido Pirúvico , Catálise
2.
Isotopes Environ Health Stud ; 60(2): 141-161, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38270129

RESUMO

We characterized the elemental and C and N stable isotope compositions of Tillandsia fasciculata Sw., Tillandsia balbisiana Schult. & Schult.f. and Tillandsia recurvata (L.) L. samples collected in Cienfuegos (Cuba). Results showed high enrichment factors for S, Hg, Cd, Pb, P, Zn, Cu, Mo, Sb and Ca in all Tillandsia species, indicating inputs from local anthropogenic activities (road traffic, industries and cement production). Carbon concentrations and δ13C varied from 38.3-47.7 % and -20.4 to -13.4 ‰ within the three species, respectively. δ13C showed seasonal dependence with the dry and wet periods and more 13C-depleted values in urban/industrial areas, coherent with the input of anthropogenic emissions. Nitrogen concentrations (0.4-1.3 %) and δ15N values (-9.9-4.4 ‰) exhibit larger variations and are positively correlated in the three species. The most positive δ15N in T. recurvata (-0.2-4.4 ‰) are attributed to contributions from industrial activities and road traffic. In fact, both δ15N and total nitrogen (TN) values increase in sites with higher road traffic and show significant correlations with typical road traffic and industrial tracers. Finally, we calculate an average total nitrogen deposition rate of 4.4 ± 2.3 kg ha-1 a-1 from N content in T. recurvata, similar to the existing values determined in the region by field measurements, but higher than the global terrestrial average.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Tillandsia , Tillandsia/química , Poluentes Atmosféricos/análise , Monitoramento Biológico , Monitoramento Ambiental/métodos , Poluição do Ar/análise , Região do Caribe , Nitrogênio , Isótopos
3.
Small ; : e2309283, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38230862

RESUMO

The appeal of carbon dots (CDs) has grown recently, due to their established biocompatibility, adjustable photoluminescence properties, and excellent water solubility. For the first time in the literature, copper chlorophyllin-based carbon dots (Chl-D CDs) are successfully synthesized. Chl-D CDs exhibit unique spectroscopic traits and are found to induce a Fenton-like reaction, augmenting photodynamic therapy (PDT) efficacies via ferroptotic and apoptotic pathways. To bolster the therapeutic impact of Chl-D CDs, a widely used cancer drug, temozolomide, is linked to their surface, yielding a synergistic effect with PDT and chemotherapy. Chl-D CDs' biocompatibility in immune cells and in vivo models showed great clinical potential.Proteomic analysis was conducted to understand Chl-D CDs' underlying cancer treatment mechanism. The study underscores the role of reactive oxygen species formation and pointed toward various oxidative stress modulators like aldolase A (ALDOA), aldolase C (ALDOC), aldehyde dehydrogenase 1B1 (ALDH1B1), transaldolase 1 (TALDO1), and transketolase (TKT), offering a deeper understanding of the Chl-D CDs' anticancer activity. Notably, the Chl-D CDs' capacity to trigger a Fenton-like reaction leads to enhanced PDT efficiencies through ferroptotic and apoptotic pathways. Hence, it is firmly believed that the inherent attributes of Chl-CDs can lead to a secure and efficient combined cancer therapy.

4.
Sci Adv ; 9(37): eadi8219, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37713491

RESUMO

Nonoxidative propane dehydrogenation (PDH) produces on-site propylene for value-added chemicals. While commercial, its modest selectivity and catalyst deactivation hamper the process efficiency and limit operation to lower temperatures. We demonstrate PDH in a microwave (MW)-heated reactor over PtSn/SiO2 catalyst pellets loaded in a SiC monolith acting as MW susceptor and a heat distributor while ensuring comparable conditions with conventional reactors. Time-on-stream experiments show active and stable operation at 500°C without hydrogen addition. Upon increasing temperature or feed partial pressure at high space velocity, catalysts under MWs show resistance in coking and sintering, high activity, and selectivity, starkly contrasting conventional reactors whose catalyst undergoes deactivation. Mechanistic differences in coke formation are exposed. Gas-solid temperature gradients are computationally investigated, and nanoscale temperature inhomogeneities are proposed to rationalize the different performances of the heating modes. The approach highlights the great potential of electrification of endothermic catalytic reactions.

5.
Nanoscale ; 15(35): 14399-14408, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37609926

RESUMO

Catalytic conversion of glucose represents an interesting field of research with multiple applications. From the biotechnology point of view, glucose conversion leads to the fabrication of different added-value by-products. In the field of nanocatalytic medicine, the reduction of glucose levels within the tumor microenvironment (TME) represents an appealing approach based on the starvation of cancer cells. Glucose typically achieves high conversion rates with the aid of glucose oxidase (GOx) enzymes or by fermentation. GOx is subjected to degradation, possesses poor recyclability and operates under very specific reaction conditions. Gold-based materials have been typically explored as inorganic catalytic alternatives to GOx in order to convert glucose into building block chemicals of interest. Still, the lack of sufficient selectivity towards certain products such as gluconolactone, the requirement of high fluxes of oxygen or the critical size dependency hinder their full potential, especially in liquid phase reactions. The present work describes the synthesis of platinum-based nanodendrites as novel enzyme-mimicking inorganic surrogates able to convert glucose into gluconolactone with outstanding selectivity values above 85%. We have also studied the enzymatic behavior of these Pt-based nanozymes using the Michaelis-Menten and Lineweaver-Burk models and used the main calculation approaches available in the literature to determine highly competitive glucose turnover rates for Pt or Pt-Au nanodendrites.


Assuntos
Gluconatos , Glucose Oxidase , Catálise , Glucose , Platina
6.
Nanoscale Adv ; 5(14): 3749-3760, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37441254

RESUMO

In vivo cell tracking by non-invasive imaging technologies is needed to accelerate the clinical translation of innovative cell-based therapies. In this regard, 19F-MRI has recently gained increased attention for unbiased localization of labeled cells over time. To push forward the use of 19F-MRI for cell tracking, the development of highly performant 19F-probes is required. PLGA-based NPs containing PERFECTA, a multibranched superfluorinated molecule with an optimal MRI profile thanks to its 36 magnetically equivalent fluorine atoms, are promising 19F-MRI probes. In this work we demonstrate the importance of the surface functionalization of these NPs in relation to their interaction with the biological environment, stressing the pivotal role of the formation of the protein corona (PC) in their cellular labelling efficacy. In particular, our studies showed that the formation of PC NPs strongly promotes the cellular internalization of these NPs in microglia cells. We advocate that the formation of PC NPs in the culture medium can be a key element to be used for the optimization of cell labelling with a considerable increase of the detection sensitivity by 19F-MRI.

7.
Cancers (Basel) ; 15(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37173946

RESUMO

Small extracellular vesicle (EV) membranes display characteristic protein-lipidic composition features that are related to their cell of origin, providing valuable clues regarding their parental cell composition and real-time state. This could be especially interesting in the case of cancer cell-derived EVs, as their membranes could serve as valuable tools in liquid biopsy applications and to detect changes in the tumor malignancy. X-Ray Photoelectron Spectroscopy (XPS) is a powerful surface analysis technique able to detect every chemical element present, being also sensitive to their chemical environment. Here we explore the use of XPS as a fast technique to characterize EV membrane composition, with possible application in cancer research. Notably, we have focused on the nitrogen environment as an indicator of the relative abundance of pyridine-type bonding, primary, secondary and tertiary amines. Specifically, we have analyzed how tumoral and healthy cells have different nitrogen chemical environments that can indicate the presence or absence of malignancy. In addition, a collection of human serum samples from cancer patients and healthy donors was also analyzed. The differential XPS analysis of EVs collected from patients confirmed that the patterns of amine evolution could be related to markers of cancer disease, opening the possibility of their use as a non-invasive blood biomarker.

8.
ACS Nano ; 17(6): 5984-5993, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36916800

RESUMO

2D materials display exciting properties in numerous fields, but the development of applications is hindered by the low yields, high processing times, and impaired quality of current exfoliation methods. In this work we have used the excellent MW absorption properties of MoS2 to induce a fast heating that produces the near-instantaneous evaporation of an adsorbed, low boiling point solvent. The sudden evaporation creates an internal pressure that separates the MoS2 layers with high efficiency, and these are kept separated by the action of the dispersion solvent. Our fast method (90 s) gives high yields (47% at 0.2 mg/mL, 35% at 1 mg/mL) of highly exfoliated material (90% under 4 layers), large area (up to several µm2), and excellent quality (no significant MoO3 detected).

9.
Artigo em Inglês | MEDLINE | ID: mdl-36780137

RESUMO

Extracellular vesicles (EVs) play a crucial role in cell-to-cell communication and have great potential as efficient delivery vectors. However, a better understanding of EV in vivo behavior is hampered by the limitations of current imaging tools. In addition, chemical labels present the risk of altering the EV membrane features and, thus, in vivo behavior. 19F-MRI is a safe bioimaging technique providing selective images of exogenous probes. Here, we present the first example of fluorinated EVs containing PERFECTA, a branched molecule with 36 magnetically equivalent 19F atoms. A PERFECTA emulsion is given to the cells, and PERFECTA-containing EVs are naturally produced. PERFECTA-EVs maintain the physicochemical features, morphology, and biological fingerprint as native EVs but exhibit an intense 19F-NMR signal and excellent 19F relaxation times. In vivo 19F-MRI and tumor-targeting capabilities of stem cell-derived PERFECTA-EVs are also proved. We propose PERFECTA-EVs as promising biohybrids for imaging biodistribution and delivery of EVs throughout the body.

10.
Nano Lett ; 23(3): 804-811, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36648322

RESUMO

Bioorthogonal metallocatalysis has opened up a xenobiotic route to perform nonenzymatic catalytic transformations in living settings. Despite their promising features, most metals are deactivated inside cells by a myriad of reactive biomolecules, including biogenic thiols, thereby limiting the catalytic functioning of these abiotic reagents. Here we report the development of cytocompatible alloyed AuPd nanoparticles with the capacity to elicit bioorthogonal depropargylations with high efficiency in biological media. We also show that the intracellular catalytic performance of these nanoalloys is significantly enhanced by protecting them following two different encapsulation methods. Encapsulation in mesoporous silica nanorods resulted in augmented catalyst reactivity, whereas the use of a biodegradable PLGA matrix increased nanoalloy delivery across the cell membrane. The functional potential of encapsulated AuPd was demonstrated by releasing the potent chemotherapy drug paclitaxel inside cancer cells. Nanoalloy encapsulation provides a novel methodology to develop nanoreactors capable of mediating new-to-life reactions in cells.


Assuntos
Nanotubos , Paládio , Ligas , Paclitaxel , Catálise
11.
Pharmaceutics ; 14(12)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36559257

RESUMO

The inhaled route is regarded as one of the most promising strategies as a treatment against pulmonary infections. However, the delivery of drugs in a dry powder form remains challenging. In this work, we have used alginate to form microparticles containing an antibiotic model (colistin sulfate). The alginate microparticles were generated by atomization technique, and they were characterized by antimicrobial in vitro studies against Pseudomonas aeruginosa. Optimization of different parameters allowed us to obtain microparticles as a dry powder with a mean size (Feret diameter) of 4.45 ± 1.40 µm and drug loading of 8.5 ± 1.50%. The process developed was able to concentrate most of the colistin deposits on the surface of the microparticles, which could be observed by SEM and a Dual-Beam microscope. This produces a fast in vitro release of the drug, with a 100% release achieved in 4 h. Physicochemical characterization using the FTIR, EDX and PXRD techniques revealed information about the change that occurs from the amorphous to a crystalline form of colistin. Finally, the cytotoxicity of microparticles was tested using lung cell lines (A549 and Calu-3). Results of the study showed that alginate microparticles were able to inhibit bacterial growth while displaying non-toxicity toward lung cells.

12.
Rev. latinoam. cienc. soc. niñez juv ; 20(3): 239-270, sep.-dic. 2022. graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1424008

RESUMO

Resumen (analítico) Este estudio tiene como objetivo describir la adaptación de las ideas de la cognición 4E en el estudio del aprendizaje de las matemáticas en la investigación contemporánea, de manera que pueda proporcionar estrategias para cualificar los procesos pedagógicos y didácticos en las aulas en tiempos de pospandemia. Se realizó la búsqueda de artículos a texto completo en las bases de datos Science Direct y Ebsco Academic Search Ultimate, de los últimos cuatro años. Se seleccionaron 56 artículos, que se analizaron mediante análisis de conglomerados, nubes de palabras y mapas jerárquicos en Nvivo 11. Se obtuvieron cuatro núcleos temáticos (andamiaje, trayectoria socio-cultural, numerosidad y adquisición de conceptos básicos en matemáticas y exploración de nichos matemáticos) que permiten avanzar en la implementación de mejoras en la enseñanza y el aprendizaje en pospandemia.


Abstract (analytical) This study aims to describe the adaptation of the ideas of 4E cognition in research on Mathematics learning in contemporary research. These ideas can provide strategies to improve pedagogical and didactic processes in classrooms during the post-pandemic period. Fulltext articles published in the last 4 years were searched for in the Science Direct and Ebsco Academic Search Ultimate databases. A total of 56 articles were selected and were analyzed through the generation of cluster analysis, word clouds and hierarchical maps in the NVivo 11 software. Four thematic cores were identified (scaffolding; sociocultural trajectory; numeracy and acquisition of basic concepts in mathematics; and exploration of mathematical niches) that contribute to improvements in teaching and learning in the post-pandemic period.


Resumo (analítico) Este estudo tem como objetivo descrever a adaptação das ideias da cognição 4E no estudo da aprendizagem da Matemática na pesquisa contemporânea, de modo que possa fornecer estratégias para qualificar processos pedagógicos e didáticos em sala de aula em tempos pós-pandêmicos. Artigos de texto completo foram pesquisados nas bases de dados Science Direct e Ebsco Academic Search Ultimate nos últimos 4 anos. Foram selecionados 56 artigos, os quais foram analisados por meio de análise de cluster, nuvem de palavras e mapas hierárquicos no Nvivo 11. Foram obtidos quatro núcleos temáticos (andaimes, trajetória sociocultural, multiplicidade e aquisição de conceitos básicos em matemática e exploração de nichos matemáticos) que permitem avançar na implementação de melhorias no ensino e aprendizagem no pós-pandemia.

13.
J Nanobiotechnology ; 20(1): 473, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36335359

RESUMO

BACKGROUND: Platinum nanoparticles have been demonstrated to have excellent anticancer properties. However, because of the lack of specificity they must be delivered to the tumor in amounts sufficient to reach the desired therapeutic objectives. Interestingly, exosomes are considered as excellent natural selective delivery nanotools, but until know their targeting properties have not being combined with the anticancer properties of platinum nanoparticles. RESULTS: In this work we combine the targeting capabilities of exosomes and the antitumoral properties of ultrasmall (< 2 nm) platinum nanoparticles as a novel, low toxicity alternative to the use of cisplatin. A mild methodology based on the room temperature CO-assisted in situ reduction of Pt2+ precursor was employed to preserve the integrity of exosomes, while generating ultrasmall therapeutic PtNPs directly inside the vesicles. The resulting PtNPs-loaded exosomes constitute a novel hybrid bioartificial system that was readily internalized by the target cells inducing antiproliferative response, as shown by flow cytometry and microscopy experiments in vitro. In vivo Pt-Exos showed antitumoral properties similar to that of cisplatin but with a strongly reduced or in some cases no toxic effect, highlighting the advantages of this approach and its potential for translation to the clinic. CONCLUSIONS: In this study, a nanoscale vector based on ultrasmall PtNPs and exosomes has been created exhibiting antitumoral properties comparable or higher to those of the FDA approved cisplatin. The preferential uptake of PtNPs mediated by exosomal transfer between certain cell types has been exploited to create a selective antitumoral novel bioartificial system. We have demonstrated their anticancer properties both in vitro and in vivo comparing the results obtained with the administration of equivalent amounts of cisplatin, and showing a spectacular reduction of toxicity.


Assuntos
Exossomos , Nanopartículas Metálicas , Nanopartículas , Neoplasias , Humanos , Cisplatino/farmacologia , Platina , Linhagem Celular Tumoral
14.
Colloids Surf B Biointerfaces ; 220: 112932, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36272281

RESUMO

Fluorine-19 (19F) Magnetic Resonance Imaging (MRI) is an emergent imaging technique for molecular imaging and cell tracking. Lack of intrinsic 19F signals in tissues allows unambiguous in vivo detection of exogenous fluorinated probes, complementary to the anatomical and multiparametric information obtained by standard 1H-MRI. However, the intrinsic low sensitivity of MRI technique requires the need of designing increasingly effective fluorinated tracers. PERFECTA, with its 36 magnetically equivalent 19F atoms and a designed branched molecular structure, represents an excellent superfluorinated tracer. In this paper, we report the development of PERFECTA loaded PLGA NPs stabilized by different coatings as promising 19F-MRI probes. The results clearly show the optimal cellular uptake of the produced colloidally stable PERFECTA loaded PLGA NPs without impact on cells viability. Importantly, NPs stabilization with the anionic surfactant sodium cholate (NaC) clearly enhances NPs internalization within cells with respect to PVA-coated NPs. Moreover, the optimized NPs are characterized by shorter T1 relaxation times with respect to other PERFECTA formulations that would allow the increase of 19F-MRI sensitivity with fast imaging acquisitions.


Assuntos
Nanopartículas , Nanopartículas/química , Imageamento por Ressonância Magnética , Rastreamento de Células , Sobrevivência Celular , Estrutura Molecular
15.
Chem Sci ; 13(28): 8307-8320, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35919722

RESUMO

The present work sheds light on a generally overlooked issue in the emerging field of bio-orthogonal catalysis within tumour microenvironments (TMEs): the interplay between homogeneous and heterogeneous catalytic processes. In most cases, previous works dealing with nanoparticle-based catalysis in the TME focus on the effects obtained (e.g. tumour cell death) and attribute the results to heterogeneous processes alone. The specific mechanisms are rarely substantiated and, furthermore, the possibility of a significant contribution of homogeneous processes by leached species - and the complexes that they may form with biomolecules - is neither contemplated nor pursued. Herein, we have designed a bimetallic catalyst nanoparticle containing Cu and Fe species and we have been able to describe the whole picture in a more complex scenario where both homogeneous and heterogeneous processes are coupled and fostered under TME relevant chemical conditions. We investigate the preferential leaching of Cu ions in the presence of a TME overexpressed biomolecule such as glutathione (GSH). We demonstrate that these homogeneous processes initiated by the released by Cu-GSH interactions are in fact responsible for the greater part of the cell death effects found (GSH, a scavenger of reactive oxygen species, is depleted and highly active superoxide anions are generated in the same catalytic cycle). The remaining solid CuFe nanoparticle becomes an active catalyst to supply oxygen from oxygen reduced species, such as superoxide anions (by-product from GSH oxidation) and hydrogen peroxide, another species that is enriched in the TME. This activity is essential to sustain the homogeneous catalytic cycle in the oxygen-deprived tumour microenvironment. The combined heterogeneous-homogeneous mechanisms revealed themselves as highly efficient in selectively killing cancer cells, due to their higher GSH levels compared to healthy cell lines.

16.
Chem Soc Rev ; 51(17): 7662-7681, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-35983786

RESUMO

Platinum nanoparticles (Pt NPs) have a well-established role as a classic heterogeneous catalyst. Also, Pt has traditionally been employed as a component of organometallic drug formulations for chemotherapy. However, a new role in cancer therapy is emerging thanks to its outstanding catalytic properties, enabling novel approaches that are surveyed in this review. Herein, we critically discuss results already obtained and attempt to ascertain future perspectives for Pt NPs as catalysts able to modify key processes taking place in the tumour microenvironment (TME). In addition, we explore relevant parameters affecting the cytotoxicity, biodistribution and clearance of Pt nanosystems. We also analyze pros and cons in terms of biocompatibility and potential synergies that emerge from combining the catalytic capabilities of Pt with other agents such as co-catalysts, external energy sources (near-infrared light, X-ray, electric currents) and conventional therapies.


Assuntos
Nanopartículas Metálicas , Neoplasias , Catálise , Humanos , Neoplasias/tratamento farmacológico , Platina , Distribuição Tecidual , Microambiente Tumoral
17.
Nanoscale ; 14(19): 7332-7340, 2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35535713

RESUMO

Ethylene oxide is one of the most important raw materials in the chemical industry, with an annual production close to 35 million metric tons. Despite its importance, to date, no metal has been found that can compete with the original silver bulk material catalyst discovered in 1931. Recently, a few copper and copper-silver based nanostructures have demonstrated remarkable selectivity and activity, especially when coupled with an industrial chlorine promoter. The present work evaluates the mechanistic role of chlorine as an active promoter of the selective oxidation of ethylene to ethylene oxide in the presence of a silver-copper oxide hybrid nanocatalyst (AgCuO). Experimental kinetic studies combined with density functional theory (DFT) calculations provide insight into the influence that Ag/CuO-supported chlorine atoms have over the ethylene epoxidation reaction. Remarkably, the typically described indirect route via the formation of an oxametallacycle (OMC) is also accompanied by a direct route. Furthermore, the presence of chlorine seems to facilitate a more favorable adsorption energy for ethylene oxide (EO) than for acetaldehyde (AA), the main reaction by-product. As a result, complete oxidation of EO can be further prevented in the presence of this AgCuO hybrid heteronanostructure.

18.
Nat Chem ; 14(6): 695-700, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35469006

RESUMO

The most widespread method for the synthesis of 2D-2D heterostructures is the direct growth of one material on top of the other. Alternatively, flakes of different materials can be manually stacked on top of each other. Both methods typically involve stacking 2D layers through van der Waals forces-such that these materials are often referred to as van der Waals heterostructures-and are stacked one crystal or one device at a time. Here we describe the covalent grafting of 2H-MoS2 flakes onto graphene monolayers embedded in field-effect transistors. A bifunctional molecule featuring a maleimide and a diazonium functional group was used, known to connect to sulfide- and carbon-based materials, respectively. MoS2 flakes were exfoliated, functionalized by reaction with the maleimide moieties and then anchored to graphene by the diazonium groups. This approach enabled the simultaneous functionalization of several devices. The electronic properties of the resulting heterostructure are shown to be dominated by the MoS2-graphene interface.

19.
J Colloid Interface Sci ; 617: 704-717, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35316784

RESUMO

Heterogeneous catalysis has emerged as a promising alternative for the development of new cancer therapies. In addition, regarding the tumor microenvironment as a reactor with very specific chemical features has provided a new perspective in the search for catalytic nanoarchitectures with specific action against chemical species playing a key role in tumor metabolism. One of these species is glutathione (GSH), whose depletion is the cornerstone of emerging strategies in oncology, since this metabolite plays a pivotal regulatory role as antioxidant agent, dampening the harmful effects of intracellular reactive oxidative species (ROS). Herein, we present copper-iron oxide spinel nanoparticles that exhibit a versatile and selective catalytic response to reduce GSH levels while generating ROS in a cascade reaction. We demonstrate a clear correlation between GSH depletion and apoptotic cell death in tumor cells in the presence of the copper-iron nanocatalyst. Furthermore, we also provide a novel analytical protocol, alternative to state-of-the-art commercial kits, to accurately monitoring the concentration of GSH intracellular levels in both tumor and healthy cells. We observe a selective action of the nanoparticles, with lower toxicity in healthy cell lines, whose intrinsic GSH levels are lower, and intense apoptosis in tumor cells accompanied by a fast reduction of GSH levels.


Assuntos
Nanopartículas , Neoplasias , Catálise , Linhagem Celular Tumoral , Cobre/farmacologia , Glutationa/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Ferro/farmacologia , Neoplasias/tratamento farmacológico , Óxidos/farmacologia , Espécies Reativas de Oxigênio , Microambiente Tumoral
20.
J Extracell Vesicles ; 11(3): e12193, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35257503

RESUMO

The main current challenges in oncology are (1) avoiding systemic side effects in therapy, and (2) developing alternative treatment strategies for metastatic tumours. Nanomedicine was assumed to provide answers to these issues, but delivering enough therapeutic nanoparticles (NPs) to tumours still remains a huge challenge in nanomaterials-based treatments. Extracellular vesicles (EVs) play a key role in cell communication processes and can be combined with nanomaterials to improve their targeting capabilities. In this work, we leverage the ability of EVs derived from stem cells to reach tumour areas successfully, being used as delivery vehicles for nanoparticles acting as hyperthermia agents. Once small extracellular vesicles (sEVs) loaded with NIR-sensitive hollow gold NPs reached primary subcutaneous solid tumours, they were irradiated with a NIR laser and almost complete tumour remission was obtained. More interestingly, those sEV vehicles were also able to reach multinodular areas similar to those on advanced metastatic phases, eradicating most tumour growth regions in multiple cancerous nodules located in the pancreas region.


Assuntos
Vesículas Extracelulares , Hipertermia Induzida , Nanopartículas , Linhagem Celular Tumoral , Nanopartículas/uso terapêutico , Células-Tronco
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