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1.
Angew Chem Int Ed Engl ; 63(6): e202315280, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38088497

RESUMO

We report the first experimental evidence for rapid formation of hydrogen clathrates under mild pressure and temperature conditions within the cavities of a zirconium-metalloporphyrin framework, specifically PCN-222. PCN-222 has been selected for its 1D mesoporous channels, high water-stability, and proper hydrophilic behavior. Firstly, we optimize a microwave (MW)-assisted method for the synthesis of nanosized PCN-222 particles with precise structure control (exceptional homogeneity in morphology and crystalline phase purity), taking advantage of MW in terms of rapid/homogeneous heating, time and energy savings, as well as potential scalability of the synthetic method. Second, we explore the relevance of the large mesoporous 1D open channels within the PCN-222 to promote the nucleation and growth of confined hydrogen clathrates. Experimental results show that PCN-222 drives the nucleation process at a lower pressure than the bulk system (1.35 kbar vs 2 kbar), with fast kinetics (minutes), using pure water, and with a nearly complete water-to-hydrate conversion. Unfortunately, PCN-222 cannot withstand these high pressures, which lead to a significant alteration of the mesoporous structure while the microporous network remains mainly unchanged.

2.
Nanoscale Horiz ; 8(12): 1700-1710, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37819240

RESUMO

A selenium-containing metal-organic framework with remarkable antioxidant capacity and ROS-scavenging activity was constructed by a controlled de novo encapsulation approach of a glycoconjugate mimetic, specifically a sp2-iminoglycolipid bearing a selenoureido fragment (DSeU), within a zeolitic-imidazolate framework exoskeleton. Biocompatible and homogeneous nanosized particles of ∼70 nm (DSeU@ZIF8) were obtained, which could be efficiently internalized in cells, overcoming the poor solubility in biological media and limited bioavailability of glycolipids. The ZIF-particle served as nanocarrier for the intracellular delivery of the selenocompound to cells, promoted by the acidic pH inside endosomes/lysosomes. As demonstrated by in vitro studies, the designed DSeU@ZIF8 nanoparticles displayed a high antioxidant activity at low doses; lower intracellular ROS levels were observed upon the uptake of DSeU@ZIF8 by human endothelial cells. Even more interesting was the finding that these DSeU@ZIF8 particles were able to reverse to a certain level the oxidative stress induced in cells by pre-treatment with an oxidizing agent. This possibility of modulating the oxidative stress in living cells may have important implications in the treatment of diverse pathological complications that are generally accompanied with elevated ROS levels.


Assuntos
Antioxidantes , Nanopartículas , Humanos , Antioxidantes/uso terapêutico , Células Endoteliais , Espécies Reativas de Oxigênio , Estresse Oxidativo
3.
ACS Appl Mater Interfaces ; 15(23): 27600-27611, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37249914

RESUMO

We report for the first time the controlled drug release from a nanoscale Zr-based metal-organic framework (MOF), UiO-66, in the presence of the enzyme alkaline phosphatase (ALP). This unprecedented reactivity was possible thanks to the prior functionalization of the MOF with N3-PEG-PO3 ligands, which were designed for three specific aims: (1) to impart colloidal stability in phosphate-containing media; (2) to endow the MOF with multifunctionality thanks to azide groups for the covalent attachment of an imaging agent by click-chemistry; and (3) to confer stimuli-responsive properties, specifically the selective release of doxorubicin triggered by the enzymatic activity of ALP. Cell studies revealed that the functionalization of the MOF with N3-(PEG)20-PO3 ligands improved their intracellular stability and led to a sustained drug release compared to the bare MOF. More importantly, an enhanced drug release was observed in cells with higher expression of ALP genes (HeLa versus MDA-MB-231 and MCF7), confirming the ALP-responsiveness of the system inside living cells.


Assuntos
Estruturas Metalorgânicas , Humanos , Estruturas Metalorgânicas/química , Fosfatos , Ligantes , Sistemas de Liberação de Medicamentos , Doxorrubicina/farmacologia , Doxorrubicina/química , Liberação Controlada de Fármacos
4.
Anal Bioanal Chem ; 415(11): 2005-2023, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36598537

RESUMO

The deployment of metal-organic frameworks (MOFs) in a plethora of analytical and bioanalytical applications is a growing research area. Their unique properties such as high but tunable porosity, well-defined channels or pores, and ease of post-synthetic modification to incorporate additional functional units make them ideal candidates for sensing applications. This is possible because the interaction of analytes with a MOF often results in a change in its structure, eventually leading to a modification of the intrinsic physicochemical properties of the MOF which is then transduced into a measurable signal. The high porosity allows for the adsorption of analytes very efficiently, while the tunable pore sizes/nature and/or installation of specific recognition groups allow modulating the affinity towards different classes of compounds, which in turn lead to good sensor sensitivity and selectivity, respectively. Some figures are given to illustrate the potential of MOF-based sensors in the most relevant application fields, and future challenges and opportunities to their possible translation from academia (i.e., laboratory testing of MOF sensing properties) to industry (i.e., real-world analytical sensor devices) are critically discussed.

5.
Nanoscale ; 14(47): 17543-17549, 2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36421023

RESUMO

We demonstrate for the first time the potential of zeolitic-imidazolate framework-8 nanoparticles to be incorporated within a renal scaffold while retaining their ability to remove uremic toxins (mainly hydrophobic toxins like p-cresol) under flow conditions. This work may pave the way for the future development of novel adsorbents for dialysis and/or artificial kidneys.


Assuntos
Zeolitas , Rim
6.
Front Physiol ; 13: 848172, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35360235

RESUMO

The human body is a complex system maintained in homeostasis thanks to the interactions between multiple physiological regulation systems. When faced with physical or biological perturbations, this system must react by keeping a balance between adaptability and robustness. The SARS-COV-2 virus infection poses an immune system challenge that tests the organism's homeostatic response. Notably, the elderly and men are particularly vulnerable to severe disease, poor outcomes, and death. Mexico seems to have more infected young men than anywhere else. The goal of this study is to determine the differences in the relationships that link physiological variables that characterize the elderly and men, and those that characterize fatal outcomes in young men. To accomplish this, we examined a database of patients with moderate to severe COVID-19 (471 men and 277 women) registered at the "Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán" in March 2020. The sample was stratified by outcome, age, and sex. Physiological networks were built using 67 physiological variables (vital signs, anthropometric, hematic, biochemical, and tomographic variables) recorded upon hospital admission. Individual variables and system behavior were examined by descriptive statistics, differences between groups, principal component analysis, and network analysis. We show how topological network properties, particularly clustering coefficient, become disrupted in disease. Finally, anthropometric, metabolic, inflammatory, and pulmonary cluster interaction characterize the deceased young male group.

7.
Front Nutr ; 9: 813485, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35155539

RESUMO

INTRODUCTION: Coronavirus disease (COVID-19) is a global pandemic. Vitamin D deficiency has been associated with susceptibility to infectious disease. In this study, the association between COVID-19 outcomes and vitamin D levels in patients attending a COVID-19 reference center in Mexico City are examined. METHODS: Consecutive patients with confirmed COVID-19 were evaluated. All patients underwent clinical evaluation and follow-up, laboratory measurements and a thoracic computerized tomography, including the measurement of epicardial fat thickness. Low vitamin D was defined as levels <20 ng/ml (<50nmol/L) and deficient Vitamin D as a level ≤12 ng/ml (<30 nmol/L). RESULTS: Of the 551 patients included, low vitamin D levels were present in 45.6% and deficient levels in 10.9%. Deficient Vitamin D levels were associated with mortality (HR 2.11, 95%CI 1.24-3.58, p = 0.006) but not with critical COVID-19, adjusted for age, sex, body-mass index and epicardial fat. Using model-based causal mediation analyses the increased risk of COVID-19 mortality conferred by low vitamin D levels was partly mediated by its effect on D-dimer and cardiac ultrasensitive troponins. Notably, increased risk of COVID-19 mortality conferred by low vitamin D levels was independent of BMI and epicardial fat. CONCLUSION: Vitamin D deficiency (≤12 ng/ml or <30 nmol/L), is independently associated with COVID-19 mortality after adjustment for visceral fat (epicardial fat thickness). Low vitamin D may contribute to a pro-inflammatory and pro-thrombotic state, increasing the risk for adverse COVID-19 outcomes.

8.
Int J Obes (Lond) ; 46(4): 866-873, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35017712

RESUMO

BACKGROUND: Increased adiposity and visceral obesity have been linked to adverse COVID-19 outcomes. The amount of epicardial adipose tissue (EAT) may have relevant implications given its proximity to the heart and lungs. Here, we explored the role of EAT in increasing the risk for COVID-19 adverse outcomes. METHODS: We included 748 patients with COVID-19 attending a reference center in Mexico City. EAT thickness, sub-thoracic and extra-pericardial fat were measured using thoracic CT scans. We explored the association of each thoracic adipose tissue compartment with COVID-19 mortality and severe COVID-19 (defined as mortality and need for invasive mechanical ventilation), according to the presence or absence of obesity. Mediation analyses evaluated the role of EAT in facilitating the effect of age, body mass index and cardiac troponin levels with COVID-19 outcomes. RESULTS: EAT thickness was associated with increased risk of COVID-19 mortality (HR 1.18, 95% CI 1.01-1.39) independent of age, gender, comorbid conditions and BMI. Increased EAT was associated with lower SpO2 and PaFi index and higher levels of cardiac troponins, D-dimer, fibrinogen, C-reactive protein, and 4 C severity score, independent of obesity. EAT mediated 13.1% (95% CI 3.67-28.0%) and 5.1% (95% CI 0.19-14.0%) of the effect of age and 19.4% (95% CI 4.67-63.0%) and 12.8% (95% CI 0.03-46.0%) of the effect of BMI on requirement for intubation and mortality, respectively. EAT also mediated the effect of increased cardiac troponins on myocardial infarction during COVID-19. CONCLUSION: EAT is an independent risk factor for severe COVID-19 and mortality independent of obesity. EAT partly mediates the effect of age and BMI and increased cardiac troponins on adverse COVID-19 outcomes.


Assuntos
COVID-19 , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo/metabolismo , Adiposidade , Adulto , Índice de Massa Corporal , Humanos , Pericárdio/diagnóstico por imagem , Pericárdio/metabolismo , Adulto Jovem
9.
ACS Nano ; 15(10): 16924-16933, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34658232

RESUMO

We describe a microporous plasmonic nanoreactor to carry out designed near-infrared (NIR)-driven photothermal cyclizations inside living cells. As a proof of concept, we chose an intramolecular cyclization that is based on the nucleophilic attack of a pyridine onto an electrophilic carbon, a process that requires high activation energies and is typically achieved in bulk solution by heating at ∼90 °C. The core-shell nanoreactor (NR) has been designed to include a gold nanostar core, which is embedded within a metal-organic framework (MOF) based on a polymer-stabilized zeolitic imidazole framework-8 (ZIF-8). Once accumulated inside living cells, the MOF-based cloak of NRs allows an efficient diffusion of reactants into the plasmonic chamber, where they undergo the transformation upon near-IR illumination. The photothermal-driven reaction enables the intracellular generation of cyclic fluorescent products that can be tracked using fluorescence microscopy. The strategy may find different type of applications, such as for the spatio-temporal activation of prodrugs.


Assuntos
Estruturas Metalorgânicas , Ouro , Nanotecnologia , Polímeros
10.
Nanomaterials (Basel) ; 11(8)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34443736

RESUMO

Nanoparticles (NPs) functionalized with antibodies (Abs) on their surface are used in a wide range of bioapplications. Whereas the attachment of antibodies to single NPs to trigger the internalization in cells via receptor-mediated endocytosis has been widely studied, the conjugation of antibodies to larger NP assemblies has been much less explored. Taking into account that NP assemblies may be advantageous for some specific applications, the possibility of incorporating targeting ligands is quite important. Herein, we performed the effective conjugation of antibodies onto a fluorescent NP assembly, which consisted of fluorinated Quantum Dots (QD) self-assembled through fluorine-fluorine hydrophobic interactions. Cellular uptake studies by confocal microscopy and flow cytometry revealed that the NP assembly underwent the same uptake procedure as individual NPs; that is, the antibodies retained their targeting ability once attached to the nanoassembly, and the NP assembly preserved its intrinsic properties (i.e., fluorescence in the case of QD nanoassembly).

11.
Nanomaterials (Basel) ; 11(5)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064799

RESUMO

Biomass-derived materials are put forward as eco-friendly alternatives to design heterogeneous catalysts. To contribute in this field, we explored the potential of mesoporous biogenic silica (RH-Silica) obtained from lignocellulosic waste, in particular from rice husk, as an inorganic support to prepare heterogenized iron oxide-based catalysts. Mechanochemistry, considered as a green and sustainable technique, was employed to synthetize iron oxide nanoparticles in pure hematite phase onto the biosilica (α-Fe2O3/RH-Silica), making this material a good candidate to perform catalyzed organic reactions. The obtained material was characterized by different techniques, and its catalytic activity was tested in the selective oxidation of styrene under microwave irradiation. α-Fe2O3/RH-Silica displayed a good catalytic performance, achieving a conversion of 45% under optimized conditions, and more importantly, with a total selectivity to benzaldehyde. Furthermore, a good reusability was achieved without decreasing its activity after multiple catalytic cycles. This work represents a good example of using sustainable approaches and green materials as alternatives to conventional methods in the production of high-added value products.

12.
Foods ; 10(3)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808639

RESUMO

One of the main concerns in gluten analysis is to achieve efficient extraction of gluten proteins. Conventional ethanol-based extraction solutions are inefficient and, because of this, it is necessary to use reducing agents or acids for proper solubilization. The extraction recommended by CODEX Standard 118-1979 (revised 2008) utilizes Cocktail solution (patent WO 02/092633 A1). However, it is harmful with a disgusting odor and is not compatible with some immunological techniques. Here, the versatility and extraction capacity of a new Universal Gluten Extraction Solution (UGES) (patent ES 2 392 412 A1) were evaluated using different methodological conditions, food matrices, and various immunological methods. UGES includes safer compounds for both the user and the environment, and it displayed similar extraction efficiency to that of the extraction method recommended for sandwich enzyme-linked immunosorbent assay (ELISA). The extraction time was significantly reduced from 100 to 40 min, depending on the type of the sample. Furthermore, unlike the currently used solution, UGES is compatible with competitive ELISA.

13.
Int J Biol Macromol ; 178: 193-228, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33631269

RESUMO

Although nanotechnology-driven drug delivery systems are relatively new, they are rapidly evolving since the nanomaterials are deployed as effective means of diagnosis and delivery of assorted therapeutic agents to targeted intracellular sites in a controlled release manner. Nanomedicine and nanoparticulate drug delivery systems are rapidly developing as they play crucial roles in the development of therapeutic strategies for various types of cancer and malignancy. Nevertheless, high costs, associated toxicity and production of complexities are some of the critical barriers for their applications. Green nanomedicines have continually been improved as one of the viable approaches towards tumor drug delivery, thus making a notable impact on which considerably affect cancer treatment. In this regard, the utilization of natural and renewable feedstocks as a starting point for the fabrication of nanosystems can considerably contribute to the development of green nanomedicines. Nanostructures and biopolymers derived from natural and biorenewable resources such as proteins, lipids, lignin, hyaluronic acid, starch, cellulose, gum, pectin, alginate, and chitosan play vital roles in the development of cancer nanotherapy, imaging and management. This review uncovers recent investigations on diverse nanoarchitectures fabricated from natural and renewable feedstocks for the controlled/sustained and targeted drug/gene delivery systems against cancers including an outlook on some of the scientific challenges and opportunities in this field. Various important natural biopolymers and nanomaterials for cancer nanotherapy are covered and the scientific challenges and opportunities in this field are reviewed.


Assuntos
Biopolímeros , Portadores de Fármacos , Nanomedicina/métodos , Nanoestruturas , Neoplasias/tratamento farmacológico , Biopolímeros/farmacologia , Biopolímeros/uso terapêutico , Portadores de Fármacos/química , Humanos , Nanoestruturas/química , Nanoestruturas/uso terapêutico
14.
Cell Rep Phys Sci ; 1(6): 100076, 2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-32685935

RESUMO

Translating the potential of transition metal catalysis to biological and living environments promises to have a profound impact in chemical biology and biomedicine. A major challenge in the field is the creation of metal-based catalysts that remain active over time. Here, we demonstrate that embedding a reactive metallic core within a microporous metal-organic framework-based cloak preserves the catalytic site from passivation and deactivation, while allowing a suitable diffusion of the reactants. Specifically, we report the fabrication of nanoreactors composed of a palladium nanocube core and a nanometric imidazolate framework, which behave as robust, long-lasting nanoreactors capable of removing propargylic groups from phenol-derived pro-fluorophores in biological milieu and inside living cells. These heterogeneous catalysts can be reused within the same cells, promoting the chemical transformation of recurrent batches of reactants. We also report the assembly of tissue-like 3D spheroids containing the nanoreactors and demonstrate that they can perform the reactions in a repeated manner.

15.
Small ; 16(36): e2001160, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32431081

RESUMO

Protein corona formation on the surface of nanoparticles (NPs) is observed in situ by measuring diffusion coefficients of the NPs under the presence of proteins with a 19 F nuclear magnetic resonance (NMR) based methodology. Formation of a protein corona reduces the diffusion coefficient of the NPs, based on an increase in their effective hydrodynamic radii. With this methodology it is demonstrated that the apparent dissociation constant of protein-NP complexes may vary over at least nine orders of magnitude for different types of proteins, in line with the Vroman effect. Using this methodology, the interaction between one type of protein and one type of nanoparticle can be studied quantitatively. Due to the NMR-based detection, this methodology has no interference by absorption/scattering effects, by which optical detection schemes are affected. By using the potential of the NMR chemical shift, the detection of multiple 19 F signals simultaneously opens the possibility to study the diffusion of several NPs at the same time. The 19 F labeling of the NPs has negligible effect on their acute toxicity and moderate effect on NPs uptake by cells.


Assuntos
Monitoramento Ambiental , Espectroscopia de Ressonância Magnética , Nanopartículas , Difusão , Monitoramento Ambiental/instrumentação , Nanopartículas/análise , Nanopartículas/química , Coroa de Proteína/análise , Proteínas/química
16.
Rev. estomatol. Hered ; 30(2): 94-107, abr.-jun 2020. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS, BBO - Odontologia | ID: biblio-1144607

RESUMO

RESUMEN Objetivo: El propósito de la investigación fue evaluar la resistencia a la tracción diametral in vitro de cinco cementos dentales: BisCem, Duolink, Ketac Cem, Meron, Allcem, cuatro adhesivos convencionales y un autoadhesivo polimerizado químicamente utilizados como cementantes de puentes y coronas en prótesis fijas. Materiales y métodos: Se prepararon 100 especímenes conformados por cementos: BisCem, Duolink, Ketac Cem, Meron, Allcem, los cuales se dividieron aleatoriamente en 5 grupos de 20 especímenes cada grupo sujetas a fotopolimerización y auto polimerización de 8mm de diámetro y 5mm de alto, con 2mm de distancia aproximadamente de la lámpara para la polimerización, se utilizó un formador de probetas de polietileno de alta densidad estandarizado, el tipo de muestreo es no probabilístico. Se sometieron a los especímenes de cada grupo a la prueba de tracción utilizando una máquina de ensayo universal (zwickiLine by Zwick/Roell), hasta lograr el fracaso del cemento, sometidas a una fuerza continua de 500 kg, con una velocidad de desplazamiento fija de 1 cm/min. Resultados: La resistencia promedio a la tracción diametral de probetas del cemento BisCem fue de 38,75 ± 11,56 MPa, del cemento Duolink fue 64,30 MPa, del cemento Meron 57,14 MPa, del cemento Ketac Cem es de 32,23 MPa, del cemento BisCem (38,753 MPa) y el cemento Ketac Cem (39,233 MPa). El cemento dental Duolink es aquel que presenta mayor resistencia a la tracción diametral de probetas en comparación a Meron (57,137 MPa) que es su similar. La tabulación y el análisis han sido sometidos a los test de Shapiro Wilk, análisis de varianza ANOVA y la prueba de Tuckey los valores de cada muestra se distribuyen normalmente existiendo diferencias significativas entre los grupos estudiados. Conclusiones: Las probetas del cemento de resina adhesiva Duolink evidenció una mayor resistencia a la tracción diametral con mejores valores significativos de resistencia a diferencia de los cementos Ketac Cem, Allcem, Meron y BisCem.


SUMMARY Objetive: The purpose of the research was to evaluate the in vitro diametral tensile strength of five dental cements: BisCem, Duolink, Ketac Cem, Meron, Allcem, four conventional adhesives and a chemically polymerized self-adhesive used as bridge cements and crowns in fixed dentures . Materials and methods : 100 specimens consisting of cements were prepared: BisCem, Duolink, Ketac Cem, Meron, Allcem, which were randomly divided into 5 groups of 20 specimens each group subject to photopolymerization and self-polymerization of 8mm in diameter and 5mm high, with an approximate distance of 2mm from the lamp for polymerization, a standardized high density polyethylene specimen was used, the type of sampling is not probabilistic. The specimens of each group were subjected to tensile testing using a universal testing machine (zwickiLine by Zwick / Roell), until the failure of the cement was achieved, subjected to a continuous force of 500 kg, with a fixed displacement speed of 1 cm / min Results: The average tensile strength of diametral tensile specimens of BisCem cement was 38.75 ± 11.56 MPa, Duolink cement was 64.30 MPa, Meron cement 57.14 MPa, Ketac Cem cement was 32.23 MPa, BisCem cement (38.753 MPa ) and Ketac Cem cement (39,233 MPa). Duolink dental cement is the one with the highest tensile strength of diametral specimens compared to Meron (57,137 MPa), which is similar. The tabulation and the analysis have been submitted to the Shapiro Wilk test, ANOVA analysis of variance and the Tuckey test. The values of each sample are normally distributed with significant differences between the studied groups. Conclusions : Duolink adhesive resin cement specimens showed a higher diametral tensile strength with better significant strength values unlike Ketac Cem, Allcem, Meron and BisCem cements.

17.
Anal Bioanal Chem ; 412(1): 37-54, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31734711

RESUMO

Metal-organic frameworks (MOFs) have emerged as one of the most fascinating libraries of porous materials with a huge potential in very diverse application areas. In particular, the bioanalytical and biomedical fields have evolved tremendously due to the emergence of these hybrid inorganic-organic MOF-based materials. This is because these materials possess a series of key properties essential for bioapplications, such as minimal toxicity to living cells, intrinsic biodegradability, and possibility of synthesizing with nanoscale sizes. Additional properties of MOFs such as ultra-large surface-to-volume ratios, tunable pore size, high drug loading capacity, tunable structure and chemical composition, and potential for multiple postsynthetic modification make them ideal candidates for drug delivery. This review highlights recent research progress on MOF-based drug delivery systems (DDS), pointing out the evolution of these systems toward the development of theranostic nanoplatforms. Rather than a comprehensive review, representative recent examples are selected to illustrate such an evolution, and a critical discussion of the advantages and limitations of the different DDS types is given. Finally, the remaining challenges and future opportunities in this field are presented, highlighting that overcoming the current issues will pave the way toward the elusive dream of "personalized medicine." Graphical Abstract.


Assuntos
Sistemas de Liberação de Medicamentos , Estruturas Metalorgânicas/química , Nanoestruturas , Nanomedicina Teranóstica
18.
Angew Chem Int Ed Engl ; 58(21): 7078-7082, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-30897254

RESUMO

A plasmonic core-shell gold nanostar/zeolitic-imidazolate-framework-8 (ZIF-8) nanocomposite was developed for the thermoplasmonic-driven release of encapsulated active molecules inside living cells. The nanocomposites were loaded, as a proof of concept, with bisbenzimide molecules as functional cargo and wrapped with an amphiphilic polymer that prevents ZIF-8 degradation and bisbenzimide leaking in aqueous media or inside living cells. The demonstrated molecule-release mechanism relies on the use of near-IR light coupled to the plasmonic absorption of the core gold nanostars, which creates local temperature gradients and thus, bisbenzimide thermodiffusion. Confocal microscopy and surface-enhanced Raman spectroscopy (SERS) were used to demonstrate bisbenzimide loading/leaking and near-IR-triggered cargo release inside cells, thereby leading to DNA staining.

19.
ACS Nano ; 13(4): 4631-4639, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30875468

RESUMO

Colloidal CdSe/ZnS quantum dots were water solubilized by overcoating with an amphiphilic polymer. Human serum albumin (HSA) as a model protein was either adsorbed or chemically linked to the surface of the polymer-coated quantum dots. As the quantum dots are intrinsically fluorescent, and as the polymer coating and the HSA were fluorescent labeled, the final nanoparticle had three differently fluorescent components: the quantum dot core, the polymer shell, and the human serum albumin corona. Cells were incubated with these hybrid nanoparticles, and after removal of non-internalized nanoparticles, exocytosis of the three components of the nanoparticles was observed individually by flow cytometry and confocal microscopy. The data indicate that HSA is partly transported with the underlying polymer-coated quantum dots into cells. Upon desorption of proteins, those initially adsorbed to the quantum dots remain longer inside cells compared to free proteins. Part of the polymer shell is released from the quantum dots by enzymatic degradation, which is on a slower time scale than protein desorption. Data are quantitatively analyzed, and experimental pitfalls, such as the impact of cell proliferation and fluorescence quenching, are discussed.


Assuntos
Compostos de Cádmio/metabolismo , Coroa de Proteína/metabolismo , Pontos Quânticos/metabolismo , Compostos de Selênio/metabolismo , Albumina Sérica Humana/metabolismo , Sulfetos/metabolismo , Compostos de Zinco/metabolismo , Adsorção , Compostos de Cádmio/análise , Técnicas de Cultura de Células , Exocitose , Corantes Fluorescentes/análise , Corantes Fluorescentes/metabolismo , Células HeLa , Humanos , Microscopia de Fluorescência , Coroa de Proteína/análise , Pontos Quânticos/análise , Compostos de Selênio/análise , Albumina Sérica Humana/análise , Sulfetos/análise , Compostos de Zinco/análise
20.
Colloids Surf B Biointerfaces ; 173: 148-154, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30286431

RESUMO

Fluorescent inorganic quantum dots are highly promising for biomedical applications as sensing and imaging agents. However, the low internalization of the quantum dots, as well as for most of the nanoparticles, by living cells is a critical issue which should be solved for success in translational research. In order to increase the internalization rate of inorganic CdSe/ZnS quantum dots, they were functionalized with a fluorinated organic ligand. The fluorinated quantum dots displayed an enhanced surface activity, leading to a significant cell uptake as demonstrated by in vitro experiments with HeLa cells. We combined the experimental and computational results of Langmuir monolayers of the DPPC phospholipid as a model cell membrane with in vitro experiments for analyzing the mechanism of internalization of the fluorinated CdSe/ZnS quantum dots. Surface pressure-molecular area isotherms suggested that the physical state of the DPPC molecules was greatly affected by the quantum dots. UV-vis reflection spectroscopy and Brewster Angle Microscopy as in situ experimental techniques further confirmed the significant surface concentration of quantum dots. The disruption of the ordering of the DPPC molecules was assessed. Computer simulations offered detailed insights in the interaction between the quantum dots and the phospholipid, pointing to a significant modification of the physical state of the hydrophobic region of the phospholipid molecules. This phenomenon appeared as the most relevant step in the internalization mechanism of the fluorinated quantum dots by cells. Thus, this work sheds light on the role of fluorine on the surface of inorganic nanoparticles for enhancing their cellular uptake.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/análogos & derivados , Compostos de Cádmio/química , Membrana Celular/efeitos dos fármacos , Pontos Quânticos/química , Compostos de Selênio/química , Sulfetos/química , Compostos de Zinco/química , 1,2-Dipalmitoilfosfatidilcolina/química , Compostos de Cádmio/farmacologia , Membrana Celular/química , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Endocitose , Halogenação , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cinética , Simulação de Dinâmica Molecular , Compostos de Selênio/farmacologia , Sulfetos/farmacologia , Termodinâmica , Lipossomas Unilamelares , Compostos de Zinco/farmacologia
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