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1.
Small ; 20(23): e2310331, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38183369

RESUMO

The applications of nanoreactors in biology are becoming increasingly significant and prominent. Specifically, nanoreactors with spatially confined, due to their exquisite design that effectively limits the spatial range of biomolecules, attracted widespread attention. The main advantage of this structure is designed to improve reaction selectivity and efficiency by accumulating reactants and catalysts within the chambers, thus increasing the frequency of collisions between reactants. Herein, the recent progress in the synthesis of spatially confined nanoreactors and their biological applications is summarized, covering various kinds of nanoreactors, including porous inorganic materials, porous crystalline materials with organic components and self-assembled polymers to construct nanoreactors. These design principles underscore how precise reaction control could be achieved by adjusting the structure and composition of the nanoreactors to create spatial confined. Furthermore, various applications of spatially confined nanoreactors are demonstrated in the biological fields, such as biocatalysis, molecular detection, drug delivery, and cancer therapy. These applications showcase the potential prospects of spatially confined nanoreactors, offering robust guidance for future research and innovation.


Assuntos
Nanotecnologia , Nanotecnologia/métodos , Sistemas de Liberação de Medicamentos , Polímeros/química , Humanos , Porosidade
2.
Small ; : e2401796, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38966879

RESUMO

As a novel type of catalytic material, hollow nanoreactors are expected to bring new development opportunities in the field of persulfate-based advanced oxidation processes due to their peculiar void-confinement, spatial compartmentation, and size-sieving effects. For such materials, however, further clarification on basic concepts and construction strategies, as well as a discussion of the inherent correlation between structure and catalytic activity are still required. In this context, this review aims to provide a state-of-the-art overview of hollow nanoreactors for activating persulfate. Initially, hollow nanoreactors are classified according to the constituent components of the shell structure and their dimensionality. Subsequently, the different construction strategies of hollow nanoreactors are described in detail, while common synthesis methods for these construction strategies are outlined. Furthermore, the most representative advantages of hollow nanoreactors are summarized, and their intrinsic connections to the nanoreactor structure are elucidated. Finally, the challenges and future prospects of hollow nanoreactors are presented.

3.
Small ; 19(13): e2202962, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35988151

RESUMO

A cell, the fundamental unit of life, contains the requisite blueprint information necessary to survive and to build tissues, organs, and systems, eventually forming a fully functional living creature. A slight structural alteration can result in data misprinting, throwing the entire life process off balance. Advances in synthetic biology and cell engineering enable the predictable redesign of biological systems to perform novel functions. Individual functions and fundamental processes at the core of the biology of cells can be investigated by employing a synthetically constrained micro or nanoreactor. However, constructing a life-like structure from nonliving building blocks remains a considerable challenge. Chemical compartments, cascade signaling, energy generation, growth, replication, and adaptation within micro or nanoreactors must be comparable with their biological counterparts. Although these reactors currently lack the power and behavioral sophistication of their biological equivalents, their interface with biological systems enables the development of hybrid solutions for real-world applications, such as therapeutic agents, biosensors, innovative materials, and biochemical microreactors. This review discusses the latest advances in cell membrane-engineered micro or nanoreactors, as well as the limitations associated with high-throughput preparation methods and biological applications for the real-time modulation of complex pathological states.


Assuntos
Engenharia Celular , Biologia Sintética , Transdução de Sinais , Membrana Celular
4.
Small ; 19(50): e2303928, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37625020

RESUMO

The catalytic oxidation of toxic organic pollutants in water requires enhanced efficiency for commercial applications. A ZnO nanorod array grown on a carbon fiber cloth (CFC) serves as the zinc source to ensure that the Ni/ZIF-8/ZnO nanoreactor is constructed. The Ni/ZIF-8/ZnO/CFC nanoreactor efficiently activates peroxymonosulfate (PMS) for bisphenol A (BPA) degradation owing to its high density of active sites, high adsorbability, and dispersibility structure, which concentrates catalytic and adsorptive sites within a confined space. Experimental and theoretical calculations clearly show that the introduction of Ni is beneficial for improving the adsorption of BPA and the activation of PMS. The synergistic mechanism of BPA adsorption-PMS activation is also investigated, and the degradation pathway of BPA is examined. Moreover, a filter catalytic unit is constructed using Ni/ZIF-8/ZnO/CFC to achieve a continuous zero discharge of BPA, which is convenient for nanocatalyst recycling. This study aims to develop a new strategy for the removal of emerging organic pollutants from water using a system with strong adsorption and catalytic capabilities.

5.
Small ; 19(50): e2304008, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37632316

RESUMO

Nanoreactors, as a new class of materials with highly enriched and ordered pore channel structures, can achieve special catalytic effects by precisely identifying and controlling the molecular diffusion behavior within the ordered pore channel system. Nanoreactors-driven molecular diffusion within the ordered pore channels can be highly dependent on the local microenvironment in the nanoreactors' pore channel system. Although the diffusion process of molecules within the ordered pore channels of nanoreactors is crucial for the regulation of catalytic behaviors, it has not yet been as clearly elucidated as it deserves to be in this study. In this review, fundamental theory and measurement techniques for molecular diffusion in the pore channel system of nanoreactors are presented, structural regulation strategies of pore channel parameters for controlling molecular diffusion are discussed, and the effects of molecular diffusion in the pore channel system on catalytic reactivity and selectivity are further analyzed. This article attempts to further develop the underlying theory of molecular diffusion within the theoretical framework of nanoreactor-driven catalysis, and the proposed perspectives may contribute to the rational design of advanced catalytic materials and the precise control of complex catalytic kinetics.

6.
Small ; 19(50): e2303403, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37649230

RESUMO

Metal-organic frameworks (MOFs) have emerged as promising novel therapeutics for treating malignancies due to their tunable porosity, biocompatibility, and modularity to functionalize with various chemotherapeutics drugs. However, the design and synthesis of dual-stimuli responsive MOFs for controlled drug release in tumor microenvironments are vitally essential but still challenging. Meanwhile, the catalytic effect of metal ions selection and ratio optimization in MOFs for enhanced chemodynamic therapy (CDT) is relatively unexplored. Herein, a series of MnFe-based MOFs with pH/glutathione (GSH)-sensitivity are synthesized and then combined with gold nanoparticles (Au NPs) and cisplatin prodrugs (DSCP) as a cascade nanoreactor (SMnFeCGH) for chemo-chemodynamic-starvation synergistic therapy. H+ and GSH can specifically activate the optimal SMnFeCGH nanoparticles in cancer cells to release Mn2+/4+ /Fe2+/3+ , Au NPs, and DSCP rapidly. The optimal ratio of Mn/Fe shows excellent H2 O2 decomposition efficiency for accelerating CDT. Au NPs can cut off the energy supply to cancer cells for starvation therapy and strengthen CDT by providing large amounts of H2 O2 . Then H2 O2 is catalyzed by Mn2+ /Fe2+ to generate highly toxic •OH with the depletion of GSH. Meanwhile, the reduced DSCP accelerates cancer cell regression for chemotherapy. The ultrasensitivity cascade nanoreactor can enhance the anticancer therapeutic effect by combining chemotherapy, CDT, and starvation therapy.


Assuntos
Nanopartículas Metálicas , Estruturas Metalorgânicas , Nanopartículas , Neoplasias , Humanos , Ouro , Glutationa , Microambiente Tumoral , Nanotecnologia , Concentração de Íons de Hidrogênio , Neoplasias/tratamento farmacológico , Linhagem Celular Tumoral , Peróxido de Hidrogênio
7.
Small ; 19(5): e2206592, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36437115

RESUMO

Starvation therapy kills tumor cells via consuming glucose to cut off their energy supply. However, since glucose oxidase (GOx)-mediated glycolysis is oxygen-dependent, the cascade reaction based on GOx faces the challenge of a hypoxic tumor microenvironment. By decomposition of glycolysis production of H2 O2 into O2 , starvation therapy can be enhanced, but chemodynamic therapy is limited. Here, a close-loop strategy for on demand H2 O2 and O2 delivery, release, and recycling is proposed. The nanoreactor (metal-protein-polyphenol capsule) is designed by incorporating two native proteins, GOx and hemoglobin (Hb), in polyphenol networks with zeolitic imidazolate framework as sacrificial templates. Glycolysis occurs in the presence of GOx with O2 consumption and the produced H2 O2 reacts with Hb to produce highly cytotoxic hydroxyl radicals (•OH) and methemoglobin (MHb) (Fenton reaction). Benefiting from the different oxygen carrying capacities of Hb and MHb, oxygen on Hb is rapidly released to supplement its consumption during glycolysis. Glycolysis and Fenton reactions are mutually reinforced by oxygen supply, consuming more glucose and producing more hydroxyl radicals and ultimately enhancing both starvation therapy and chemodynamic therapy. This cascade nanoreactor exhibits high efficiency for tumor suppression and provides an effective strategy for oxygen-mediated synergistic starvation therapy and chemodynamic therapy.


Assuntos
Nanopartículas , Neoplasias , Humanos , Oxigênio , Polifenóis , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Metais , Radical Hidroxila , Glucose Oxidase/metabolismo , Glucose , Nanotecnologia , Peróxido de Hidrogênio , Linhagem Celular Tumoral , Microambiente Tumoral
8.
Small ; 19(32): e2301011, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37066705

RESUMO

Site-selective and partial decoration of supported metal nanoparticles (NPs) with transition metal oxides (e.g., FeOx ) can remarkably improve its catalytic performance and maintain the functions of the carrier. However, it is challenging to selectively deposit transition metal oxides on the metal NPs embedded in the mesopores of supporting matrix through conventional deposition method. Herein, a restricted in situ site-selective modification strategy utilizing poly(ethylene oxide)-block-polystyrene (PEO-b-PS) micellar nanoreactors is proposed to overcome such an obstacle. The PEO shell of PEO-b-PS micelles interacts with the hydrolyzed tungsten salts and silica precursors, while the hydrophobic organoplatinum complex and ferrocene are confined in the hydrophobic PS core. The thermal treatment leads to mesoporous SiO2 /WO3-x framework, and meanwhile FeOx nanolayers are in situ partially deposited on the supported Pt NPs due to the strong metal-support interaction between FeOx and Pt. The selective modification of Pt NPs with FeOx makes the Pt NPs present an electron-deficient state, which promotes the mobility of CO and activates the oxidation of CO. Therefore, mesoporous SiO2 /WO3-x -FeOx /Pt based gas sensors show a high sensitivity (31 ± 2 in 50 ppm of CO), excellent selectivity, and fast response time (3.6 s to 25 ppm) to CO gas at low operating temperature (66 °C, 74% relative humidity).

9.
Small ; 19(35): e2301190, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37096899

RESUMO

Silicon nanostructures (SiNSs) can provide multifaceted bioapplications; but preserving their subhundred nm size during high-temperature silica-to-silicon conversion is the major bottleneck. The SC-SSR utilizes an interior metal-silicide stratum space at a predetermined radial distance inside silica nanosphere to guide the magnesiothermic reduction reaction (MTR)-mediated synthesis of hollow and porous SiNSs. In depth mechanistic study explores solid-to-hollow transformation encompassing predefined radial boundary through the participation of metal-silicide species directing the in-situ formed Si-phase accumulation within the narrow stratum. Evolving thin-porous Si-shell remains well protected by the in-situ segregated MgO emerging as a protective cast against the heat-induced deformation and interparticle sintering. Retrieved hydrophilic SiNSs (<100 nm) can be conveniently processed in different biomedia as colloidal solutions and endocytosized inside cells as photoluminescence (PL)-based bioimaging probes. Inside the cell, rattle-like SiNSs encapsulated with Pd nanocrystals can function as biorthogonal nanoreactors to catalyze intracellular synthesis of probe molecules through C-C cross coupling reaction.


Assuntos
Nanosferas , Nanoestruturas , Silício/química , Nanoestruturas/química , Dióxido de Silício/química , Nanosferas/química , Porosidade
10.
Small ; 19(42): e2303253, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37330663

RESUMO

Tumor-dependent glucose and glutamine metabolisms are essential for maintaining survival, while the accordingly metabolic suppressive therapy is limited by the compensatory metabolism and inefficient delivery efficiency. Herein, a functional metal-organic framework (MOF)-based nanosystem composed of the weakly acidic tumor microenvironment-activated detachable shell and reactive oxygen species (ROS)-responsive disassembled MOF nanoreactor core is designed to co-load glycolysis and glutamine metabolism inhibitors glucose oxidase (GOD) and bis-2-(5-phenylacetmido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES) for tumor dual-starvation therapy. The nanosystem excitingly improves tumor penetration and cellular uptake efficiency via integrating the pH-responsive size reduction and charge reversal and ROS-sensitive MOF disintegration and drug release strategy. Furthermore, the degradation of MOF and cargoes release can be self-amplified via additional self-generation H2 O2 mediated by GOD. Last, the released GOD and BPTES collaboratively cut off the energy supply of tumors and induce significant mitochondrial damage and cell cycle arrest via simultaneous restriction of glycolysis and compensatory glutamine metabolism pathways, consequently realizing the remarkable triple negative breast cancer killing effect in vivo with good biosafety via the dual starvation therapy.


Assuntos
Estruturas Metalorgânicas , Neoplasias , Humanos , Estruturas Metalorgânicas/farmacologia , Glutamina/metabolismo , Glutamina/uso terapêutico , Espécies Reativas de Oxigênio , Glucose , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Nanotecnologia , Glucose Oxidase/metabolismo , Linhagem Celular Tumoral , Microambiente Tumoral
11.
Small ; 19(26): e2207808, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36942684

RESUMO

Optimizing the coordination structure and microscopic reaction environment of isolated metal sites is promising for boosting catalytic activity for electrocatalytic CO2 reduction reaction (CO2 RR) but is still challenging to achieve. Herein, a newly electrostatic induced self-assembly strategy for encapsulating isolated Ni-C3 N1 moiety into hollow nano-reactor as I-Ni SA/NHCRs is developed, which achieves FECO  of 94.91% at -0.80 V, the CO partial current density of ≈-15.35 mA cm-2 , superior to that with outer Ni-C2 N2 moiety (94.47%, ≈-12.06 mA cm-2 ), or without hollow structure (92.30%, ≈-5.39 mA cm-2 ), and high FECO of ≈98.41% at 100 mA cm-2 in flow cell. COMSOL multiphysics finite-element method and density functional theory (DFT) calculation illustrate that the excellent activity for I-Ni SA/NHCRs should be attributed to the structure-enhanced kinetics process caused by its hollow nano-reactor structure and unique Ni-C3 N1 moiety, which can enrich electron on Ni sites and positively shift d-band center to the Fermi level to accelerate the adsorption and activation of CO2 molecule and *COOH formation. Meanwhile, this strategy also successfully steers the design of encapsulating isolated iron and cobalt sites into nano-reactor, while I-Ni SA/NHCRs-based zinc-CO2 battery assembled with a peak power density of 2.54 mW cm--2 is achieved.

12.
Chembiochem ; 24(7): e202200718, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-36715701

RESUMO

Polymersome-based biomimetic nanoreactors (PBNs) have generated great interest in nanomedicine and cell mimicry due to their robustness, tuneable chemistry, and broad applicability in biologically relevant fields. In this concept review, we mainly discuss the state of the art in functional polymersomes as biomimetic nanoreactors with membrane-controlled transport. PBNs that use environmental changes or external stimuli to adjust membrane permeability while maintaining structural integrity are highlighted. By encapsulating catalytic species, PBNs are able to convert inactive substrates into functional products in a controlled manner. In addition, special attention is paid to the use of PBNs as tailored artificial organelles with biomedical applications in vitro and in vivo, facilitating the fabrication of next-generation artificial organelles as therapeutic nanocompartments.


Assuntos
Células Artificiais , Biomimética , Nanomedicina , Transporte Biológico , Polímeros/química
13.
Chemistry ; 29(62): e202302253, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37580312

RESUMO

In this study, we explore a possible platform for the CO2 reduction (CO2 R) in one of water's solid phases, namely clathrate hydrates (CHs), by ab initio molecular dynamics and well-tempered metadynamics simulations with periodic boundary conditions. We found that the stacked H2 O nanocages in CHs help to initialize CO2 R by increasing the electron-binding ability of CO2 . The substantial CO2 R processes are further influenced by the hydrogen bond networks in CHs. The first intermediate CO2 - in this process can be stabilized through cage structure reorganization into the H-bonded [CO2 - ⋅⋅⋅H-OHcage ] complex. Further cooperative structural dynamics enables the complex to convert into a vital transient [CO2 2- ⋅⋅⋅H-OHcage ] intermediate in a low-barrier disproportionation-like process. Such a highly reactive intermediate spontaneously triggers subsequent double proton transfer along its tethering H-bonds, finally converting it into HCOOH. These hydrogen-bonded nanoreactors feature multiple functions in facilitating CO2 R such as confining, tethering, H-bond catalyzing and proton pumping. Our findings have a general interest and extend the knowledge of CO2 R into porous aqueous systems.

14.
Macromol Rapid Commun ; 44(23): e2300389, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37661804

RESUMO

Traumatic optic neuropathy (TON) is a severe condition characterized by retinal ganglion cell (RGC) death, often leading to irreversible vision loss, and the death of RGCs is closely associated with oxidative stress. Unfortunately, effective treatment options for TON are lacking. To address this, catalase (CAT) is encapsulated in a tannic acid (TA)/poly(ethylenimine)-crosslinked hollow nanoreactor (CAT@PTP), which exhibited enhanced anchoring in the retina due to TA-collagen adhesion. The antioxidative activity of both CAT and TA synergistically eliminated reactive oxygen species (ROS) to save RGCs in the retina, thereby treating TON. In vitro experiments demonstrated that the nanoreactors preserve the enzymatic activity of CAT and exhibit high adhesion to type I collagen. The combination of CAT and TA-based nanoreactors enhanced ROS elimination while maintaining high biocompatibility. In an optic nerve crush rat model, CAT@PTP is effectively anchored to the retina via TA-collagen adhesion after a single vitreous injection, and RGCs are significantly preserved without adverse events. CAT@PTP exhibited a protective effect on retinal function. Given the abundance of collagen that exists in ocular tissues, these findings may contribute to the further application of this multifunctional nanoreactor in ocular diseases to improve therapeutic efficacy and reduce adverse effects.


Assuntos
Traumatismos do Nervo Óptico , Células Ganglionares da Retina , Ratos , Animais , Células Ganglionares da Retina/metabolismo , Colágeno Tipo I/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Nervo Óptico/metabolismo , Traumatismos do Nervo Óptico/metabolismo , Nanotecnologia , Sobrevivência Celular , Modelos Animais de Doenças
15.
J Nanobiotechnology ; 21(1): 256, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37550745

RESUMO

BACKGROUND: Organophosphate (OP)-induced delayed neurological damage is attributed to permanent neuropathological lesions caused by irreversible OP-neurocyte interactions, without potent brain-targeted etiological antidotes to date. The development of alternative therapies to achieve intracerebral OP detoxification is urgently needed. METHODS: We designed a brain-targeted nanoreactor by integrating enzyme immobilization and biomimetic membrane camouflaging protocols with careful characterization, and then examined its blood-brain barrier (BBB) permeability both in vitro and in vivo. Subsequently, the oxidative stress parameters, neuroinflammatory factors, apoptotic proteins and histopathological changes were measured and neurobehavioral tests were performed. RESULTS: The well-characterized nanoreactors exerted favourable BBB penetration capability both in vitro and in vivo, significantly inhibiting OP-induced intracerebral damage. At the cellular and tissue levels, nanoreactors obviously blocked oxidative stress, cellular apoptosis, inflammatory reactions and brain histopathological damage. Furthermore, nanoreactors radically prevented the occurrence of OP-induced delayed cognitive deficits and psychiatric abnormality. CONCLUSION: The nanoreactors significantly prevented the development of OP-induced delayed neurological damage, suggesting a potential brain-targeted etiological strategy to attenuate OP-related delayed neurological and neurobehavioral disorders.


Assuntos
Intoxicação por Organofosfatos , Organofosfatos , Humanos , Organofosfatos/metabolismo , Intoxicação por Organofosfatos/metabolismo , Intoxicação por Organofosfatos/patologia , Encéfalo/metabolismo , Antídotos/metabolismo , Nanotecnologia
16.
J Nanobiotechnology ; 21(1): 385, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37875918

RESUMO

Triple-negative breast cancer (TNBC) represents a formidable challenge due to the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression, rendering it unresponsive to conventional hormonal and targeted therapies. This study introduces the development of mesoporous nanoreactors (NRs), specifically mPDA@CuO2 NRs, as acid-triggered agents capable of self-supplying H2O2 for chemodynamic therapy (CDT). To enhance therapeutic efficacy, these NRs were further modified with immune checkpoint antagonists, specifically anti-PD-L1 and anti-CD24 antibodies, resulting in the formation of dual antibody-aided mesoporous nanoreactors (dAbPD-L1/CD24-mPDA@CuO2 NRs). These NRs were designed to combine CDT and checkpoint blockade immunotherapy (CBIT) for precise targeting of 4T1 TNBC cells. Remarkably, dAbPD-L1/CD24-mPDA@CuO2 NRs exhibited tumor-targeted CDT triggered by H2O2 and successfully activated immune cells including T cells and macrophages. This integrated approach led to a remarkable inhibition of tumor growth by leveraging the collaborative effects of the therapies. The findings of this study introduce a novel and promising strategy for the integrative and collaborative treatment of refractory cancers, providing valuable insights into addressing the challenges posed by aggressive breast cancer, particularly TNBC.


Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Antígeno B7-H1 , Peróxido de Hidrogênio , Inibidores de Checkpoint Imunológico , Imunoterapia/métodos , Anticorpos Monoclonais/uso terapêutico , Nanotecnologia
17.
Small ; 18(32): e2201361, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35760757

RESUMO

Rationally modulating the catalytic microenvironment is important for targeted induction of specific molecular behaviors to fulfill complicated catalytic purposes. Herein, a metal pre-chelating assisted assembly strategy is developed to facilely synthesize the hollow carbon spheres with ultrafine ruthenium clusters embedded in pore channels of the carbon shell (Ru@Shell-HCSs), which can be employed as nanoreactors with preferred electronic and geometric catalytic microenvironments for the efficient tandem hydrogenation of biomass-derived furfural toward 2-methylfuran. The channel-embedding structure is proved to confer the ultrafine ruthenium clusters with an electron-deficient property via a reinforced interfacial charge transfer mechanism, which prompts the hydrogenolysis of intermediate furfuryl alcohol during the tandem reaction, thus resulting in an enhanced 2-methylfuran generation. Meanwhile, lengthening the shell pore channel can offer reactant molecules with a prolonged diffusion path, and correspondingly a longer retention time in the channel, thereafter delivering an accelerated tandem hydrogenation progression. This paper aims to present a classic case that emphasizes the critical role of precisely controlling the catalytic microenvironment of the metal-loaded hollow nanoreactors in coping with the arduous challenges from multifunctional catalyst-driven complex tandem reactions.


Assuntos
Furaldeído , Rutênio , Carbono/química , Furaldeído/química , Hidrogenação , Nanotecnologia , Rutênio/química
18.
Small ; 18(20): e2200414, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35426247

RESUMO

Thermal decomposition is a very efficient synthesis strategy to obtain nanosized metal oxides with controlled structures and properties. For the iron oxide nanoparticle synthesis, it allows an easy tuning of the nanoparticle's size, shape, and composition, which is often explained by the LaMer theory involving a clear separation between nucleation and growth steps. Here, the events before the nucleation of iron oxide nanocrystals are investigated by combining different complementary in situ characterization techniques. These characterizations are carried out not only on powdered iron stearate precursors but also on a preheated liquid reaction mixture. They reveal a new nucleation mechanism for the thermal decomposition method: instead of a homogeneous nucleation, the nucleation occurs within vesicle-like-nanoreactors confining the reactants. The different steps are: 1) the melting and coalescence of iron stearate particles, leading to "droplet-shaped nanostructures" acting as nanoreactors; 2) the formation of a hitherto unobserved iron stearate crystalline phase within the nucleation temperature range, simultaneously with stearate chains loss and Fe(III) to Fe(II) reduction; 3) the formation of iron oxide nuclei inside the nanoreactors, which are then ejected from them. This mechanism paves the way toward a better mastering of the metal oxide nanoparticles synthesis and the control of their properties.


Assuntos
Nanopartículas Metálicas , Óxidos , Meios de Cultura , Compostos Férricos/química , Ferro , Nanopartículas Metálicas/química , Óxidos/química , Estearatos
19.
J Fluoresc ; 32(3): 907-920, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35102460

RESUMO

Nonionic surfactant vesicles (Niosomes) were prepared using polyoxyethylene alkyl ether (Brij 58).The impact of variation of the Brij: cholesterol molar ratio on the niosomal structure was studied. Fluorescence studies performed with the membrane probe 1,6-Diphenyl-1,3,5-triene (DPH) gave important insight on the bilayer integrity of the niosomes in response to environmental perturbations. The aim of the work being assessment of the efficacy of the niosomes as "drug release vehicles", release studies were performed with a xanthene dye Carboxyfluorescein (CF). Further, the vesicles were used as nanoreactors for the synthesis of gold nanoparticles (GNPs) as it is often useful to house nanoparticles in biological /biomimicking environments. Stable, spherical GNPs of diameter 6-10 nm were formed in these vesicles. As the vesicular bilayer mimics the cell membrane, the present work is relevant to the use of the GNPs for diagnostic and therapeutic purpose. It has also been established that fluorescence resonance energy transfer (FRET) effectively occurs between DPH and CF in the niosomes. The FRET studies provide important insight on the location of dyes within the vesicles thus indicating the prospective applications of this fluorescence technique for tracking the location of probes in biomimicking systems which maybe extrapolated to in vivo biological systems in future.


Assuntos
Lipossomos , Nanopartículas Metálicas , Ouro , Lipossomos/química , Nanotecnologia , Tamanho da Partícula , Tensoativos/química
20.
Angew Chem Int Ed Engl ; 61(6): e202113784, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34779553

RESUMO

In eukaryotic cells, enzymes are compartmentalized into specific organelles so that different reactions and processes can be performed efficiently and with a high degree of control. In this work, we show that these features can be artificially emulated in robust synthetic organelles constructed using an enzyme co-compartmentalization strategy. We describe an in situ encapsulation approach that allows enzymes to be loaded into silica nanoreactors in well-defined compositions. The nanoreactors can be combined into integrated systems to produce a desired reaction outcome. We used the selective enzyme co-compartmentalization and nanoreactor integration to regulate competitive cascade reactions and to modulate the kinetics of sequential reactions involving multiple nanoreactors. Furthermore, we show that the nanoreactors can be efficiently loaded into giant polymer vesicles, resulting in multi-compartmentalized microreactors.


Assuntos
Células Artificiais/metabolismo , Glucose Oxidase/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Nanopartículas/metabolismo , Dióxido de Silício/metabolismo , Células Artificiais/química , Glucose Oxidase/química , Peroxidase do Rábano Silvestre/química , Humanos , Nanopartículas/química , Tamanho da Partícula , Dióxido de Silício/química
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