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1.
Proc Natl Acad Sci U S A ; 121(13): e2314646121, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38502697

ABSTRACT

The design of protein-protein interfaces using physics-based design methods such as Rosetta requires substantial computational resources and manual refinement by expert structural biologists. Deep learning methods promise to simplify protein-protein interface design and enable its application to a wide variety of problems by researchers from various scientific disciplines. Here, we test the ability of a deep learning method for protein sequence design, ProteinMPNN, to design two-component tetrahedral protein nanomaterials and benchmark its performance against Rosetta. ProteinMPNN had a similar success rate to Rosetta, yielding 13 new experimentally confirmed assemblies, but required orders of magnitude less computation and no manual refinement. The interfaces designed by ProteinMPNN were substantially more polar than those designed by Rosetta, which facilitated in vitro assembly of the designed nanomaterials from independently purified components. Crystal structures of several of the assemblies confirmed the accuracy of the design method at high resolution. Our results showcase the potential of deep learning-based methods to unlock the widespread application of designed protein-protein interfaces and self-assembling protein nanomaterials in biotechnology.


Subject(s)
Nanostructures , Proteins , Models, Molecular , Proteins/chemistry , Amino Acid Sequence , Biotechnology , Protein Conformation
2.
Proc Natl Acad Sci U S A ; 121(29): e2404958121, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38985767

ABSTRACT

Hydrogen production through water splitting is a vital strategy for renewable and sustainable clean energy. In this study, we developed an approach integrating nanomaterial engineering and synthetic biology to establish a bionanoreactor system for efficient hydrogen production. The periplasmic space (20 to 30 nm) of an electroactive bacterium, Shewanella oneidensis MR-1, was engineered to serve as a bionanoreactor to enhance the interaction between electrons and protons, catalyzed by hydrogenases for hydrogen generation. To optimize electron transfer, we used the microbially reduced graphene oxide (rGO) to coat the electrode, which improved the electron transfer from the electrode to the cells. Native MtrCAB protein complex on S. oneidensis and self-assembled iron sulfide (FeS) nanoparticles acted in tandem to facilitate electron transfer from an electrode to the periplasm. To enhance proton transport, S. oneidensis MR-1 was engineered to express Gloeobacter rhodopsin (GR) and the light-harvesting antenna canthaxanthin. This led to efficient proton pumping when exposed to light, resulting in a 35.6% increase in the rate of hydrogen production. The overexpression of native [FeFe]-hydrogenase further improved the hydrogen production rate by 56.8%. The bionanoreactor engineered in S. oneidensis MR-1 achieved a hydrogen yield of 80.4 µmol/mg protein/day with a Faraday efficiency of 80% at a potential of -0.75 V. This periplasmic bionanoreactor combines the strengths of both nanomaterial and biological components, providing an efficient approach for microbial electrosynthesis.


Subject(s)
Graphite , Hydrogen , Shewanella , Hydrogen/metabolism , Shewanella/metabolism , Shewanella/genetics , Graphite/metabolism , Hydrogenase/metabolism , Hydrogenase/genetics , Electron Transport , Bioreactors , Synthetic Biology/methods , Electrodes , Rhodopsins, Microbial/metabolism , Rhodopsins, Microbial/genetics , Periplasm/metabolism , Bioelectric Energy Sources/microbiology
3.
Proc Natl Acad Sci U S A ; 120(39): e2306841120, 2023 Sep 26.
Article in English | MEDLINE | ID: mdl-37722061

ABSTRACT

Although direct generation of high-value complex molecules and feedstock by coupling of ubiquitous small molecules such as CO2 and N2 holds great appeal as a potential alternative to current fossil-fuel technologies, suitable scalable and efficient catalysts to this end are not currently available as yet to be designed and developed. To this end, here we prepare and characterize SbxBi1-xOy clusters for direct urea synthesis from CO2 and N2 via C-N coupling. The introduction of Sb in the amorphous BiOx clusters changes the adsorption geometry of CO2 on the catalyst from O-connected to C-connected, creating the possibility for the formation of complex products such as urea. The modulated Bi(II) sites can effectively inject electrons into N2, promoting C-N coupling by advantageous modification of the symmetry for the frontier orbitals of CO2 and N2 involved in the rate-determining catalytic step. Compared with BiOx, SbxBi1-xOy clusters result in a lower reaction potential of only -0.3 V vs. RHE, an increased production yield of 307.97 µg h-1 mg-1cat, and a higher Faraday efficiency (10.9%), pointing to the present system as one of the best catalysts for urea synthesis in aqueous systems among those reported so far. Beyond the urea synthesis, the present results introduce and demonstrate unique strategies to modulate the electronic states of main group p-metals toward their use as effective catalysts for multistep electroreduction reactions requiring C-N coupling.

4.
Proc Natl Acad Sci U S A ; 120(20): e2218739120, 2023 05 16.
Article in English | MEDLINE | ID: mdl-37155879

ABSTRACT

Carbon-based nanomaterials (CNMs) have recently been found in humans raising a great concern over their adverse roles in the hosts. However, our knowledge of the in vivo behavior and fate of CNMs, especially their biological processes elicited by the gut microbiota, remains poor. Here, we uncovered the integration of CNMs (single-walled carbon nanotubes and graphene oxide) into the endogenous carbon flow through degradation and fermentation, mediated by the gut microbiota of mice using isotope tracing and gene sequencing. As a newly available carbon source for the gut microbiota, microbial fermentation leads to the incorporation of inorganic carbon from the CNMs into organic butyrate through the pyruvate pathway. Furthermore, the butyrate-producing bacteria are identified to show a preference for the CNMs as their favorable source, and excessive butyrate derived from microbial CNMs fermentation further impacts on the function (proliferation and differentiation) of intestinal stem cells in mouse and intestinal organoid models. Collectively, our results unlock the unknown fermentation processes of CNMs in the gut of hosts and underscore an urgent need for assessing the transformation of CNMs and their health risk via the gut-centric physiological and anatomical pathways.


Subject(s)
Gastrointestinal Microbiome , Nanostructures , Nanotubes, Carbon , Humans , Animals , Mice , Gastrointestinal Microbiome/physiology , Nanotubes, Carbon/adverse effects , Fermentation , Butyrates/metabolism
5.
Annu Rev Biomed Eng ; 26(1): 273-306, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38959389

ABSTRACT

Nanomaterials are becoming important tools for vaccine development owing to their tunable and adaptable nature. Unique properties of nanomaterials afford opportunities to modulate trafficking through various tissues, complement or augment adjuvant activities, and specify antigen valency and display. This versatility has enabled recent work designing nanomaterial vaccines for a broad range of diseases, including cancer, inflammatory diseases, and various infectious diseases. Recent successes of nanoparticle vaccines during the coronavirus disease 2019 (COVID-19) pandemic have fueled enthusiasm further. In this review, the most recent developments in nanovaccines for infectious disease, cancer, inflammatory diseases, allergic diseases, and nanoadjuvants are summarized. Additionally, challenges and opportunities for clinical translation of this unique class of materials are discussed.


Subject(s)
COVID-19 , Nanostructures , SARS-CoV-2 , Vaccine Development , Humans , Nanostructures/chemistry , COVID-19/prevention & control , SARS-CoV-2/immunology , COVID-19 Vaccines/chemistry , Animals , Adjuvants, Immunologic/chemistry , Neoplasms/immunology , Neoplasms/prevention & control , Nanoparticles/chemistry , Vaccines , Pandemics/prevention & control
6.
Nano Lett ; 24(27): 8268-8276, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38940535

ABSTRACT

The elegance and accuracy of biological ion channels inspire the fabrication of artificial devices with similar properties. Here, we report the fabrication of iontronic devices capable of delivering ions at the nanomolar (nmol) level of accuracy. The triangular nanofluidic device prepared with reconstructed vanadium pentoxide (VO) membranes of thickness 45 ± 5.5 µm can continuously deliver K+, Na+, and Ca2+ ions at the rate of 0.44 ± 0.24, 0.35 ± 0.06, and 0.03 nmol/min, respectively. The ionic flow rate can be further tuned by modulating the membrane thickness and salt concentration at the source reservoir. The triangular VO device can also deliver ions in minuscule doses (∼132 ± 9.7 nmol) by electrothermally heating (33 °C) with a nichrome wire (NW) or applying light of specific intensities. The simplicity of the fabrication process of reconstructed layered material-based nanofluidic devices allows the design of complicated iontronic devices such as the three-terminal-Ni-VO (3T-Ni-VO) devices.

7.
Nano Lett ; 24(15): 4554-4561, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38573122

ABSTRACT

Three-dimensionally (3D) integrated metallic nanomaterials composed of two or more different types of nanostructures make up a class of advanced materials due to the multidimensional and synergistic effects between different components. However, designing and synthesizing intricate, well-defined metallic 3D nanomaterials remain great challenges. Here, a novel single-particle soft-enveloping strategy using a core-shell Au NP@mSiO2 particle as a template was proposed to synthesize 3D nanomaterials, namely, a Au nanoparticle@center-radial nanorod-Au-Pt nanoparticle (Au NP@NR-NP-Pt NP) superstructure. Taking advantage of the excellent plasmonic properties of Au NP@NR-NP by the synergistic plasmonic coupling of the outer Au NPs and inner Au nanorods, we can enhance the catalytic performance for 4-nitrophenol hydrogenation using Au NP@NR-NP-Pt NP as a photocatalyst with plasmon-excited hot electrons from Au NP@NR-NP under light irradiation, which is 2.76 times higher than in the dark. This process opens a door for the design of a new generation of 3D metallic nanomaterials for different fields.

8.
Coord Chem Rev ; 5002024 Feb 01.
Article in English | MEDLINE | ID: mdl-38645709

ABSTRACT

Photonic nanomaterials, characterized by their remarkable photonic tunability, empower a diverse range of applications, including cutting-edge advances in cancer nanomedicine. Recently, ferroptosis has emerged as a promising alternative strategy for effectively killing cancer cells with minimizing therapeutic resistance. Novel design of photonic nanomaterials that can integrate photoresponsive-ferroptosis inducers, -diagnostic imaging, and -synergistic components provide significant benefits to effectively trigger local ferroptosis. This review provides a comprehensive overview of recent advancements in photonic nanomaterials for image-guided ferroptosis cancer nanomedicine, offering insights into their strengths, constraints, and their potential as a future paradigm in cancer treatment.

9.
Biochem Biophys Res Commun ; 712-713: 149939, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38640729

ABSTRACT

Human heavy-chain ferritin is a naturally occurring protein with high stability and multifunctionality in biological systems. This study aims to utilize a prokaryotic expression system to produce recombinant human heavy-chain ferritin nanoparticles and investigate their targeting ability in brain tissue. The human heavy-chain ferritin gene was cloned into the prokaryotic expression vector pET28a and transformed into Escherichia coli BL21 (DE3) competent cells to explore optimal expression conditions. The recombinant protein was then purified to evaluate its immunoreactivity and characteristics. Additionally, the distribution of the administered protein in normal mice and its permeability in an in vitro blood-brain barrier (BBB) model were measured. The results demonstrate that the purified protein can self-assemble extracellularly into nano-cage structures of approximately 10 nm and is recognized by corresponding antibodies. The protein effectively penetrates the blood-brain barrier and exhibits slow clearance in mouse brain tissue, showing excellent permeability in the in vitro BBB model. This study highlights the stable expression of recombinant human heavy-chain ferritin using the Escherichia coli prokaryotic expression system, characterized by favorable nano-cage structures and biological activity. Its exceptional brain tissue targeting and slow metabolism lay an experimental foundation for its application in neuropharmaceutical delivery and vaccine development fields.


Subject(s)
Blood-Brain Barrier , Brain , Escherichia coli , Ferritins , Nanoparticles , Recombinant Proteins , Animals , Humans , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Mice , Blood-Brain Barrier/metabolism , Brain/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Nanoparticles/chemistry , Ferritins/metabolism , Ferritins/genetics , Ferritins/chemistry , Apoferritins/metabolism , Apoferritins/genetics , Apoferritins/chemistry , Tissue Distribution
10.
BMC Plant Biol ; 24(1): 116, 2024 Feb 17.
Article in English | MEDLINE | ID: mdl-38365618

ABSTRACT

Water deficit stress is one of the most significant environmental abiotic factors influencing plant growth and metabolism globally. Recently, encouraging outcomes for the use of nanomaterials in agriculture have been shown to reduce the adverse effects of drought stress on plants. The present study aimed to investigate the impact of various carbon nanomaterials (CNMs) on the physiological, morphological, and biochemical characteristics of bell pepper plants subjected to water deficit stress conditions. The study was carried out as a factorial experiment using a completely randomized design (CRD) in three replications with a combination of three factors. The first factor considered was irrigation intensity with three levels [(50%, 75%, and 100% (control) of the field capacity (FC)] moisture. The second factor was the use of carbon nanomaterials [(fullerene C60, multi-walled carbon nanotubes (MWNTs) and graphene nanoplatelets (GNPs)] at various concentrations [(control (0), 100, 200, and 1000 mg/L)]. The study confirmed the foliar uptake of CNMs using the Scanning Electron Microscopy (SEM) technique. The effects of the CNMs were observed in a dose-dependent manner, with both stimulatory and toxicity effects being observed. The results revealed that exposure to MWNTs (1000 mg/L) under well-watered irrigation, and GNPs treatment (1000 mg/L) under severe drought stress (50% FC) significantly (P < 0.01) improved fruit production and fruit dry weight by 76.2 and 73.2% as compared to the control, respectively. Also, a significant decrease (65.9%) in leaf relative water content was obtained in plants subjected to soil moisture of 50% FC over the control. Treatment with GNPs at 1000 mg/L under 50% FC increased electrolyte leakage index (83.6%) compared to control. Foliar applied MWNTs enhanced the leaf gas exchange, photosynthesis rate, and chlorophyll a and b concentrations, though decreased the oxidative shock in leaves which was demonstrated by the diminished electrolyte leakage index and upgrade in relative water content and antioxidant capacity compared to the control. Plants exposed to fullerene C60 at 100 and 1000 mg/L under soil moisture of 100 and 75% FC significantly increased total flavonoids and phenols content by 63.1 and 90.9%, respectively, as compared to the control. A significant increase (184.3%) in antioxidant activity (FRAP) was observed in plants exposed to 200 mg/L MWCNTs under irrigation of 75% FC relative to the control. The outcomes proposed that CNMs could differentially improve the plant and fruit characteristics of bell pepper under dry conditions, however, the levels of changes varied among CNMs concentrations. Therefore, both stimulatory and toxicity effects of employed CNMs were observed in a dose-dependent manner. The study concludes that the use of appropriate (type/dose) CNMs through foliar application is a practical tool for controlling the water shortage stress in bell pepper. These findings will provide the basis for more research on CNMs-plant interactions, and with help to ensure their safe and sustainable use within the agricultural chains.


Subject(s)
Capsicum , Fullerenes , Graphite , Nanotubes, Carbon , Nanotubes, Carbon/toxicity , Nanotubes, Carbon/chemistry , Capsicum/physiology , Chlorophyll A , Graphite/chemistry , Dehydration , Antioxidants/metabolism , Water/metabolism , Soil
11.
BMC Plant Biol ; 24(1): 239, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38570782

ABSTRACT

The postharvest life of cut flowers is limited, which is a major challenge and varies greatly depending on plant varieties, cut flower stage, flower length of the harvested shoots, and storage conditions including postharvest treatments. As a result, improving the vase life and quality of cut flowers in regulating postharvest characteristics and overcoming these challenges is critical to the horticulture business. Novel engineered nanocomposites were created and tested for possible impacts on flower bud opening, postharvest life extension, longevity regulation, and preservation and enhancement of the strength and appearance of cut flowers. The experiment was conducted as a factorial experiment using a completely randomized design (CRD) with two factors. The first factor was two holding solutions (without or with sucrose at 20 gL-1). The second factor was 12 pulsing treatments for 24 h; distilled water as a control, 75 ppm GA3, multi-walled carbon nanotubes MWCNTs at 10, 20, 30, 40, and 50 ppm, and MWCNTs (10, 20, 30, 40, and 50 ppm)/GA3 (75 ppm) composites; each treatment had 3 replicates, for a total of 72 experimental units. In the present study, gibberellic acid (GA3) was synthesized in functionalized (MWCNT/GA3 composites) as a novel antisenescence agent, and their effect on the vase life quality of cut rose flowers Rosa hybrida cv. 'Moonstone' was compared by assaying several parameters critical for vase life. The adsorption of GA3 on MWCNTs was proven by performing FTIR spectroscopy which ensures that the formation of the MWCNTs/GA3 composite preserves the nanostructure and was examined by high-resolution transmission electron microscopy (HR-TEM). The results revealed that sucrose in the holding solution showed a significant increase in fresh weight, flower diameter, and vase life by 10.5, 10.6, and 3.3% respectively. Applying sucrose with MWCNTs 20 ppm/GA3 75 ppm composites or MWCNTs 20 ppm alone, was critical for the significant increase in flower opening by 39.7 and 28.7%, and longevity by 34.4 and 23.2%, respectively, and significantly increased chlorophyll a, b, total chlorophyll, anthocyanin, total phenolic content, and 2,2-Diphenyl-1-picrylhydrazyl scavenging activity as compared to the control.


Subject(s)
Gibberellins , Nanotubes, Carbon , Rosa , Chlorophyll A , Sucrose
12.
Small ; 20(14): e2307815, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37985947

ABSTRACT

Nanozymes, as innovative materials, have demonstrated remarkable potential in the field of electrochemical biosensors. This article provides an overview of the mechanisms and extensive practical applications of nanozymes in electrochemical biosensors. First, the definition and characteristics of nanozymes are introduced, emphasizing their significant role in constructing efficient sensors. Subsequently, several common categories of nanozyme materials are delved into, including metal-based, carbon-based, metal-organic framework, and layered double hydroxide nanostructures, discussing their applications in electrochemical biosensors. Regarding their mechanisms, two key roles of nanozymes are particularly focused in electrochemical biosensors: selective enhancement and signal amplification, which crucially support the enhancement of sensor performance. In terms of practical applications, the widespread use of nanozyme-based electrochemical biosensors are showcased in various domains. From detecting biomolecules, pollutants, nucleic acids, proteins, to cells, providing robust means for high-sensitivity detection. Furthermore, insights into the future development of nanozyme-based electrochemical biosensors is provided, encompassing improvements and optimizations of nanozyme materials, innovative sensor design and integration, and the expansion of application fields through interdisciplinary collaboration. In conclusion, this article systematically presents the mechanisms and applications of nanozymes in electrochemical biosensors, offering valuable references and prospects for research and development in this field.


Subject(s)
Biosensing Techniques , Metal-Organic Frameworks , Nanostructures , Nanostructures/chemistry , Proteins , Carbon/chemistry , Catalysis
13.
Small ; 20(7): e2306135, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37803439

ABSTRACT

Biofilm is a spatially organized community formed by the accumulation of both microorganisms and their secretions, leading to persistent and chronic infections because of high resistance toward conventional antibiotics. In view of the tunable physicochemical properties and the related unique biological behavior (e.g., size-, shape-, and surface charge-dependent penetration, protein corona endowed targeting, catalytic- and electronic-related oxidative stress, optical- and magnetic-associated hyperthermia, etc.), nanomaterials-based therapeutics are widely used for the treatment of biofilm-associated infections. In this review, the biological characteristics of biofilm are introduced. And the nanomaterials-based antibacterial strategies are further discussed via biofilm targeting, including preventing biofilm formation, enhancing biofilm penetration, disrupting the mature biofilm, and acting as drug delivery systems. In which, the interactions between biofilm and nanomaterials include mechanical disruption, electron transfer, enzymatic degradation, oxidative stress, and hyperthermia. Additionally, the current advances of nanomaterials for antibacterial nanomaterials by biofilm targeting are summarized. This review aims to present a complete vision of antibacterial nanomaterials-biofilm (nano-bio) interactions, paving the way for the future development and clinical translation of effective antibacterial nanomedicines.


Subject(s)
Nanostructures , Nanostructures/chemistry , Anti-Bacterial Agents/chemistry , Biofilms , Nanomedicine , Drug Delivery Systems
14.
Small ; : e2307750, 2024 Mar 03.
Article in English | MEDLINE | ID: mdl-38431939

ABSTRACT

As an innovative technology, four-dimentional (4D) printing is built upon the principles of three-dimentional (3D) printing with an additional dimension: time. While traditional 3D printing creates static objects, 4D printing generates "responsive 3D printed structures", enabling them to transform or self-assemble in response to external stimuli. Due to the dynamic nature, 4D printing has demonstrated tremendous potential in a range of industries, encompassing aerospace, healthcare, and intelligent devices. Nanotechnology has gained considerable attention owing to the exceptional properties and functions of nanomaterials. Incorporating nanomaterials into an intelligent matrix enhances the physiochemical properties of 4D printed constructs, introducing novel functions. This review provides a comprehensive overview of current applications of nanomaterials in 4D printing, exploring their synergistic potential to create dynamic and responsive structures. Nanomaterials play diverse roles as rheology modifiers, mechanical enhancers, function introducers, and more. The overarching goal of this review is to inspire researchers to delve into the vast potential of nanomaterial-enabled 4D printing, propelling advancements in this rapidly evolving field.

15.
Small ; : e2311571, 2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38385823

ABSTRACT

Parkinson's disease (PD) is currently the second most incurable central neurodegenerative disease resulting from various pathogenesis. As the "energy factory" of cells, mitochondria play an extremely important role in supporting neuronal signal transmission and other physiological activities. Mitochondrial dysfunction can cause and accelerate the occurrence and progression of PD. How to effectively prevent and suppress mitochondrial disorders is a key strategy for the treatment of PD from the root. Therefore, the emerging mitochondria-targeted therapy has attracted considerable interest. Herein, the relationship between mitochondrial dysfunction and PD, the causes and results of mitochondrial dysfunction, and major strategies for ameliorating mitochondrial dysfunction to treat PD are systematically reviewed. The study also prospects the main challenges for the treatment of PD.

16.
Small ; : e2312268, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38721981

ABSTRACT

The rapid development in nanotechnology has necessitated accurate and efficient assembly strategies for nanomaterials. Monolayer assembly of nanomaterials (MAN) represents a challenging and important architecture to manufacture and is critical in understanding interactions among nanomaterials, solvents, and substrates. MAN enables highly tunable performance in electronic and photonic devices. This review summarizes the recent progress on the methods to achieve MAN and discusses important control factors. Moreover, the importance of MAN is elaborated by a broad range of applications in electronics and photonics. In the end, the opportunities as well as challenges in manufacturing and new applications are outlooked.

17.
Small ; : e2400531, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38742980

ABSTRACT

A new generation of an FFP2 (Filtering Face Piece of type 2) smart face mask is achieved by integrating broadband hybrid nanomaterials and a self-assembled optical metasurface. The multifunctional FFP2 face mask shows simultaneously white light-assisted on-demand disinfection properties and versatile biosensing capabilities. These properties are achieved by a powerful combination of white light thermoplasmonic responsive hybrid nanomaterials, which provide excellent photo-thermal disinfection properties, and optical metasurface-based colorimetric biosensors, with a very low limit of pathogens detection. The realized system is studied in optical, morphological, spectroscopic, and cell viability assay experiments and environmental monitoring of harmful pathogens, thus highlighting the extraordinary properties in reusability and pathogens detection of the innovative face mask.

18.
Small ; : e2400650, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38566534

ABSTRACT

Holey graphenic nanomaterials with porosity within the basal plane attract significant interest. It is observed that the perforation of graphene can enhance the specific surface area of the nanosheet, ensuring effective wetting and penetration of electrolytes to the electrode surface, facilitating rapid charge transfer, and boosting the electrocatalytic efficacy of the transducers. This study reports the first example of nitrogen-doped holey reduced graphene oxide with a mesoporous morphology of the graphene basal plane (N-MHG). It is shown that N-MHG can be synthesized through a one-step hydrothermal treatment of GO using NH3 and H2O2. A straightforward procedure for the purification of N-MHG has also been developed. AFM, TEM, and Raman analyses have revealed that N-MHG possesses a highly mesoporous network structure with a pore size ranging from 10 to 50 nm. X-ray photoelectron spectroscopy data have indicated a partial reduction of the graphene oxide sheets during the etching process but also show a 3-5 times higher content of C═O and O-C═O fragments compared to rGO. This could account for the remarkable stability of the N-MHG aqueous suspension. An electrochemical sensor for dopamine analysis is assembled on a glassy carbon electrode with N-MHG/Nafion membrane and characterized by cyclic voltammetry and electrochemical impedance spectroscopy.

19.
Small ; : e2400164, 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38573934

ABSTRACT

Captured by high theoretical capacity and low-cost, Sodium-Sulfur (Na-S) batteries have been deemed as promising energy-storage systems. However, their electrochemical properties, containing both cycling and rate properties, still suffer from the notorious "shuttle effect" of polysulfide. Herein, through the effective regulation of pore sizes, a series of S@SiO2 cathode materials are obtained. Benefitting from the abundant pore channels of SiO2 particles, the sulfur loading is as high as 76.3%. Importantly, a suitable pore size can lead to adequate reaction and rapid diffusion behaviors, resulting in excellent electrochemical performances. Specifically, at 2.0 A g-1, the initial capacity of the as-optimized sample can be up to 1370.6 mAh g-1. Surprisingly, even after 1050 cycles, it could achieve a high reversible capacity of 1280.8 mAh g-1 with an attenuation rate of 0.089%. At 5.0 A g-1, after 500 cycles, the capacity can still remain ≈ 1132.6 mAh g-1 (capacity retention rate, 97.5%). Given this, the work is anticipated to offer an effective strategy for advanced electrodes for Na-S batteries.

20.
Small ; : e2400353, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38651235

ABSTRACT

Chemotherapy is crucial in oncology for combating malignant tumors but often encounters obatacles such as severe adverse effects, drug resistance, and biocompatibility issues. The advantages of degradable silica nanoparticles in tumor diagnosis and treatment lie in their ability to target drug delivery, minimizing toxicity to normal tissues while enhancing therapeutic efficacy. Moreover, their responsiveness to both endogenous and exogenous stimuli opens up new possibilities for integrating multiple treatment modalities. This review scrutinizes the burgeoning utility of degradable silica nanoparticles in combination with chemotherapy and other treatment modalities. Commencing the elucidation of degradable silica synthesis and degradation mechanisms, emphasis is placed on the responsiveness of these materials to endogenous (e.g., pH, redox reactions, hypoxia, and enzymes) and exogenous stimuli (e.g., light and high-intensity focused ultrasound). Moreover, this exploration delves into strategies harnessing degradable silica nanoparticles in chemotherapy alone, coupled with radiotherapy, photothermal therapy, photodynamic therapy, gas therapy, immunotherapy, starvation therapy, and chemodynamic therapy, elucidating multimodal synergies. Concluding with an assessment of advances, challenges, and constraints in oncology, despite hurdles, future investigations are anticipated to augment the role of degradable silica in cancer therapy. These insights can serve as a compass for devising more efficacious combined tumor treatment strategies.

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