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1.
Mol Cancer ; 23(1): 92, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38715072

RESUMEN

Breast cancer, the most frequent female malignancy, is often curable when detected at an early stage. The treatment of metastatic breast cancer is more challenging and may be unresponsive to conventional therapy. Immunotherapy is crucial for treating metastatic breast cancer, but its resistance is a major limitation. The tumor microenvironment (TME) is vital in modulating the immunotherapy response. Various tumor microenvironmental components, such as cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs), are involved in TME modulation to cause immunotherapy resistance. This review highlights the role of stromal cells in modulating the breast tumor microenvironment, including the involvement of CAF-TAM interaction, alteration of tumor metabolism leading to immunotherapy failure, and other latest strategies, including high throughput genomic screening, single-cell and spatial omics techniques for identifying tumor immune genes regulating immunotherapy response. This review emphasizes the therapeutic approach to overcome breast cancer immune resistance through CAF reprogramming, modulation of TAM polarization, tumor metabolism, and genomic alterations.


Asunto(s)
Neoplasias de la Mama , Resistencia a Antineoplásicos , Inmunoterapia , Microambiente Tumoral , Femenino , Humanos , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/terapia , Neoplasias de la Mama/patología , Neoplasias de la Mama/genética , Fibroblastos Asociados al Cáncer/metabolismo , Fibroblastos Asociados al Cáncer/inmunología , Fibroblastos Asociados al Cáncer/patología , Resistencia a Antineoplásicos/genética , Inmunoterapia/métodos , Microambiente Tumoral/inmunología , Macrófagos Asociados a Tumores/inmunología , Macrófagos Asociados a Tumores/metabolismo , Macrófagos Asociados a Tumores/efectos de los fármacos
2.
Dalton Trans ; 53(15): 6818-6829, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38546210

RESUMEN

Three new d8- and d10-configuration based 1,1'-bis-(diphenylphosphino)ferrocene (dppf) appended thiosquarates complexes with general composition [M(mtsq)2dppf] (M = Ni2+ (NiL2); Zn2+ (ZnL2) and Cd2+ (CdL2)) (mtsq = 3-ethoxycyclobutenedione-4-thiolate) have been synthesized and characterized spectroscopically as well as in case of NiL2 by single crystal X-ray diffraction technique. The single crystal X-ray analysis reveals square planar geometry around Ni(II) in NiL2, where Ni(II) coordinates with two sulfur centres of two mtsq ligands in monodentate fashion and two phosphorus of a dppf ligand in chelating mode. The supramolecular architecture of NiL2 is sustained by intermolecular C-H⋯O interactions to form one-dimensional chain. Further, the application of these newly synthesized complexes as sensitizers and co-sensitizers/co-absorbents with ruthenium based N719 sensitizer in dye-sensitized solar cells (DSSCs) have been explored. The DSSC set-up based on NiL2 offers best photovoltaic performance with photovoltaic efficiency (η) 5.12%, short-circuit current (Jsc) 11.60 mA cm-2, open circuit potential (Voc) 0.690 V and incident photon to current conversion efficiency (IPCE) 63%. In co-sensitized DSSC set-up, ZnL2 along with state-of-the-art N719 dye displays best photovoltaic performance with η 6.65%, Jsc 14.47 mA cm-2, Voc 0.729 V and IPCE 69%, thereby showing an improvement by 15.25% in photovoltaic efficiency in comparison to the photovoltaic efficiency of N719 sensitized DSSC set-up. Variation in co-sensitization behaviour have been ascribed to the differences in the excited state energy level of co-sensitizers. The ZnL2 and CdL2 have a higher energy level position than N719 dye, allowing efficient electron transfer to N719 during light irradiation, while excited state of NiL2 is lower than N719 dye, preventing photoexcited electron transfer to N719, resulting in its lowest overall efficiency among the three co-sensitized DSSC setups.

3.
Nanoscale Adv ; 6(6): 1661-1677, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38482032

RESUMEN

In this study, p-Co3O4/n-TiO2 nanocomposites were synthesized using different ratios of cobalt and titanium precursors through a hydrothermal method. These nanocomposites demonstrated notable potential in photocatalytic applications for hydrogen production and orange-red dye degradation under sunlight. Various techniques, including XRD, Raman spectroscopy, XPS, FESEM, TEM, and BET analysis, were used to comprehensively characterize their structural, morphological, and optical properties. The nanocomposites exhibited both cubic and tetragonal phases of Co3O4 and TiO2, and their combined effect resulted in a narrowed band gap. Additionally, the presence of Co3O4 induced surface plasmon resonance on the TiO2 surface, effectively impeding electron-hole recombination. The nanocomposites displayed an average particle size of ∼20 to 30 nm with substantial visible light absorption. High crystallinity and well-dispersed nanocomposites were confirmed by XRD and Raman, with BET surface areas ranging between 49 and 106 m2 g-1. Notably, the p-Co3O4/n-TiO2 nanocomposite showed superior photocatalytic activity, achieving a maximum hydrogen generation rate of 1120 µmol h-1 g-1 and an 83% degradation efficiency of the orange-red dye within 6 minutes under sunlight. This study emphasizes the enhanced performance of the p-Co3O4/n-TiO2 nanocomposite, indicating its potential in photocatalytic applications, conforming to a pseudo-first-order kinetics model.

4.
Carbohydr Res ; 536: 109039, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38277719

RESUMEN

N-acetyl-d-glucosamine (GlcNAc) is a commercially important amino sugar for its wide range of applications in pharmaceutical, food, cosmetics and biofuel industries. In nature, GlcNAc is polymerised into chitin biopolymer, which is one of the major constituents of fungal cell wall and outer shells of crustaceans. Sea food processing industries generate a large volume of chitin as biopolymeric waste. Because of its high abundance, chitinaceous shellfish wastes have been exploited as one of the major precursor substrates of GlcNAc production, both in chemical and enzymatic means. Nevertheless, the current process of GlcNAc extraction from shellfish wastes generates poor turnover and attracts environmental hazards. Moreover, GlcNAc isolated from shellfish could not be prescribed to certain groups of people because of the allergic nature of shell components. Therefore, an alternative route of GlcNAc production is advocated. With the advancement of metabolic construction and synthetic biology, microbial synthesis of GlcNAc is gaining much attention nowadays. Several new and cutting-edge technologies like substrate co-utilization strategy, promoter engineering, and CRISPR interference system were proposed in this fascinating area. The study would put forward the potential application of microbial engineering in the production of important pharmaceuticals. Very recently, autotrophic fermentation of GlcNAc synthesis has been proposed. The metabolic engineering approaches would offer great promise to mitigate the issues of low yield and high production cost, which are major challenges in microbial bio-processes industries. Further process optimization, optimising metabolic flux, and efficient recovery of GlcNAc from culture broth, should be investigated in order to achieve a high product titer. The current study presents a comprehensive review on microbe-based eco-friendly green methods that would pave the way towards the development of future research directions in this field for the designing of a cost-effective fermentation process on an industrial setup.


Asunto(s)
Acetilglucosamina , Glucosamina , Animales , Biotecnología , Quitina/metabolismo , Crustáceos
5.
Bioresour Technol ; 387: 129659, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37573982

RESUMEN

In order to combat the environmental issues associated with the burning of spent aromatic biomass (SAB), a method for alkaline hydrolysis of SAB has been developed to afford phenolic acids, predominantly the p-coumaric acid, lignin, and cellulose. Lignin (∼15 wt%) from alkaline hydrolysate was separated by precipitation while a mixture of phenolic acids obtained was directly reacted with a green reagent, PhI(OAc)2, under one-pot condition to afford a mixture of p-hydroxybenzaldehyde (>90 wt%) and vanillin (<10 wt%). Unreacted biomass obtained in the process was successfully used as a substrate for the production of cellulose (∼40 wt%). The developed method exhibits potential for application on an industrial scale.


Asunto(s)
Celulosa , Lignina , Aldehídos , Biomasa , Hidrólisis , Fenoles
6.
Cancer Biol Med ; 20(6)2023 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-37282627

RESUMEN

Prostate cancer, one of the most frequently occurring cancers in men, is a heterogeneous disease involving multiple cell types within tumors. This tumor heterogeneity at least partly results from genomic instability leading to sub-clonal cellular differentiation. The differentiated cell populations originate from a small subset of cells with tumor-initiating and stem-like properties. These cells, termed prostate cancer stem cells (PCSCs), play crucial roles in disease progression, drug resistance, and relapse. This review discusses the origin, hierarchy, and plasticity of PCSCs; methods for isolation and enrichment of PCSCs; and various cellular and metabolic signaling pathways involved in PCSC induction and maintenance, as well as therapeutic targeting.


Asunto(s)
Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/genética , Diferenciación Celular , Transducción de Señal , Progresión de la Enfermedad , Células Madre Neoplásicas/patología
7.
Phys Chem Chem Phys ; 25(15): 10567-10582, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-36988096

RESUMEN

The present work reports enhanced photocatalytic performance of highly crystalline, monodisperse ZnSe microspheres, synthesized by the size-selective, ETDA-assisted hydrothermal method. Systematic studies on time-dependent reaction kinetics and growth parameters indicate dependency of morphology and crystal structure on the volume % of EDTA and dependency of size on the volume % of hydrazine hydrate for ZnSe microspheres. X-ray diffraction studies confirm highly crystalline cubic zinc blende crystal structure with crystallite size in the range of 10-15 nm. Diffuse reflectance spectra show blue shift having a broad absorption peak between 415 and 425 nm, with a band gap of ∼2.6 eV from the K-M plot. Photoluminescence spectra show higher ratio of near band edge emission to deep level emission, confirming the decrease in defect related emission and depicting the higher crystallinity of ZnSe. Raman spectroscopy also confirms the crystalline and pure nature of ZnSe microspheres, from the observation of a high intensity dominant peak at 248 cm-1, attributed to longitudinal optical phonon scattering. Morphological analysis using FE-SEM and HRTEM shows monodispersed microspheres having size ∼2.5 µm, made up of small ZnSe nanocrystals with ∼10 nm size and with an interplanar spacing of ∼0.32 nm, corresponding to zinc blende ZnSe(111) planes. Brunauer-Emmett-Teller analysis indicates type-IV adsorption-isotherms and hysteresis loops, confirming the presence of mesopores on the surface of ZnSe microspheres controlling the diffusion rate of the catalyst. The degradation rate constant for methylene-blue using first-order reaction kinetics confirms improvement in photocatalytic activity by a factor of 7 to 13 times higher than that of bulk ZnSe, which is attributed to the controlled, well-defined morphology of spherical microstructures made up of small-sized ZnSe nanocrystals. Density functional theory based calculations support the preferential adsorption of EDTA at the Se site of the ZnSe(111) surface with an energy of -1.90 eV. The electronic-structure plot demonstrates semiconducting behaviour with a direct band gap of ∼1.51 eV. First-principles calculations confirm enhancement in the photocatalytic water splitting activity of the ZnSe(111) surface via adsorption of intermediates. The improvement in dye degradation can be attributed to the enhanced oxidation process through the formation of intermediates such as O* (-3.13 eV) and HO* (-2.57 eV) at the Se site of the ZnSe surface.

8.
RSC Adv ; 13(13): 9046-9054, 2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36950080

RESUMEN

Two Schiff base complexes of copper(ii) and cobalt(iii) having the formulae [CuL2] (Cu-Sal) and [CoL3] (Co-Sal) (HL = 2-(((2-hydroxyethyl)imino)methyl)phenol) have been synthesized and characterized microanalytically, spectroscopically and in the case of Cu-Sal using single crystal X-ray diffraction technique. The single crystal X-ray analysis reveals a square planar geometry around Cu(ii) satisfied by phenoxide oxygen and imine nitrogen of the L- ligand to generate a six membered chelate ring. The solid state structure of Cu-Sal is satisfied by varied intermolecular non-covalent interactions. The nature of these interactions has been addressed with the aid of Hirshfeld surface analysis. Both compounds have been used as sensitizers in TiO2 based dye sensitized solar cells (DSSCs) and the DSSC experiments revealed that Co-Sal offers better photovoltaic performance in comparison to Cu-Sal. The Co-Sal exhibited a J sc of 9.75 mA cm-2 with a V oc of -0.648 V, incident photon to current conversion efficiency (IPCE) of 57% and η of 3.84%. The relatively better photovoltaic performance of Co-Sal could be attributed to better light absorption and dye loading than that of Cu-Sal.

9.
RSC Adv ; 12(43): 28088-28097, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36320265

RESUMEN

Three new heteroleptic dithiocarbamate complexes with formula [M(Phen-dione)(Fcdtc)]PF6 (where M = Ni(ii) Ni-Fc, Cu(ii) Cu-Fc) and [Co(Phen-dione)(Fcdtc)2]PF6 (Co-Fc) (Fcdtc = N-ethanol-N-methylferrocene dithiocarbamate and Phen-dione = 1,10-phenanthroline-5,6-dione; PF6 - = hexafluorophosphate) were synthesized and characterized using microanalysis, FTIR, electronic absorption spectroscopy and mass spectrometry. The solution state electronic absorption spectroscopy for all three complexes displayed a band at ∼430 nm corresponding to the ferrocene unit and another low-intensity band in the visible region arising because of the d-d transitions. These newly synthesized complexes were used as co-sensitizers for the state-of-the-art di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(ii) (N719) dye in dye-sensitized solar cells (DSSCs). Among the three co-sensitizers/co-adsorbent-based DSSC set-ups, the assembly fabricated using Co-Fc/N719 displayed good photovoltaic performance with 5.31% efficiency (η) while a new triple component strategy inculcating N719, Co-Fc and Cu-Fc dyes offered the best photovoltaic performance with 6.05% efficiency (η) with incident photon to current conversion efficiency (IPCE) of 63%. This indicated an upliftment of the DSSC performance by ∼38% in comparison to the set-up constructed by employing only N719 dye (η = 4.39%) under similar experimental conditions.

10.
iScience ; 25(3): 103898, 2022 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-35243256

RESUMEN

High-quality growth of MoS2-xNx films is realized on single-crystal c-Al2O3 substrates by the pulsed laser deposition (PLD) in ammonia rendering highly stable and tunable 1T'/2H biphasic constitution. Raman spectroscopy reveals systematic enhancement of 1T' phase component due to the incorporation of covalently bonded N-doping in MoS2 lattice, inducing compressive strain. Interestingly, the film deposited at 300 mTorr NH3 shows ∼80% 1T' phase. The transport measurements performed on MoS2-xNx films deposited at 300 mTorr NH3 display very low room temperature resistivity of 0.03 mΩ-cm which is 100 times enhanced over the undoped MoS2 grown under comparable conditions. A triboelectric nanogenerator (TENG) device containing biphasic MoS2-xNx film as an electron acceptor exhibits a clear enhancement in the output voltage as compared to the pristine MoS2. Device architecture, p-type N doping in MoS2 lattice, favorably increased work-function, multiphasic component of MoS2, and increased surface roughness synergistically contribute to superior TENG performance.

11.
ACS Omega ; 6(24): 15686-15697, 2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34179612

RESUMEN

Currently, the limited availability of lithium sources is escalating the cost of lithium-ion batteries (LIBs). Considering the fluctuating economics of LIBs, sodium-ion batteries (SIBs) have now drawn attention because sodium is an earth-abundant, low-cost element that exhibits similar chemistry to that of LIBs. Despite developments in different anode materials, there still remain several challenges in SIBs, including lighter cell design for SIBs. The presented work designs a facile strategy to prepare nitrogen-doped free-standing pseudo-graphitic nanofibers via electrospinning. A structural and morphological study implies highly disordered graphitic structured nanofibers having diameters of ∼120-170 nm, with a smooth surface. X-ray photoelectron spectroscopy analysis showed that nitrogen was successfully doped in carbon nanofibers (CNFs). When served as an anode material for SIBs, the resultant material exhibits excellent sodium-ion storage properties in terms of long-term cycling stability and high rate capability. Notably, a binder-free self-standing CNF without a current collector was used as an anode for SIBs that delivered capacities of 210 and 87 mA h g-1 at 20 and 1600 mA g-1, respectively, retaining a capacity of 177 mA h g-1 when retained at 20 mA g-1. The as-synthesized CNFs demonstrate a long cycle life with a relatively high Columbic efficiency of 98.6% for the 900th cycle, with a stable and excellent rate capacity. The sodium storage mechanisms of the CNFs were examined with various nitrogen concentrations and carbonization temperatures. Furthermore, the diffusion coefficients of the sodium ions based on the electrochemical impedance spectra measurement have been calculated in the range of 10-15-10-12 cm2 s-1, revealing excellent diffusion mobility for Na atoms in the CNFs. This study demonstrates that optimum nitrogen doping and carbonization temperature demonstrated a lower Warburg coefficient and a higher Na-ion diffusion coefficient leads to enhanced stable electrochemical performance. Thus, our study shows that the nitrogen-doped CNFs will have potential for SIBs.

12.
Environ Res ; 199: 111321, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33989619

RESUMEN

A global upsurge in emergence and spread of antibiotic resistance (ABR) in bacterial populations is a serious threat for human health. Unfortunately, ABR is no longer confined to nosocomial environments and is frequently reported from community microbes as well. The ABR is resulting in shrinking potent antibiotics pool and thus necessitating novel and alternative therapies and therapeutics. Current investigation was aimed to assess the synergistic potential of a synthesized, phytomolecule-loaded, polysaccharide-stabilized metallic nanoparticles (NPs) against Pseudomonas aeruginosa (PA) and Escherichia coli (EC) isolated from river waters. ABR profiling of these strains characterized them as multidrug resistant (MDR). Synthesized embelin (Emb, isolated from Embelia tsjeriam-cottam)-loaded, chitosan-gold (Emb-Chi-Au) NPs were assessed for their potential synergistic activity with ciprofloxacin (CIP) via checker-board assay and time-kill curve analysis. The NPs reduced the minimal inhibitory concentration (MIC) of CIP by 16- and 4-fold against MDR PA (PA-r) and EC (EC-r) strains, respectively. Fractional inhibitory concentration (FIC) indices with ≤0.5 values confirmed the synergy between the Emb-Chi-Au NPs and CIP, which was further confirmed at ½ MICs in both PA-r and EC-r via time-kill curve analysis. In order to decipher the mode of action, efflux pump inhibitory effects of Emb-Chi-Au NPs were evaluated in terms of the increase in the EtBr mediated fluorescence in control versus NP-treated MDR strains. Molecular docking based in silico simulations were used to predict the interactions between Emb and the active sites of the efflux pump related proteins in PA-r (MexA, MexB and OprM) and EC-r (AcrA, AcrB and TolC), which revealed the probable bond formation between Emb and respective amino acid residues.


Asunto(s)
Quitosano , Proteínas de Escherichia coli , Nanopartículas del Metal , Antibacterianos/farmacología , Proteínas de la Membrana Bacteriana Externa/metabolismo , Benzoquinonas , Ciprofloxacina/farmacología , Escherichia coli , Oro , Humanos , Proteínas de Transporte de Membrana , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Proteínas Asociadas a Resistencia a Múltiples Medicamentos , Pseudomonas aeruginosa
13.
ACS Omega ; 6(8): 5717-5729, 2021 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-33681611

RESUMEN

Herein, overall improvement in the electrochemical performance of manganese dioxide is achieved through fine-tuning the microstructure of partially Co-doped manganese dioxide nanomaterial using facile hydrothermal method with precise control of preparative parameters. The structural investigation exhibits formation of a multiphase compound accompanied by controlled reflections of α-MnO2 as well as γ-MnO2 crystalline phases. The morphological examination manifests the presence of MnO2 nanowires having a width of 70-80 nm and a length of several microns. The Co-doped manganese dioxide electrode displayed a particular capacitive behavior along with a rising order of capacitance concerning with increased cobalt ion concentration suitable for certain limits. The value of specific capacitance achieved by a 5% Co-doped manganese dioxide sample was 1050 F g-1 at 0.5 A g-1, which was nearly threefold greater than that achieved by a bare manganese dioxide electrode. Furthermore, Co-doped manganese dioxide nanocomposite electrode exhibits exceptional capacitance retention (92.7%) till 10,000 cycles. It shows the good cyclability as well as stability of the material. Furthermore, we have demonstrated the solid-state supercapacitor with good energy and power density.

14.
Nanoscale Adv ; 3(2): 508-516, 2021 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-36131732

RESUMEN

Constructing a heterostructure is an effective strategy to reduce the electron-hole recombination rate, which enhances photocatalytic activity. Here, we report a facile hydrothermal method to grow CdS nanoparticles on MnWO4 nanorods and their photocatalytic hydrogen generation under solar light. A structural study shows the decoration of hexagonal CdS nanoparticles on monoclinic MnWO4. Morphological studies based on FE-TEM analysis confirm the sensitization of CdS nanoparticles (10 nm) on MnWO4 nanorods of diameter-35 nm with mean length ∼100 nm. The lower PL intensity of MnWO4 was observed with an increasing amount of CdS nanoparticles, which shows inhibition of the charge carrier recombination rate. A CdS@MnWO4 narrow band gap semiconductor was employed for photocatalytic hydrogen generation from water under solar light and the highest amount of hydrogen, i.e. 3218 µmol h-1 g-1, is obtained which is 21 times higher than that with pristine MnWO4. The enhanced photocatalytic activity is ascribed to the formation of a CdS@MnWO4 nanoheterostructure resulting in efficient spatial separation of photogenerated electron-hole pairs due to vacancy defects. More significantly, direct Z-scheme electron transfer from MnWO4 to CdS is responsible for the enhanced hydrogen evolution. This work signifies that a CdS decorated MnWO4 nanoheterostructure has the potential to improve the solar to direct fuel conversion efficiency.

15.
RSC Adv ; 11(48): 29877-29886, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-35480278

RESUMEN

Herein, we report Sn3O4 and Sn3O4 nanoflake/graphene for photocatalytic hydrogen generation from H2O and H2S under natural "sunlight" irradiation. The Sn3O4/graphene composites were prepared by a simple hydrothermal method at relatively low temperatures (150 °C). The incorporation of graphene in Sn3O4 exhibits remarkable improvement in solar light absorption, with improved photoinduced charge separation due to formation of the heterostructure. The highest photocatalytic hydrogen production rate for the Sn3O4/graphene nanoheterostructure was observed as 4687 µmol h-1 g-1 from H2O and 7887 µmol h-1 g-1 from H2S under natural sunlight. The observed hydrogen evolution is much higher than that for pure Sn3O4 (5.7 times that from H2O, and 2.2 times from H2S). The improved photocatalytic activity is due to the presence of graphene, which acts as an electron collector and transporter in the heterostructure. More significantly, the Sn3O4 nanoflakes are uniformly and parallel grown on the graphene surface, which accelerates the fast transport of electrons due to the short diffusion distance. Such a unique morphology for the Sn3O4 along with the graphene provides more adsorption sites, which are effective for photocatalytic reactions under solar light. This work suggests an effective strategy towards designing the surfaces of various oxides with graphene nanoheterostructures for high performance of energy-conversion devices.

16.
Nanoscale Adv ; 2(10): 4689-4701, 2020 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-36132928

RESUMEN

The morphology and crystal structure of electrode materials have an enormous impact on their electrochemical properties for employment in supercapacitors for various applications. In this study, the transformations of the crystal structure of WO3·H2O nanoplates were conducted by post-annealing at 200 °C and 400 °C. The morphological and structural evolution of the electrodes was studied via FEG-SEM, HRTEM, FTIR, XRD, and Raman spectroscopy. The phase transition and enhanced degree of crystallinity were observed with increasing temperature. The orthorhombic structures of the hydrate WO3·H2O (W80), the mixed-phase with mesoporous structure (W200), and finally the monoclinic phase of WO3 structures (W400) were achieved at annealing temperatures of 80 °C, 200 °C, and 400 °C respectively. The electrochemical performance of electrode W200 showed the highest specific capacitance of 606 F g-1 as compared to electrode W80 (361 F g-1), and was two-fold greater than electrode W400 (302 F g-1) at a current density of 1 A g-1. Moreover, electrode W200 exhibited excellent cyclic stability of 89% at an ultrahigh scan rate of 100 mV s-1 after 4000 cycles. The results highlight that the mixed-phase WO3 nanoplates would make a suitable electrode material for supercapacitors with desired electrochemical features.

17.
Biotechnol Bioeng ; 117(2): 567-579, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31691950

RESUMEN

The progression of liver disease from normal to cirrhotic state is characterized by modulation of the stiffness of the extracellular matrix (ECM). Mimicking this modulation in vitro scaffold could provide a better insight into hepatic cell behavior. In this study, interpenetrating poly(N-isopropylacrylamide-co-gelatin) cryogels were synthesized in 48 different compositions to yield scaffolds of different properties. It was observed that a high concentration of N-isopropylacrylamide (NIPAAm) leads to the formation of small pores while gelatin interpenetration on poly-NIPAAm framework renders porous structure. Swelling properties and porosity of the gels decreased with an increase in NIPAAm concentration owing to the increased compactness of the gels. Gelatin interpenetration relaxed the gels and enhanced these properties. An increase in gelatin concentration led to a reduction in compressive moduli indicating that gelatin interpenetration in the poly-NIPAAm network softens the cryogel. With the increase in NIPAAm concentration, the effect of gelatin interpenetration in reducing the compressive moduli expanded. The cytocompatibility studies indicated that the gels are cell-adherent and compatible with HepG2. Furthermore, biochemical and real-time polymerase chain reaction studies revealed that HepG2 and Huh-7 cells cultured on scaffolds mimicking the ECM stiffness of normal liver (1.5-2.5 kPa) exhibited optimum liver-specific functionalities. Increasing the stiffness to fibrotic (4-9 kPa) and cirrhotic (10-20 kPa) ECM decreases the functionality.


Asunto(s)
Resinas Acrílicas/química , Criogeles/química , Gelatina/química , Hígado , Andamios del Tejido/química , Supervivencia Celular/efectos de los fármacos , Fuerza Compresiva , Criogeles/farmacología , Matriz Extracelular/química , Células Hep G2 , Humanos , Hígado/citología , Hígado/metabolismo , Hígado/fisiología , Ingeniería de Tejidos
18.
Int J Nanomedicine ; 14: 8285-8302, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31802866

RESUMEN

BACKGROUND: Curcumin has been widely used owing to its various medicinal properties including antitumor effects. However, its clinical application is limited by its instability, poor solubility and low bioavailability. Folic acid (FA)-functionalized nanoformulations may enhance the sustained release of an anticancer drug (curcumin) by tumor-specific targeting to improve therapeutic benefit. This study aims to design a nanoconjugate (NC) comprised of folate-curcumin-loaded gold-polyvinylpyrrolidone nanoparticles (FA-CurAu-PVP NPs) for targeted delivery in breast cancer model systems. METHODS: We developed curcumin-loaded FA-functionalized Au-PVP NCs by layer-by-layer assembly. The folic acid-curcumin Au-PVP NCs (FA-CurAu-PVP NCs) were characterized by ultraviolet-visible spectra, Fourier transform infrared spectroscopy, X-ray powder diffraction and thermogravimetric analysis. In vitro anticancer and antimigratory effects of NCs were examined by performing MTT and wound migration assays. The in vivo antitumor efficacy of NCs was investigated using a preclinical breast cancer orthotopic mouse model. RESULTS: Curcumin (40 µg/mL) was loaded along with conjugation of folate onto Au-PVP NPs to form FA-CurAu-PVP NCs. The size and charge of the NCs were increased gradually through layer-by-layer assembly and showed 80% release of curcumin at acidic pH. The NC did not show aggregation when incubated with human serum and mimicked an intrinsic peroxidase-like property in the presence of 3,3',5,5'-tetramethylbenzidine substrate. The MTT data using these NCs showed efficient anticancer activity at lower doses in estrogen/progesterone receptor (ER/PR)-negative cells compared with ER/PR-positive cells. Furthermore, the NCs did not show cytotoxicity at the investigated concentration in human breast epithelial and mouse fibroblast cell lines. They showed inhibitory effects on cell migration and high antitumor efficacy in in vivo analysis. CONCLUSION: These results suggest that folate-based tumor targeting using CurAu-PVP NCs is a promising approach for tumor-specific therapy of breast cancer without harming normal cells.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Ácido Fólico/química , Oro/química , Nanopartículas del Metal/química , Polímeros/química , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/patología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Curcumina/farmacología , Curcumina/uso terapéutico , Portadores de Fármacos/química , Liberación de Fármacos , Femenino , Humanos , Concentración de Iones de Hidrógeno , Nanopartículas del Metal/ultraestructura , Ratones , Nanoconjugados/química , Povidona/química , Suero/metabolismo
19.
Sci Rep ; 9(1): 12036, 2019 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-31427636

RESUMEN

The hierarchical nanostructured CdS@MoS2 core shell was architectured using template free facile solvothermal technique. More significantly, the typical hexagonal phase of core CdS and shell MoS2 has been obtained. Optical study clearly shows the two steps absorption in the visible region having band gap of 2.4 eV for CdS and 1.77 eV for MoS2. The FESEM of CdS@MoS2 reveals the formation of CdS microsphere (as a core) assemled with 40-50 nm nanoparticles and covered with ultrathin nanosheets of MoS2 (Shell) having size 200-300 nm and the 10-20 nm in thickness. The overall size of the core shell structure is around 8 µm. Intially, there is a formation of CdS microsphre due to high affinity of Cd ions with sulfur and further growth of MoS2 thin sheets on the surface. Considering band gap ideally in visible region, photocatalytic hydrogen evolution using CdS@MoS2 core shell was investigated under natural sunlight. The utmost hydrogen evolution rate achieved for core shell is 416.4 µmole h-1 with apparent quantum yield 35.04%. The photocatalytic activity suggest that an intimate interface contact, extended visible light absorption and effective photo generated charge carrier separation contributed to the photocatalytic enhancement of the CdS@MoS2 core shell. Additional, the enhanced hole trapping process and effective electrons transfer from CdS to MoS2 in CdS@MoS2 core shell heterostructures can significantly contribute for photocatalytic activity. Such core shell heterostructure will also have potential in thin film solar cell and other microelectronic devices.

20.
Med Chem ; 15(7): 781-789, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31208313

RESUMEN

BACKGROUND: The drug formulations used to control mosquito vectors and helminth infections have resulted in the development of resistance, and negative impact on non-target organisms and environment. OBJECTIVE: Plant-mediated synthesis of silver nanoparticles (P-AgNPs) using aqueous fruit peel extract of M. charantia, applications of P-AgNPs for helminthicidal activity against Indian earthworms (P. posthuma) and larvicidal activity against larvae of mosquito A. albopictus and A. aegypti. METHODS: Aqueous fruit peel extract of Momordica charantia was used to reduce silver ions to silver nanoparticles (P-AgNPs). UV-Visible (UV-Vis) Spectroscopy, X-ray diffraction, Fourier Transform Infrared Spectroscopy and Transmission Electron Microscopy characterize synthesized P-AgNPs. The motility and survival rate of the worms were recorded for the helminthicidal activity. Percent mortality of larvae of A. albopictus and A. aegypti was recorded for larvicidal activity. RESULTS: The UV-Vis absorption spectrum of P-AgNPs showed a strong surface plasmon absorption band in the visible region with a maximum absorption at 445 nm indicating the synthesis of silver nanoparticles by the addition of aqueous fruit peel extract. The XRD spectrum of P-AgNPs showed Bragg's reflection peaks 2θ value characteristics for the Face-Centered Cubic (FCC) structure of silver. The sharp absorption peak in FTIR at 1659 cm-1 assigned to C=O stretching vibration in carbonyl compounds represents terpenoids, flavonoids and polyphenols in the corona of PAgNPs; a 2 mg/mL of P-AgNPs. The concentration aqueous extract and P-AgNPs showed complete death of worms (the morphological alteration/coiling of body). A 20 ppm concentration of PAgNPs showed 85% mortality in larvae of Ae. albopictus and Ae. aegypti. P-AgNPs were nontoxic at low concentrations. CONCLUSION: The aqueous extracts played a dual role as reducing and capping agent during the biosynthesis of AgNPs as per FTIR and XRD results. The surface reactivity facilitated by biomolecule corona attached to silver nanoparticles can further help to functionalize AgNPs in various pharmaceuticals, biomedicals, and environmental applications.


Asunto(s)
Aedes/efectos de los fármacos , Insecticidas/farmacología , Nanopartículas del Metal/química , Momordica charantia/química , Plantas Medicinales/química , Plata/farmacología , Animales , Relación Dosis-Respuesta a Droga , Insecticidas/química , Insecticidas/metabolismo , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Estructura Molecular , Plata/química , Plata/metabolismo , Relación Estructura-Actividad
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