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1.
Pharm Res ; 37(12): 246, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33215292

RESUMO

PURPOSE: The present study made an attempt to develop copper nanoparticles (Cu-NP) with antifungal property using green synthesis method. Copper oxide nanoparticles (CuO-NPs) botanically synthesized using Neem leaf extract (Azadirachta indica A. Juss) were characterized by using different techniques like; UV-visible spectrophotometry, FTIR, XRD, SEM and TEM. METHODS: Materials were chosen the disease free and fresh Azadirachta indica A. Juss were collected and identified at Center of Biodiversity and Taxonomy. The plant samples were vigorously washed with distilled water then shade dried followed by sterilization with 0.1% mercuric chloride for 20 s and again it was washed with distilled water. 15 g powder form of plant material was added to 200 ml double distilled, CO2 free and deionized water and kept in shaker at 80°C and 1500 rpm for six hours. After agitation, the extract was separated by regular centrifugation at 10,000 rpm followed by filtration by using whatmann filter paper. The final volume of 100 ml of supernatant was collected as pure extract and stored in cool place for further use. RESULTS: The final results confirm a significant inhibition of CuO-NPs for the test fungi. Additionally, CuO-NPs demonstrated an enhanced effect when combined with Neem leaf extract. A total of 20-30% improvement in activity was noticed after combination, which correlates with commonly used synthetic fungicides. The toxicity results reveal that A. indica extract and their combined fractions with CuO-NP were less toxic to the test seeds of experimental plant while as bulk Cu followed by biosynthesized CuO-NPs influenced the germination rate as compared to control pots. CONCLUSIONS: The study drops a concern of research and offers a promising route of developing Copper based green fungicides that can help to combat with modern issues of synthetic fungicides. An average size of 80 ± 15 nm monoclinic cupric oxide (CuO) and cubic cuprous oxides (Cu2O) nanocrystals that existed in mixed form were successfully developed.


Assuntos
Azadirachta/metabolismo , Cobre/metabolismo , Frutas/microbiologia , Fungicidas Industriais/metabolismo , Química Verde , Malus/microbiologia , Nanopartículas Metálicas , Extratos Vegetais/metabolismo , Alternaria/efeitos dos fármacos , Alternaria/crescimento & desenvolvimento , Ascomicetos/efeitos dos fármacos , Ascomicetos/crescimento & desenvolvimento , Cobre/farmacologia , Fungicidas Industriais/farmacologia , Folhas de Planta/metabolismo
2.
Biotechnol Lett ; 42(5): 853-863, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32040672

RESUMO

OBJECTIVE: This study aims to detect pathogenic Escherichia coli (E. coli) bacteria using non-destructive fluorescence microscopy and micro-Raman spectroscopy. RESULTS: Raman vibrational spectroscopy provides additional information regarding biochemical changes at the cellular level. We have used two nanomaterials zinc oxide nanoparticles (ZnO-NPs) and gold nanoparticles (Au-NPs) to detect pathogenic E. coli. The scanning electron microscope (SEM) with energy dispersive X-ray (EDAX) spectroscopy exhibit surface morphology and the elemental composition of the synthesized NPs. The metal NPs are useful contrast agents due to the surface plasmon resonance (SPR) to detect the signal intensity and hence the bacterial cells. The changes due to the interaction between cells and NPs are further correlated to the change in the surface charge and stiffness of the cell surface with the help of the fluorescence microscopic assay. CONCLUSIONS: We conclude that when two E. coli strains (MTCC723 and MTCC443) and NPs are respectively mixed and kept overnight, the growth of bacteria are inhibited by ZnO-NPs due to changes in cell membrane permeability and intracellular metabolic system under fluorescence microscopy. However, SPR possessed Au-NPs result in enhanced fluorescence of both pathogens. In addition, with the help of Raman microscopy and element analysis, significant changes are observed when Au-NPs are added with the two strains as compared to ZnO-NPs due to protein, lipid and DNA/RNA induced conformational changes.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/isolamento & purificação , Ouro/farmacologia , Óxido de Zinco/farmacologia , Antibacterianos/química , Permeabilidade da Membrana Celular , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Proteínas de Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/metabolismo , Ouro/química , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Propriedades de Superfície , Óxido de Zinco/química
3.
J Nanosci Nanotechnol ; 18(5): 3523-3531, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442861

RESUMO

Spinel MnFe2O4 nanostructures were synthesized by simple, economical and eco-friendly microwave combustion (MCM) and conventional combustion (CCM) methods using metal nitrates and glycine used as the fuel, instead of toxic inorganic/organic catalyst, template and surfactant. Powder XRD and FT-IR, EDX and SAED results were confirmed the products have a cubic phase spinel structure. EDX and SAED results confirmed purity and high crystallinity without any other secondary phase impurities. HR-SEM and HR-TEM analysis indicate that the MCM and CCM products consist of nano- and microstructures, respectively. The optical band gap (Eg) was measured using Kubelka-Munk model and it shows higher value (2.37 eV) for MnFe2O4-MCM than MnFe2O4-CCM (2.15 eV), due to the smaller particle size of MnFe2O4-MCM. VSM results showed a superparamagnetic behavior and the magnetization (Ms) value of MnFe2O4-MCM is higher i.e., 39.68 emu/g than MnFe2O4-CCM (33.59 emu/g). It was found that the sample MnFe2O4-MCM have higher surface area than MnFe2O4-CCM, which in turn leads to the improved performance towards the photocatalytic degradation (PCD) of methylene blue (MB) and it was found that the sample MnFe2O4-MCM show higher PCD efficiency (96.48%) than MnFe2O4-CCM (84.95%). Also, MnFe2O4 show higher activity with good reusability, and eco-friendly materials for industrial and technological applications.


Assuntos
Óxido de Alumínio/química , Compostos Férricos/química , Óxido de Magnésio/química , Compostos de Manganês/química , Nanoestruturas/química , Magnetismo , Óptica e Fotônica , Espectroscopia de Infravermelho com Transformada de Fourier
4.
J Nanosci Nanotechnol ; 18(8): 5380-5389, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29458589

RESUMO

Carbon nanotubes (CNTs) are still receiving much attention in bio-sensing applications due to their remarkable properties. In this present research work, fibre-like carbon nanotubes (f-CNTs) were successfully fabricated over copper-molybdenum (Cu-Mo) substituted alumina nanoparticles at atmospheric pressure by chemical vapor deposition (CVD) technique and effectively employed as a neurotransmitter dopamine (DA) sensor. The obtained product was purified and structurally characterized by various techniques such as, field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, high resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectroscopy (XPS) analysis. Structural characterization, which reveals the material contains fibre-like multi walled carbon nanotubes with graphene layers having diameter in the range of 10-20 nm and 200-300 nm inner and outer, respectively and has certain crystallinity. The weight percentages of Cu, Mo in Alumina catalyst, reaction temperature, acetylene flow rate and reaction time have been optimised to yield maximum of carbon product. Electrochemical properties of the material towards DA sensing were studied by cyclic voltammetry (CV), and diffuse pulse voltammetry (DPV) techniques. The sensor exhibits linear relationship among the peak current and DA concentration from 8 to 45 µM with detection limit of 5.3 µM (S/N = 3). The presence of structural analogues of DA has no deleterious effect on the DA anodic peak current.

5.
J Nanosci Nanotechnol ; 18(6): 3991-3999, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442735

RESUMO

In the present work, Poly(o-phenylenediamine) (POPD) stabilized silver nanoparticles (POPD@AgNPs) nanocomposites was synthesized by solid state oxidative polymerization method using o-phenylenediamine dihydrochloride (oPD-HCl) as monomer and silver nitrate (AgNO3) used as metal precursor as well as oxidizing agent no other external oxidizing agent was used. POPD@AgNPs nanocomposites were characterized by various instrumental techniques to confirm their size, shape and its composition. The electrocatalytic activity of POPD and POPD@AgNPs modified electrode was investigated over the oxidation of hydrazine (N2H4) and reduction of hydrogen peroxide (H2O2) using Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and Chronoamperometry techniques. POPD and POPD@AgNPs were characterized using HR-TEM, FE-SEM, XRD, UV-Visible, FT-IR, Micro Raman spectroscopy and those results were confirmed their chemical purity, particle size, shape and its elemental compositions. Moreover, the DPV and chronoamperometry reveals that POPD@AgNPs is a good sensor for the electrochemical gas detection of N2H4 and H2O2 because it has good stability, easy-operation, excellent reproducibility, high sensitivity and good limit of detection when compared to with pure POPD. This system shows good stability, excellent sensitivity, response and the detection limit was obtained for the detection of N2H4 and H2O2 in trace level gases, which was lower than some of the modified electrodes.

6.
Sci Rep ; 14(1): 10821, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734707

RESUMO

Nickel copper cobalt oxide (NiCuCoO) ternary metal oxide nanoparticles were synthesized by employing the hydrothermal method. NiCuCoO electrode demonstrates a specified capacity of 596 C g-1 at 1 A g-1, high capacitance retaining of 99% even if 1000 sequences at the density of current 10 A g-1, and significant extended cyclic strength over 1000 sequences. The gathered asymmetric supercapacitor (ASC) tool via NiCuCoO as the cathode and activated carbon as anode materials achieve a specified capacity of 168 C g-1 at a current density of 1 Ag-1, an excellent capacity retaining of 95% even later than 5000 sequences at a density of current 10 A g-1. The fabricated device exhibits a high density of energy and power is 96 Wh kg-1 and 841 W kg-1. The prepared material confirms an excellent capacitance routine, so this work represents for a next-generation energy storage device.

7.
Sci Rep ; 14(1): 2432, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38287065

RESUMO

The present study reports synthesis of phenathroimidazole derivatives structures following donor-acceptor relation for high performance deep-blue light emitting diodes. Herein, methyl substituted benzodioxin-6-amine phenanthroimidazoles Cz-SBDPI and TPA-SBDPI derivatives that provide the blue light were designed and synthesized. These Cz-SBDPI and TPA-SBDPI show higher glass transition (Tg) temperatures of 199 and 194 °C and demonstrate enhanced thermal properties. Apart from enhanced thermal stability these compounds also exhibit superior photophysical, electrochemical and electroluminescent properties. The non-doped carbazole based device display improved electroluminescent performances than those of TPA-based devices. The strong orbital-coupling due to decreased energy barrier between Cz-SBDPI transitions result in deep blue emission with CIE-0.15, 0.06. For non-doped Cz-SBDPI device; high L (brightness):12,984 cd/m2; ηc (current efficiency): 5.9 cd/A; ηp (power efficiency): 5.7 lm/W and ηex (external quantum efficiency): 6.2% was observed. The results show that the D-A emitters can serve as simple but also as an effective approach to devise cheap electroluminescent materials that has high efficiency and can serve as OLED devices.

8.
Trop Doct ; 53(1): 148-150, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36254551

RESUMO

Influenza virus primarily affects ciliated cells of respiratory epithelium. Humans do not have innate immunity for these viruses and are vulnerable to get attacked. Benign acute childhood myositis usually occurs at the early convalescent phase of a influenza viral illness when fever, cough, myalgia, nasal discharge are the initial presentation.


Assuntos
Infecções por Herpesviridae , Influenza Humana , Miosite , Humanos , Criança , Influenza Humana/complicações , Influenza Humana/diagnóstico , Miosite/diagnóstico , Miosite/etiologia , Doença Aguda , Tosse
9.
Sci Rep ; 12(1): 3468, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-35236882

RESUMO

Single phase CeO2 nanocrystals were bio-synthesized using Hoodia gordonii natural extract as an effective chelating agent. The nanocrystals with an average diameter of 〈Ø〉 ~ 5-26 nm with 4+ electronic valence of Ce displayed a remarkable UV selectivity and an exceptional photostability. The diffuse reflectivity profile of such CeO2 exhibited a unique UV selectivity, in a form of a Heaviside function-like type profile in the solar spectrum. While the UV reflectivity is significantly low; within the range of 0.7%, it reaches 63% in the VIS and NIR. Their relative Reactive Oxygen Species (ROS) production was found to be < 1 within a wide range of concentration (0.5-1000 µg/ml). This exceptional photostability conjugated to a sound UV selectivity opens a potential horizon to a novel family of green nano-cosmetics by green nano-processing.


Assuntos
Cério , Nanopartículas , Antioxidantes/química , Cério/química , Nanopartículas/química , Espécies Reativas de Oxigênio
10.
Nanotechnology ; 22(33): 335702, 2011 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-21778569

RESUMO

Several different synthetic methods have been developed to fabricate tungsten oxide (WO(3)) nanostructures, but most of them require exotic reagents or are unsuitable for mass production. In this paper, we present a systematic investigation demonstrating that arc discharge is a fast and inexpensive synthesis method which can be used to produce high quality tungsten oxide nanostructures for NO(2) gas sensing measurements. The as-synthesized WO(3) nanostructures are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), finger-print Raman spectroscopy and proton induced x-ray emission (PIXE). The analysis shows that spheroidal-shaped monoclinic WO(3) crystal nanostructures were produced with an average diameter of 30 nm (range 10-100 nm) at an arc discharge current of 110 A and 300 Torr oxygen partial pressure. It is found that the morphology is controlled by the arc discharge parameters of current and oxygen partial pressure, e.g. a high arc discharge current combined with a low oxygen partial pressure results in small WO(3) nanostructures with improved conductivity. Sensors produced from the WO(3) nanostructures show a strong response to NO(2) gas at 325 °C. The ability to tune the morphology of the WO(3) nanostructures makes this method ideal for the fabrication of gas sensing materials.

11.
J Nanosci Nanotechnol ; 10(9): 5602-11, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21133080

RESUMO

Zinc Oxide (ZnO) is a promising candidate material for optical and electronic devices due to its direct wide band gap (3.37 eV) and high exciton binding energy (60 meV). For applications in various fields such as light emitting diode (LED) and laser diodes, growth of p-type ZnO is a prerequisite. ZnO is an intrinsically n-type semiconductor. In this paper we report on the synthesis of Zinc Oxide-Carbon (ZnO:C) thin films using pulsed laser deposition technique (PLD). The deposition parameters were optimized to obtain high quality epitaxial ZnO films over a carbon layer. The structural and optical properties were studied by glazing index X-ray diffraction (GIXRD), photoluminescence (PL), optical absorption (OA), and Raman spectroscopy. Rutherford backscattering spectroscopy (RBS), scanning electron microscopy with energy dispersive spectroscopy (SEMEDS) and atomic force microscopy (AFM) were employed to determine the composition and surface morphology of these thin films. The GIXRD pattern of the synthesized films exhibited hexagonal wurtzite crystal structure with a preferred (002) orientation. PL spectroscopy results showed that the emission intensity was maximum at -380 nm at a deposition temperature of 573 K. In the Raman spectra, the E2 phonon frequency around at 438 cm(-1) is a characteristic peak of the wurtzite lattice and could be seen in all samples. Furthermore, the optical direct band gap of ZnO films was found to be in the visible region. The growth of the epitaxial layer is discussed in the light of carbon atoms from the buffer layer. Our work demonstrates that the carbon is a novel dopant in the group of doped ZnO semiconductor materials. The introduction of carbon impurities enhanced the visible emission of red-green luminescence. It is concluded that the carbon impurities promote the zinc related native defect in ZnO.

12.
J Nanosci Nanotechnol ; 20(9): 5525-5532, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32331130

RESUMO

Zn1-xCoxO nanoparticles with three different values of 'x' (x = 0.05, 0.10, 0.15) were prepared by chemical co-precipitation process without any further heat treatment. The X-ray diffraction studies confirmed the wurtzite hexagonal crystal structure for synthesized Zn1-xCoxO nanoparticles. The dislocation density results reveal that there is an increase in the concentration of lattice imperfections with increasing the concentration of Co ions. The true values of lattice constants were calculated by using Nelson-Riley Function (NRF). Further, the average bond length (BL) were also calculated and presented. The optical and magnetic properties of Zn1-xCoxO nanoparticles were examined by room-temperature photoluminescence (PL) spectroscopy and vibrating sample magnetometer (VSM), respectively. The calculated values of magnetic susceptibility for Zn1-xCoxO nanoparticles with x = 0.05, 0.10, 0.15 were found to be 9.883×10-4, 2.29×10-2 and 2.37×10-2, respectively.

13.
J Nanosci Nanotechnol ; 20(4): 2482-2487, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492265

RESUMO

Herein, we studied the effect of nickel (Ni) doping on the properties of hydroxyapatite (HAp) nanoparticles synthesized by facile ultrasonication assisted wet chemical synthesis process. Various doping concentrations of nickel, i.e., 0.01 M, 0.05 M and 0.10 M, were used to dope into hydroxyapatite nanoparticles. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) pattern, scanning electron spectroscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, UV-Visible spectroscopy and Raman-scattering spectroscopy. The detailed structural characterizations confirmed that the crystallite sizes of the Ni-doped hydroxyapatite nanoparticles were reduced up to 53% compared to pure hydroxyapatite upon the doping of different concentrations of Ni ions. The agglomeration in the nanoparticles was also reduced by increasing the doping concentration of Ni ions. The XRD studies revealed that the average crystallite size of the synthesized Ni-doped HAp was decreased with increasing the concentration of Ni2+ ion doping and this observation was well-consistent with the SEM results. The FTIR and Raman studies well-confirmed the formation of pure HAp and Ni-doped HAp. Further, doping with Ni creates a new level of energy between the conductive band and the valence band and hence with increasing the concentration of Ni2+, the intensity in the UV-vis spectra was enhanced.

14.
Sci Rep ; 10(1): 10982, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620923

RESUMO

We report on the synthesis and enhanced thermal conductivity of stable Ag-decorated 2-D graphene nanocomposite in ethylene glycol based nanofluid by laser liquid solid interaction. A surfactant free nanofluid of Ag nanoparticles anchored onto the 2-D graphene sheets were synthesized using a two-step laser liquid solid interaction approach. In order to understand a pulsed Nd:YAG laser at the fundamental frequency (λ = 1,064 nm) to ablate Ag and graphite composite target submerged in ethylene glycol (EG) to form AgNPs decorated 2-D GNs-EG based nanofluid. From a heat transfer point of view, it was observed that the thermal conductivity of this stable Ag-graphene/EG is significantly enhanced by a factor of about 32.3%; this is highest reported value for a graphene based nanofluid.

15.
J Nanosci Nanotechnol ; 20(2): 924-933, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383088

RESUMO

Herein, we report a simple synthesis, characterization and photocatalytic degradation application of composite NiO-WO3 nanoparticles. The nanoparticles were synthesized by facile low-temperature method and characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectra (DRS). The synthesized NiO-WO3 nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of Eosin yellow (EY) dye. Interestingly, the synthesized photocatalytic exhibited a significant visible-light driven photocatalytic degradation of Eosin yellow (EY) dye. Under optimized conditions (pH = 5, catalyst dosage = 3 µM and initial dye concentration= 1.0 g/L), the obtained photo degradation of EY dye was above 95% in 180 min under visible light irradiation. Remarkably, reusability of the prepared photocatalyst was also observed and the photo-degradation reactions follow the pseudo-first-order model.

16.
J Hazard Mater ; 380: 120900, 2019 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-31326841

RESUMO

This study reports on the biodegradation of free cyanide (FCN) by cyanide degrading bacteria (CDB) that were isolated from mining wastewater and thiocyanate containing wastewater. The performance of these isolates was compared to cryopreserved CDBs that were used in previous studies. The performance of the isolates to degrade FCN was studied in batch cultures. It was observed that the CDB from the thiocyanate wastewater showed higher biodegradation rates (2.114 g CN-. L-1.O.D600 nm-1.h-1) compared to the isolates from the mining wastewater. The isolates from the cryopreserved CDBs and from the mining wastewater achieved a biodegradation rate of 1.285 g CN- L-1.O.D600 nm-1.h-1 and 1.209 g CN-.L-1.O.D600 nm-1.h-1, respectively. This study demonstrated that the source of the organisms plays a significant role on FCN biodegradation.


Assuntos
Bactérias/metabolismo , Biodegradação Ambiental , Cianetos/metabolismo , Poluentes Químicos da Água/metabolismo , Mineração , Águas Residuárias
17.
J Photochem Photobiol B ; 179: 119-125, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29367146

RESUMO

In the present day, nanotechnology is one of the most promising leading scientific and potentials areas in modern key technology development toward to the humankind. The synthesis of noble metal nanoparticles (NPs) is an expanding research area due to the possible applications for the development of bio-medical applications. Eco-friendly approach for the biosynthesis of gold nanoparticles (AuNPs) using the aqueous extract from Ruellia tuberosa and Phyllanthus acidus (leaf and twig) for the first time. Surface active AuNPs were characterized by UV-Vis spectroscopy, FTIR (Fourier transform infrared) spectroscopy, DSC (differential scanning colorimetry), DLS (dynamic light scattering) and environmental SEM (scanning electron microscope) analysis at room temperature (RT). Enhanced surface plasmon resonance (SPR) absorbance UV visible optical spectra were detected in the range of 552, 548, 558 and 536 nm. SEM and DLS (transmission mode) analysis confirmed the morphology of the nanoparticles to be spherical with the average size in the range of 88.37, 94.31, 82.23 and 81.36 nm. Further they have enhanced the enzyme activity on α-amylase, cellulase, and xylanase. The results suggest that the phyto-fabricated AuNPs from R. tuberosa and P. acidus is simple, less expensive, eco-friendly, green synthesis and also can be exploited for the potential future industrial and bio-medical applications.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Acanthaceae/química , Acanthaceae/metabolismo , Difusão Dinâmica da Luz , Química Verde , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Phyllanthus/química , Phyllanthus/metabolismo , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Ressonância de Plasmônio de Superfície
18.
J Photochem Photobiol B ; 166: 220-231, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28012416

RESUMO

The powder composites are predominantly used for filling of voids in bone and as drug delivery carrier to prevent the infection or inflammatory reaction in the damaged tissues. The objective of this work was to study the synthesis of agarose encapsulation on carbonated hydroxyapatite powder and their biological and drug delivery properties. Mesoporous, nanosized carbonated hydroxyapatite/agarose (CHAp/agarose) powder composites were prepared by solvothermal method and subsequently calcined to study the physico-chemical changes, if it subjected to thermal exposure. The phase of the as-synthesized powder was CHAp/agarose whereas the calcinated samples were non-stoichiometric HAp. The CHAp/agarose nanorods were of length 10-80nm and width 40-190nm for the samples synthesized at temperatures 120°C (ST120) and 150°C (ST150). The calcination process produced spheres (10-50nm) and rods with reduced size (40-120nm length and 20-30nm width). Composites were partially dissolved in SBF solution followed by exhibited better bioactivity than non-stoichiometric HAp confirmed by gravimetric method. Hemo and biocompatibility remained unaffected by presence of agarose or carbonate in the HAp. Specific surface area of the composites was high and exhibited an enhanced amoxicillin and 5-fluorouracil release than the calcined samples. The composites demonstrated a strong antimicrobial activity against E. coli, S. aureus and S. epidermidis. The ST120 showed prolonged drug (AMX and 5-Fcil) release and antimicrobial efficacy than ST150 and calcined samples. This technique would be simple and rapid for composites preparation, to produce high quality crystalline, resorbable, mesoporous and bioactive nanocomposite (CHAp/agarose) powders. This work provides new insight into the role of agarose coated on bioceramics by solvothermal technique and suggests that CHAp/agarose composites powders are promising materials for filling of void in bone and drug delivery applications.


Assuntos
Sistemas de Liberação de Medicamentos , Durapatita/química , Nanocompostos/química , Sefarose/química , Materiais Biocompatíveis , Carbonatos/química , Linhagem Celular , Humanos , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Termogravimetria , Difração de Raios X
19.
J Photochem Photobiol B ; 175: 163-172, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28888169

RESUMO

The aim of the current study is to synthesize nanosized silicon incorporated HAp (Si-HAP) using sodium metasilicate as the silicon source. The sol-gel derived samples were further subjected to microwave irradiation. Incorporation of Si into HAp did not alter the HAp phase, as confirmed by the X-ray diffraction analysis (XRD). Moreover, variation in the lattice parameters of the Si-incorporated HAp indicates that Si is substituted into the HAp lattice. The decrease in the intensity of the peaks attributed to hydroxyl groups, which appeared in the FTIR and Raman spectra of Si-HAp, further confirms the Si substitution in HAp lattices. The silicon incorporation enhanced the nanorods length by 70%, when compared to that of pure HAp. Microwave irradiation improved the crystallinity of Si-HAp when compared to as-synthesized Si-HAp samples. As-synthesized Si-incorporated HAp sample showed an intense blue emission under UV excitation. Microwave irradiation reduced the intensity of blue emission and exhibited red shift due to the reduction of defects in the Si-HAp crystal. The morphological change from rod to spherical and ribbon-like forms was observed with an increase in silicon content. Further, Si-HAp exhibited better bioactivity and low dissolution rate. Initially there was a burst release of amoxicillin from all the samples, subsequently it followed a sustained release. The microwave-irradiated HAp showed extended period of sustained release than that of as-synthesized HAp and Si-HAp. Similarly, the microwave-irradiated Si-incorporated samples exhibited prolonged drug release, as compared to that of the as-synthesized samples. Hence, Si-HAp is rapidly synthesized by a simple and cost effective method without inducing any additional phases, as compared to the conventional sintering process. This study provides a new insight into the rapid green synthesis of Si-HAp. Si-HAp could emerge as a promising material for the bone tissue replacement and as a drug delivery system.


Assuntos
Antibacterianos/metabolismo , Portadores de Fármacos/química , Durapatita/química , Nanoestruturas/química , Silicatos/química , Silício/química , Antibacterianos/química , Liberação Controlada de Fármacos , Química Verde , Microscopia Eletrônica de Varredura , Micro-Ondas , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Propriedades de Superfície , Raios Ultravioleta
20.
J Photochem Photobiol B ; 173: 99-107, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28570910

RESUMO

The present study tried for a phyto-synthetic method of producing silver nanoparticles (Ag-NPs) with size controlled as and eco-friendly route that can lead to their advanced production with decorative tranquil morphology. By inducing temperature fluctuation of the reaction mixture from 25 to 80°C the plasmon resonance band raised slowly which had an ultimate effect on size and shape of Ag-NPs as shown by UV-visible spectroscopy and TEM results. The biosynthesized nanoparticles showed good cytotoxic impact against MCF-7, A549 and Hep2 cells compared to normal cell lines. Compared to control plates, the percentage of cell growth inhibition was found to be high with as concentrations of Ag-NPs becomes more as determined by MTT assay. The AO/EtBr staining observations demonstrated that the mechanism of cell death induced by Ag-NPs was due to apoptosis in cancer cells. These present results propose that the silver nanoparticles (Ag-NPs) may be utilized as anticancer agents for the treatment of various cancer types. However, there is a need for study of in vivo examination of these nanoparticles to find their role and mechanism inside human body. Further, studies we plan to do biomarker fabrication from the green synthesized plant extract nanoparticles like silver, gold and copper nanoparticles with optimized shape and sizes and their enhancement of these noble nanoparticles.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Beta vulgaris/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata/química , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Beta vulgaris/metabolismo , Linhagem Celular Tumoral , Química Verde , Humanos , Células MCF-7 , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Tamanho da Partícula , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
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