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1.
RSC Adv ; 14(23): 15964-15978, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38765473

RESUMO

Herein, a series of heterocyclic organic compounds (PYFD1-PYFD7) are designed with different acceptor moieties at the terminal position of a reference compound (PYFR) for nonlinear optical (NLO) active materials. The optoelectronic characteristics of the designed chromophores were investigated using density functional theory (DFT) calculations with the M06/6-311G(d,p) functional. Frontier molecular orbital (FMO) analysis revealed a significant decrease in the energy of the band gaps (2.340-2.602 eV) for the derivatives as compared to the PYFR reference compound (3.12 eV). An efficient transfer of charge from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) was seen, which was further corroborated by the density of states (DOS) and transition density matrix (TDM) heat maps. The results of the global reactivity parameters (GRPs) indicated that all derivatives exhibited greater softness (σ = 0.384-0.427 eV) and lower hardness (η = 0.394-1.302 eV) as compared to PYFR, indicating a higher level of polarizability in the derivatives. Moreover, all of the derivatives showed significant findings in terms of nonlinear optical (NLO) results as compared to the reference chromophore. PYFD2 showed the most effective NLO response (α = 1.861 × 10-22 and ßtot = 2.376 × 10-28 esu), including a lowered band gap of 2.340 eV, the maximum softness value of 0.4273 eV, and the lowest hardness value of 1.170 eV as compared to other chromophores. The incorporation of different acceptors and thiophene as a π-spacer in this structural alteration significantly contributed to achieving remarkable NLO responses. Therefore, our findings may motivate experimentalists to synthesize these designed NLO active materials for the current advanced technological applications.

2.
J Mol Model ; 30(5): 126, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38581440

RESUMO

CONTEXT: Due to their unique photophysical properties, organic charge transfer crystals are becoming promising materials for next-generation optoelectronic devices. This research paper explores the impact of s-block metals on a charge transfer crystal of indol-2-one for enhanced nonlinear optical (NLO) responses with efficient energetic offsets. The study reveals that alkali metals can enhance NLO performance due to their free electrons. METHOD: The Perdew-Burke-Ernzerhof functional of DFT with dispersion correction (D3) was used, and the λmax values ranged between 596 and 669 nm, with the highest value for dichloromethane (DCM). Leveraging the unique properties of metals allowed for the development of nonlinear optical materials with improved performance and versatility. Softness (σ) values provide insight into electron density changes, with higher values indicating a greater tendency for changes and lower values indicating the opposite. The NLO results for the chromophores MMI1-MMI6 show varying linear polarizability (< α0 >) along with their first (ß0) and second (γ0) hyperpolarizabilities. Chromophore MMI4 stands out with the highest NLO performance, having two potassium (K) atoms. Its < α0 > , ß0, and γ0 values of 4.19, 7.09, and 17.43 (× 10-24 e.s.u), respectively, indicate a significant enhancement in NLO response compared to the other chromophores. The transitions involving (O20)LP → (C3-N5)π* and (O19)LP → (N12-C13)π* exhibit the highest level of stabilization, followed by (O23)π → (C10-C11)π*, while (C6-N12)π → (C6-C7)π* shows the lowest level of stabilization for chromophore MMI4. The present research work is facile in its nature, and it can be helpful for synthetic scientist to design the new materials for uniting crystal properties with metal doping for efficient NLO devices.

3.
Sci Rep ; 14(1): 2732, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302494

RESUMO

Triazoles, nitrogen-containing heterocycles, have gained attention for their applications in medicinal chemistry, drug discovery, agrochemicals, and material sciences. In the current study, we synthesized novel derivatives of N-substituted 2-((5-(3-bromophenyl)-4-methyl-4H-1,2,4-triazol-3-yl)thio)-N-phenylpropanamide and conducted a comprehensive investigation using density functional theory (DFT). These novel structural hybrids of 1,2,4-triazole were synthesized through the multi-step chemical modifications of 3-bromobenzoic acid (1). Initially, compound 1 was converted into its methyl-3-bromobenzoate (2) which was then transformed into 3-bromobenzohydrazide (3). The final step involved the cyclization of compound 3, producing its 1,2,4-triazole derivative (4). This intermediate was then coupled with different electrophiles, resulting in the formation of the final derivatives (7a-7c). Additionally, the characterization of these triazole-based compounds (7a, 7b, and 7c) were carried out using techniques such as IR, HNMR, and UV-visible spectroscopy to understand their structural and spectroscopic properties. The DFT study utilized M06/6-311G(d,p) functional to investigate geometrical parameters, HOMO-LUMO energies, natural bond orbital analyses, transition density matrix (TDM), density of states, and nonlinear optical (NLO) properties. The FMO analysis revealed that compound 7c exhibited the lowest band gap value (4.618 eV). Notably, compound 7c exhibited significant linear polarizability (4.195 > × 10-23) and first and second hyperpolarizabilities (6.317 > × 10-30, 4.314 × 10-35), signifying its potential for nonlinear optical applications. These NLO characteristics imply that each of our compounds, especially 7c, plays a crucial part in fabricating materials showing promising NLO properties for optoelectronic applications.

4.
ACS Omega ; 9(3): 3596-3608, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38284097

RESUMO

Organic-based nonlinear optical (NLO) materials may be used in many optical-electronic systems and other next-generation defense technologies. With the importance of NLO materials, a series of push-pull architecture (D-π-A) derivatives (DTMD2-DTMD6) were devised from DTMR1 through structural alteration of different efficient donor heterocyclic groups. Density functional theory-based computations were executed at the MPW1PW91/6-31G(d,p) level to explore the NLO behavior of the derivatives. To investigate the optoelectronic behavior of the said compounds, various analyses like the frontier molecular orbital (FMO), global reactivity parameters, density of state (DOS), absorption spectra (UV-vis), natural bond orbital, and transition density matrix (TDM) were performed. The derivatives have a smaller band gap (2.156-1.492 eV) and a larger bathochromic shift (λmax = 692.838-969.605 nm) as compared to the reference chromophore (ΔE = 2.306 eV and λmax = 677.949 nm). FMO analysis revealed substantial charge conduction out of the donor toward the acceptor via a spacer that was also shown by TDM and DOS analyses. All derivatives showed promising NLO results, with the maximum amplitude of linear polarizability ⟨α⟩ and first (ßtotal) and second (γtotal) hyperpolarizabilities over their reference chromophore. DTMD2 contained the highest ßtotal (7.220 × 10-27 esu) and γtotal (1.720 × 10-31 esu) values corresponding with the reduced band gap (1.492 eV), representing potential futures for a large NLO amplitude. This structural modification through the use of various donors has played a significant part in achieving promising NLO behavior in the modified compounds.

5.
RSC Adv ; 14(6): 3782-3789, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38274172

RESUMO

Employing a combination of Density Functional Theory (DFT) calculations and Molecular Dynamics (MD) simulations, the adsorption of molecular hydrogen (H2) on Be3Al2(SiO3)6-beryl, a prominent silicate mineral, has been studied. The crystal structure of beryl, which consists of interconnected tetrahedral and octahedral sites, provides a fascinating framework for comprehending H2 adsorption behavior. Initial investigation of the interaction between H2 molecules and the beryl surface employed DFT calculations. We identified favorable adsorption sites and gained insight into the binding mechanism through extensive structural optimizations and energy calculations. H2 molecules preferentially adsorb on the exposed oxygen atoms surrounding the octahedral sites, producing weak van der Waals interactions with the beryl surface, according to our findings. To further investigate the dynamic aspects of H2 adsorption, MD simulations employing a suitable force field were conducted. To precisely represent interatomic interactions within the Be3Al2(SiO3)6-beryl-H2 system, the force field parameters were meticulously parameterized. By subjecting the system to a variety of temperatures, we were able to obtain valuable information about the stability, diffusion, and desorption kinetics of H2 molecules within the beryl structure. The comprehensive understanding of the H2 adsorption phenomenon on Be3Al2(SiO3)6-beryl is provided by the combined DFT and MD investigations. The results elucidate the mechanisms underlying H2 binding, highlighting the role of surface oxygen atoms and the effect of temperature on H2 dynamics. This research contributes to a fundamental understanding of hydrogen storage and release in beryllium-based silicates and provides valuable guidance for the design and optimization of materials for hydrogen storage, catalysis, gas separation, sensing and environmental applications.

6.
EJNMMI Radiopharm Chem ; 7(1): 19, 2022 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-35870027

RESUMO

BACKGROUND: Myocardial perfusion imaging (MPI) is one of the most commonly performed investigations in nuclear medicine procedures. Due to the longer half-life of the emerging positron emitter copper-64 and its availability from low energy cyclotron, together with its well-known coordination chemistry, we have synthesized 64Cu-labeled NOTA- and 64Cu-NOTAM-rhodamine conjugates as potential cardiac imaging agents using PET. RESULTS: 64Cu-NOTA- and 64Cu-NOTAM-rhodamine conjugates were synthesized using a traightforward and one-step simple reaction. Radiochemical yields were greater than 97% (decay corrected), with a total synthesis time of less than 25 min. Radiochemical purities were always greater than 98% as assessed by TLC and HPLC. These synthetic approaches hold considerable promise as a simple method for 64Cu-rhodamine conjugates synthesis, with high radiochemical yield and purity. Biodistribution studies in normal Fischer rats at 60 min post-injection, demonstrated significant heart uptake and a good biodistribution profile for both the radioconjugates. However, the 64Cu-NOTAM-rhodamine conjugate has shown more heart uptake (~ 10% ID/g) over the 64Cu-NOTA-rhodamine conjugate (5.6% ID/g). CONCLUSIONS: These results demonstrate that these radioconjugates may be useful probes for the PET evaluation of MPI.

7.
Cancers (Basel) ; 13(9)2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-34062991

RESUMO

Magnetic nanoparticles gained considerable attention in last few years due to their remarkable properties. Superparamaganetism, non-toxicity, biocompatibility, chemical inertness, and environmental friendliness are some of the properties that make iron oxide nanoparticles (IONPs) an ideal choice for biomedical applications. Along with being easily tuneable and a tailored surface for conjugation of IONPs, their physio-chemical and biological properties can also be varied by modifying the basic parameters for synthesis that enhances the additional possibilities for designing novel magnetic nanomaterial for theranostic applications. This review highlights the synthesis, surface modification, and different applications of IONPs for diagnosis, imaging, and therapy. Furthermore, it also represents the recent report on the application of IONPs as enzyme mimetic compounds and a contrasting agent, and its significance in the field as an anticancer and antimicrobial agent.

8.
J Phys Condens Matter ; 33(19)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33761496

RESUMO

In this present investigation, we report the effect of aluminum (Al) doping on the photoelectric performance of cadmium sulfide (CdS) thin films prepared by cost-effective automatic nebulizer spray method. The doping of Al concentrations varied from 1 at.% to 9 at.% in the steps of 3 at.%. X-ray diffraction (XRD) patterns show hexagonal crystal structure with polycrystalline nature and the enrichment of crystallite sizes as a function of Al doping concentrations. The formed impurity phase i.e. CdO might be helpful in enhancing the photoelectric performance by its additional photo-generated charge carriers. The optical studies confirm the maximum absorption showed in the visible spectral range with the corresponding minimum bandgap of 2.28 eV for 6 at.% of Al. The room temperature photoluminescence studies show an increase of near-band-edge (NBE) emission as a function of Al doping concentration and this NBE is close to the obtained bandgap in terms of wavelength. In addition, the observed red emission at 635 nm is due to the surface-related impurities or native defect states. From the present work, the observed responsivity (R), external quantum efficiency (EQE) and detectivity (D*) of the CdS:Al detectors are 8.64 AW-1, ∼2018% and 9.29 × 1011jones, respectively for the optimum 6 at.% of CdS:Al film. The performance of CdS:Al films reported in this work are significantly improved when compared with literature reports. The present investigation, therefore offers a potential material, CdS:Al, as a photodetector for various scientific and industrial applications.

9.
J Am Chem Soc ; 143(1): 463-470, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33375782

RESUMO

The anion [P4O11]2-, employed as its bis(triphenylphosphine)iminium (PPN) salt, is shown herein to be a versatile reagent for nucleophile tetraphosphorylation. Treatment under anhydrous conditions with an alkylamine base and a nucleophile (HNuc1), such as an alcohol (neopentanol, cyclohexanol, 4-methylumbelliferone, and Boc-Tyr-OMe), an amine (propargylamine, diethylamine, morpholine, 3,5-dimethylaniline, and isopropylamine), dihydrogen phosphate, phenylphosphonate, azide ion, or methylidene triphenylphosphorane, results in nucleophile substituted tetrametaphosphates ([P4O11Nuc1]3-) as mixed PPN and alkylammonium salts in 59% to 99% yield. Treatment of the resulting functionalized tetrametaphosphates with a second nucleophile (HNuc2), such as hydroxide, a phenol (4-methylumbelliferone), an amine (propargylamine and ethanolamine), fluoride, or a nucleoside monophosphate (uridine monophosphate, deoxyadenosine monophosphate, and adenosine monophosphate), results in ring opening to linear tetraphosphates bearing one nucleophile on each end ([Nuc1(PO3)3PO2Nuc2]4-). When necessary, these linear tetraphosphates are purified by reverse phase or anion exchange HPLC, yielding triethylammonium or ammonium salts in 32% to 92% yield from [PPN]2[P4O11]. Phosphorylation of methylidene triphenylphosphorane as Nuc1 yields a new tetrametaphosphate-based ylide ([Ph3PCHP4O11]3-, 94% yield). Wittig olefination of 2',3'-O-isopropylidene-5'-deoxy-5'-uridylaldehyde using this ylide results in a 3'-deoxy-3',4'-didehydronucleotide derivative, isolated as the triethylammonium salt in 54% yield.


Assuntos
Nucleotídeos/síntese química , Polifosfatos/síntese química , Fosforilação
10.
Int J Biol Macromol ; 164: 3864-3872, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827620

RESUMO

In the present study, we have fabricated a novel chitosan based nanocomposite (g-C3N4/Ag3PO4/CS) containing g-C3N4 and Ag3PO4 nanoparticles. The fabricated nanocomposite was characterized successfully and used as a catalyst for photocatalytic degradation of ciprofloxacin (CIP) under visible light. The TEM results revealed that the g-C3N4 and Ag3PO4 nanoparticles are well dispersed into the polymer matrix. The surface area of the nanocomposite was determine using N2adsorption and desorption isotherm and calculated using BET equation and found to be 112.47 m2/g. The photocatalytic degradation of CIP was studied at different initial concentrations. The intermediate of and the degradation mechanism was determining using LCMS and DFT techniques. The results revealed that as-fabricated nanocomposite, g-C3N4/Ag3PO4/CS shows, 90.34% degradation of CIP within 60 min at room temperature in neutral medium. The CIP degradation kinetics displays the first-order kinetics with 0.01771 min-1. The reusability of the photocatalyst was observed after six cycles and g-C3N4/Ag3PO4/CS catalyst remains 79.43% degradation of CIP in similar condition.


Assuntos
Biodegradação Ambiental , Quitosana/química , Ciprofloxacina/química , Complexos de Coordenação/química , Nanocompostos/química , Fosfatos/química , Processos Fotoquímicos , Compostos de Prata/química , Complexos de Coordenação/síntese química , Redes e Vias Metabólicas , Estrutura Molecular
11.
Small ; 16(12): e1902934, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31603273

RESUMO

Mesoporous noble metals and their patterning techniques for obtaining unique patterned structures are highly attractive for electrocatalysis, photocatalysis, and optoelectronics device applications owing to their expedient properties such as high level of exposed active locations, cascade electrocatalytic sites, and large surface area. However, patterning techniques for mesoporous substrates are still limited to metal oxide and silica films, although there is growing demand for developing techniques related to patterning mesoporous metals. In this study, the first demonstration of mesoporous metal films on patterned gold (Au) substrates, prefabricated using photolithographic techniques, is reported. First, different growth rates of mesoporous Au metal films on patterned Au substrates are demonstrated by varying deposition times and voltages. In addition, mesoporous Au films are also fabricated on various patterns of Au substrates including stripe and mesh lines. An alternative fabrication method using a photoresist insulating mask also yields growth of mesoporous Au within the patterning. Moreover, patterned mesoporous films of palladium (Pd) and palladium-copper alloy (PdCu) are demonstrated on the same types of substrates to show versatility of this method. Patterned mesoporous Au films (PMGFs) show higher electrochemically active surface area (ECSA) and higher sensitivity toward glucose oxidation than nonpatterned mesoporous Au films (NMGF).

12.
J Nanosci Nanotechnol ; 20(6): 3823-3831, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748082

RESUMO

Multiferroic compounds are prime important materials for future electronic and magnetic devices and overcome the fundamental limits of conventional materials. In present work, we reported the preparation of purely one phase of nano-sized BiFeO3 compound by microemulsion micellar method for the first time by employing rapid quenching of sample at 500 °C, that is the main driving force to get the pure phase of BiFeO3 nanoparticles at low temperature method. The nanoparticles that we obtained were almost uniform with sphere shaped and these prepare nanoparticles possess high surface. The increase in permittivity in the form of dielectric constants were reported that depends on temperature and frequency that supports the ferroelectric nature and was further confirmed by the ferroelectric loops even at the room temperature has been found in theses prepared nanoparticles.

13.
Sci Rep ; 9(1): 14139, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578464

RESUMO

Mesoporous α-iron oxide@graphitized-carbon nitride nanocomposites (α-Fe2O3@g-C3N4-NCs) were synthesized using urea-formaldehyde (UF) resins at 400 °C/2 h. The mesoporous nature of the prepared nanocomposites was observed from electron microscopy and surface area measurements. The electrochemical measurements show the bifunctional nature of mesoporous α-Fe2O3@g-C3N4-NCs in electrolysis of water for oxygen evolution and oxygen reduction reactions (OER/ORR) using 0.5 M KOH. Higher current density of mesoporous α-Fe2O3@g-C3N4-NCs reveals the enhanced electrochemical performance compared to pure Fe2O3 nanoparticles (NPs). The onset potential, over-potential and Tafel slopes of mesoporous α-Fe2O3@g-C3N4-NCs were found lower than that of pure α-Fe2O3-NPs. Rotating disc electrode experiments followed by the K-L equation were used to investigate 4e- redox system. Therefore, the mesoporous α-Fe2O3@g-C3N4-NCs bifunctional electro-catalysts can be considered as potential future low-cost alternatives for Pt/C catalysts, which are currently used in fuel cells.

14.
Nanomaterials (Basel) ; 8(10)2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-30332819

RESUMO

Stable polymeric micelles have been demonstrated to serve as suitable templates for creating mesoporous metals. Herein, we report the utilization of a core-shell-corona type triblock copolymer of poly(styrene-b-2-vinylpyridine-b-ethylene oxide) and H2PtCl6·H2O to synthesize large-sized mesoporous Pt particles. After formation of micelles with metal ions, the reduction process has been carried out by vapor infiltration of a reducing agent, 4-(Dimethylamino)benzaldehyde. Following the removal of the pore-directing agent under the optimized temperature, mesoporous Pt particles with an average pore size of 15 nm and surface area of 12.6 m²·g-1 are achieved. More importantly, the resulting mesoporous Pt particles exhibit superior electrocatalytic activity compared to commercially available Pt black.

15.
Spectrochim Acta A Mol Biomol Spectrosc ; 173: 502-509, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-27732928

RESUMO

Functionalized (MWCNTs-COOH), non-functionalized multiwalled carbon nanotubes (MWCNTs) and polyaniline (PANI) based conducting nanocomposites (PANI/polymer/MWCNTs and PANI/polymer/MWCNTs-COOH) have been prepared in polymer matrix. The prepared nanocomposites were characterized via FTIR, TGA, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was observed that the prepared conducting nanocomposites show excellent sensing performances toward CH4 at room temperature and both the response and recovery time were recorded at around 5s, respectively, at the room. The PANI/polymer/MWCNTs based detector had quicker/shorter response time (<1s), as well as higher sensitivity (3.1%) than that of the PANI/polymer/MWCNTs-COOH based detector. This was attributed to nonconductive -COOH that results in a poor sensitivity of PANI/polymer/MWCNTs-COOH-based prototype. The PANI/polymer/MWCNTs-COOH nanocomposites show almost 10 time higher sensitivity at higher temperature (60°C) than that at room temperature.

16.
Carbohydr Polym ; 151: 135-143, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27474552

RESUMO

A novel catalyst for the reduction of 4-nitrophenol (4-NP) was prepared using carboxyl group-functionalized multiwalled carbon nanotubes (MWCNTs), polymer matrix, and silver nanoparticles (AgNPs). The AgNPs were prepared by the reduction of silver nitrate by trisodium citrate in the MWCNTs-polymer nanocomposite; the size of the synthesized AgNPs was found to be 3nm (average diameter). The synthesized nanocomposites were characterized using several analytical techniques. Ag@MWCNTs-polymer composite in the presence of sodium borohydride (NaBH4) in aqueous solution is an effective catalyst for the reduction of 4-NP. The apparent kinetics of reduction has a pseudo-first-order kinetics, and the rate constant and catalytic activity parameter were found to be respectively 7.88×10(-3)s(-1)and 11.64s(-1)g(-1). The MWCNTs-polymer nanocomposite renders stability to AgNPs against the environment and the reaction medium, which means that the Ag@MWCNTs-polymer composite can be re-used for many catalytic cycles.


Assuntos
Quitosana/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Nitrofenóis/química , Prata/química , Catálise , Reagentes de Ligações Cruzadas/química , Glutaral/química , Oxirredução
18.
Int J Pharm ; 504(1-2): 39-47, 2016 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-26945735

RESUMO

Macroporous natural sporopollenin exine capsules (SEC) were extracted from date palm (Phoenix dactylifera L.) and coated by natural polymer composite (carboxymethyl cellulose with epichlorohydrin). The polymer coated exine capsules (PCEC) were used in in-vitro investigations for controlled delivery of paracetamol. SEC, PCEC, and drugs loaded capsules (PCEC-PAR) were characterized by scanning electron microscope (SEM), surface area (BET), Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The length of SEC was found to be 20-20.5 µm, and the pore sized was 50-135 nm, as measured using SEM. The studies revealed that maximum loading of the drug was at pH 6.0 (97.2%, with 50 mg mL(-1)). The results indicate that by increasing the pH from 1.4 to 7.4, the cumulative release rates of paracetamol in physiological buffer solution (PBS) is more than two times as in simulated gastric fluid (SGF). In addition, the in-vitro toxicity of PCEC against Caco-2 cells was tested by the 3-[4,5-dimethylthiazole-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assay, and the results revealed that PCEC are biocompatible materials. The overall results encourage further studies on the clinical use of PCEC as drug carriers.


Assuntos
Acetaminofen/administração & dosagem , Biopolímeros/administração & dosagem , Carboximetilcelulose Sódica/química , Carotenoides/administração & dosagem , Sistemas de Liberação de Medicamentos , Phoeniceae , Esporos/química , Acetaminofen/química , Administração Oral , Biopolímeros/química , Células CACO-2 , Cápsulas , Carotenoides/química , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Epicloroidrina/química , Humanos , Porosidade
19.
Eur J Pharm Sci ; 88: 158-65, 2016 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-26872877

RESUMO

Sporopollenin macroporous capsules (SMCs) were extracted from date palm (Phoenix dactylifera L.) spores and coated by a natural polymer composite (chitosan with glutaraldehyde). The polymer coated macroporous capsules SMC@poly were used in the in vitro-controlled delivery of ibuprofen. The materials obtained were characterized through spectral, thermal, scanning electron microscopy (SEM), X-ray diffraction (XRD), and nitrogen adsorption-desorption isotherms. The IBU loading and releasing was studied by investigating the changes in various factors such as pH, temperature, and initial concentration. The results revealed that the loading of IBU increased when the concentration of IBU was decreased, following the Langmuir adsorption isotherm. The maximum loading of the IBU was observed at pH6.0 (97.2%, with 50mg/mL). The releasing results indicate that IBU was released faster when the pH was changed from 1.4 to 7.4. In addition, the cytotoxicity of the SMC, SMC@poly, and SMC@poly-IBU were tested against human intestinal Caco-2 cell line using MTT assay, and the results revea'led that all the materials in this study were biocompatible.


Assuntos
Biopolímeros/química , Carotenoides/química , Ibuprofeno/administração & dosagem , Ibuprofeno/química , Phoeniceae/química , Adsorção , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/toxicidade , Células CACO-2 , Cápsulas/química , Sobrevivência Celular , Química Farmacêutica , Liberação Controlada de Fármacos , Humanos , Concentração de Íons de Hidrogênio , Ibuprofeno/toxicidade , Teste de Materiais , Pólen/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
20.
Carbohydr Polym ; 138: 229-36, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26794757

RESUMO

Silver nanoparticles (AgNPs) containing hydrogel composite were first synthesized by preparing a new hydrogel from carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and the cross-linker ethylene glycol diglycidyl ether (EGDE), followed by the incorporation of AgNPs by microwave radiation. The resulting neat hydrogels and AgNPs-hydrogel composites were characterized using spectral, thermal, microscopic analysis and X-ray diffraction (XRD) analyses. The SEM and TEM results demonstrated that the synthesized AgNPs were spherical with diameters ranging from 8 to 14nm. In addition, the XRD analysis confirmed the nanocrystalline phase of silver with face-centered cubic (FCC) crystal structure. Energy dispersive spectroscopy (EDS) analysis of the AgNPs confirmed the presence of an elemental silver signal, and no peaks of any other impurities were detected. Additionally, the antibacterial activities of the neat hydrogel and AgNPs-hydrogel composites were measured by Kirby-Bauer method against urinary tract infection (UTI) pathogens. The rheology measurement revealed that the values of storage modulus (G') were higher than that of loss modulus (G″). The AgNPs-hydrogel composites exhibited higher antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus and Proteus mirabilis compared to the corresponding neat hydrogel.


Assuntos
Anti-Infecciosos/química , Carboximetilcelulose Sódica/química , Hidrogéis/química , Nanopartículas Metálicas/química , Prata/química , Animais , Anti-Infecciosos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Infecções Urinárias/microbiologia
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