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1.
J Am Chem Soc ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38785086

RESUMO

The continuous dissolution and oxidation of active sites in Ru-based electrocatalysts have greatly hindered their practical application in proton exchange membrane water electrolyzers (PEMWE). In this work, we first used density functional theory (DFT) to calculate the dissolution energy of Ru in the 3d transition metal-doped MRuOx (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) to evaluate their stability for acidic oxygen evolution reaction (OER) and screen out ZnRuOx as the best candidate. To confirm the theoretical predictions, we experimentally synthesized these MRuOx materials and found that ZnRuOx indeed displays robust acidic OER stability with a negligible decay of η10 after 15 000 CV cycles. Of importance, using ZnRuOx as the anode, the PEMWE can run stably for 120 h at 200 mA cm-2. We also further uncover the stability mechanism of ZnRuOx, i.e., Zn atoms doped in the outside of ZnRuOx nanocrystal would form a "Zn-rich" shell, which effectively shortened average Ru-O bond lengths in ZnRuOx to strengthen the Ru-O interaction and therefore boosted intrinsic stability of ZnRuOx in acidic OER. In short, this work not only provides a new study paradigm of using DFT calculations to guide the experimental synthesis but also offers a proof-of-concept with 3d metal dopants as RuO2 stabilizer as a universal principle to develop high-durability Ru-based catalysts for PEMWE.

2.
ACS Sens ; 9(4): 1735-1742, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38572917

RESUMO

Carbon dioxide (CO2) gas sensing and monitoring have gained prominence for applications such as smart food packaging, environmental monitoring of greenhouse gases, and medical diagnostic tests. Although CO2 sensors based on metal oxide semiconductors are readily available, they often suffer from limitations such as high operating temperatures (>250 °C), limited response at elevated humidity levels (>60% RH), bulkiness, and limited selectivity. In this study, we designed a chemiresistive sensor for CO2 detection to overcome these problems. The sensing material of this sensor consists of a CO2 switchable polymer based on N-3-(dimethylamino)propyl methacrylamide (DMAPMAm) and methoxyethyl methacrylate (MEMA) [P(D-co-M)], and diethylamine. The designed sensor has a detection range for CO2 between 103 and 106 ppm even at high humidity levels (>80% RH), and it is capable of differentiating ammonia at low concentrations (0.1-5 ppm) from CO2. The addition of diethylamine improved sensor performance such as selectivity, response/recovery time, and long-term stability. These data demonstrate the potential of using this sensor for the detection of food spoilage.


Assuntos
Dióxido de Carbono , Dióxido de Carbono/análise , Umidade , Acrilamidas/química , Polímeros/química , Metacrilatos/química , Gases/análise
3.
Adv Mater ; 36(9): e2310690, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38048484

RESUMO

Designing robust bifunctional catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction in all-pH conditions for overall water splitting (OWS) is an effective way to achieve sustainable development. Herein, a composite Ru-VO2 containing Ru-doped VO2 and Ru nanoparticles (NPs) is synthesized, and it shows a high OWS performance in full-pH range due to their synergist effect. In particular, the OER mass activities of Ru-VO2 at 1.53 V (vs RHE) in acidic, alkaline, and PBS solutions are ≈65, 36, and 235 times of commercial RuO2 in the same conditions. The "Ru-VO2 || Ru-VO2 " two-electrode electrolyzer only needs a voltage of 1.515 V (at 10 mA cm-2 ) in acidic water splitting, which can operate stably for 125 h at 10 mA cm-2 without significant voltage decay. In situ Raman spectra and in situ differential electrochemical mass spectrometry prove that the OER of Ru-VO2 in acid follows the adsorption evolution mechanism. Density functional theory calculations further reveal the synergistic effect between Ru NP and Ru-doped VO2 , which breaks the hydrogen bond network formed by *OH adsorbed on the Ru single-atom site, and thereby significantly enhances the OER activity. This work provides new insights into the design of novel bifunctional pH-universal catalysts for OWS.

4.
ACS Appl Mater Interfaces ; 15(28): 34181-34194, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37402131

RESUMO

In this study, multilayered NiMo/CoMn/Ni cathodic electrodes were prepared by the multilayered electrodeposition method. The multilayered structure includes a nickel screen substrate, CoMn nanoparticles at the bottom, and cauliflower-like NiMo nanoparticles at the top. The multilayered electrodes have a lower overpotential, preferable stability, and better electrocatalytic performance than monolayer electrodes. In a three-electrode system, the overpotentials of the multilayered NiMo/CoMn/Ni cathodic electrodes at 10 and 500 mA/cm2 are only 28.7 and 259.1 mV, respectively. The overpotential rise rate of the electrodes after constant current tests at 200 and 500 mA/cm2 was 4.42 and 8.74 mV/h, respectively, and the overpotential rise rate after 1000 cycles of cyclic voltammetry of the electrodes was 1.9 mV/h, while the overpotential rise rate after the three stability tests of the nickel screen was 5.49, 11.42, and 5.1 mV/h. According to the Tafel extrapolation polarization curve, the Ecorr and Icorr of the electrodes were -0.3267 V and 1.954 × 10-5 A/cm2, respectively. The charge transfer rate of the electrodes is slightly slower than that of the monolayer electrodes, indicating that its corrosion resistance is more excellent. An electrolytic cell was designed for the overall water-splitting test, and the current density of the electrodes was 121.6 mA/cm2 at 1.8 V. In addition, the stability of the electrodes is excellent after intermittent testing for 50 h, which can greatly reduce power consumption and is more suitable for industrial overall water-splitting tests. In addition, the three-dimensional model was used to simulate the three-electrode system and alkaline water electrolytic cell system, and the simulation results are consistent with the experimental results. The hydrogen adsorption free energy (ΔGH) of the electrodes was -1.0191 eV, which was evaluated by density functional theory (DFT). The ΔGH is closer to zero than that of the monolayer electrodes, indicating that the surface has stronger adsorption of hydrogen atoms.

5.
Small ; 19(40): e2302338, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37267930

RESUMO

Electrochemical synthesis of hydrogen peroxide (H2 O2 ) through the selective oxygen reduction reaction (ORR) offers a promising alternative to the energy-intensive anthraquinone method, while its success relies largely on the development of efficient electrocatalyst. Currently, carbon-based materials (CMs) are the most widely studied electrocatalysts for electrosynthesis of H2 O2 via ORR due to their low cost, earth abundance, and tunable catalytic properties. To achieve a high 2e- ORR selectivity, great progress is made in promoting the performance of carbon-based electrocatalysts and unveiling their underlying catalytic mechanisms. Here, a comprehensive review in the field is presented by summarizing the recent advances in CMs for H2 O2 production, focusing on the design, fabrication, and mechanism investigations over the catalytic active moieties, where an enhancement effect of defect engineering or heteroatom doping on H2 O2 selectivity is discussed thoroughly. Particularly, the influence of functional groups on CMs for a 2e- -pathway is highlighted. Further, for commercial perspectives, the significance of reactor design for decentralized H2 O2 production is emphasized, bridging the gap between intrinsic catalytic properties and apparent productivity in electrochemical devices. Finally, major challenges and opportunities for the practical electrosynthesis of H2 O2 and future research directions are proposed.

6.
Adv Mater ; 35(31): e2210235, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37219533

RESUMO

Water harvesting using the metal-organic framework (MOF)-801 is restricted by limited working capacity, powder structuring, and finite stability. To overcome these issues, MOF-801 is crystallized on the surface of macroporous poly(N-isopropylacrylamide-glycidyl methacrylate) spheres, called P(NIPAM-GMA), through an in situ confined growth strategy, forming spherical MOF-801@P(NIPAM-GMA) composite with temperature-responsive function. By lowering the nucleation energy barrier, the average size of the MOF-801 crystals decreases by 20 times. Thus, abundant defects as adsorption sites for water can be installed in the crystals lattices. As a consequence, the composite provides an unprecedented high water harvesting efficiency. The composite is produced in the kilogram-scale and can capture 1.60 kg H2 O/kg composite/day from 20% relative humidity between 25 and 85 °C. This study provides an effective methodology for improving the adsorption capacity through controlled defects formation as adsorption sites and to improve the kinetics through the design of a composite with macroporous transport channel network.

7.
ACS Omega ; 7(26): 22232-22243, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35811921

RESUMO

Amine-functionalized polymers (AFPs) are able to react with carbon dioxide (CO2) and are therefore useful in CO2 capture and sensing. To develop AFP-based CO2 sensors, it is critical to examine their electrical responses to CO2 over long periods of time, so that the device can be used consistently for measuring CO2 concentration. To this end, we synthesized poly(N-[3-(dimethylamino)propyl] methacrylamide) (pDMAPMAm) by free radical polymerization and tested its ability to behave as a CO2-responsive polymer in a transducer. The electrical response of this polymer to CO2 upon long exposure times was measured in both the aqueous and solid phases. Direct current resistance measurement tests on pDMAPMAm films printed along with the silver electrodes in the presence of CO2 at various concentrations reveal a two-region electrical response. Upon continuous exposure to different CO2 flow rates (at a constant pressure of 0.2 MPa), the resistance first decreased over time, reaching a minimum, followed by a gradual increase with further exposure to CO2. A similar trend is observed when CO2 is introduced to an aqueous solution of pDMAPMAm. The in situ monitoring of pH suggests that the change in resistance of pDMAPMAm can be attributed to the protonation of tertiary amine groups in the presence of CO2. This two-region response of pDMAPMAm is based on a proton-hopping mechanism and a change in the number of free amines when pDMAPMAm is exposed to various levels of CO2.

8.
Angew Chem Int Ed Engl ; 61(37): e202206915, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-35894267

RESUMO

The electrochemical oxygen reduction reaction (ORR) provides a green route for decentralized H2 O2 synthesis, where a structure-selectivity relationship is pivotal for the control of a highly selective and active two-electron pathway. Here, we report the fabrication of a boron and nitrogen co-doped turbostratic carbon catalyst with tunable B-N-C configurations (CNB-ZIL) by the assistance of a zwitterionic liquid (ZIL) for electrochemical hydrogen peroxide production. Combined spectroscopic analysis reveals a fine tailored B-N moiety in CNB-ZIL, where interfacial B-N species in a homogeneous distribution tend to segregate into hexagonal boron nitride domains at higher pyrolysis temperatures. Based on the experimental observations, a correlation between the interfacial B-N moieties and HO2 - selectivity is established. The CNB-ZIL electrocatalysts with optimal interfacial B-N moieties exhibit a high HO2 - selectivity with small overpotentials in alkaline media, giving a HO2 - yield of ≈1787 mmol gcatalyst -1 h-1 at -1.4 V in a flow-cell reactor.

9.
Small ; 18(4): e2103530, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34766456

RESUMO

Herein, it is shown that by engineering defects on Cex Si1- x O2- δ nanocomposites synthesized via flame spray pyrolysis, oxygen vacancies can be created with an increased density of trapped electrons, enhancing the formation of reactive oxygen species (ROSs) and hydroxyl radicals in an ozone-filled environment. Spectroscopic analysis and density functional theory calculations indicate that two-electron oxygen vacancies (OV 0 ) or peroxide species, and their degree of clustering, play a critical role in forming reactive radicals. It is also found that a higher Si content in the binary oxide imposes a high OV 0 ratio and, consequently, higher catalytic activity. Si inclusion in the nanocomposite appears to stabilize the surface oxygen vacancies as well as increase the reactive electron density at these sites. A mechanistic study on effective ROSs generated during catalytic ozonation reveals that the hydroxyl radical is the most effective ROS for organic degradation and is formed primarily through H2 O2 generation in the presence of the OV 0 . Examining the binary oxides offers insights on the contribution of oxygen vacancies and their state of charge to catalytic reactions, in this instance for the catalytic ozonation of organic compounds.

10.
ACS Omega ; 6(39): 25506-25517, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34632208

RESUMO

Phenol is a nocuous water pollutant that threatens human health and the ecological environment. CoOx-doped micron-sized hollow MgO rods were prepared for the treatment of phenol wastewater by catalytic ozonation. Magnesium sources, precipitants, initial precursor concentration, Co/Mg molar ratio, and catalyst calcination temperature were optimized to obtain the best catalysts. Prepared catalysts were also well characterized by various methods to analyze their structure and physical and chemical properties. In this process, CoOx/MgO with the largest large surface area (151.3 m3/g) showed the best catalytic performance (100 and 79.8% of phenol and chemical oxygen demand (COD) removal ratio, respectively). The hydrolysis of CoOx/MgO plays a positive role in the degradation of phenol. The catalytic mechanism of the degradation of O3 to free radicals over catalysts has been investigated by in situ electronic paramagnetic resonance (EPR). The catalyst can be reused at least five times without any activity decline. The prepared CoOx/MgO catalyst also showed excellent catalytic performance for removal and degradation of ciprofloxacin, norfloxacin, and salicylic acid.

11.
ACS Appl Mater Interfaces ; 13(18): 21775-21785, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33908751

RESUMO

We present a kilogram-scale experiment for assessing the prospects of a novel composite material of metal-organic framework (MOF) and polyacrylates (PA), namely NbOFFIVE-1-Ni@PA, for trace CO2 capture. Through the interfacial enrichment of metal ions and organic ligands as well as heterogeneous crystallization, the sizes of microporous NbOFFIVE-1-Ni crystals are downsized to 200-400 nm and uniformly anchored on the macroporous surface of PA via interfacial coordination, forming a unique dual-framework structure. Specifically, the NbOFFIVE-1-Ni@PA composite with a loading of 45.8 wt % NbOFFIVE-1-Ni yields a superior CO2 uptake (ca. 1.44 mol·kg-1) compared to the pristine NbOFFIVE-1-Ni (ca. 1.30 mol·kg-1) at 400 ppm and 298 K, indicating that the adsorption efficiency of NbOFFIVE-1-Ni has been raised by 2.42 times. Meanwhile, the time cost for realizing a complete adsorption/desorption cycle in a fluidized bed has been shortened to 25 min, and the working capacity (ca. 0.84 mol·kg-1) declines only by 1.3% after 2000 cycles. The device is capable of harvesting 2.1 kg of CO2 per kilogram of composite daily from simulated air with 50% relatively humidity (RH). To the best of our knowledge, the excellent adsorption/desorption performances of NbOFFIVE-1-Ni@PA position it as the most advantageous and practically applicable candidate for trace CO2 capture.

12.
Chemosphere ; 274: 129769, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33548638

RESUMO

Bisphenol A (BPA), a typical endocrine disrupting chemical, widely exists in water and threatens human health. The degradation of BPA by ozone in water is limited by the gas-mass transfer due to the low solubility of ozone. In this study, a rotating packed bed (RPB) was employed to create a high gravity environment to intensify the ozone mass transfer and BPA degradation. The effects of operational parameters (rotation speed of RPB, pH of the solution, ozone concentration, BPA concentration, gas volumetric flow rate and liquid volumetric flow rate) on BPA degradation efficiency and overall volumetric mass transfer coefficient of ozone were investigated. The results show that RPB effectively promoted the ozone mass transfer and BPA degradation and can be used for the ozonation of micropollutants that have fast reaction rates with ozone. Quenching experiments suggest that both ozone and HO∙ participated in BPA degradation from acidic to alkaline environments. In addition, the effects of co-existing chemicals on BPA degradation efficiency were studied. The addition of H2O2 or Cl- had no obvious impact on BPA degradation; the addition of HCO3- is beneficial for BPA degradation while the addition of fulvic acid suppressed the degradation. These results indicate that the pH value, which affects the reaction rate between ozone and BPA, is a major factor to be considered during the ozonation of BPA in RPB.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Compostos Benzidrílicos , Humanos , Peróxido de Hidrogênio , Fenóis , Poluentes Químicos da Água/análise
13.
RSC Adv ; 11(4): 2040-2046, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-35424171

RESUMO

In this study, monodispersed NiRu nanocrystals with a diameter of 3 nm were synthesized at 90 °C via a tuning hot-inject method to lower the temperature of the organic phase synthesis of monodispersed nanomaterials. The key factor for the nanocrystalline formation of NiRu alloy nanocrystals was summarized in detail. Simultaneously, the synergistic effect of Ni and Ru in CO2 methanation was explored. Doping trace Ru can significantly improve the conversion rate of CO2 methanation and CH4 selectivity. The underlying mechanism was studied in detail via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed hydrogen reduction (H2-TPR) and desorption (H2-TPD) tests, and temperature-programmed desorption of CO2 (CO2-TPD). This study gives out a new way for the general synthesis of monodisperse nickel-based nanocrystals and provides a reference for the development and application of monodispersed nanoparticles for CO2 methanation.

14.
Environ Sci Technol ; 54(18): 11356-11364, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32794698

RESUMO

Photoluminescent metal-organic frameworks (MOFs) were grown in a living plant (Syngonium podophyllum) via immersing their roots in an aqueous solution of disodium terephthalate and terbium chloride hexahydrate sequentially for 12 h without affecting their viability. Then, app-assisted living MOF-plant nanobiohybrids were used for the detection of various toxic metal ions and organic pollutants. Their performance and sensing mechanism were also evaluated. The results demonstrated that the living plants served as self-powered preconcentrators via their passive fluid transport systems and accumulated the pollutants around the embedded MOFs, resulting in relative changes in fluorescence intensity. Therefore, the living MOF-plant nanobiohybrids initiate superior selectivity and sensitivity (0.05-0.5 µM) in water for Ag+, Cd2+, and aniline with a "turn-up" fluorescence response and for Fe3+ and Cu2+ with "turn-down" fluorescence response in the linear range of 0.05-10 µM with excellent precision and accuracy of 5 and 10%, respectively. With the easy-to-read visual signals under ultraviolet light, the app translates plant luminescent signals into digital information on a smartphone for on-site monitoring of environmental pollutants with high sensitivity and specificity. These results suggest that interfacing synthetic and living materials may contribute to the development of smart sensors for on-site environmental pollutant sensing with high accuracy.


Assuntos
Poluentes Ambientais , Estruturas Metalorgânicas , Íons , Plantas , Espectrometria de Fluorescência
15.
Carbohydr Polym ; 212: 289-296, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30832859

RESUMO

Degradation of cellulose to reducing sugar is the key step for the conversion of cellulose to valuable chemicals. Cellulose was degraded by WCl6 in 1-butyl-3-methyl imidazole chloride at 80 °C and lower. 83% and 85.5% yield of total reducing sugar was gotten at 70 and 80 °C, respectively. Compared with inorganic acid, heteropoly acid, acidic ionic liquid and other metal chlorides, WCl6 has shown better catalytic performance for degradation of cellulose to reducing sugar. The effect of reaction temperature, reaction time, WCl6 amount and cellulose concentration were investigated. Degradation of cellulose by WCl6 in 1-butyl-3-methyl imidazole chloride is a zero reaction. WCl6 also showed excellent catalytic performance for the degradation of nature cellulose and lignocellulose. Catalyst can be reused at least 5 times without decrease of reducing sugar yield. The mechanism of degradation of WCl6 was also suggested.

16.
RSC Adv ; 9(58): 34065-34075, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-35528902

RESUMO

Molybdovanadylphosphoric acid (HPMV) was supported on a carbon nitride-modified SBA-15 (CN-SBA-15) molecular sieve to enhance its catalytic performance for oxidation of methacrolein (MAL) to methacrylic acid (MAA). HPMV/CN-SBA exhibited increased catalytic activity (20%) and five times greater MAA selectivity (98.9%) compared to bulk HPMV. HPMV supported on CN-SBA-15 exhibited much better catalytic performance as compared to that on other supports, such as KIT-6, HY zeolite, TiO2, Al2O3, SiO2, CNTs, and NH3-modified CNTs. The supported HPMV was well characterized by FT-IR, XRD, SEM, N2 physical desorption, TG-DTA, NH3-TPD, CO2-TPD, XPS, and solid-state NMR. The CN minimized the interaction between the silica support and HPMV. HPMV was successfully separated from SBA-15, which was restricted by CN to increase stability and prevent interaction between the catalysts and support that would lead to decomposition of the catalysts during calcination and reaction. HPMV reacted with amino groups on the CN, which improved MAA selectivity and enhanced the thermal stability of the supported heteropoly acid (HPA) catalysts. This work identifies a new approach to preparing highly efficient and stable supported HPA catalysts for oxidation reactions.

17.
Mater Sci Eng C Mater Biol Appl ; 64: 303-309, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27127057

RESUMO

Molecular targeted cancer therapy is a promising strategy to overcome the lack of specificity of anticancer drug. While the binding of c(RGDfK) (cyclic Arginine-Glycine-Aspartic acid-Phenylalanine-Lysine) to αvß3 over-expressed on tumor cell has been validated, the underlying interaction remains poorly understood. In this work, docking calculation was applied to investigate the interactions between c(RGDfK)/c(RGDfK)-PEG and αvß3. The calculated results indicated that c(RGDfK) interacted with αvß3 mainly by electrostatic interaction, stabilization interaction, and hydrophobic interaction. Conjugation of PEG chain to the c(RGDfK) weakened the binding affinity of c(RGDfK) to αvß3. Accordingly, docetaxel(DTX)-loaded target micelles (c(RGDfK)-PEG-PLA/PEG-PLA/DTX) were designed, characterized and evaluated using HeLa cells. In vitro release studies demonstrated both target and non-target micelles displayed almost the same profiles, which best fit in Ritger-Peppas model. Cellular uptake and MTT studies revealed that the target micelles with the presence of c(RGDfK) were more efficiently taken up by HeLa cells and significantly improved the cytotoxicity compared to that of non-target micelles. Cell inhibition rate of target micelles was improved by 20% after 24h. Our findings suggest that target micelles may be a potential anticancer drug delivery system in the treatment of integrin αvß3 over-expressed on tumor cell.


Assuntos
Citotoxinas , Sistemas de Liberação de Medicamentos/métodos , Micelas , Peptídeos Cíclicos , Poliésteres , Polietilenoglicóis , Taxoides , Citotoxinas/química , Citotoxinas/farmacologia , Docetaxel , Células HeLa , Humanos , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Poliésteres/química , Poliésteres/farmacologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Taxoides/química , Taxoides/farmacologia
18.
Int J Pharm ; 498(1-2): 134-41, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26685725

RESUMO

Resveratrol (RES) is a natural polyphenol which can be considered as a nutraceutical because of its benefits such as anticancer and antioxidant activity. In this paper, we designed polymer-RES conjugates as anticancer drug carrier for synergistic therapeutic effect in cancer treatment. Bicalutamide (BIC) was used as a model drug to investigate the drug release behaviors and in vitro anticancer performance. PEG-RES and PEG-Glycine-RES nanoparticles were prepared and characterized. The size of the prepared particles was around 50 nm with RES content of 17.2 and 16.3 wt% for PEG-RES and PEG-Glycine-RES, respectively, and BIC loading efficiency were of 81.6% and 84.5%, separately. Release rate of RES from conjugates depended on the stability of ester group against hydrolysis. BIC release was much faster than RES release. The anticancer activity of BIC loaded PEGylated RES nanoparticles was much better than that of free BIC, indicating the conjugates provided a synergetic cytotoxicity to cancer cells. Confocal laser scanning microscopy observation and flow cytometry analyses indicated that PEGylated RES conjugates were more efficiently internalized into cells, released drug into cytoplasm. These results suggest that PEGylated RES conjugates show great potential for cancer therapy.


Assuntos
Antineoplásicos/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Polietilenoglicóis/química , Estilbenos/química , Antineoplásicos/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Portadores de Fármacos/administração & dosagem , Sinergismo Farmacológico , Células HeLa , Humanos , Células MCF-7 , Polietilenoglicóis/administração & dosagem , Resveratrol , Estilbenos/administração & dosagem
19.
Int J Pharm ; 430(1-2): 98-103, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22486960

RESUMO

An innovative strategy of fabricating uniform spore like drug particles to improve pulmonary drug delivery efficiency was disclosed in the present study. Spore like particles were prepared through combination of high gravity controlled precipitation and spray drying process with insulin as model drug first, showing rough surface and hollow core. The shell of such spore-like particle was composed of nanoparticles in loose agglomerate and could form nanosuspension upon contacting antisolvent. Further characterization confirmed secondary structure and bio-activity was well preserved in spore like particles of insulin. Stable aerosol performance at different dosages with fine powder fraction (FPF) of 80% and comparable FPF (69-76%) for formulated powder were achieved, significantly higher than marketed product Exubera. On the other hand spore like particles of bovine serum albumin, lysozyme and salbutamol sulfate showed similar high FPF of 80%, regardless of different shape of primary nanoparticles, indicating various application of this new process in significant improvement of pulmonary drug delivery.


Assuntos
Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Insulina/química , Pulmão/metabolismo , Administração por Inalação , Aerossóis , Albuterol/administração & dosagem , Albuterol/química , Animais , Glicemia/efeitos dos fármacos , Precipitação Química , Química Farmacêutica , Portadores de Fármacos , Estabilidade de Medicamentos , Inaladores de Pó Seco , Feminino , Gravitação , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/metabolismo , Injeções Subcutâneas , Insulina/metabolismo , Muramidase/administração & dosagem , Muramidase/química , Nanopartículas , Nanotecnologia , Tamanho da Partícula , Pós , Ratos , Ratos Wistar , Soroalbumina Bovina/administração & dosagem , Soroalbumina Bovina/química , Solventes/química , Tecnologia Farmacêutica/métodos
20.
Langmuir ; 27(2): 843-50, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-21171579

RESUMO

A facile method of stabilizing magnetic iron oxide nanoparticles (MNPs) in biological media (RPMI-1640) via surface modification with fetal bovine serum (FBS) is presented herein. Dynamic light scattering (DLS) shows that the size of the MNP aggregates can be maintained at 190 ± 2 nm for up to 16 h in an RPMI 1640 culture medium containing ≥4 vol % FBS. Under transmission electron microscopy (TEM), a layer of protein coating is observed to cover the MNP surface following treatment with FBS. The adsorption of proteins is further confirmed by X-ray photoelectron spectroscopy (XPS). Gel electrophoresis and LC-MS/MS studies reveal that complement factor H, antithrombin, complement factor I, α-1-antiproteinase, and apolipoprotein E are the proteins most strongly attached to the surface of an MNP. These surface-adsorbed proteins serve as a linker that aids the adsorption of other serum proteins, such as albumin, which otherwise adsorb poorly onto MNPs. The size stability of FBS-treated MNPs in biological media is attributed to the secondary adsorbed proteins, and the size stability in biological media can be maintained only when both the surface-adsorbed proteins and the secondary adsorbed proteins are present on the particle's surface.


Assuntos
Meios de Cultura/química , Compostos Férricos/química , Sangue Fetal/química , Magnetismo , Nanopartículas/química , Animais , Bovinos , Tamanho da Partícula , Propriedades de Superfície
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