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1.
Chem Soc Rev ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38855878

RESUMO

Seawater electrolysis for the production of fuels and chemicals involved in onshore and offshore plants powered by renewable energies offers a promising avenue and unique advantages for energy and environmental sustainability. Nevertheless, seawater electrolysis presents long-term challenges and issues, such as complex composition, potential side reactions, deposition of and poisoning by microorganisms and metal ions, as well as corrosion, thus hindering the rapid development of seawater electrolysis technology. This review focuses on the production of value-added fuels (hydrogen and beyond) and fine chemicals through seawater electrolysis, as a promising step towards sustainable energy development and carbon neutrality. The principle of seawater electrolysis and related challenges are first introduced, and the redox reaction mechanisms of fuels and chemicals are summarized. Strategies for operating anodes and cathodes including the development and application of chloride- and impurity-resistant electrocatalysts/membranes are reviewed. We comprehensively summarize the production of fuels and chemicals (hydrogen, carbon monoxide, sulfur, ammonia, etc.) at the cathode and anode via seawater electrolysis, and propose other potential strategies for co-producing fine chemicals, even sophisticated and electronic chemicals. Seawater electrolysis can drive the oxidation and upgrading of industrial pollutants or natural organics into value-added chemicals or degrade them into harmless substances, which would be meaningful for environmental protection. Finally, the perspective and prospects are outlined to address the challenges and expand the application of seawater electrolysis.

2.
Small ; 20(11): e2307349, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38105349

RESUMO

Co electroreduction of carbon dioxide and nitrate to synthesize urea provides an alternative strategy to high energy-consumption traditional methods. However, the complexity of the reaction mechanism and the high energy barrier of nitrate reduction result in a diminished production of urea. Herein, a convenient electrodeposition technique to prepare the FeOOH with low spin state iron that increases the yield rate of urea efficiently is employed. According to soft X-ray Absorption Spectroscopy and theoretical calculations, the unique configuration of low spin state iron as electron acceptors can effectively induce electron pair transfer from the occupied σ orbitals of intermediate * NO to empty d orbitals of iron. This σ→d donation mechanism leads to a reduction in the energy barrier associated with the rate-determining step (* NOOH→* NO + * OH), hence augmenting the urea generation. The low spin state iron presents a high urea yield rate of 512 µg h-1  cm-2 , representing approximately two times compared to the medium spin state iron. The key intermediates (* NH2 and * CO) in the formation of C─N bond are detected with in situ Fourier transform infrared spectroscopy. The coupling of * NH2 and * CO contributes to the formation of * CONH2 , which subsequently endures multi-step proton-coupled electron transfer to generate urea.

3.
Chem Soc Rev ; 51(11): 4763-4785, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35584360

RESUMO

The dependence on fossil fuels has caused excessive emissions of greenhouse gases (GHGs), leading to climate changes and global warming. Even though the expansion of electricity generation will enable a wider use of electric vehicles, biotechnology represents an attractive route for producing high-density liquid transportation fuels that can reduce GHG emissions from jets, long-haul trucks and ships. Furthermore, to achieve immediate alleviation of the current environmental situation, besides reducing carbon footprint it is urgent to develop technologies that transform atmospheric CO2 into fossil fuel replacements. The integration of bio-catalysis and electrocatalysis (bio-electrocatalysis) provides such a promising avenue to convert CO2 into fuels and chemicals with high-chain lengths. Following an overview of different mechanisms that can be used for CO2 fixation, we will discuss crucial factors for electrocatalysis with a special highlight on the improvement of electron-transfer kinetics, multi-dimensional electrocatalysts and their hybrids, electrolyser configurations, and the integration of electrocatalysis and bio-catalysis. Finally, we prospect key advantages and challenges of bio-electrocatalysis, and end with a discussion of future research directions.


Assuntos
Dióxido de Carbono , Efeito Estufa , Biotecnologia , Catálise , Combustíveis Fósseis
4.
Nano Lett ; 22(7): 3054-3061, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35315677

RESUMO

Novel anode materials for lithium-ion batteries were synthesized by in situ growth of spheres of graphene and carbon nanotubes (CNTs) around silicon particles. These composites possess high electrical conductivity and mechanical resiliency, which can sustain the high-pressure calendering process in industrial electrode fabrication, as well as the stress induced during charging and discharging of the electrodes. The resultant electrodes exhibit outstanding cycling durability (∼90% capacity retention at 2 A g-1 after 700 cycles or a capacity fading rate of 0.014% per cycle), calendering compatibility (sustain pressure over 100 MPa), and adequate volumetric capacity (1006 mAh cm-3), providing a novel design strategy toward better silicon anode materials.

5.
J Am Chem Soc ; 144(23): 10193-10200, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35586910

RESUMO

Integrated/cascade plasma-enabled N2 oxidation and electrocatalytic NOx- (where x = 2, 3) reduction reaction (pNOR-eNOx-RR) holds great promise for the renewable synthesis of ammonia (NH3). However, the corresponding activated effects and process of plasma toward N2 and O2 molecules and the mechanism of eNOx-RR to NH3 are unclear and need to be further uncovered, which largely limits the large-scale deployment of this process integration technology. Herein, we systematically investigate the plasma-enabled activation and recombination processes of N2 and O2 molecules, and more meaningfully, the mechanism of eNOx-RR at a microscopic level is also decoupled using copper (Cu) nanoparticles as a representative electrocatalyst. The concentration of produced NOx in the pNOR system is confirmed as a function of the length for spark discharge as well as the volumetric ratio for N2 and O2 feeding gas. The successive protonation process of NOx- and the key N-containing intermediates (e.g., -NH2) of eNOx-RR are detected with in situ infrared spectroscopy. Besides, in situ Raman spectroscopy further reveals the dynamic reconstruction process of Cu nanoparticles during the eNOx-RR process. The Cu nanoparticle-driven pNOR-eNOx-RR system can finally achieve a high NH3 yield rate of ∼40 nmol s-1 cm-2 and Faradaic efficiency of nearly 90%, overperforming the benchmarks reported in the literature. It is anticipated that this work will stimulate the practical development of the pNOR-eNOx-RR system for the green electrosynthesis of NH3 directly from air and water under ambient conditions.


Assuntos
Amônia , Cobre , Amônia/química , Cobre/química , Oxirredução , Espectrofotometria Infravermelho
6.
Nano Lett ; 21(6): 2572-2579, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33650431

RESUMO

Lithium iron phosphate (LiFePO4) is broadly used as a low-cost cathode material for lithium-ion batteries, but its low ionic and electronic conductivity limit the rate performance. We report herein the synthesis of LiFePO4/graphite composites in which LiFePO4 nanoparticles were grown within a graphite matrix. The graphite matrix is porous, highly conductive, and mechanically robust, giving electrodes outstanding cycle performance and high rate capability. High-mass-loading electrodes with high reversible capacity (160 mA h g-1 under 0.2 C), ultrahigh rate capability (107 mA h g-1 under 60 C), and outstanding cycle performance (>95% reversible capacity retention over 2000 cycles) were achieved, providing a new strategy toward low-cost, long-life, and high-power batteries. Adoption of such material leads to electrodes with volumetric energy density as high as 427 W h L-1 under 60 C, which is of great interest for electric vehicles and other applications.

7.
Angew Chem Int Ed Engl ; 61(37): e202203836, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-35852815

RESUMO

The design of efficient non-noble metal catalysts for CO2 hydrogenation to fuels and chemicals is desired yet remains a challenge. Herein, we report that single Mo atoms with a MoN3 (pyrrolic) moiety enable remarkable CO2 adsorption and hydrogenation to CO, as predicted by density functional theory studies and evidenced by a high and stable conversion of CO2 reaching about 30.4 % with a CO selectivity of almost 100 % at 500 °C and very low H2 partial pressure. Atomically dispersed MoN3 is calculated to facilitate CO2 activation and reduces CO2 to CO* via the direct dissociation path. Furthermore, the highest transition state energy in CO formation is 0.82 eV, which is substantially lower than that of CH4 formation (2.16 eV) and accounts for the dominant yield of CO. The enhanced catalytic performances of Mo/NC originate from facile CO desorption with the help of dispersed Mo on nitrogen-doped carbon (Mo/NC), and in the absence of Mo nanoparticles. The resulting catalyst preserves good stability without degradation of CO2 conversion rate even after 68 hours of continuous reaction. This finding provides a promising route for the construction of highly active, selective, and robust single-atom non-precious metal catalysts for reverse water-gas shift reaction.

8.
J Sci Food Agric ; 101(6): 2371-2379, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33009832

RESUMO

BACKGROUND: Chinese horsebean-chili-paste (CHCP) is a traditional fermented condiment in China, known as 'the soul of Sichuan cuisine'. The horsebean-to-meju phase in its preparation is important for CHCP production and contributes significantly to its taste and odor. In this study, a comprehensive flavor compound profiling analysis of the naturally brewed horsebean meju (NBHM) and the temperature-controlled brewed horsebean meju (TCBHM) was performed with two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS), and the analysis of physicochemical characteristics and free amino acids. Their aroma-active components and characteristic flavor compounds were evaluated. The flavor compounds responsible for differentiating NBHM and TCBHM were also determined based on the Fisher ratio and principal component analysis. RESULTS: The pH and the reducing sugar and amino-acid nitrogen content of NBHM were 5.38, 64.43, and 5.76 g kg-1 , respectively, whereas those of TCBHM were 5.13, 29.20, and 7.43 g kg-1 . A total of 356 volatiles were identified from 2571 compounds, and 257 volatile compounds were identified in NBHM compared to 322 volatiles in TCBHM. These two horsebean mejus (HMs) exhibited a similar proportion profile for 30 aroma-active compounds. Benzoic acid ethyl ester, 4-ethyl-2-methoxy-phenol and argnine were determined to be characteristic flavor components for NBHM, while 1-(2-furanyl)-ethanone, 2,6-dimethyl-pyrazine, threonine, valine and tyrosine were specific to TCBHM. CONCLUSION: Temperature-controlled brewed horsebean meju possessed better physicochemical and flavor characteristics than NBHM. The temperature-controlled brewing technique in CHCP production can be used as a promising alternative to the traditional natural brewing method. © 2020 Society of Chemical Industry.


Assuntos
Manipulação de Alimentos/métodos , Vicia faba/química , China , Condimentos/análise , Fermentação , Alimentos Fermentados/análise , Aromatizantes/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Odorantes/análise , Sementes/química , Paladar , Temperatura
9.
Angew Chem Int Ed Engl ; 60(7): 3587-3595, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33251665

RESUMO

An efficient chemical synthesis route, with an aim of reaching an ultrahigh nitrogen (N)-doping level in carbon materials can provide a platform where the type and amount of N dopant can be tuned over a wide range. We propose a C-S-C linkage-triggered confined-pyrolysis strategy for the high-efficiency in situ N-doping into carbon matrix and an ultrahigh doping level up to 13.5 at %, which is close to the theoretical upper limit (15.2 at %) is realized at a high carbonization temperature of 1000 °C. The pyridinic N is dominant with a maximum percent of 48.7 %. By using I3 - reduction as an example, the resultant NCM-5 exhibits the best activity with a power conversion efficiency of 8.77 %. A pyridinic N site-dependent activity is demonstrated in which the amount of active sites increases with the increase of pyridinic N, and the carbon atom adjacent to electron-withdrawing pyridinic N at the armchair edge acts as the most favorable site for the adsorption of I2 .

10.
Mol Pharm ; 17(9): 3177-3191, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32697099

RESUMO

The oral delivery of macromolecules using nanoparticles is limited by secreted mucus, resulting in low contact or internalization via intestinal cells and, thus, both mucus trapping and further low cellular uptake need to be overcome. Here, hydrophilic and electroneutral nanoparticles were developed to overcome mucus trapping and enhance the oral delivery of macromolecules. Mesoporous silica nanoparticles (MSNs) were synthesized and modified with a hydrophilic block polymer (poly(lactic acid)-methoxy poly(ethylene glycol), PLA-PEG), and then an overall electroneutrality and promoted cellular uptake were achieved by sequential modification with cell-penetrating peptides (CPPs). Reduced hydrophobic and electrostatic interactions of MSN@PLA-PEG-CPP with mucus decreased mucus trapping by 36.0%, increased the cellular uptake of MSN@PLA-PEG-CPP by 2.3-folds in mucous conditions via active heparan sulfate proteoglycan receptor (HSPG)-mediated and caveolae-mediated endocytosis and electrostatic interactions. Furthermore, insulin, a model macromolecular drug, was successfully loaded into the nanoparticles (INS@MSN@PLA-PEG-CPP). Compared with insulin solution, in vitro cellular uptake in mucous conditions and in vivo pharmacodynamic effects were significantly increased by 9.1- and 14.2-folds, respectively. As well, all nanoparticles with or without insulin loading presented negligible in vitro and in vivo toxicity. Herein, hydrophilic and electroneutral nanoparticles with sequential PEG and CPP modification could promote cellular uptake against mucus trapping and finally show good prospects for oral insulin delivery.


Assuntos
Insulina/administração & dosagem , Insulina/química , Muco/metabolismo , Nanopartículas/química , Administração Oral , Animais , Transporte Biológico/fisiologia , Células CACO-2 , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Endocitose/fisiologia , Células HT29 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lactatos/química , Masculino , Camundongos , Polietilenoglicóis/química , Ratos , Ratos Sprague-Dawley , Dióxido de Silício/química
11.
Food Microbiol ; 85: 103309, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31500715

RESUMO

The production of Chinese horse bean-chili-paste (CHCP) involves three fermentation phases: chili-to-moromi fermentation (CF) phase, horse bean-to-meju fermentation (HF) phase and moromi-meju mixed fermentation (MF) phase. To understand the microbial dynamics among these three phases and the potential roles of viable microbes for fermentation, microbial community dynamics was investigated by using culture-dependent and culture-independent methods. Furthermore, the capacities of enzyme-producing of the isolates were determined. During the CF phase, reducing sugar content increased from 3.1% to 3.49%, while pH declined from 4.85 to 4.5. The protein content in the HF phase and MF phase reduced sharply from 22.23% to 10.29% and 4.39%-1.19%, respectively. Bacillus sp., Staphylococcus sp., Oceanobacillus sp., Candida sp., Zygosaccharomyces sp. and Aspergillus sp. dominated the CF phase, while Bacillus sp., Candida sp. and Zygosaccharomyces sp. were the dominant microorganisms in both the HF and MF phases. B. amyloliquefaciens, B. methylotrophicus, B. subtilis, B. licheniformis and A. oryzae possessed strong capacities of producing enzymes, i.e. α-amylase, cellulase and xylanase, acid protease and leucine aminopeptidase, and could make a great contribution to CHCP fermentation.


Assuntos
Bactérias/isolamento & purificação , Fermentação , Microbiologia de Alimentos , Glycine max/microbiologia , Microbiota , Biodiversidade , Capsicum/microbiologia , Células-Tronco , Vicia faba/microbiologia
12.
AAPS PharmSciTech ; 21(7): 277, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033942

RESUMO

The purpose of this research is to develop a liposomal drug delivery system, which can selectively target hepatocellular carcinoma (HCC) to deliver the antitumor agent N-14NCTDA, a C14 alkyl chain norcantharimide derivative of norcantharidin. N-14NCTDA-loaded liposomes were successfully prepared by lipid membrane hydration and extrusion methods. SP94, a targeting peptide for HCC cells, was attached to the liposomes loaded with N-14NCTDA by the post-insertion method to obtain SP94 modified liposomes (SP94-LPs). SP94-LPs had a significant cytotoxicity against Hep G2 cells with the IC50 of 15.395 ± 0.89 µg/mL, which is lower than that of NCTD-S (IC50 = 20.863 ± 0.56 µg/mL) and GAL-LPs (IC50 = 24.589 ± 1.02 µg/mL). Compared with conventional liposomes (Con-LPs), SP94-LPs showed greater cellular uptake in Hep G2 cells. Likewise, significant tumor suppression was achieved in H22 tumor-bearing mice which were treated with SP94-LPs. The tumor inhibition rate (IRw) of SP94-LPs was 82 ± 0.98%, obviously higher than that of GAL-LPs (69 ± 1.39%), Con-LPs (60 ± 2.78%), and NCTD-S (51 ± 3.67%). SP94-LPs exhibited a significant hepatocellular carcinoma-targeting activity in vitro and in vivo, which will provide a new alternative for hepatocellular carcinoma treatment in future. Graphical Abstract.


Assuntos
Antineoplásicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/química , Carcinoma Hepatocelular/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Lipossomos , Neoplasias Hepáticas/tratamento farmacológico , Peptídeos/química , Animais , Antineoplásicos/administração & dosagem , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Cantaridina/análogos & derivados , Células Hep G2 , Humanos , Imidas/química , Camundongos
13.
Small ; 15(18): e1901015, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30957431

RESUMO

Coordination tuning of catalysts is a highly effective strategy for activating and improving the intrinsic activity. Herein, a Co-engineered FeOOH catalyst integrated on carbon fiber paper (Co-FeOOH/CFP) is reported, which realized a great improvement of the oxygen evolution activity by tuning the coordination geometry of the Fe species with an electrochemically driven method. Experiments and theoretical calculation demonstrate that the FeO bonds of FeOOH are partially broken, which is rooted in the Co incorporation, thus resulting in unsaturated FeO6 ligand structures and a relatively narrow bandgap. Consequently, the reorganized Fe sites on the surface show an enhanced capability for adsorbing OH- species and the Co-FeOOH exhibits an improved conductivity. As expected, the Co-FeOOH/CFP hybrids exhibit an extremely low overpotential of ≈250 mV at 10 mA cm-2 and a small Tafel slope, which far outperforms that of electrochemically sluggish FeOOH. The present work emphasizes the importance of local Fe coordination in catalysis and provides an in-depth insight into the mechanism of the enhanced catalytic activity.

14.
Small ; 14(42): e1803310, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30238603

RESUMO

A safe, high-capacity, and long-life Li metal anode is highly desired due to recent developments in high-energy-density Li-metal batteries. However, there are still rigorous challenges associated with the undesirable formation of Li dendrites, lack of suitable host materials, and unstable chemical interfaces. Herein, a carbon nanofiber-stabilized graphene aerogel film (G-CNF film), inspired by constructional engineering, is constructed. As the host material for Li deposition, the G-CNF film features a large surface area, porous structure, and a robust skeleton that can render low local current density. This allows for dendrite-free Li deposition and mitigation of problems associated with large volume change. Importantly, the G-CNF film can keep high Li plating/stripping efficiency at nearly 99% for over 700 h with an areal capacity of 10 mA h cm-2 (the specific capacity up to 2588 mA h g-1 based on the total mass of carbon host and Li metal). The symmetric cells can stably run for more than 1000 h with low voltage hysteresis. The full cell with the LiFePO4 cathode also delivers enhanced capacity and lowered overpotential. As two-in-one host materials for both cathodes and anodes in Li-O2 batteries, the battery exhibits a capacity of 1.2 mA h cm-2 .

15.
Mol Pharm ; 15(7): 2870-2882, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29863879

RESUMO

In this work, a nano-in-micro carrier was constructed by loading polymer-lipid hybrid nanoparticles (NPs) into porous and hollow yeast cell wall microparticles (YPs) for macrophage-targeted oral delivery of cabazitaxel (CTX). The YPs, primarily composed of natural ß-1,3-d-glucan, can be recognized by the apical membrane receptor, dectin-1, which has a high expression on macrophages and intestinal M cells. By combining electrostatic force-driven self-deposition with solvent hydration/lyophilization methods, the positively charged NPs loaded with CTX or fluorescence probes were efficiently packaged into YPs, as verified by scanning electron microscope (SEM), atomic force mircoscope (AFM), and confocal laser scanning microscopy (CLSM) images. NP-loaded YPs (NYPs) showed a slower in vitro drug release and higher drug stability compared with NPs in a simulated gastrointestinal environment. Biodistribution experiments confirmed a widespread distribution and extended retention time of NYPs in the intestinal tract after oral administration. Importantly, a large amount of NYPs were primarily accumulated and transported in the intestinal Peyer's patches as visualized in distribution and absorption site studies, implying that NYPs were mainly absorbed through the lymphatic pathway. In vitro cell evaluation further demonstrated that NYPs were rapidly and efficiently taken up by macrophages via receptor dectin-1-mediated endocytosis using a mouse macrophage RAW 264.7 cell line. As expected, in the study of in vivo pharmacokinetics, the oral bioavailability of CTX was improved to 32.1% when loaded in NYPs, which is approximately 5.7 times higher than that of the CTX solution, indicating the NYPs are efficient for oral targeted delivery. Hence, this nano-in-micro carrier is believed to become a hopeful alternative strategy for increasing the oral absorption of small molecule drugs.


Assuntos
Antineoplásicos/administração & dosagem , Portadores de Fármacos/química , Macrófagos/efeitos dos fármacos , Taxoides/administração & dosagem , Administração Oral , Animais , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Parede Celular/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/farmacocinética , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Absorção Intestinal , Macrófagos/imunologia , Masculino , Camundongos , Modelos Animais , Nanopartículas/química , Neoplasias/tratamento farmacológico , Tamanho da Partícula , Proteoglicanas , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley , Saccharomyces cerevisiae/química , Taxoides/farmacocinética , Distribuição Tecidual , beta-Glucanas/química
16.
Pharm Res ; 36(1): 9, 2018 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-30411255

RESUMO

PURPOSE: The aim of this study was to design agomelatine loaded long acting injectable microspheres, with an eventual goal of reducing the frequency of administration and improving patient compliance in treatment of depression. METHODS: AGM-loaded microspheres were prepared by an O/W emulsion solvent evaporation method. The physicochemical properties and in vitro performance of the microspheres were characterized. The pharmacokinetics of different formulations with various particle sizes and drug loadings were evaluated. RESULTS: AGM-loaded microspheres with drug loading of 23.7% and particle size of 60.2 µm were obtained. The in vitro release profiles showed a small initial burst release (7.36%) followed by a fast release, a period of lag time and a second accelerated release. Pore formation and pore closure were observed in vitro, indicating that the release of drug from microspheres is dominated by water-filled pores. Pharmacokinetic studies showed that AGM microspheres could release up to 30 days in vivo at a steady plasma concentration. As well, particle size and drug loading could significantly influence the in vivo release of AGM microspheres. CONCLUSIONS: AGM-loaded microspheres are a promising carrier for the treatment of major depressant disorder.


Assuntos
Acetamidas/farmacocinética , Portadores de Fármacos/química , Microesferas , Poliglactina 910/química , Acetamidas/administração & dosagem , Animais , Injeções Intramusculares , Masculino , Tamanho da Partícula , Ratos Sprague-Dawley
17.
Pharm Res ; 35(11): 208, 2018 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-30215146

RESUMO

PURPOSE: A novel polymer micelle was prepared with a high drug loading, good stability, high tolerance and better anti-tumor effect. METHODS: TM-2 was encapsulated in poly-block-poly (D, L-lactic acid) self-assembled micelles by the thin-film hydration method. From the critical micelle concentrations of the copolymers, particle size, drug loading and encapsulation efficiency of drug-loading micelles, the appropriate polymer material could be assessed. Comparisons between TM-2 solution and TM-2 micelles were done to evaluate the pharmacokinetics and toxicity in rats, compared with Taxol to evaluate the anti-tumor effect in mice. RESULTS: The optimized TM-2 micelles achieved a high drug loading (~20%) with the polymer material of PEG2k-PLA2.5k, with a particle size of 30 nm and no significant change in particle size after lyophilization. The result of pharmacokinetic experiment displayed that the half-life in vivo was obviously prolonged. The maximum tolerated dose of TM-2 micelles was approximately 25 mg/kg in rats, and the relative tumor growth rate of Taxol (15 mg/kg), TM-2 (10 mg/kg), TM-2 (15 mg/kg) and TM-2 (40 mg/kg) in mice were 49.35%, 49.14%, 36.44 and 9.98% respectively. CONCLUSIONS: TM-2 micelles with high drug loading increased drug solubility, improved tolerance, antitumor effects and reduced toxicity.


Assuntos
Antineoplásicos/administração & dosagem , Portadores de Fármacos/química , Micelas , Paclitaxel/administração & dosagem , Polietilenoglicóis/química , Taxoides/administração & dosagem , Administração Intravenosa , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Masculino , Camundongos , Neoplasias/tratamento farmacológico , Paclitaxel/farmacocinética , Paclitaxel/uso terapêutico , Ratos Sprague-Dawley , Taxoides/farmacocinética , Taxoides/uso terapêutico
18.
Pharm Res ; 34(12): 2787-2797, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28948463

RESUMO

PURPOSE: The mechanism of PRG release from PLGA microspheres was studied and the correlation of in vitro and in vivo analyses was assessed. METHODS: PRG-loaded microspheres were prepared by the emulsion-evaporate method. The physical state of PRG and microstructure changings during the drug release period were evaluated by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) respectively. Pharmacokinetic studies were performed in male Sprague-Dawley rats, and the in vivo-in vitro correlation (IVIVC) was established by linear fitting of the cumulative release (%) in vitro and fraction of absorption (%) in vivo. RESULTS: PXRD results indicated recrystallization of PRG during release. The changes of microstructure of PRG-loaded microspheres during the release period could be observed in SEM micrographs. Pharmacokinetics results performed low burst-release followed a steady-released manner. The IVIVC assessment exhibited a good correlation between vitro and in vivo. CONCLUSIONS: The burst release phase was caused by diffusion of amorphous PRG near the surface, while the second release stage was impacted by PRG-dissolution from crystal depots formed in microspheres. The IVIVC assessment suggests that the in vitro test method used in this study could predict the real situation in vivo and is helpful to study the release mechanism in vivo.


Assuntos
Portadores de Fármacos/química , Ácido Láctico/química , Ácido Poliglicólico/química , Progesterona/administração & dosagem , Progestinas/administração & dosagem , Animais , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Masculino , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Progesterona/química , Progesterona/farmacocinética , Progestinas/química , Progestinas/farmacocinética , Ratos Sprague-Dawley , Difração de Raios X
19.
J Sep Sci ; 40(1): 272-287, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27226152

RESUMO

Metal-organic frameworks are a new category of advanced porous materials with large surface areas and porosities, uniform pore sizes, tunable surface chemistry, and structural diversity. In combination with monoliths, they allow the fine tuning of desired interactions required in a variety of applications. This review article summarizes results of recent studies focused on synthetic strategies enabling incorporation of metal-organic frameworks in monolithic structures. A diverse array of applications including chromatographic separation, solid-phase microextraction, sample enrichment, heterogeneous catalysis, and enzymatic catalysis are also described.


Assuntos
Cromatografia/instrumentação , Metais/química , Compostos Orgânicos/química , Microextração em Fase Sólida/instrumentação , Catálise , Porosidade
20.
AAPS PharmSciTech ; 18(6): 1987-1997, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27933587

RESUMO

Gambogic acid (GA) has been proven to be a potent chemotherapeutic agent for the treatment of lung cancer in clinical trials. However, GA is limited in its therapeutic value by properties such as poor water solubility and low chemical stability. In clinical trials, cationic arginine (Arg) was added to solubilize GA, and this may also cause other side effects. Here, we have designed and developed a more efficient human serum albumin (HSA)-based delivery system for GA with low toxicity which helps improve its solubility, chemical stability and increases its antitumor efficacy. The GA-HSA nanoparticles (NPs) were prepared by albumin-bound (nabTM) technology, with a particle size of 135.2 ± 35.03 nm, a zeta potential of -21.81 ± 1.24 mV, and a high entrapment efficiency. Compared with GA-Arg solution, the physical and chemical stability of the NPs were improved when stored at pH 7.4 in PBS or freeze-dried. The in vitro drug release showed that GA-HSA NPs had a more sustained release than GA-Arg solution. Furthermore, HSA NPs improved the therapeutic efficacy of GA and were less toxic compared with GA-Arg solution in A549-bearing mice. Therefore, this delivery system is a promising polymeric carrier for GA when used for tumor therapy.


Assuntos
Portadores de Fármacos/toxicidade , Neoplasias Pulmonares/tratamento farmacológico , Albumina Sérica/toxicidade , Carga Tumoral/efeitos dos fármacos , Xantonas/toxicidade , Células A549 , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/toxicidade , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Humanos , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos SCID , Nanopartículas/química , Tamanho da Partícula , Albumina Sérica/química , Resultado do Tratamento , Carga Tumoral/fisiologia , Xantonas/química
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