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1.
Eur J Appl Physiol ; 124(6): 1861-1874, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38233706

RESUMO

BACKGROUND: This study examined the effects of a single all-out bout of 30-s sprint-cycle performed daily for 5 consecutive days per week for 6 weeks, on aerobic fitness, muscle strength and metabolic-health markers in physically active young males and females. METHODS: Healthy, physically active 20-28 year olds, were randomly assigned to either experimental (EXP, N = 11) or non-training control (CON, N = 8) group. With supervision, the EXP group performed one bout of 30-s sprint-cycle daily, Mondays to Fridays over 6 weeks, while CON group continued with their usual lifestyle. The followings were measured at pre- and post-intervention: maximal aerobic power, peak torque of knee extensors and flexors at velocities 30° s-1 and 300° s-1, resting heart rate, resting blood pressure, body fat percentage, fasting lipid profile, fasting blood glucose, and fasting insulin levels. RESULTS: There were no significant improvements in the EXP group for all the measured variables (all P > 0.05); except for significant interaction effects in peak torque of knee extensors at 30° s-1 (P = 0.044) and low-density lipoprotein-cholesterol (P = 0.046). Post hoc test indicate that CON group showed decline in their low-density lipo-proteins levels (P = 0.024). CONCLUSION: Six weeks of one all-out bout of 30-s sprint-cycle per day, for 5 consecutive days per week, was ineffective in improving cardiovascular fitness, maximal strength, and most health markers in physically active young adults. The present results when combined with the previous literature suggest that there is a possibility of a minimum threshold for a number of sprint-cycle bouts needed to be performed before any form of cardio-metabolic-health benefit is accrued.


Assuntos
Força Muscular , Humanos , Masculino , Feminino , Adulto , Força Muscular/fisiologia , Adulto Jovem , Aptidão Cardiorrespiratória/fisiologia , Exercício Físico/fisiologia , Aptidão Física/fisiologia , Biomarcadores/sangue , Frequência Cardíaca/fisiologia , Pressão Sanguínea/fisiologia
2.
Biomacromolecules ; 24(6): 2674-2690, 2023 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-37143361

RESUMO

This study aimed to develop a multifunctional polymer platform that could address the issue of treatment resistance when using conventional chemotherapeutics to treat glioblastoma (GBM). An antibody-conjugated, multi-drug loaded hyperbranched polymer was developed that provided a platform to evaluate the role of targeted nanomedicine treatments in overcoming resistant GBM by addressing the various complications with current clinically administered formulations. The polymer was synthesized via reversible addition fragmentation chain transfer polymerization and included the clinical first-line alkylating agent temozolomide (TMZ) which was incorporated as a polymerizable monomer, poly (ethylene glycol) (PEG) units to impart biocompatibility and enable conjugation with αPEG-αEphA2 bispecific antibody (αEphA2 BsAb) for tumor targeting, and hydrazide moieties for attachment of a secondary drug which allows exploration of synergistic therapies. To overcome the resistance to TMZ, the O6 alkylguanine DNA alkyltransferase (AGT, DNA repair protein) inhibitor, dialdehyde O6 benzylguanine (DABG) was subsequently conjugated to the polymer via an acid labile hydrazone linker to facilitate controlled release under conditions encountered within the tumor microenvironment. The prolonged degradation half-life (4-5 h) of the polymer conjugated TMZ in vitro offered a potential avenue to overcome the inability to deliver these drugs in combination at therapeutic doses. Although only 20% of DABG could be released within the studied timeframe (192 h) under conditions mimicking the acidic nature of the tumor environment, cytotoxicity evaluation using cell assays confirmed the improved therapeutic efficacy toward resistant GBM cells after attaching DABG to the polymer delivery vehicle. Of note, when the polymeric delivery vehicle was specifically targeted to receptors (Ephrin A2) on the surface of the GBM cells using our in-house developed EphA2 specific BsAb, the dual-drug-loaded polymer exhibited an improved therapeutic effect on TMZ-resistant cells compared to the free drug combination. Both in vitro and in vivo targeting studies showed high uptake of the construct to GBM tumors with an upregulated EphA2 receptor (T98G and U251) compared to a tumor that had low expression (U87MG), where a dual tumor xenograft model was used to demonstrate the enhanced accumulation in tumor tissue in vivo. Despite the synthetic challenges of developing systems to effectively deliver controlled doses of TMZ and DABG, these studies highlight the potential benefit of this formulation for delivering multi-drug combinations to resistant GBM tumor cells and offer a platform for future optimization in therapeutic studies.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Preparações Farmacêuticas , Medicina de Precisão , Recidiva Local de Neoplasia/tratamento farmacológico , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Glioblastoma/tratamento farmacológico , Neoplasias Encefálicas/tratamento farmacológico , Polímeros/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Ensaios Antitumorais Modelo de Xenoenxerto , Microambiente Tumoral
3.
Sci Rep ; 9(1): 1882, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30760785

RESUMO

In this work, the inclusion complexes of hydrophobic herbicide bensulfuron-methyl (BSM) with ß-cyclodextrin (ß-CD) and (2-hydroxypropyl)-ß-CD (2-HP-ß-CD) were prepared and characterized. Phase solubility study showed that both ß-CD and 2-HP-ß-CD increased the solubility of BSM. Three-dimensional structures of the inclusion complexes were simulated by the molecular docking method. The docking results indicated that guest BSM could enter into the cavities of host CDs, folded, and centrally aligned inside the inclusion complexes. The benzene ring of the guest molecule was close to the wide rim of the host molecules; the pyrimidine ring and side chains of the guest molecule were oriented toward the narrow rim of the host molecule. The inclusion complexes were successfully prepared by the coprecipitation method. The physiochemical characterization data of 1H NMR, FT-IR, XRD, and DSC showed that the guest and host molecules were well included. BSM had lower soil adsorption and higher herbicidal activity in the complexation form with ß-CD or 2-HP-ß-CD than in the pure form. The present study provides an approach to develop a novel CDs-based formulation for hydrophobic herbicides.

4.
ACS Nano ; 12(6): 5605-5614, 2018 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-29741863

RESUMO

For a typical perovskite solar cell (PKSC), the electron transport layer (ETL) has a great effect on device performance and stability. Herein, we manifest that low-temperature solution-processed ZnSe can be used as a potential ETL for PKSCs. Our optimized device with ZnSe ETL has achieved a high power conversion efficiency (PCE) of 17.78% with negligible hysteresis, compared with the TiO2 based cell (13.76%). This enhanced photovoltaic performance is attributed to the suitable band alignment, high electron mobility, and reduced charge accumulation at the interface of ETL/perovskite. Encouraging results were obtained when the thin layer of ZnSe cooperated with TiO2. It shows that the device based on the TiO2/ZnSe ETL with cascade conduction band level can effectively reduce the interfacial charge recombination and promote carrier transfer with the champion PCE of 18.57%. In addition, the ZnSe-based device exhibits a better photostability than the control device due to the greater ultraviolet (UV) light harvesting of the ZnSe layer, which can efficiently prevent the perovskite film from intense UV-light exposure to avoid associated degradation. Consequently, our results present that a promising ETL can be a potential candidate of the n-type ETL for commercialization of efficient and photostable PKSCs.

5.
Sci Total Environ ; 634: 1034-1041, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29660861

RESUMO

Potential risk of endocrine disrupting compounds on non-target organisms has received extensive attentions in recent years. The present work aimed to investigate the behavior and effect of a synthetic steroid estrogen quinestrol in duckweed Spirodela polyrhiza L. Experimental results showed that quinestrol could be uptaken, accumulated, and biotransformed into 17 α-ethynylestradiol in S. polyrhiza L. The accumulation of quinestrol had a positive relation to the exposure concentration. The bioaccumulation rate was higher when the duckweed was exposed to quinestrol solutions at low concentrations than at high concentration. While the transformation of quinestrol showed no concentration-dependent manner. Quinestrol reduced the biomass and pigment content and increased superoxide dismutase and catalase activities and malondialdehyde contents in the duckweed. The results demonstrated that quinestrol could be accumulated and biotransformed in aquatic plant S. polyrhiza L. This work would provide supplemental data on the behavior of this steroid estrogen compound in aquatic system.


Assuntos
Araceae/efeitos dos fármacos , Estrogênios/toxicidade , Quinestrol/toxicidade , Poluentes Químicos da Água/toxicidade , Araceae/fisiologia , Disruptores Endócrinos/toxicidade , Malondialdeído/metabolismo , Superóxido Dismutase/metabolismo
6.
J Control Release ; 264: 76-88, 2017 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-28842315

RESUMO

Bone is the most common organ affected by metastatic breast cancer. Targeting cancers within the bone remains a great challenge due to the inefficient delivery of therapeutic to bone. In this study, a polyethylene glycol (PEG) coated nanoparticles (NPs) made of a Zn2+ coordination polymer was linked with a bone seeking moiety, alendronate (ALN), to deliver cisplatin prodrug (DSP) to the bone. The particle sizes of this novel system, DSP-Zn@PEG-ALN NPs, were regulated by adjusting the volume ratio of water phase to oil phase in microemulsion. It was small enough (about 55nm) to extravasate through the clefts (80nm) of the bone's sinusoidal capillaries and localize into metastatic bones. DSP-Zn@PEG-ALN NPs showed much higher affinity for hydroxyapatite in vitro and bone in vivo than non-targeted DSP-Zn@PEG NPs and cisplatin. In addition, the in vivo biodistribution studies demonstrated that about 4-fold of platinum was delivered to the bone metastatic lesions than that in healthy bones by DSP-Zn@PEG-ALN NPs intravenously. Finally, DSP-Zn@PEG-ALN NPs not only inhibited the tumor growth efficiently but also reduced the osteocalastic bone destruction. Besides, DSP-Zn@PEG-ALN NPs showed significantly reduced toxicity of cisplatin. These results indicate that the DSP-Zn@PEG-ALN NPs have a great potential in enhancing chemotherapeutic efficacy for the treatment of bone metastatic breast cancer.


Assuntos
Alendronato/administração & dosagem , Antineoplásicos/administração & dosagem , Cisplatino/administração & dosagem , Portadores de Fármacos/administração & dosagem , Estruturas Metalorgânicas/administração & dosagem , Nanopartículas/administração & dosagem , Zinco/administração & dosagem , Alendronato/química , Alendronato/farmacocinética , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/química , Cisplatino/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos , Humanos , Masculino , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacocinética , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/química , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Pró-Fármacos/administração & dosagem , Pró-Fármacos/química , Pró-Fármacos/farmacocinética , Ratos Sprague-Dawley , Ensaios Antitumorais Modelo de Xenoenxerto , Zinco/química , Zinco/farmacocinética
7.
ACS Appl Mater Interfaces ; 9(47): 41354-41362, 2017 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-29111639

RESUMO

For a typical perovskite solar cell (PKSC), both the electron transport layers (ETLs) and hole transport materials (HTMs) play a very important role in improving the device performance and long-term stability. In this paper, we firstly improve the electron transport properties by modification of TiO2 ETLs with Na species, and an enhanced power conversion efficiency (PCE) of 16.91% has been obtained with less hysteresis. Subsequently, an inorganic CuI film prepared by a facile spray deposition method has been employed to replace the conventional spiro-OMeTAD as the HTM in PKSCs. Because of the improved transport properties at the ETL/perovskite and perovskite/HTM interfaces, a maximum photovoltaic efficiency of 17.6% with reduced hysteresis has been achieved in the PKSC with both the Na-modified TiO2 ETL and 60 nm-thick CuI layer HTM. To our knowledge, the PCE achieved in this paper is one of the highest values ever reported for the PKSC devices with inorganic HTMs. More significantly, the PKSCs exhibit an outstanding device stability, their PCE remains constant after storage in the dark for 50 days, and they can retain approximately 92% of their initial efficiency after storage even for 90 days.

8.
Nanoscale ; 9(28): 10002-10019, 2017 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-28682411

RESUMO

Cisplatin (CDDP) is a potent anti-carcinogen that is widely used for various solid tumors; however, its clinical application is limited by its severe nephrotoxicity. Novel platinum-bisphosphonate polymer-metal complex nanoparticles (Pt-bp NPs), based on platinum-bisphosphonate coordination, have been established. Three polymer carriers bearing alendronate (ALN) ligands, while containing different lengths of alkyl hydrophobic chains, were synthesized. Their structures were characterized by 1H NMR, 31P NMR and FTIR. The ALN was used to coordinate to the CDDP precursor [Pt(NH3)2(OSO3)(OH2)], and the Pt-bp NPs were formed spontaneously. The Pt-bp NPs formed by the polymer carrier, ALN-PEG2k-ASAC18, which contained the poly(ethylene glycol) chain with ALN on one side and the octadecyl hydrophobic chain on the other side, was denoted as ALN-ASAC18-CDDP; its diameter was within 200 nm. CDDP was released in a Cl- or pH-dependent manner. The cytotoxic effects to the HeLa, A549 and MCF-7 cell lines were relatively weak, compared to CDDP. However, ALN-ASAC18-CDDP showed significantly prolonged blood circulation time and tumor accumulation of platinum of 2.5-fold, compared to CDDP at 8 h. Besides, ALN-ASAC18-CDDP was demonstrated to remarkably reduce systemic toxicity without compromising in vivo antitumor activity. These results indicate that the facilely prepared ALN-ASAC18-CDDP has great utilization potential for CDDP delivery in a clinical setting.


Assuntos
Antineoplásicos/administração & dosagem , Cisplatino/administração & dosagem , Difosfonatos/química , Portadores de Fármacos/química , Nanopartículas Metálicas , Platina/química , Células A549 , Animais , Células HeLa , Humanos , Células MCF-7 , Camundongos , Polímeros , Ratos Sprague-Dawley , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Int J Pharm ; 516(1-2): 352-363, 2017 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-27887884

RESUMO

Because of the peculiarity of the bone microstructure, the uptake of chemotherapeutics often happens at non-targeted sites, which induces side effects. In order to solve this problem, we designed a bone-targeting drug delivery system that can release drug exclusively in the nidus of the bone. Alendronate (ALN), which has a high ability to target to hydroxyapatite, was used to fabricate double ALN-conjugated poly (ethylene glycol) 2000 material (ALN-PEG2k-ALN). The ALN-PEG2k-ALN was characterized using 1H NMR and 31P NMR and FTIR. ALN-PEG2k-ALN-modified calcium phosphate nanoparticles (APA-CPNPs) with an ALN targeting moiety and hydrophilic poly (ethylene glycol) arms tiled on the surface was prepared for bone-targeted drug delivery. The distribution of ALN-PEG2k-ALN was tested by X-ray photoelectron spectroscopy. Isothermal titration calorimetry data indicated that similar to free ALN, both ALN-PEG2k-ALN and APA-CPNPs can bind to calcium ions. The bone-binding ability of APA-CPNPs was verified via ex vivo imaging of bone fragments. An in vitro release experiment demonstrated that APA-CPNPs can release drug faster in an acid environment than a neutral environment. Cell viability experiments indicated that blank APA-CPNPs possessed excellent biocompatibility with normal cells. Methotrexate (MTX) loaded APA-CPNPs have the same ability to inhibit cancer cells as free drug at high concentrations, while they are slightly weaker at low concentrations. All of these experiments verified the prospective application of APA-CPNPs as a bone-targeting drug delivery system.


Assuntos
Alendronato/química , Neoplasias Ósseas/tratamento farmacológico , Fosfatos de Cálcio/química , Metotrexato/administração & dosagem , Alendronato/metabolismo , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/farmacocinética , Antimetabólitos Antineoplásicos/farmacologia , Neoplasias Ósseas/secundário , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Durapatita/metabolismo , Feminino , Humanos , Metotrexato/farmacocinética , Metotrexato/farmacologia , Camundongos , Nanopartículas , Espectroscopia Fotoeletrônica , Polietilenoglicóis/química , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
10.
ACS Appl Mater Interfaces ; 9(34): 28558-28565, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28792200

RESUMO

The effect of Al-, Ga-, and In-doping on the thermoelectric (TE) properties of Cu3SbSe4 has been comparatively studied on the basis of theoretical prediction and experimental validation. It is found that tiny Al/Ga/In substitution leads to a great enhancement of electrical conductivity with high carrier concentration and also large Seebeck coefficient due to the preserved high band degeneracy and thereby a remarkably high power factor. Ultimately, coupled with the depressed lattice thermal conductivity, all three elements (Al/Ga/In) substituted samples have obtained a highly improved thermoelectric performance with respect to undoped Cu3SbSe4. Compared to the samples at the same Al/In doping level, the slightly Ga-doped sample presents better TE performance over the wide temperature range, and the Cu3Sb0.995Ga0.005Se4 sample presents a record high ZT value of 0.9 among single-doped Cu3SbSe4 at 623 K, which is about 80% higher than that of pristine Cu3SbSe4. This work offers an alternative approach to boost the TE properties of Cu3SbSe4 by selecting efficient dopant to weaken the coupling between electrical conductivity and Seebeck coefficient.

11.
Int J Pharm ; 473(1-2): 250-8, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25014368

RESUMO

A new continuous dissolution-permeation system, consisting of an intrinsic dissolution apparatus and an Ussing chamber, was developed for screening and identification of high-bioavailability polymorphisms at pre-formulation stages. Three different solid forms of two model drugs (agomelatine and carbamazepine) were used to confirm the system's predictive ability. Ranks for cumulative permeation of the three solids were: Form III>Form I>Form II for agomelatine, and Form III>Form I>the dihydrate form for carbamazepine. Regression analysis of these parameters and published pharmacokinetics confirmed linear IVIVCs (most correlation coefficients >0.9). To confirm dissolution-absorption relationships, permeability coefficients were calculated. Relatively constant values among various polymorphisms for each drug supported a linear dependency between polymorphism-increased dissolution and polymorphism-enhanced permeation. A combined analysis of intrinsic dissolution rates and permeability coefficients revealed that both drugs are of the BCS II class and have dissolution-limited absorption. In conclusion, our new system was valuable not only for high-bioavailability polymorphism screening, but also for drug classification within the BCS system.


Assuntos
Acetamidas/farmacocinética , Biofarmácia , Carbamazepina/farmacocinética , Animais , Disponibilidade Biológica , Duodeno/metabolismo , Íleo/metabolismo , Técnicas In Vitro , Absorção Intestinal , Jejuno/metabolismo , Permeabilidade , Ratos Sprague-Dawley , Solubilidade
12.
Int J Nanomedicine ; 9: 4867-78, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25364245

RESUMO

Layered double hydroxide (LDH) has attracted considerable attention as a drug carrier. However, because of its poor in vivo behavior, polyethylene glycolylated (PEGylated) phospholipid must be used as a coformer to produce self-assembled core-shell nanoparticles. In the present study, we prepared a PEGylated phospholipid-coated LDH (PLDH) (PEG-PLDH) delivery system. The PEG-PLDH nanoparticles had an average size of 133.2 nm. Their core-shell structure was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy. In vitro liposome-cell-association and cytotoxicity experiments demonstrated its ability to be internalized by cells. In vivo studies showed that PEGylated phospholipid membranes greatly reduced the blood clearance rate of LDH nanoparticles. PEG-PLDH nanoparticles demonstrated a good control of tumor growth and increased the survival rate of mice. These results suggest that PEG-PLDH nanoparticles can be a useful drug delivery system for cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/farmacocinética , Portadores de Fármacos/química , Hidróxidos/química , Nanopartículas/química , Animais , Antineoplásicos/sangue , Antineoplásicos/química , Proteínas Sanguíneas/química , Peso Corporal/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/toxicidade , Células HeLa , Humanos , Hidróxidos/toxicidade , Metotrexato/sangue , Metotrexato/química , Metotrexato/farmacocinética , Metotrexato/farmacologia , Camundongos , Nanopartículas/toxicidade , Tamanho da Partícula , Fosfolipídeos/química , Fosfolipídeos/toxicidade , Polietilenoglicóis/química , Polietilenoglicóis/toxicidade , Ratos Sprague-Dawley , Ensaios Antitumorais Modelo de Xenoenxerto
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