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1.
ACS Appl Mater Interfaces ; 13(38): 45315-45324, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34520665

RESUMO

Active targeted therapy for bowel cancer using untethered microrobots has attracted extensive attention. However, traditional microrobots face challenges, such as issues of mobility, biocompatibility, drug loading, sustained-release capabilities, and targeting accuracy. Here, we propose an untethered triple-configurational magnetic robot (TCMR) that is composed of three geometrically nested parts: actuation and guarding, anchoring and seeding, and drug release part. A targeting magnetic driving system actuates the TCMR along the predetermined trajectory to the target position. The pH-sensitive actuation and guarding part formed by electrodeposition is degraded in the intestinal environment and separates from the two other parts. A majority of magnetic nanoparticles encapsulated in this part are retrieved. The anchoring and seeding part anchors the lesion area and seeds the drug release part in the gaps of intestinal villi by hydrolysis. Ultimately, the drug release part containing the therapeutic completes the sustained release to prolong the duration of the therapeutic agent. Cytotoxicity and therapeutic tests reveal that TCMRs are biocompatible and suitable for targeted therapy and have good therapeutic performance. The newly designed TCMR will provide new ideas for targeted therapy, thus expanding the application scope of robotics technology in the biomedical field.

2.
J Mater Chem B ; 9(4): 1030-1039, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33398321

RESUMO

Small intestine-targeted drug delivery by oral administration has aroused the growing interest of researchers. In this work, the child-parent microrobot (CPM) as a vehicle protects the child microrobots (CMs) under a gastric acid environment and releases them in the small intestinal environment. The intelligent hydrogel-based CPMs with sphere, mushroom, red blood cell, and teardrop shapes are fabricated by an extrusion-dripping method. The CPMs package uniform CMs, which are fabricated by designed microfluidic (MF) devices. The fabrication mechanism and tunability of CMs and CPMs with different sizes and shapes are analyzed, modeled, and simulated. The shape of CPM can affect its drug release efficiency and kinetic characteristics. A vision-feedback magnetic driving system (VMDS) actuates and navigates CPM along the predefined path to the destination and continuously releases drug in the simulated intestinal fluid (SIF, a low Reynolds number (Re) regime) using a new motion control method with the tracking-learning-detection (TLD) algorithm. The newly designed CPM combines the advantages of powerful propulsion, good biocompatibility, and remarkable drug loading and release capacity at the intestinal level, which is expected to be competent for oral administration of small intestine-targeted therapy in the future.


Assuntos
Doxorrubicina/química , Sistemas de Liberação de Medicamentos , Hidrogéis/química , Nanopartículas de Magnetita/química , Robótica , Células Cultivadas , Criança , Humanos , Dispositivos Lab-On-A-Chip , Fenômenos Magnéticos , Tamanho da Partícula , Robótica/instrumentação , Propriedades de Superfície
3.
Crit Rev Food Sci Nutr ; 61(6): 1049-1064, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32292045

RESUMO

vitexin, an apigenin-8-C-glucoside, is widely present in numerous edible and medicinal plants. vitexin possesses a variety of bioactive properties, including antioxidation, anti-inflammation, anti-cancer, neuron-protection, and cardio-protection. Other beneficial health effects, such as fat reduction, glucose metabolism, and hepatoprotection, have also been reported in recent studies. This review briefly discusses the absorption and metabolism of vitexin, as well as its influence on gut microbiota. Recent advances in understanding the pharmacological and biological effects of vitexin are then reviewed. Improved knowledge of the absorption, metabolism, bioactivity, and molecular targets of vitexin is crucial for the better utilization of this emerging nutraceutical as a chemopreventive and chemotherapeutic agent.


Assuntos
Antioxidantes , Apigenina , Anti-Inflamatórios , Apigenina/farmacologia , Suplementos Nutricionais
4.
J Hazard Mater ; 374: 195-202, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31003120

RESUMO

The three-dimensional (3D) porous graphene hydrogel (GH) was synthetized by an environmentally friendly one-step hydrothermal reduction method. The characterization methods, such as Environmental scanning electron microscope, Contact angle, and Fourier transform infrared spectroscopy, were used to analyze the possible reduction mechanism. In order to investigate the relationship between adsorption properties of ciprofloxacin (CIP) and moisture content, GH with different moisture contents, was synthesized via different reaction variables (initial graphene oxide concentration, proportion of reductant, temperature, and reduction time). Besides, GH synthesis parameters were also optimized using variable control methods. More importantly, the multiple adsorption mechanisms of CIP on GH was also be investigated and summarized, indicating GH possesses a promising potential in practical application. These results indicate that GH may be an efficient adsorbent for antibiotic pollutants removal in water purification.


Assuntos
Ciprofloxacina/análise , Grafite/química , Hidrogéis/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Antibacterianos/análise , Microscopia Eletrônica de Varredura , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
5.
Gene ; 689: 18-23, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30521886

RESUMO

Osteosarcoma is the most common malignant bone tumor in children and adolescents. Aberrant expression of HOXA5 results in various diseases, including cancers. However, the specific function and molecular mechanism of HOXA5 in osteosarcoma is not fully understood. In the present study, we focused on HOXA5 in U2OS and MG63 cells in vitro. We observed lower expression of HOXA5 in U2OS, MG63, and SaOS2 human osteosarcoma cells, compared with hFOB1.19 human osteoblastic cells. HOXA5 overexpression in U2OS and MG63 cells markedly reduced cell survival and proliferation and elevated cell apoptosis and caspase-3 activity. HOXA5 also activated the p38α MAPK pathway by increasing p53. Treating U2OS and MG63 cells with the p53 inhibitor α-pifithrin or the p38α MAPK inhibitor SB203580 led to higher cell survival and proliferation and lower cell apoptosis, compared with the pcDNA3.1-HOXA5 group. In conclusion, our study showed that the p53 and p38α MAPK signal axis facilitated HOXA5's role in inhibiting growth and stimulating apoptosis of osteosarcoma cells.


Assuntos
Apoptose/genética , Neoplasias Ósseas/patologia , Proteínas de Homeodomínio/genética , Osteossarcoma/patologia , Neoplasias Ósseas/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 14 Ativada por Mitógeno/genética , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Osteossarcoma/genética , Proteína Supressora de Tumor p53/genética , Regulação para Cima/genética
6.
World J Clin Cases ; 7(24): 4420-4425, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31911927

RESUMO

BACKGROUND: Extramedullary myelinolysis is a rare demyelinating disease, often caused by rapid increases in serum sodium concentration in patients with hyponatremia. Clinical manifestations are neuropsychiatric symptoms, limb weakness, and dysarthria. Because of its poor prognosis and high disability rate, it poses a huge burden on the global economy, societies, and families. This article reports rehabilitation in a patient with pituitary dysfunction combined with extramedullary myelinolysis. CASE SUMMARY: A 27-year-old Chinese man developed anorexia, vomiting, and limb weakness and was diagnosed with pituitary insufficiency. He had low serum sodium, slow movement, muscle weakness, and muscle tone abnormalities after sodium supplementation, involuntary limb shaking, ataxia, and dysarthria. According to the symptoms and signs and imaging reports, he was diagnosed with extramedullary myelinolysis. After treatment with hormone therapy and neurotrophic drugs, motor and speech function did not improve, so he was treated in the rehabilitation department for 4 wk. The patient's physical status was improved substantially during his stay at the rehabilitation department. CONCLUSION: Patients with extramedullary myelinolysis who actively participate in rehabilitation intervention can significantly improve their activities of daily living.

7.
J Knee Surg ; 31(1): 78-86, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28460408

RESUMO

This meta-analysis was conducted to study whether kinematically aligned total knee arthroplasty (TKA) improves short-term functional outcomes compared with mechanical alignment without changing the hip-knee-ankle angle. Prospective cohort studies were searched from electronic literature databases, including PubMed, Web of Science, Embase (Ovid interface), and Cochrane Library (Ovid interface). Total 1,159 records were identified. Six trials involving 561 patients were eligible for data extraction and meta-analysis. The included studies recorded outcomes in the follow-up range from 6 to 34 months. Primary outcomes were to assess the functional outcomes in follow-up, and KA group achieved better performance on WOMAC score (mean difference [MD] = -18.82, 95% CI: -16.06 to -5.58), knee function score (MD = 7.23, 95% CI: 0.52-13.94), Oxford knee score (MD = 4.76, 95% CI: 0.40-9.12), and knee range of flexion (MD = 4.48, 95% CI: 2.09-6.86), whereas other parameters including Knee Society score, knee range of extension, VAS pain score, and the occurrence of the complications were without significant difference (p > 0.05). Second outcomes evaluated the perioperative clinic indexes. Our meta-analysis showed that KA group had a shorter time of operation (MD = -15.44, 95% CI: -27.47 to -3.71) and a longer walk distance before discharge (MD = 53.24, 95% CI: 21.32-85.15) when compared with the MA group, whereas the change in hemoglobin, incision length, knee range of flexion before discharge, and length of stays were without significant difference (p > 0.05). Third outcomes were used to analyze the alignment data. Our study showed that KA had larger angles of femoral component and mechanical axis of the femur (MD = -1.95,95% CI: -2.77 to -1.13), tibial component and mechanical axis of tibia (MD = 2.06, 95% CI: 1.43-2.70), anatomic knee angle (MD = -0.72, 95% CI: -1.33 to -0.11), and operative limb alignment (MD = -1.97, 95% CI: -2.50 to -1.45,) compared with the MA group, but the hip-knee-ankle angles between the two groups were similar. KA provided better functional outcomes and better flexion following short-term follow-up of TKA. However, longer-term follow-up and larger sample studies are needed to put into research in the future.


Assuntos
Artroplastia do Joelho/métodos , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/cirurgia , Avaliação de Resultados da Assistência ao Paciente , Amplitude de Movimento Articular , Escala Visual Analógica
8.
mBio ; 8(6)2017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29138305

RESUMO

Understanding how bacteria coordinate growth with cell cycle events to maintain cell size homeostasis remains a grand challenge in biology. The period of chromosome replication (C period) is a key stage in the bacterial cell cycle. However, the mechanism of in vivo regulation of the C period remains unclear. In this study, we found that titration of the expression of ribonucleotide reductase (RNR), which changes the intracellular deoxynucleoside triphosphate (dNTP) pools, enables significant perturbations of the C period, leading to a substantial change in cell size and DNA content. Our work demonstrates that the intracellular dNTP pool is indeed an important parameter that controls the progression of chromosome replication. Specially, RNR overexpression leads to a shortened C period compared with that of a wild-type strain growing under different nutrient conditions, indicating that the dNTP substrate levels are subsaturated under physiological conditions. In addition, perturbing the C period does not significantly change the D period, indicating that these two processes are largely independent from each other. Overall, titration of ribonucleotide reductase expression can serve as a standard model system for studying the coordination between chromosome replication, cell division, and cell size.IMPORTANCE Bacteria must coordinate growth with cell cycle progression to maintain cell size hemostasis. Cell cycle and cell size regulation is a fundamental concern in biology. The period required for chromosome replication (the C period) is a key stage in the bacterial cell cycle. However, how the C period is controlled in vivo remains largely an open question in this field of bacterial cell cycle regulation. Through introducing a genetic circuit into Escherichia coli for titrating the expression of ribonucleotide reductase, we achieve substantial perturbation of the C period and cell size. Our work demonstrates that the intracellular dNTP pool is an important parameter that controls the progression of chromosome replication. Moreover, our work indicates that bacterial cells manage to maintain subsaturated dNTP levels under different nutrient conditions, leading to a submaximal speed of DNA replication fork movement.


Assuntos
Ciclo Celular , Período de Replicação do DNA , Escherichia coli/citologia , Escherichia coli/enzimologia , Nucleotídeos/metabolismo , Ribonucleotídeo Redutases/metabolismo , Escherichia coli/genética , Expressão Gênica , Ribonucleotídeo Redutases/genética
9.
Environ Sci Technol ; 51(21): 12283-12292, 2017 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-28960065

RESUMO

Water as the universal solvent has well-demonstrated its ability to dissolve many substances, but buried water inside different nanoporous materials always exhibits some unusual behaviors. Herein, 3D porous graphene hydrogel (GH) is developed as a super-adsorbent to remove different pollutants (antibiotics, dyes, and heavy ions) for water purification. Due to its highly porous structure and high content of water, GH also demonstrated its super adsorption capacity for adsorbing and removing different pollutants (antibiotics, dyes, and heavy ions) as compared to conventional graphene aerogel (GA). More fundamentally, the buried-water enhanced adsorption mechanism was proposed and demonstrated, such that buried water in GH plays the combinatorial roles as (1) supporting media, (2) transport nanochannels, and (3) hydrogen bondings in promoting pollutant adsorption. In parallel, molecular dynamics simulations further confirm that buried water in GH has the stronger interaction with pollutants via hydrogen bonds than other buried alcohols. GH integrates the merit of both graphene (e.g., fine chemical resistance and excellent mechanical property) and hydrogel (e.g., high water content, porous structure, and simple solution-based processability and scalability), giving it promising potential for environmental applications.


Assuntos
Grafite , Hidrogéis , Poluentes Químicos da Água , Adsorção , Água , Purificação da Água
10.
Proc Natl Acad Sci U S A ; 114(12): E2460-E2465, 2017 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-28193863

RESUMO

A large number of genes are necessary for the biosynthesis and activity of the enzyme nitrogenase to carry out the process of biological nitrogen fixation (BNF), which requires large amounts of ATP and reducing power. The multiplicity of the genes involved, the oxygen sensitivity of nitrogenase, plus the demand for energy and reducing power, are thought to be major obstacles to engineering BNF into cereal crops. Genes required for nitrogen fixation can be considered as three functional modules encoding electron-transport components (ETCs), proteins required for metal cluster biosynthesis, and the "core" nitrogenase apoenzyme, respectively. Among these modules, the ETC is important for the supply of reducing power. In this work, we have used Escherichia coli as a chassis to study the compatibility between molybdenum and the iron-only nitrogenases with ETC modules from target plant organelles, including chloroplasts, root plastids, and mitochondria. We have replaced an ETC module present in diazotrophic bacteria with genes encoding ferredoxin-NADPH oxidoreductases (FNRs) and their cognate ferredoxin counterparts from plant organelles. We observe that the FNR-ferredoxin module from chloroplasts and root plastids can support the activities of both types of nitrogenase. In contrast, an analogous ETC module from mitochondria could not function in electron transfer to nitrogenase. However, this incompatibility could be overcome with hybrid modules comprising mitochondrial NADPH-dependent adrenodoxin oxidoreductase and the Anabaena ferredoxins FdxH or FdxB. We pinpoint endogenous ETCs from plant organelles as power supplies to support nitrogenase for future engineering of diazotrophy in cereal crops.


Assuntos
Escherichia coli/enzimologia , Eucariotos/enzimologia , Nitrogenase/metabolismo , Organelas/enzimologia , Anabaena/enzimologia , Anabaena/genética , Transporte de Elétrons , Escherichia coli/genética , Escherichia coli/metabolismo , Eucariotos/genética , Eucariotos/metabolismo , Ferredoxina-NADP Redutase/genética , Ferredoxina-NADP Redutase/metabolismo , Molibdênio/metabolismo , Nitrogenase/genética , Organelas/genética , Oxirredução
11.
Sci Rep ; 5: 13578, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26336922

RESUMO

An environmentally benign and efficient hydrothermal reduction method was applied for the preparation of three-dimensional (3D) porous graphene hydrogel (GH) adsorbents. The physicochemical properties of GH granules were systematically characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectra and Brunauer-Emmett-Teller (BET) method. GH granules showed an excellent adsorption capacity (235.6 mg/g) for ciprofloxacin via combined adsorption interaction mechanisms (e.g. π-π EDA interaction, hydrogen bonding, and hydrophobic interaction). Moreover, reducing the size of the hydrogels can significantly accelerate the adsorption process and enhance the removal efficiency of pollutants from aqueous solution. Water (more than 99 wt%) within hydrogels played a key role in enhancing adsorption performance. The GO hydrogels exhibited an excellent adaptability to environmental factors. These findings demonstrate that GH granules are promising adsorbents for the removal of antibiotic pollutants from aqueous solutions.


Assuntos
Ciprofloxacina/isolamento & purificação , Grafite/química , Ultrafiltração/métodos , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Água/química , Absorção Fisico-Química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Ciprofloxacina/química , Hidrogéis/química , Teste de Materiais , Nanopartículas/química , Nanopartículas/ultraestrutura , Nanoporos/ultraestrutura , Porosidade , Poluentes Químicos da Água/química
12.
J Colloid Interface Sci ; 444: 24-32, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25585283

RESUMO

We report a facile solid method to synthesize efficient carbon-based Fenton-like catalyst (CNTs/FeS) using as-prepared carbon nanotubes (APCNTs), which makes full use of the iron nanoparticles in APCNTs without needless purification. Furthermore, the CNTs/FeS was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric (TG) and other analysis techniques, and then the CNTs/FeS was used as a Fenton-like catalyst for removing ciprofloxacin from aqueous solution. Response Surface Methodology (RSM) was applied to find the effect of the reaction parameter and the optimum operating condition. Results shows the catalytic reaction had better suitability than previous studies in a wide range of pH values (pH 3-8) and the Fenton-like catalyst CNTs/FeS exhibits good catalytic activity for removing of antibiotic, which be attributed to the synergistic effect of adsorption-advanced oxidation and significantly improves efficiency of advanced oxidation. More importantly, the CNTs/FeS catalyst exhibit good regeneration performance and retains a high catalytic capacity (>75%) even after four reaction cycles. The catalytic mechanism were also studied further, the removal mechanism of ciprofloxacin by a CNTs/FeS heterogeneous Fenton-like process primarily involves three removal pathways occurring simultaneously: (a) adsorption removal by CNTs, (b) Fenton-like degradation catalyzed by FeS, (c) catalytic degradation by CNTs catalyst. And these actions also have synergistic effects for ciprofloxacin removal.


Assuntos
Antibacterianos/isolamento & purificação , Ciprofloxacina/isolamento & purificação , Compostos Ferrosos/química , Nanotubos de Carbono/química , Águas Residuárias/análise , Poluentes Químicos da Água/isolamento & purificação , Catálise , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Ferro/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Técnicas de Síntese em Fase Sólida , Eliminação de Resíduos Líquidos/métodos
13.
J Colloid Interface Sci ; 434: 9-17, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25151091

RESUMO

Carbon nanotubes (CNTs) functionalized with magnetic nanoparticles are attractive for environmental remediation applications due to their high specific surface area conducive for adsorption of water contaminants and the possibility of recovering these nanohybrids after remediation using an external magnetic field. Most of existing methods for synthesizing magnetic iron oxide/CNTs (MIO-CNTs) composites are carried out in the liquid medium and are tedious, uneconomical, and environmentally unfriendly. Herein, we report a one-pot solid-phase route to synthesize MIO-CNTs composites based on pristine CNTs. MIO-CNTs possess a high specific surface area, good dispersibility, and desirable magnetic properties, making them promising as adsorbents for arsenic removal. The maximum arsenic adsorption capacities are 47.41 and 24.05 mg g(-)(1) for As(V) and As(III), respectively. These values are among the highest for carbon-based materials. Oxygen-containing groups on the surface of MIO-CNTs play a crucial role in arsenic adsorption. This work is very important for the practical applications of pristine CNTs containing catalyst nanoparticles without the need of purifications.

14.
Dalton Trans ; 42(5): 1356-9, 2013 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-23207979

RESUMO

We designed a facile one-pot method to synthesize iron oxide/activated carbon nanotubes (IO/ACNTs) using as-prepared carbon nanotubes (APCNTs) modified by alkali solid-activation. The open-ended CNTs and iron oxide loading could be realized in one step. The resulting IO/ACNT hybrids, as an anode material for lithium-ion batteries (LIBs), exhibited high reversible lithium storage capacity and excellent rate capability, which make APCNTs potentially useful for large-scale applications in LIBs.

15.
ACS Appl Mater Interfaces ; 4(11): 5749-60, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23062571

RESUMO

An alkali-acitvated method was explored to synthesize activated carbon nanotubes (CNTs-A) with a high specific surface area (SSA), and a large number of mesopores. The resulting CNTs-A were used as an adsorbent material for removal of anionic and cationic dyes in aqueous solutions. Experimental results indicated that CNTs-A have excellent adsorption capacity for methyl orange (149 mg/g) and methylene blue (399 mg/g). Alkali-activation treatment of CNTs increased the SSA and pore volume (PV), and introduced oxygen-containing functional groups on the surface of CNTs-A, which would be beneficial to improving the adsorption affinity of CNTs-A for removal of dyes. Kinetic regression results shown that the adsorption kinetic was more accurately represented by a pseudo second-order model. The overall adsorption process was jointly controlled by external mass transfer and intra-particle diffusion, and intra-particle diffusion played a dominant role. Freundlich isotherm model showed a better fit with adsorption data than Langmuir isotherm model. Adsorption interactions of dyes onto CNTs-A from aqueous solutions were investigated using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) method. The remarkable adsorption capacity of dye onto CNTs-A can be attributed to the multiple adsorption interaction mechanisms (hydrogen bonding, π-π electron-donor-acceptor interactions, electrostatic interactions, mesopore filling) on the CNTs-A. Results of this work are of great significance for environmental applications of activated CNTs as a promising adsorbent nanomaterial for organic pollutants from aqueous solutions.


Assuntos
Álcalis/química , Compostos Azo/isolamento & purificação , Azul de Metileno/isolamento & purificação , Nanotubos de Carbono/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Água/química , Adsorção , Compostos Azo/química , Azul de Metileno/química , Nanotubos de Carbono/ultraestrutura , Porosidade , Soluções , Ultrafiltração/métodos , Poluentes Químicos da Água/química
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