Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Dent Traumatol ; 30(6): 447-54, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25146129

RESUMEN

The aim of this study was to apply biomechanical analysis model to evaluate the effects of bioabsorbable internal fixation devices on maxillary Lefort Ι fracture. CT scan technology and the finite element software (ansys) were used to establish three-dimensional finite element models of five resorbable internal fixation devices in maxillary Lefort Ι fractures. We used the model to calculate the stress of the upper jaw and internal fixation. We further analyzed the stability of fixation under four occlusions. The fixation using two bioabsorbable plates was not stable. The zygomaticomaxillary pillars fixation is more stable than other fixations. The stability of fracture fixation was influenced with the molar occlusion. The current study developed a functional three-dimensional finite element model of bioabsorbable internal fixation and compared the stability of five fixation methods for maxillary Lefort Ι fractures. The results would facilitate the application of bioabsorbable materials in dental clinic.


Asunto(s)
Implantes Absorbibles , Análisis de Elementos Finitos , Fijación Interna de Fracturas/instrumentación , Fijadores Internos , Fracturas Maxilares/cirugía , Fenómenos Biomecánicos , Placas Óseas , Tornillos Óseos , Oclusión Dental , Diseño de Equipo , Humanos , Imagenología Tridimensional/métodos , Masculino , Maxilar/cirugía , Modelos Biológicos , Poliésteres/química , Estudios Prospectivos , Estrés Mecánico , Propiedades de Superficie , Tomografía Computarizada Espiral/métodos , Cigoma/cirugía
2.
Colloids Surf B Biointerfaces ; 232: 113599, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37857183

RESUMEN

Interventional therapies are increasingly used in clinical trials for hepatocellular carcinoma (HCC). Sorafenib is the front-line remedy for HCC, however, chemoresistance occurs immutably and affects the effectiveness of treatment. In a previous study, a norcantharidin liposome emulsion hybrid (NLEH) delivery system for HCC was developed. This study aims to examine the therapeutic effects of the combination of intratumoral injection of NLEH and sorafenib in treating HCC. Sorafenib combined with NLEH activated the apoptosis pathway by synergistically upregulating caspase-9, promoting cytotoxicity, apoptosis (64.57%), and G2/M cell cycle arrest (48.96%). Norcantharidin could alleviate sorafenib resistance by counteracting sorafenib-induced phosphorylation of Akt. Additionally, intratumoral injection of NLEH exhibited a sustained accumulation in the tumor within 24 h and didn't distribute to other major organs. Intratumoral injection of NLEH in combination with oral sorafenib displayed the most potent tumor growth inhibitory effect (77.91%) in vivo. H&E staining results and the indicators of the renal and liver function tests demonstrated the safety of this combination therapy. Overall, these results showed that intratumoral injection of NLEH in combination with oral sorafenib treatment represented a rational potential therapeutic option for HCC.


Asunto(s)
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patología , Sorafenib/farmacología , Sorafenib/uso terapéutico , Liposomas/farmacología , Neoplasias Hepáticas/patología , Emulsiones/farmacología , Inyecciones Intralesiones , Línea Celular Tumoral , Apoptosis , Proliferación Celular
3.
Environ Monit Assess ; 184(7): 4161-70, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21805075

RESUMEN

A molecularly imprinted polymer (MIP) was prepared using chlorsulfuron (CS), a herbicide as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linker, methanol and toluene as a porogen, and 2,2-azobisisobutyronitrile as an initiator. The binding behaviors of the template chlorsulfuron and its analog on MIP were evaluated by equilibrium adsorption experiments, which showed that the MIP particles had specific affinity for the template CS. Solid-phase extraction (SPE) with the chlorsulfuron molecularly imprinted polymer as an adsorbent was investigated. The optimum loading, washing, and eluting conditions for chlorsulfuron molecularly imprinted polymer solid-phase extraction (CS-MISPE) were established. The optimized CS-MISPE procedure was developed to enrich and clean up the chlorsulfuron residue in water, soils, and wheat plants. Concentrations of chlorsulfuron in the samples were analyzed by HPLC-UVD. The average recoveries of CS spiked standard at 0.05~0.2 mg L(-1) in water were 90.2~93.3%, with the relative standard deviation (RSD) being 2.0~3.9% (n=3). The average recoveries of 1.0 mL CS spiked standard at 0.1~0.5 mg L(-1) in 10 g soil were 91.1~94.7%, with the RSD being 3.1~5.6% (n=3). The average recoveries of 1.0 mL CS spiked standard at 0.1~0.5 mg L(-1) in 5 g wheat plant were 82.3~94.3%, with the RSD being 2.9~6.8% (n=3). Overall, our study provides a sensitive and cost-effective method for accurate determination of CS residues in water, soils, and plants.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Herbicidas/química , Impresión Molecular , Polímeros/química , Suelo/química , Sulfonamidas/química , Triazinas/química , Triticum/química , Cromatografía Líquida de Alta Presión , Herbicidas/análisis , Metacrilatos/química , Residuos de Plaguicidas/análisis , Residuos de Plaguicidas/química , Extracción en Fase Sólida/métodos , Sulfonamidas/análisis , Triazinas/análisis , Agua/química
4.
Int J Pharm ; 624: 122002, 2022 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-35817272

RESUMEN

Tumor immunotherapy is a promising strategy to activate the immune system and eliminate tumors. Major histocompatibility complex I (MHC-I) is usually applied to potentiate antigen presentation, but it is associated with upregulation of programmed death ligand 1 (PD-L1) expression, which is unfavorable for activation of immune responses. Moreover, poor permeability of various therapeutic antibodies results in the limited immune response rates of most patients. It is necessary to develop combined small molecule drug delivery systems for simultaneous upregulation of MHC-I expression and downregulation of PD-L1 expression, promoting effective tumor treatment. A moderate dose of doxorubicin hydrochloride (DOX) can induce upregulation of MHC-I expression, while deferasirox (DFX) can inhibit the PI3K-Akt pathway, which potentially downregulates PD-L1 expression. In the present study, we designed a pH-sensitive liposome to incorporate DOX in the hydrophilic cavity and embed DFX in the hydrophobic shell, forming a dual delivery system (DOX-DFXL). In a B16F10 melanoma-bearing mouse model, DOX and DFX were released in acidic tumor microenvironment, which further lead to enhanced antigen presentation and infiltration of T cells into tumor tissues as a result of tumor remission. This codelivery system holds great potential for clinical applications of tumor immunotherapy.


Asunto(s)
Melanoma , Nanopartículas , Animales , Antígeno B7-H1 , Línea Celular Tumoral , Deferasirox , Regulación hacia Abajo , Doxorrubicina , Inmunoterapia/métodos , Liposomas , Complejo Mayor de Histocompatibilidad , Ratones , Nanopartículas/química , Fosfatidilinositol 3-Quinasas , Microambiente Tumoral , Regulación hacia Arriba
5.
Adv Healthc Mater ; 11(19): e2200776, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35912918

RESUMEN

Immunotherapy efficacy has been limited by tumor-associated macrophages (TAMs), which are the most abundant immune regulatory cells infiltrating around tumor tissues. The repolarization of pro-tumor M2 TAMs to anti-tumor M1 TAMs is a very promising immunotherapeutic strategy for cancer therapy. In this manuscript, multifunctional 2D iron-based nanosheets (FeNSs) are synthesized via a simple hydrothermal method for the first time, which not only possess photothermal and photodynamic properties, but also can repolarize TAMs from M2 to M1. After modifying with polyethylene glycol and loading with bioreductive prodrug banoxantrone (AQ4N), abbreviated as AP FeNSs, it can effectively repolarize TAMs from M2 to M1 and deliver AQ4N to tumor microenvironment (TME). Moreover, the repolarized M1 TAMs overexpress inducible nitric oxide synthase, which can convert nontoxic AQ4N to cytotoxic AQ4 under hypoxic TME, enabling immunomodulation-activated chemotherapy. A series of in vitro and in vivo results corroborate that AP FeNSs effectively exert photothermal and photodynamic effects and repolarize M2 TAMs to M1 TAMs, releasing inflammatory factors and activating the chemotherapeutic effect, thereby realizing synergistic tumor therapy.


Asunto(s)
Neoplasias , Profármacos , Antraquinonas , Humanos , Factores Inmunológicos/farmacología , Inmunoterapia/métodos , Hierro/farmacología , Macrófagos , Neoplasias/tratamiento farmacológico , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo II/farmacología , Fototerapia , Polietilenglicoles/farmacología , Profármacos/farmacología , Microambiente Tumoral
6.
Arch Environ Contam Toxicol ; 61(3): 359-67, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21127849

RESUMEN

A new and efficient analytic methodology based on cloud point extraction (CPE) was developed for determination of pesticide residues of metsulfuron-methyl (MSM), chlorsulfuron (CS), and bensulfuron-methyl (BSM) in water, soil, and rice grain by high-performance liquid chromatography (HPLC). Multiple experimental conditions that affected CPE efficiency-including surfactant type and concentration, equilibration temperature and duration, ionic strength, and solution pH were identified. CPE conditions were optimized as follows: 1.5% Triton X-114 (w/v), 12% Na(2)SO(4) (w/v) solution (pH 2.0), and heat-assisted at 50 °C for 15 min. The calibration curves for all analytes were linear, ranging from 0.05 to 4.0 mg L(-1), with the correlation coefficients >0.9995 by HPLC-ultraviolet detector and were linear, ranging from 0.004 to 2.0 mg L(-1), with correlation coefficients >0.9983 by CPE-HPLC. The average recoveries at the three spiked levels using CPE ranged from 86.0% to 94.5% for water samples with relative SDs (RSDs) of 0.4% to approximately 7.8%; from 85.6% to 94.8% for soil samples with RSDs of 1.2% to approximately 9.5%; and from 81.9% to 91.3% for rice samples with RSDs of 1.7% to approximately 5.8%. The proposed CPE-HPLC method can be successfully used to analyze MSM, CS, and BSM residues from contaminated water, soil, and rice grain samples.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Oryza/química , Residuos de Plaguicidas/aislamiento & purificación , Polietilenglicoles/química , Suelo/química , Agua/química , Arilsulfonatos/aislamiento & purificación , Calibración , Monitoreo del Ambiente/métodos , Herbicidas/análisis , Octoxinol , Reproducibilidad de los Resultados , Contaminantes del Suelo/análisis , Sulfonamidas/aislamiento & purificación , Compuestos de Sulfonilurea/aislamiento & purificación , Triazinas/aislamiento & purificación , Contaminantes Químicos del Agua/análisis
7.
ACS Appl Mater Interfaces ; 13(17): 19825-19835, 2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-33881837

RESUMEN

Tumor-associated macrophages (TAMs) of M2 phenotype have mediated the immunosuppression in a tumor microenvironment, facilitating the escape of tumor cells from immunosurveillance. Reprograming the immunosuppressive M2 TAMs to immunostimulatory M1 phenotype can activate the antitumor immune responses for cancer immunotherapy. Herein, hollow iron oxide (Fe3O4) nanoparticles (NPs) were employed to reprogram M2 TAMs toward M1 TAMs, aiming to release proinflammatory cytokines and recruit T cells to kill tumor cells. After loaded with l-arginine (l-Arg) and sealed with poly(acrylic acid) (PAA), hollow Fe3O4 NPs were fabricated into LPFe3O4 NPs, which could release l-Arg based on pH-responsive PAA and produce nitric oxide (NO) with the help of nitric oxide synthase (iNOS) overexpressed by M1 TAMs, as a result of additional tumor elimination for gas therapy. In vitro and in vivo studies demonstrate that LPFe3O4 NPs could effectively reprogram M2 to M1 macrophages, activating T cells, releasing TNF-α, and producing high levels of NO, leading to synergistic tumor therapy.


Asunto(s)
Arginina/administración & dosificación , Gases/química , Inmunoterapia/métodos , Macrófagos/inmunología , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapéutico , Neoplasias/tratamiento farmacológico , Microambiente Tumoral , Resinas Acrílicas/química , Animales , Humanos , Macrófagos/enzimología , Macrófagos/metabolismo , Ratones , Neoplasias/inmunología , Neoplasias/patología , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Cell Prolif ; 53(5): e12810, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32472648

RESUMEN

OBJECTIVES: Gli1+ cells have received extensive attention in tissue homeostasis and injury mobilization. The aim of this study was to investigate whether Gli1+ cells respond to force and contribute to bone remodelling. MATERIALS AND METHODS: We established orthodontic tooth movement (OTM) model to assess the bone response for mechanical force. The transgenic mice were utilized to label and inhibit Gli1+ cells, respectively. Additionally, mice that conditional ablate Yes-associated protein (Yap) in Gli1+ cells were applied in the present study. The tooth movement and bone remodelling were analysed. RESULTS: We first found Gli1+ cells expressed in periodontal ligament (PDL). They were proliferated and differentiated into osteoblastic cells under tensile force. Next, both pharmacological and genetic Gli1 inhibition models were utilized to confirm that inhibition of Gli1+ cells led to arrest of bone remodelling. Furthermore, immunofluorescence staining identified classical mechanotransduction factor Yap expressed in Gli1+ cells and decreased after suppression of Gli1+ cells. Additionally, conditional ablation of Yap gene in Gli1+ cells inhibited the bone remodelling as well, suggesting Gli1+ cells are force-responsive cells. CONCLUSIONS: Our findings highlighted that Gli1+ cells in PDL directly respond to orthodontic force and further mediate bone remodelling, thus providing novel functional evidence in the mechanism of bone remodelling and first uncovering the mechanical responsive property of Gli1+ cells.


Asunto(s)
Remodelación Ósea/fisiología , Huesos/metabolismo , Huesos/fisiología , Proteína con Dedos de Zinc GLI1/metabolismo , Animales , Diferenciación Celular/fisiología , Mecanotransducción Celular/fisiología , Ratones , Ratones Transgénicos , Osteoclastos/metabolismo , Osteoclastos/fisiología , Ligamento Periodontal/metabolismo , Ligamento Periodontal/fisiología , Estrés Mecánico , Técnicas de Movimiento Dental/métodos
9.
Adv Mater ; 29(34)2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28714205

RESUMEN

Posterior capsule opacification (PCO) is the most common complication after cataract surgery. So far, the only method for PCO treatment is the precisely focused laser surgery. However, it causes severe complications such as physical damages and neuron impairments. Here, a nanostructured photothermal ring integrated intraocular lens (Nano-IOLs) is reported, in which the rim of commercially available IOLs (C-IOLs) is decorated with silica coated Au nanorods (Au@SiO2 ), for high-efficient prevention of PCO after cataract surgery. The Nano-IOLs is capable of eliminating the residual lens epithelial cells (LECs) around Nano-IOLs under mild laser treatment and block the formation of disordered LECs fibrosis, which eventually leads to the loss of vision. The Nano-IOLs shows good biocompatibility as well as extraordinary region-confined photothermal effect. In vivo studies reveal that PCO occurrence in rabbit models is about 30%-40% by using Nano-IOLs, which is significantly lower than the control group that treated with C-IOLs (100% PCO occurrence) 30 d postsurgery. To the best of our knowledge, it is the first example to integrate nanotechnology with intraocular implants aiming to clinically relevant PCO. Our findings indicate that spatial controllability of photothermal effect from nanomaterials may provide a unique way to intervene the PCO-induced loss of vision.


Asunto(s)
Lentes Intraoculares , Resinas Acrílicas , Animales , Oftalmopatías , Ojo Artificial , Implantación de Lentes Intraoculares , Conejos , Dióxido de Silicio
10.
Mol Med Rep ; 12(4): 5127-34, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26239849

RESUMEN

The dental pulp contains a relatively low number of stem cells; however, it is considered to be a promising source of stem cells for use in regenerative therapy. To date, it has remained elusive whether there are certain differences in the dental pulp stem cells (DPSCs) from donors of different ages. In the present study, DPSC lines were derived using teeth from children, adolescents, adults and aged donors. The derivation efficiency, the proliferative and apoptotic rate, cell marker expression and the differentiation capacity were investigated and compared among these DPSC lines. The derivation efficacy was decreased with increasing donor age. Although a large part of cell surface markers was expressed in all DPSC lines, the expression of CD29 was downregulated in the DPSCs from aged teeth. In addition, the doubling time of DPSCs from aged teeth was prolonged and the number of apoptotic cells was increased with the propagation. These DPSCs were able to differentiate into a neuronal linage, which positively expressed the neuron-specific class III beta-tubulin and microtubule­associated protein 2, as well as into an osteogenic lineage, which positively expressed CD45; however, these DPSCs from aged teeth were completely or partially deprived of differentiation capacity. By contrast, DPSCs from younger teeth displayed significantly higher vitality and a higher potential for use in dental regenerative medicine.


Asunto(s)
Pulpa Dental/citología , Células Madre/citología , Células Madre/fisiología , Adolescente , Adulto , Factores de Edad , Anciano , Antígenos de Superficie/metabolismo , Biomarcadores , Diferenciación Celular , Línea Celular , Proliferación Celular , Niño , Preescolar , Humanos , Inmunofenotipificación , Cariotipo , Masculino , Persona de Mediana Edad , Osteogénesis , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA