Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 67
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Mol Pharm ; 21(5): 2148-2162, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38536949

RESUMEN

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer for which effective therapies are lacking. Targeted remodeling of the immunosuppressive tumor microenvironment (TME) and activation of the body's immune system to fight tumors with well-designed nanoparticles have emerged as pivotal breakthroughs in tumor treatment. To simultaneously remodel the immunosuppressive TME and trigger immune responses, we designed two potential therapeutic nanodelivery systems to inhibit TNBC. First, the bromodomain-containing protein 4 (BRD4) inhibitor JQ1 and the cyclooxygenase-2 (COX-2) inhibitor celecoxib (CXB) were coloaded into chondroitin sulfate (CS) to obtain CS@JQ1/CXB nanoparticles (NPs). Then, the biomimetic nanosystem MM@P3 was prepared by coating branched polymer poly(ß-amino ester) self-assembled NPs with melittin embedded macrophage membranes (MM). Both in vitro and in vivo, the CS@JQ1/CXB and MM@P3 NPs showed excellent immune activation efficiencies. Combination treatment exhibited synergistic cytotoxicity, antimigration ability, and apoptosis-inducing and immune activation effects on TNBC cells and effectively suppressed tumor growth and metastasis in TNBC tumor-bearing mice by activating the tumor immune response and inhibiting angiogenesis. In summary, this study offers a novel combinatorial immunotherapeutic strategy for the clinical TNBC treatment.


Asunto(s)
Azepinas , Celecoxib , Triazoles , Neoplasias de la Mama Triple Negativas , Microambiente Tumoral , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/inmunología , Neoplasias de la Mama Triple Negativas/patología , Microambiente Tumoral/efectos de los fármacos , Animales , Femenino , Ratones , Humanos , Celecoxib/administración & dosificación , Línea Celular Tumoral , Sulfatos de Condroitina/química , Sulfatos de Condroitina/administración & dosificación , Nanopartículas/química , Nanopartículas/administración & dosificación , Meliteno/administración & dosificación , Meliteno/química , Apoptosis/efectos de los fármacos , Sistema de Administración de Fármacos con Nanopartículas/química , Ensayos Antitumor por Modelo de Xenoinjerto , Ratones Endogámicos BALB C , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Inhibidores de la Ciclooxigenasa 2/farmacología , Inhibidores de la Ciclooxigenasa 2/uso terapéutico , Polímeros/química , Ratones Desnudos , Sistemas de Liberación de Medicamentos/métodos
2.
BMC Oral Health ; 24(1): 515, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38698359

RESUMEN

OBJECTIVE: Low impacted third molars are usually asymptomatic and are often found by X-ray examination. The removal of asymptomatic low impacted third molars is one of the most controversial clinical issues in oral and maxillofacial surgery. METHODS: In this study, 806 patients with low impacted mandibular third molars (LIMTMs) (full bony impaction) were analyzed to determine the prevalence and risk factors for cystic lesions and adjacent tooth root resorption throughout the patients' entire life cycle. RESULTS: The results showed that the prevalence of adjacent tooth root resorption and cystic lesions was age-related, exhibiting a trend of first increasing and then decreasing; prevalence peaked at the age of 41 to 45 years old, the prevalence rates were 12.50% and 11.11% respectively. And the lowest prevalence rate was 2.86% and 2.44% in ≥ 61 group and 56- to 60-year age group respectively. Age was an independent risk factor for adjacent tooth root resorption of LIMTMs, whereas age and impaction type (especially inverted impaction) were independent risk factors for cystic lesions. CONCLUSIONS: The full life cycle management strategy for LIMTMs may need to be individualized. Surgical removal is recommended for LIMTMs in patients younger than 41 to 45 years, especially for inverted, mesioangular, and horizontally impacted LIMTMs. LIMTMs in patients older than 41 to 45 years may be treated conservatively with regular follow-up, but surgical removal of inverted impacted LIMTMs is still recommended to avoid cyst formation.


Asunto(s)
Tercer Molar , Resorción Radicular , Diente Impactado , Humanos , Diente Impactado/complicaciones , Diente Impactado/diagnóstico por imagen , Resorción Radicular/etiología , Femenino , Estudios Retrospectivos , Masculino , Adulto , Persona de Mediana Edad , Factores de Riesgo , Mandíbula , Prevalencia , Adulto Joven , Adolescente , Factores de Edad , Anciano
3.
Int J Legal Med ; 137(3): 721-731, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36717384

RESUMEN

Teeth-based age and sex estimation is an important task in mass disasters, criminal scenes, and archeology. Although various methods have been proposed, most of them are subjective and influenced by observers' experiences. In this study, we aimed to develop a deep learning model for automatic dental age and sex estimation from orthopantomograms (OPGs) and compare to manual methods. A large dataset of 15,195 OPGs (age range, 16 ~ 50 years; mean age, 29.65 years ± 9.36 [SD]; 10,218 females) was used to train and test a hybrid deep learning model which is a combination of convolutional neural network and transformer model. The final performance of this model was evaluated on additional independent 100 OPGs and compared to the manual method for external validation. In the test of 1413 OPGs, the mean absolute error (MAE) of age estimation was 2.61 years by this model. The accuracy and the area under the receiver operating characteristic curve (AUC) of sex estimation were 95.54% and 0.984. The heatmap indicated that the crown and pulp chamber of premolars and molars contain the most age-related information. In the additional independent 100 OPGs, this model achieved an MAE of 3.28 years for males and 3.79 years for females. The accuracy of this model was much higher than that of the manual models. Therefore, this model has the potential to assist radiologists in automated age and sex estimation.


Asunto(s)
Diente Molar , Redes Neurales de la Computación , Masculino , Femenino , Humanos , Adolescente , Adulto , Preescolar , Diente Premolar , Corona del Diente , Cavidad Pulpar
4.
Biomacromolecules ; 23(7): 2989-2998, 2022 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-35758844

RESUMEN

The incorporation of a phenylboronic acid group has appeared as an attractive strategy to build smart drug delivery systems. Here, we report novel synthesis of phenylboronic acid-functionalized copolypeptides based on an l-boronophenylalanine N-carboxyanhydride (BPA-NCA) monomer and their application for robust co-encapsulation and responsive release of dual anticancer drugs. By employing different poly(ethylene glycol) (PEG) initiators and copolymerizing with varying NCA monomers, linear and star PEG-poly(l-boronophenylalanine) copolymers (PEG-PBPA, star-PEG-PBPA), PEG-poly(l-tyrosine-co-l-boronophenylalanine) [PEG-P(Tyr-co-BPA)], PEG-poly(l-lysine-co-l-boronophenylalanine) [PEG-P(Lys-co-BPA)], and PEG-poly(ß-benzyl-l-aspartate-co-l-boronophenylalanine) [PEG-P(BLA-co-BPA)] were obtained with controlled compositions. Interestingly, PEG-PBPA self-assembled into uniform micellar nanoparticles that mediated robust co-encapsulation and hydrogen peroxide (H2O2) and acid-responsive release of dual antitumor drugs, curcumin (Cur) and sorafenib tosylate (Sor). These dual drug-loaded nanoparticles (PBN-Cur/Sor) exhibited a greatly enhanced anticancer effect toward U87 MG-luciferase glioblastoma cells. The facile synthesis of phenylboronic acid-functionalized copolypeptides from BPA coupled with their robust drug loading and responsive drug release behaviors make them interesting for construction of smart cancer nanomedicines.


Asunto(s)
Antineoplásicos , Curcumina , Nanopartículas , Antineoplásicos/química , Antineoplásicos/farmacología , Ácidos Borónicos , Curcumina/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Peróxido de Hidrógeno , Micelas , Nanopartículas/química , Polietilenglicoles/química
5.
BMC Oral Health ; 22(1): 558, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36456973

RESUMEN

BACKGROUND: Cleidocranial dysplasia (CCD) is a rare and underdiagnosed congenital disorder in dentistry. The purpose of this study was to illustrate and quantify the maxillofacial bone abnormalities detected on panoramic radiographs from a relatively large retrospective case series and to provide a series of diagnostic references for dentists to indicate the presence of disease and help in making an early and accurate diagnosis. METHODS: The dental panoramic radiographs of thirty CCD patients aged 11 to 45 years (18 males and 12 females) were examined retrospectively. The dentition states, including supernumerary teeth and impacted teeth, were recorded. Twelve quantified measurements were adopted to determine the abnormalities of maxillofacial bones, including the degree of the zygomatic arch downward bend, bicondylar breadth, ramal height, mandibular height, mandibular aspect ratio, mandibular body height, condylar height, coronoid height, distance between the coronoid process and the condyle, bigonial width, gonial angle and best-fit gonial circle diameter. The Wilcoxon rank-sum test was used to compare the findings of the CCD patients with those of their matched controls (n = 300). RESULTS: Supernumerary teeth were detected in 27 patients (90.0%), and all 30 patients presented impacted teeth. Compared to the matched controls, the CCD patients had a significantly larger degree of zygomatic arch downward bend (ZAD), a larger diameter of the best-fit gonial circle (BGC), and a shorter distance between the coronoid process and the condyle (DCC) in panoramic radiographs (P < 0.001). According to the reference cutoff values established from the 5th or 95th percentile of the measurements in the control group, ZAD higher than 6.90 mm, DDC less than 22.37 mm and BGC higher than 52.41 mm were significantly associated with the CCD features identified. Other panoramic measurements were not significantly different between the two groups. CONCLUSIONS: Panoramic radiographs had great value in the diagnosis of CCD. In this study, we identified some dental and maxillofacial features on panoramic radiographs from a relatively large retrospective case series of CCD. A series of reliable quantitative indicators were provided for dentists that can indicate the presence of disease and improve the diagnostic specificity.


Asunto(s)
Displasia Cleidocraneal , Diente Impactado , Diente Supernumerario , Femenino , Masculino , Humanos , Radiografía Panorámica , Estudios Retrospectivos , Diente Supernumerario/diagnóstico por imagen
6.
Langmuir ; 37(48): 14096-14104, 2021 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-34808057

RESUMEN

Ultrasmall nanoparticles (USNPs) with sizes below 10 nm have shown great potentials in medical applications owing to their outstanding physical, chemical, optical, and biological properties. However, they suffer from a rapid renal clearance and biodegradation rate in the biological environment due to the small size. Liposomes are one of the most promising delivery nanocarriers for loading USNPs because of their excellent biocompatibility and lipid bilayer structure. Encapsulation of USNPs into liposomes in an efficient and controllable manner remains a challenge. In this study, we achieved a high loading of graphene quantum dots (GQDs, ∼4 nm), a typical USNP, into the aqueous core of liposomes (45.68 ± 1.44%), which was controllable by the pressure. The GQDs-loaded liposomes (GQDs-LPs) exhibited a very good aqueous stability for over a month. Furthermore, indocyanine green (ICG), an efficient near-infrared (NIR) photothermal agent, was introduced in the GQDs-LP system that could convert NIR laser energy into thermal energy and break down the liposomes, causing the release of GQDs in 6 min. Moreover, this NIR light-controlled release system (GQDs-ICG-LPs) also exhibited a good photothermal therapeutic performance in vitro, and 75% of cancer cells were killed at a concentration of 200 µg/mL. Overall, the successful development of the NIR light-controlled release system has laid a solid foundation for the future biomedical application of USNPs-loaded liposomes.


Asunto(s)
Grafito , Nanopartículas , Puntos Cuánticos , Liposomas , Fototerapia
7.
Environ Sci Technol ; 55(10): 7015-7024, 2021 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-33905246

RESUMEN

This work proposed an innovative and energy-efficient Donnan Dialysis (DD) and Osmotic Distillation (OD) hybrid process for alkali-driven ammonium recovery from wastewater. The efficiency and feasibility of ammonium removal and recovery from synthetic and real wastewater using NaOH and waste alkali were investigated. Ammonium in the feed first transported across the cation exchange membrane and accumulated in the receiver chamber. It is then deprotonated as ammonia, passing through the gas permeable membrane and finally is fixed as ammonium salt in the acid chamber. Our results indicated that employing waste alkali (red mud leachate) as driving solution led to excellent ammonium recovery performances (recovery efficiency of >80%), comparable to those of NaOH solution. When the initial ammonium concentration was 5 and 50 mM, the waste alkali driven DD-OD process achieved acceptable NH4+-N flux density of 16.8 and 169 g N m-2 d-1, at energy cost as low as 8.38 and 2.06 kWh kg-1 N, respectively. Since this alkali driven DD-OD hybrid process is based on solute concentration (or partial pressure) gradient, it could be an energy-effective technology capable of treating wastewaters containing ammonium using waste alkali to realize nutrients recovery in a sustainable manner.


Asunto(s)
Compuestos de Amonio , Destilación , Álcalis , Membranas Artificiales , Ósmosis , Diálisis Renal , Aguas Residuales
8.
J Nanobiotechnology ; 17(1): 109, 2019 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-31623608

RESUMEN

BACKGROUND: Multidrug resistance (MDR) generally leads to breast cancer treatment failure. The most common mechanism of MDR is the overexpression of ATP-binding cassette (ABC) efflux transporters such as P-glycoprotein (P-gp) that reduce the intracellular accumulation of various chemotherapeutic agents. Celecoxib (CXB), a selective COX-2 inhibitor, can dramatically enhance the cytotoxicity of doxorubicin (DOX) in breast cancer cells overexpressing P-gp. Thus it can be seen that the combination of DOX and CXB maybe obtain synergistic effects against breast cancer by overcoming drug resistance. RESULTS: In this study, we designed a pH and redox dual-responsive nanocarrier system to combine synergistic effects of DOX and CXB against drug resistant breast cancer. This nanocarrier system denoted as HPPDC nanoparticles showed good in vitro stability and significantly accelerated drug releases under the acidic and redox conditions. In drug-resistant human breast cancer MCF-7/ADR cells, HPPDC nanoparticles significantly enhanced the cellular uptake of DOX through the endocytosis mediated by CD44/HA specific binding and the down-regulated P-gp expression induced by COX-2 inhibition, and thus notably increased the cytotoxicity and apoptosis-inducing activity of DOX. In MCF-7/ADR tumor-bearing nude mice, HPPDC nanoparticles showed excellent tumor-targeting ability, remarkably enhanced tumor chemosensitivity and reduced COX-2 and P-gp expressions in tumor tissues. CONCLUSION: All results demonstrated that HPPDC nanoparticles can efficiently overcome drug resistance in breast cancer both in vitro and in vivo by combining chemotherapy and COX-2 inhibitor. In a summary, HPPDC nanoparticles show a great potential for combination treatment of drug resistant breast cancer.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Celecoxib/administración & dosificación , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Preparaciones de Acción Retardada/química , Doxorrubicina/administración & dosificación , Polímeros/química , Animales , Celecoxib/farmacocinética , Celecoxib/uso terapéutico , Inhibidores de la Ciclooxigenasa 2/farmacocinética , Inhibidores de la Ciclooxigenasa 2/uso terapéutico , Doxorrubicina/farmacocinética , Doxorrubicina/uso terapéutico , Resistencia a Antineoplásicos , Femenino , Humanos , Concentración de Iones de Hidrógeno , Células MCF-7 , Ratones Desnudos , Nanopartículas/química , Oxidación-Reducción
9.
Biomed Chromatogr ; 33(1): e4390, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30238674

RESUMEN

In this work, a general and novel separation technique gas-assisted three-liquid-phase extraction was established and applied in separating and concentrating isoflavonoids from the actual sample of puerariae extract by one step. For the gas-assisted three-liquid-phase extraction method, optimal conditions were selected: polyethylene glycol 2000 and ethyl acetate as the flotation solvent, pH 5, (NH4 )2 SO4 concentration 350 g/L in aqueous phase, N2 flow rate 30 mL/min, flotation time 50 min, and flotation twice. Five isoflavonoids compounds puerarin, 3'-methoxydaidzin, puerarinxyloside, daidzin and daidzein were separated with recoveries of 82, 84, 80, 88 and 89%, respectively. The separated products were purified by preparative high-performance liquid chromatography, and the purity of the final products was >96%. The established general gas-assisted three-liquid-phase extraction was used to separate anthraquinones from Cassiae Semen under the optimal conditions, and the recoveries were >75%. The experimental results showed that the established gas-assisted three-liquid-phase extraction method is a general technique for separating active compounds from herb extract.


Asunto(s)
Isoflavonas/aislamiento & purificación , Extracción Líquido-Líquido/métodos , Extractos Vegetales/química , Pueraria/química , Acetatos , Cromatografía Líquida de Alta Presión , Isoflavonas/análisis , Isoflavonas/química , Polietilenglicoles
10.
Nanotechnology ; 29(32): 325101, 2018 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-29761789

RESUMEN

A novel pH- and redox-responsive nanoparticle system was designed based on a charge-reversible pullulan derivative (CAPL) and disulfide-containing poly(ß-amino ester) (ssPBAE) for the co-delivery of a gene and chemotherapeutic agent targeting hepatoma. The end-alkene groups of ssPBAE were reacted with diethylenetriamine to form amino-modified ssPBAE (NH-ssPBAE). Methotrexate (MTX), a chemotherapy agent, was then conjugated to NH-ssPBAE via an amide bond to obtain the polymeric prodrug ssPBAE-MTX. ssPBAE-MTX exhibited a good capability for condensing genes, including plasmid DNA (pDNA) and tetramethyl rhodamine-labeled DNA (TAMRA-DNA), and almost completely condensed pDNA at the weight ratio of 5/1 to form spherical nanocomplexes with a uniform size. In a D,L-dithiothreitol solution, the ssPBAE-MTX/pDNA nanocomplexes showed rapid release of pDNA and MTX, indicating their redox-responsive capability. CAPL, a pullulan derivative containing ß-carboxylic amide bond, was efficiently coated on the surfaces of ssPBAE-MTX/pDNA nanocomplexes to form polysaccharide shells, thus realizing co-loading of the gene and chemotherapeutic agent. CAPL/ssPBAE-MTX/pDNA nanoparticles displayed an obvious pH-responsive charge reversal ability due to the rupture of the ß-carboxylic amide bond under the weakly acidic condition. In human hepatoma HepG2 cells, CAPL/ssPBAE-MTX/TAMRA-DNA nanoparticles were efficiently internalized via endocytosis and successfully escaped from the endo/lysosomes into the cytoplasm, and CAPL/ssPBAE-MTX/pDNA nanoparticles remarkably inhibited the cell growth. In summary, this nanoparticle system based on CAPL and ssPBAE showed great potential for combined gene/chemotherapy on hepatomas.


Asunto(s)
Disulfuros/química , Sistemas de Liberación de Medicamentos , Técnicas de Transferencia de Gen , Glucanos/química , Nanopartículas/química , Polímeros/química , Muerte Celular/efectos de los fármacos , ADN/metabolismo , Endocitosis/efectos de los fármacos , Células Hep G2 , Humanos , Concentración de Iones de Hidrógeno , Metotrexato/farmacología , Nanopartículas/ultraestructura , Oxidación-Reducción , Plásmidos/metabolismo , Polímeros/síntesis química , Espectroscopía de Protones por Resonancia Magnética
11.
Med Sci Monit ; 24: 26-36, 2018 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-29293490

RESUMEN

BACKGROUND The objective of this study was to analyze the factors that can increase the possibility of mandibular canal (MC) defect in Chinese people, to evaluate the risk of nerve impairment, and to choose the proper operative method to reduce the risk of mandibular alveolar nerve injury during the extraction of mandibular third molar (MTM). MATERIAL AND METHODS A total of 954 patients (1,304 MTMs) who underwent orthopantomography (OPG) and cone-beam computed tomography (CBCT) between July 2014 and December 2014 were included in this study. The age and gender of patients, impacted type (high impaction, moderate impaction, and low impaction), Winter classification of MTM, position of MTM relative to MC, vertical classification of MTM and MC, and the feature images of OPG were collected and compared to the imperfection of the MC wall in CBCT images. RESULTS The wall situation of MC was significantly correlated with the age of the patient, the depth of the molar, the position of the roots, and six imaging appearances on OPG. There was no significant difference based on gender. CONCLUSIONS Most incomplete walls of MCs could be inferred by OPG. However, images based on CBCT could clarify the defect of the MC and also could clearly display the spatial relationship between the root and inferior alveolar canal.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Mandíbula/diagnóstico por imagen , Tercer Molar/cirugía , Adolescente , Adulto , Anciano , Pueblo Asiatico/genética , China , Femenino , Humanos , Masculino , Mandíbula/fisiología , Nervio Mandibular/diagnóstico por imagen , Nervio Mandibular/fisiología , Persona de Mediana Edad , Diente Molar , Tercer Molar/fisiología , Radiografía Panorámica/métodos , Factores de Riesgo , Raíz del Diente
12.
Macromol Rapid Commun ; 37(17): 1453-9, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27377646

RESUMEN

Controlling the topologies of polymers is a hot topic in polymer chemistry because the physical and/or chemical properties of polymers are determined (at least partially) by their topologies. This study exploits the host-guest interactions between dibenzo-24-crown-8 and secondary ammonium salts and metal coordination interactions between 2,6-bis(benzimidazolyl)-pyridine units with metal ions (Zn(II) and/or Eu(III) ) as orthogonal non-covalent interactions to prepare supramolecular polymers. By changing the ratios of the metal ion additives (Zn(NO3 )2 and Eu(NO3 )3 ) linkers to join the host-guest dimeric complex, the linear supramolecular polymers (100 mol% Zn(NO3 )2 per ligand) and hyperbranched supramolecular polymers (97 mol% Zn(NO3 )2 and 3 mol% Eu(NO3 )3 per ligand) are separately and successfully constructed. This approach not only expands topological control over polymeric systems, but also paves the way for the functionalization of smart and adaptive materials.


Asunto(s)
Europio/química , Compuestos Organometálicos/síntesis química , Polímeros/síntesis química , Zinc/química , Sustancias Macromoleculares/síntesis química , Sustancias Macromoleculares/química , Estructura Molecular , Compuestos Organometálicos/química , Polímeros/química , Estereoisomerismo
13.
Exp Cell Res ; 338(2): 261-6, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26297530

RESUMEN

Electrospinning permits fabrication of biodegradable matrices that can resemble the both scale and mechanical behavior of the native extracellular matrix. However, achieving high-cellular density and infiltration of cells within matrices with traditional technique remain challenging and time consuming. The cell electrospinning technique presented in this paper can mitigate the problems associated with these limitations. Cells encapsulated by the material in the cell electrospinning technique survived well and distributed homogenously within the nanofibrous membrane, and their vitality was improved to 133% after being cultured for 28 days. The electrospun nanofibrous membrane has a certain degradation property and favorable cell-membrane interaction that supports the active biocompatibility of the membrane. Its properties are helpful for supporting cell attachment and growth, maintaining phenotypic shape, and secreting an ample amount of extracellular matrix (ECM). This novel membrane may be a potential application within the field of tissue engineering. The ability of cell electrospinning to microintegrate cells into a biodegradable fibrous matrix embodies a novel tissue engineering approach that could be applied to fabricate a high cell density elastic tissue mimetic.


Asunto(s)
Membranas/metabolismo , Microscopía Electrónica de Rastreo/métodos , Ingeniería de Tejidos/métodos , Tejido Adiposo/metabolismo , Materiales Biocompatibles/metabolismo , Células Cultivadas , Matriz Extracelular/metabolismo , Humanos , Nanofibras , Nanotecnología/métodos
14.
Small ; 10(7): 1308-13, 2014 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-24829962

RESUMEN

A novel opal closest-packing (OCP) photonic crystal (PC) is successfully prepared for naked-eye glucose detection. This PC is fabricated via a vertical convective self-assembly method with a new type of monodisperse microsphere polymerized by co-monomers, namely, methyl methacrylate (MMA), N-isopropylacrylamide (NIPA), and 3-acrylamidophenylboronic acid (AAPBA). The OCP PC has high stability and periodically-ordered structure, showing the desired structural color. The proposed PC material displays a red shift and reduced reflection intensity when detecting glucose molecules. The red-shift wavelength reaches 75 nm, which clearly changes the structural color from brilliant blue to emerald green. This visually distinguishable color change facilitates the detection of the glucose concentrations from 3 to 20 mm, which demonstrates the potential of the opal PC material for naked-eye detection. Thus, the novel PMMA­NIPA­AAPBA OCP PC is a simply prepared and sensitive material, which shows promising use in the diagnosis of diabetes mellitus and in real-time monitoring of diabetes. Different types of appropriated recognition groups are expected to be introduced into the 3D OCP PC to form new functional materials or chemical sensors, which will extensively broaden the PC material application.


Asunto(s)
Glucosa/análisis , Fotones , Acrilamidas/química , Ácidos Borónicos/química , Cristalización , Concentración de Iones de Hidrógeno , Iones , Metales/análisis , Microscopía Electrónica de Rastreo , Concentración Osmolar , Espectroscopía de Fotoelectrones , Polimetil Metacrilato/química , Reciclaje , Espectroscopía Infrarroja por Transformada de Fourier
15.
Macromol Rapid Commun ; 35(16): 1424-9, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24943122

RESUMEN

Supramolecular polymer networks have attracted considerable attention not only due to their topological importance but also because they can show some fantastic properties such as stimuli-responsiveness and self-healing. Although various supramolecular networks are constructed by supramolecular chemists based on different non-covalent interactions, supramolecular polymer networks based on multiple orthogonal interactions are still rare. Here, a supramolecular polymer network is presented on the basis of the host-guest interactions between dibenzo-24-crown-8 (DB24C8) and dibenzylammonium salts (DBAS), the metal-ligand coordination interactions between terpyridine and Zn(OTf)2 , and between 1,2,3-triazole and PdCl2 (PhCN)2 . The topology of the networks can be easily tuned from monomer to main-chain supramolecular polymer and then to the supramolecular networks. This process is well studied by various characterization methods such as (1) H NMR, UV-vis, DOSY, viscosity, and rheological measurements. More importantly, a supramolecular gel is obtained at high concentrations of the supramolecular networks, which demonstrates both stimuli-responsiveness and self-healing properties.


Asunto(s)
Geles/química , Polímeros/química , Complejos de Coordinación/química , Éteres Corona/química , Mesilatos/química , Paladio/química , Piridinas/química , Triazoles/química
16.
Int J Biol Macromol ; 259(Pt 2): 129355, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38218295

RESUMEN

Polylactide/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blends were compatibilized using dicumyl peroxide (DCP) and poly(ethylene glycol) 600 diacrylate (PEG600DA) through a one-step melt-blending process. The compatibility and performance of these blends were subsequently characterized. The results showed that grafts formed "in situ" effectively improved the compatibility and interfacial adhesion between PLA and PBAT phases. Melt viscosity and elasticity of both the PLA/PBAT/DCP and PLA/PBAT/DCP/PEG600DA blends evinced significant increases. Compared to PLA alone, both cold and melt crystallization abilities of the PLA/PBAT/DCP/PEG600DA blends were enhanced, with crystallinities increasing by 5 % - 10 %. Furthermore, the thermal stability, as well as hydrophobicity and oleophobicity of the compatibilized blends improved. In comparison with PLA, the elongation at break and notched impact strength for the PLA/PBAT/DCP/PEG600DA (60/40/0.1/4) blend achieved increases of 290 % and 44.23 kJ/m2, corresponding to improvements of 279 % and 1457 %, respectively. The toughening effect was substantially influenced by the ductile matrix (either a co-continuous phase or a flexible PBAT matrix) in addition to the strong interfacial adhesion and fine phase domain. These eco-friendly blends exhibit considerable potential for packaging articles and 3D printing products owing to their excellent mechanical properties and enhanced melt rheology.


Asunto(s)
Alquenos , Peróxidos , Ácidos Ftálicos , Poliésteres , Polietilenglicoles , Poliésteres/química , Adipatos/química
17.
J Imaging Inform Med ; 37(2): 611-619, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38343227

RESUMEN

Adult age estimation is one of the most challenging problems in forensic science and physical anthropology. In this study, we aimed to develop and evaluate machine learning (ML) methods based on the modified Gustafson's criteria for dental age estimation. In this retrospective study, a total of 851 orthopantomograms were collected from patients aged 15 to 40 years old. The secondary dentin formation (SE), periodontal recession (PE), and attrition (AT) of four mandibular premolars were analyzed according to the modified Gustafson's criteria. Ten ML models were generated and compared for age estimation. The partial least squares regressor outperformed other models in males with a mean absolute error (MAE) of 4.151 years. The support vector regressor (MAE = 3.806 years) showed good performance in females. The accuracy of ML models is better than the single-tooth model provided in the previous studies (MAE = 4.747 years in males and MAE = 4.957 years in females). The Shapley additive explanations method was used to reveal the importance of the 12 features in ML models and found that AT and PE are the most influential in age estimation. The findings suggest that the modified Gustafson method can be effectively employed for adult age estimation in the southwest Chinese population. Furthermore, this study highlights the potential of machine learning models to assist experts in achieving accurate and interpretable age estimation.

18.
Anal Chim Acta ; 1309: 342699, 2024 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-38772652

RESUMEN

Extracellular vesicles (EVs) are cell-released, nucleus-free particles with a double-membrane structure that effectively prevents degradation of internal components by a variety of salivary enzymes. Saliva is an easily accessible biofluid that contains a wealth of valuable information for disease diagnosis and monitoring and especially reflect respiratory and digestive tract diseases. However, the lack of efficient and high-throughput methods for proteomic analysis of salivary biomarkers poses a significant challenge. Herein, we designed a salivary EV amphiphile-dendrimer supramolecular probe (SEASP) array which enables efficient enrichment and in situ detection of EVs protein biomarkers. Detergent Tween-20 washing of SEASP arrays removes high abundance of heteroproteins from saliva well. This array shows good analytical performance in the linear range of 10 µL-150 µL (LOD = 0.4 µg protein, or 10 µL saliva), exhibiting a good recovery (80.0 %). Compared to ultracentrifugation (UC), this procedure provides simple and convenient access to high-purity EVs (1.3 × 109 particles per mg protein) with good physiological status and structure. Coupling with mass spectrometry based proteomic analysis, differentially expressed proteins as selected asthma biomarkers have been screened. Then, we validated the proteomics primary screening results through clinical samples (100 µL each) using the SEASP array. Utilizing the dual antibody fluorescence technology, SEASP enables the simultaneous high-throughput detection of two proteins. Therefore, the EVs marker protein CD81 could be used as an internal standard to normalize the number of EVs, which was stably expressed in EVs. Proteomics and array results suggested that HNRNPU (P = 4.9 * 10-6) and MUC5B (P = 4.7 * 10-11) are promising protein biomarkers for infantile asthma. HNRNPU and MUC5B may be associated with disease onset and subtypes. The SEASP arrays provide a significant advancement in the field of salivary biomarker. The array enables high-throughput in situ protein detection for highly viscous and complex biological samples. It provides a rapid, low-cost, highly specific screening procedure and experimental basis for early disease screening and diagnosis in the field of liquid biopsy.


Asunto(s)
Vesículas Extracelulares , Proteómica , Saliva , Saliva/química , Humanos , Vesículas Extracelulares/química , Vesículas Extracelulares/metabolismo , Proteómica/métodos , Biomarcadores/análisis , Ensayos Analíticos de Alto Rendimiento , Asma/diagnóstico , Asma/metabolismo
19.
ACS Biomater Sci Eng ; 10(5): 2805-2826, 2024 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-38621173

RESUMEN

Tissue engineering involves implanting grafts into damaged tissue sites to guide and stimulate the formation of new tissue, which is an important strategy in the field of tissue defect treatment. Scaffolds prepared in vitro meet this requirement and are able to provide a biochemical microenvironment for cell growth, adhesion, and tissue formation. Scaffolds made of piezoelectric materials can apply electrical stimulation to the tissue without an external power source, speeding up the tissue repair process. Among piezoelectric polymers, poly(vinylidene fluoride) (PVDF) and its copolymers have the largest piezoelectric coefficients and are widely used in biomedical fields, including implanted sensors, drug delivery, and tissue repair. This paper provides a comprehensive overview of PVDF and its copolymers and fillers for manufacturing scaffolds as well as the roles in improving piezoelectric output, bioactivity, and mechanical properties. Then, common fabrication methods are outlined such as 3D printing, electrospinning, solvent casting, and phase separation. In addition, the applications and mechanisms of scaffold-based PVDF in tissue engineering are introduced, such as bone, nerve, muscle, skin, and blood vessel. Finally, challenges, perspectives, and strategies of scaffold-based PVDF and its copolymers in the future are discussed.


Asunto(s)
Polivinilos , Ingeniería de Tejidos , Andamios del Tejido , Polivinilos/química , Andamios del Tejido/química , Ingeniería de Tejidos/métodos , Humanos , Impresión Tridimensional , Materiales Biocompatibles/química , Polímeros/química , Animales , Polímeros de Fluorocarbono
20.
Int J Biol Macromol ; 268(Pt 2): 131945, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38685544

RESUMEN

Hydroxypropyl cellulose (HPC) is a green thermochromic material in energy-saving buildings, anti-counterfeiting, and data security fields. However, the high lower critical solution temperature (LCST) of HPC, around 42 °C (higher than the human thermal comfort temperature), limits its thermochromic sensitivity, poor stability, and short lifespan. Herein, we developed a durable, high-performance cellulose-based thermochromic composite with a lower LCST and easy preparation capability by combining HPC with sodium carboxymethyl cellulose (CMC). In such thermochromic cellulose, CMC constructs a hydrophilic skeleton to enable uniform dispersion of HPC, and functions as a stronger competitor to attract the water molecules compared to HPC, both of which trigger high thermochromic sensitivity and low LCST (just 32.5 °C) of our CMC/HPC. In addition, CMC/HPC shows superior stability, such as 100-day working capability and 60-time recyclability. This advancement marks a significant step forward in creating sustainable, efficient thermochromic materials, offering new opportunities for energy conservation in the building.


Asunto(s)
Carboximetilcelulosa de Sodio , Celulosa , Temperatura , Carboximetilcelulosa de Sodio/química , Celulosa/química , Celulosa/análogos & derivados , Interacciones Hidrofóbicas e Hidrofílicas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA