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1.
Nanomedicine ; 32: 102323, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33186693

RESUMEN

Reconstituted high-density lipoproteins (rHDLs) hold promise as nanocarriers for atherosclerosis-targeted delivery, with biofunctions typified by mediating cholesterol efflux. The paradox is how rHDL offloads the delivered drugs into atherosclerotic foam cells, while simultaneously transferring cholesterol out of cells. Herein, simvastatin-loaded discoidal rHDL (ST-d-rHDL), constructed based on established paradigms, was employed to investigate its basic trafficking mechanism in foam cells. As proved, ST-d-rHDL was resecreted via lysosomal and Golgi apparatus-recycling endosome-mediated pathways following clathrin-mediated endocytosis. And the resecretion ratio reached 60% within 6-h chase with excessive ST-d-rHDLs. During the rHDL resecretion, 39% of cellular cholesterol efflux was detected, accompanied by 85% of the encapsulated cargo released intracellularly. Furthermore, the recycling rate was demonstrated to be promoted by smaller rHDL size and higher cellular lipid contents. Collectively, endocytic recycling confers the synergism in ST-d-rHDL to coordinate cholesterol efflux and intracellular drug release, providing new insights into design of biofunctional rHDL.


Asunto(s)
Colesterol/metabolismo , Endocitosis , Lipoproteínas HDL/química , Preparaciones Farmacéuticas/metabolismo , Simvastatina/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Endocitosis/efectos de los fármacos , Fluorescencia , Células Espumosas/citología , Células Espumosas/efectos de los fármacos , Espacio Intracelular/metabolismo , Liposomas/ultraestructura , Ratones , Tamaño de la Partícula , Células RAW 264.7 , Rodaminas/química
2.
Zhongguo Yi Liao Qi Xie Za Zhi ; 45(2): 119-124, 2021 Apr 08.
Artículo en Zh | MEDLINE | ID: mdl-33825367

RESUMEN

Effects of heat treatment conditions (including temperature and time) on the shape memory recovery and corrosion resistance of NiTi self-expanding vascular stents were studied based on working mechanism and clinical use. The Af temperature, dimensional recovery, crush resistance with radially applied load and point applied load of stents and corrosion resistance were characterized in diffident heat treatment conditions. The research results allow the conclusion that the stent treated at 500 ℃ for 10 min has optimum performance, and corrosion resistance meets the requirements.


Asunto(s)
Aleaciones , Calor , Corrosión , Ensayo de Materiales , Stents , Propiedades de Superficie , Temperatura , Titanio
3.
Mol Pharm ; 16(7): 2845-2857, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31244219

RESUMEN

To achieve efficient drug delivery to the posterior segment of the eye via topical instillation, novel multifunctional nanocomposites were prepared by hybridizing dexamethasone disodium phosphate (DEXP)-loaded liposome (LP) glycylsarcosine (GS)-anchored layered double hydroxides (named DEXP-HSPC@LDH-GS) and then fully characterized. The nanocomposites exhibited sustained-release performance as well as prolonged precorneal retention ability. MTT assays showed that the nanocomposites were not cytotoxic to both human corneal epithelial cells (HCEpiC) and human conjunctival epithelial cells (HConEpiC) at an LDH concentration of 100 µg/mL. The DEXP-HSPC@LDH-GS nanocomposites showed superior in vitro permeability on the HConEpiC-cell-based model. In the case of HConEpiC cells, both clathrin-mediated endocytosis and active transport by the peptide transporter-1 (PepT-1) were involved in the internalization of the nanocomposites. Fluorescent images of frozen sections of ocular tissues suggested that the possible route for the delivery of doxorubicin hydrochloride (DOX)-labeled nanocomposites from the ocular surface to the back of the eye was a non-corneal pathway. Furthermore, in rabbit eyes, the hybrid nanocomposites displayed markedly higher drug concentration in choroid-retina tissue than other single nanocarriers, such as LPs and LDH. Besides, the results of the eye irritancy test showed that nanocomposite eye drops can be classified as nonirritant, which are suitable to be used as eye drops. In a word, multifunctional nanocomposites based on LPs and LDH could be used as promising vehicles for efficient noninvasive drug delivery to the posterior segment of the eye.


Asunto(s)
Dipéptidos/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Hidróxidos/administración & dosificación , Nanocompuestos/química , Soluciones Oftálmicas/farmacocinética , Segmento Posterior del Ojo/efectos de los fármacos , Administración Tópica , Animales , Conjuntiva/citología , Dipéptidos/farmacocinética , Liberación de Fármacos , Células Epiteliales/efectos de los fármacos , Epitelio Corneal/citología , Humanos , Hidróxidos/farmacocinética , Liposomas , Masculino , Soluciones Oftálmicas/química , Permeabilidad/efectos de los fármacos , Conejos , Distribución Tisular
4.
J Nanobiotechnology ; 17(1): 86, 2019 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-31387581

RESUMEN

BACKGROUND: Controllable and multiple DNA release is critical in modern gene-based therapies. Current approaches require complex assistant molecules for combined release. To overcome the restrictions on the materials and environment, a novel and versatile DNA release method using a nano-electromechanical (NEMS) hypersonic resonator of gigahertz (GHz) frequency is developed. RESULTS: The micro-vortexes excited by ultra-high frequency acoustic wave can generate tunable shear stress at solid-liquid interface, thereby disrupting molecular interactions in immobilized multilayered polyelectrolyte thin films and releasing embedded DNA strands in a controlled fashion. Both finite element model analysis and experiment results verify the feasibility of this method. The release rate and released amount are confirmed to be well tuned. Owing to the different forces generated at different depth of the films, release of two types of DNA molecules with different velocities is achieved, which further explores its application in combined gene therapy. CONCLUSIONS: Our research confirmed that this novel platform based on a nano-electromechanical hypersonic resonator works well for controllable single and multi-DNA release. In addition, the unique features of this resonator such as miniaturization and batch manufacturing open its possibility to be developed into a high-throughput, implantable and site targeting DNA release and delivery system.


Asunto(s)
ADN/química , Nanoestructuras/química , Polielectrolitos/química , Acústica/instrumentación , Fenómenos Biofísicos , Diseño de Equipo , Análisis de Elementos Finitos , Técnicas de Transferencia de Gen , Terapia Genética/métodos , Membranas Artificiales , Propiedades de Superficie
5.
Drug Dev Ind Pharm ; 44(4): 544-552, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29130753

RESUMEN

The aim of the work presented is to prepare a controlled-release hydrophilic matrix tablet (CMT) controlling release of highly water-soluble drug applying pure combination of high- and low-Mw PEO as matrix materials, to avoid the lag time of drug release, and to overcome incomplete release in later stages. The influences of types and amounts of different Mw PEOs used, drug loading, pH of release medium and agitation rate on drug release were evaluated. The study of uptake and erosion of matrix was conducted and mechanism of improving drug release was discussed. In vivo pharmacokinetics of the CMT and reference preparation self-made controlled-release osmotic pump tablets (COPT) were performed in beagle dogs. The optimized formulation containing 43% PEO WSR 303 and 32% PEO N750 showed a zero order release from 1 h to 12 h. In vivo results demonstrated that the CMT had similar AUC0-48 h and Cmax with the COPT but smaller Tmax than the COPT and provided a more stable therapeutic concentration compared to the COPT. In conclusion, hydrophilic matrix tablet combining only different Mw PEOs as matrix materials had very good potential to be developed into a controlled-release drug delivery system for highly water-soluble drug. Besides, its manufacturing processes were succinct which would be preferable for modern medicine industry.


Asunto(s)
Preparaciones de Acción Retardada , Excipientes/química , Polietilenglicoles/química , Animales , Área Bajo la Curva , Preparaciones de Acción Retardada/farmacocinética , Perros , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Dureza , Concentración de Iones de Hidrógeno , Peso Molecular , Solubilidad , Comprimidos
6.
AAPS PharmSciTech ; 19(2): 700-709, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28971375

RESUMEN

The objective of this study was to develop an ocular drug delivery system built on the cationic liposomes, a novel bioadhesive colloidal system, which could enhance the precorneal residence time, ocular permeation, and bioavailability of ibuprofen. The optimal formulation of cationic liposomes prepared by ethanol injection method was ultimately confirmed by an orthogonal L9 (33) test design. In addition, γ-scintigraphic technology and the microdialysis technique were utilized in the assessment of in vivo precorneal retention capability and ocular bioavailability individually. In the end, we acquired the optimal formulation of ibuprofen cationic liposomes (Ibu-CL) by orthogonal test design, and the particle size and entrapment efficiency (EE%) were 121.0 ± 3.5 nm and 72.9 ± 3.4%, respectively. In comparison to ibuprofen eye drops (Ibu-ED), Ibu-CL could significantly prolong the T max to 100 min and the AUC to 1.53-folds, which indicated that the Ibu-CL could improve the precorneal retention time and bioavailability of ibuprofen. Consequently, these outcomes designated that the ibuprofen cationic liposomes we researched probably are a promising application in ocular drug delivery system.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Ibuprofeno/administración & dosificación , Ibuprofeno/farmacocinética , Soluciones Oftálmicas/administración & dosificación , Soluciones Oftálmicas/farmacocinética , Adhesivos/administración & dosificación , Adhesivos/farmacocinética , Animales , Disponibilidad Biológica , Cationes , Coloides , Liposomas , Tamaño de la Partícula , Conejos
7.
AAPS PharmSciTech ; 19(1): 242-250, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28695327

RESUMEN

The objective of this study was to investigate the fundamental properties of propranolol hydrochloride osmotic pump tablets coated by aqueous polymer dispersion, simultaneously exploring the in vitro and in vivo correlation of the tablet. The physicochemical properties and parameters of aqueous polymer dispersion membranes (SEM, water uptake, and water vapor transmission coefficient) were investigated. In addition, the release behavior and the in vitro release and in vivo absorption profiles of the tablets coated by aqueous polymer dispersion were investigated by comparing with propranolol hydrochloride osmotic pump tablets coated by an organic solvent. Results showed that the similarity factor (f 2) between cellulose acetate-coated tablet and Eudragit-coated tablet was 78.1, and f 2 between cellulose acetate-coated tablet and Kollicoat-coated tablet was 77.6. The linear IVIVC of Eudragit-coated and Kollicoat-coated osmotic pump tablets was determined, which confirmed excellent correlation between the absorption in vivo and the drug release in vitro. Consequently, the membrane coated by aqueous polymer dispersion or organic solvent has similar in vitro release rates of controlled release. Also, compared with organic solvent coating, aqueous polymer dispersion has numerous advantages, such as reduced toxicity and no environmental damage. Therefore, the aqueous polymer dispersion technology has enormous potential as a replacement of organic solvent coating.


Asunto(s)
Comprimidos/química , Animales , Celulosa/análogos & derivados , Celulosa/química , Perros , Liberación de Fármacos , Excipientes/química , Ósmosis , Polímeros/química , Ácidos Polimetacrílicos/química , Propranolol/química , Solubilidad , Solventes/química , Agua/química
8.
Fungal Genet Biol ; 108: 36-43, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28927934

RESUMEN

Annexins are calcium-phospholipid binding proteins that play a significant role in the Ca2+signaling pathway. These proteins are essential for plants to effectively respond to abiotic stresses. However, their functions and mechanisms remain largely unknown in fungi. In this study, an annexin gene, Epann, was cloned from the lichenized fungus Endocarpon pusillum, a drought resistant organism. Our results showed that Epann was induced by several abiotic stresses in E. pusillum. Heterologous expression of the Epann gene enhanced the stress tolerance of Saccharomyces cerevisiae. Under heat-shock conditions, the EpANN proteins were significantly aggregated and the aggregation sites were located on peroxisomes. In heat-shocked cells, Epann reduced the reactive oxygen species level mainly through its intracellular peroxidase activity and regulation of stress-related genes. Transgenic Arabidopsis plants overexpressing Epann exhibited a higher germination rate under oxidative stress and stronger drought tolerance. Our results provide a mechanistic understanding of the role of annexins in abiotic stress responses and suggest that this lichenized fungal gene could be a promising resource to generate stress-tolerant transgenic organisms.


Asunto(s)
Anexinas/genética , Ascomicetos/genética , Proteínas Fúngicas/genética , Anexinas/fisiología , Arabidopsis/genética , Arabidopsis/fisiología , Ascomicetos/fisiología , Clonación Molecular , Regulación Fúngica de la Expresión Génica , Respuesta al Choque Térmico/genética , Líquenes , Estrés Oxidativo , Plantas Modificadas Genéticamente , Polietilenglicoles/farmacología , Especies Reactivas de Oxígeno/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiología , Cloruro de Sodio/farmacología , Simbiosis , Activación Transcripcional/efectos de los fármacos
9.
J Am Chem Soc ; 138(13): 4626-33, 2016 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-26974858

RESUMEN

(S)-3,4-Dihydroxybutyric acid ((S)-3,4-DHBA), an endogenous straight chain fatty acid, is a normal human urinary metabolite and can be obtained as a valuable chiral biomass for synthesizing statin-class drugs. Hence, its epoxide derivatives should serve as promising monomers for producing biocompatible polymers via alternating copolymerization with carbon dioxide. In this report, we demonstrate the production of poly(tert-butyl 3,4-dihydroxybutanoate carbonate) from racemic-tert-butyl 3,4-epoxybutanoate (rac-(t)Bu 3,4-EB) and CO2 using bifunctional cobalt(III) salen catalysts. The copolymer exhibited greater than 99% carbonate linkages, 100% head-to-tail regioselectivity, and a glass-transition temperature (Tg) of 37 °C. By way of comparison, the similarly derived polycarbonate from the sterically less congested monomer, methyl 3,4-epoxybutanoate, displayed 91.8% head-to-tail content and a lower Tg of 18 °C. The tert-butyl protecting group of the pendant carboxylate group was removed using trifluoroacetic acid to afford poly(3,4-dihydroxybutyric acid carbonate). Depolymerization of poly(tert-butyl 3,4-dihydroxybutanoate carbonate) in the presence of strong base results in a stepwise unzipping of the polymer chain to yield the corresponding cyclic carbonate. Furthermore, the full degradation of the acetyl-capped poly(potassium 3,4-dihydroxybutyrate carbonate) resulted in formation of the biomasses, ß-hydroxy-γ-butyrolacetone and 3,4-dihydroxybutyrate, in water (pH = 8) at 37 °C. In addition, water-soluble platinum-polymer conjugates were synthesized with platinum loading of 21.3-29.5%, suggesting poly(3,4-dihydroxybutyric acid carbonate) and related derivatives may serve as platinum drug delivery carriers.


Asunto(s)
Butileno Glicoles/química , Butiratos/química , Dióxido de Carbono/química , Compuestos Organoplatinos/química , Platino (Metal)/química , Cemento de Policarboxilato/química , Polímeros/química , Carbonatos , Catálisis , Cobalto/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Compuestos Epoxi/química , Etilenodiaminas , Humanos , Estructura Molecular , Polimerizacion , Agua
10.
J Nanosci Nanotechnol ; 16(3): 2343-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27455639

RESUMEN

A two-step method for preparing Au@polypyrrole-chitosan core-shell nanoparticles (Au @ PPy-CS NPs) was fabricated by in situ polymerization of pyrrole monomer on the surface of Au spheres in chitosan solution. Transmission electron microscopy (TEM) images showed the presence of core-shell structure of nanoparticles. Energy-Dispersive Spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy were adopted to verify the shell is polypyrrole-chitosan. Ultraviolet-visible (UV-vis) and X-ray diffraction (XRD) showed that Au was present in the core-shell nanoparticles. The biocompatibility of Au @ PPy-CS NPs was characterized by in vitro for hemolysis assay and cytotoxicity experiments. Results indicated the Au @ PPy-CS NPs had good blood compatibility and low cytotoxicity. The Au @ PPy-CS NPs we proposed provide a promising platform of blood circulation system for early illness diagnosis and therapy.


Asunto(s)
Materiales Biocompatibles , Quitosano/química , Oro/química , Nanoestructuras , Polímeros/química , Pirroles/química , Animales , Microscopía Electrónica de Transmisión , Conejos , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
11.
J Prosthet Dent ; 111(1): 51-5, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24161258

RESUMEN

STATEMENT OF PROBLEM: Limited information is available regarding the microstructure and mechanical properties of dental alloy fabricated by selective laser melting (SLM). PURPOSE: The purpose of this study was to evaluate the mechanical properties of a cobalt-chromium (Co-Cr) dental alloy fabricated by SLM and to determine the correlation between its microstructure and mechanical properties and its porcelain bond strength. MATERIAL AND METHODS: Five metal specimens and 10 metal ceramic specimens were fabricated to evaluate the mechanical properties of SLM Co-Cr dental alloy (SLM alloy) with a tensile test and its porcelain bond strength with a 3-point bending test. The relevant properties of the SLM alloy were compared with those of the currently used Co-Cr dental alloy fabricated with conventional cast technology (cast alloy). The Student t test was used to compare the results of the SLM alloy and the cast alloy (α=.05). The microstructure of the SLM alloy was analyzed with a metallographic microscope; the metal ceramic interface of the SLM porcelain bonded alloy was studied with scanning electron microscopy, energy dispersive x-ray spectroscopy, and an electron probe microanalyzer. RESULTS: Both the mean (standard deviation) yield strength (884.37 ± 8.96 MPa) and tensile strength (1307.50 ±10.65 MPa) of the SLM alloy were notably higher than yield strength (568.10 ± 30.94 MPa) and tensile strength (758.73 ± 25.85 MPa) of the currently used cast alloy, and the differences were significant (P<.05). The porcelain bond strength of the SLM alloy was 55.78 ± 3.02 MPa, which was similar to that of the cast alloy, 54.17 ± 4.96 MPa (P>.05). Microstructure analysis suggested that the SLM alloy had a dense and obviously orientated microstructure, which led to excellent mechanical properties. Analysis from scanning electron microscopy, energy dispersive x-ray spectroscopy, and the electron probe microanalyzer indicated that the SLM alloy had an intermediate layer with elemental interpenetration between the alloy and the porcelain, which resulted in an improved bonding interface. CONCLUSIONS: Compared with the currently used cast alloy, SLM alloy possessed improved mechanical properties and similar porcelain bond strength.


Asunto(s)
Aleaciones de Cromo/química , Recubrimiento Dental Adhesivo , Porcelana Dental/química , Rayos Láser , Aleaciones de Cerámica y Metal/química , Óxido de Aluminio/química , Revestimiento para Colado Dental/química , Grabado Dental/métodos , Microanálisis por Sonda Electrónica/instrumentación , Humanos , Ensayo de Materiales , Fenómenos Mecánicos , Metalurgia , Microscopía Electrónica de Rastreo , Docilidad , Espectrometría por Rayos X , Estrés Mecánico , Propiedades de Superficie , Resistencia a la Tracción
12.
Int J Nanomedicine ; 19: 4377-4409, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38774029

RESUMEN

Angiogenesis, or the formation of new blood vessels, is a natural defensive mechanism that aids in the restoration of oxygen and nutrition delivery to injured brain tissue after an ischemic stroke. Angiogenesis, by increasing vessel development, may maintain brain perfusion, enabling neuronal survival, brain plasticity, and neurologic recovery. Induction of angiogenesis and the formation of new vessels aid in neurorepair processes such as neurogenesis and synaptogenesis. Advanced nano drug delivery systems hold promise for treatment stroke by facilitating efficient transportation across the the blood-brain barrier and maintaining optimal drug concentrations. Nanoparticle has recently been shown to greatly boost angiogenesis and decrease vascular permeability, as well as improve neuroplasticity and neurological recovery after ischemic stroke. We describe current breakthroughs in the development of nanoparticle-based treatments for better angiogenesis therapy for ischemic stroke employing polymeric nanoparticles, liposomes, inorganic nanoparticles, and biomimetic nanoparticles in this study. We outline new nanoparticles in detail, review the hurdles and strategies for conveying nanoparticle to lesions, and demonstrate the most recent advances in nanoparticle in angiogenesis for stroke treatment.


Asunto(s)
Accidente Cerebrovascular Isquémico , Nanopartículas , Neovascularización Fisiológica , Humanos , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Animales , Nanopartículas/química , Neovascularización Fisiológica/efectos de los fármacos , Barrera Hematoencefálica/efectos de los fármacos , Liposomas/química , Sistemas de Liberación de Medicamentos/métodos , Sistema de Administración de Fármacos con Nanopartículas/química , Angiogénesis
13.
Nutrients ; 15(14)2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37513507

RESUMEN

The underlying mechanisms of the relationship between the number of teeth and cognition is still unclear. We aimed to construct a mediation model between the number of residual teeth and cognitive function, using nutritional status as a mediating factor. This study was completed using the West China Health and Aging Trend cohort. A total of 6634 multi-ethnic older adults, aged 50 years or older, were included. This study measured cognitive function using the Short-Portable Mental Status Questionnaire, and nutritional status was assessed using the Mini Nutritional Assessment-Short Form. The mediation analysis examined the potential mediating role of nutritional status. The pathway analysis was supplemented and validated using the structural equation modelling framework. Multiple linear regression demonstrated that a higher number of residual teeth was correlated with enhanced cognitive function (ß = -0.15; 95% CI: -0.19 to -0.111). The mediation model, from the number of residual teeth to cognitive impairment, was partially mediated by nutritional status (ß = -0.0608; 95% CI: -0.0762 to -0.0461). The proportion of the mediating effect, expressed as a percentage, was 40.66%. Furthermore, the estimated coefficients for the number of residual teeth and nutritional status varied across ethnic groups. This study indicated that enhancing the nutrition of older adults could reduce the adverse effects of the number of residual teeth on cognitive function among older adults.


Asunto(s)
Cognición , Estado Nutricional , Diente , Estudios Transversales , Evaluación Nutricional , Disfunción Cognitiva , Análisis de Mediación , Trastornos Nutricionales/complicaciones , Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años
14.
Elife ; 112022 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-35142290

RESUMEN

Hereditary gingival fibromatosis (HGF) is the most common genetic form of gingival fibromatosis which is featured as a localized or generalized overgrowth of gingivae. Currently two genes (SOS1 and REST), as well as four loci (2p22.1, 2p23.3-p22.3, 5q13-q22, and 11p15), have been identified as associated with HGF in a dominant inheritance pattern. Here, we report 13 individuals with autosomal-dominant HGF from a four-generation Chinese family. Whole-exome sequencing followed by further genetic co-segregation analysis was performed for the family members across three generations. A novel heterozygous missense mutation (c.2812G > A) in zinc finger protein 862 gene (ZNF862) was identified, and it is absent among the population as per the Genome Aggregation Database. The functional study supports a biological role of ZNF862 for increasing the profibrotic factors particularly COL1A1 synthesis and hence resulting in HGF. Here, for the first time we identify the physiological role of ZNF862 for the association with the HGF.


Asunto(s)
Fibromatosis Gingival/genética , Predisposición Genética a la Enfermedad , Proliferación Celular , Regulación hacia Abajo , Femenino , Fibromatosis Gingival/patología , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Pruebas Genéticas , Humanos , Masculino , Mutación , Linaje , Interferencia de ARN , Análisis de Secuencia de ARN , Regulación hacia Arriba
15.
Nat Commun ; 13(1): 7138, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36414665

RESUMEN

The process of recycling poly(ethylene terephthalate) (PET) remains a major challenge due to the enzymatic degradation of high-crystallinity PET (hcPET). Recently, a bacterial PET-degrading enzyme, PETase, was found to have the ability to degrade the hcPET, but with low enzymatic activity. Here we present an engineered whole-cell biocatalyst to simulate both the adsorption and degradation steps in the enzymatic degradation process of PETase to achieve the efficient degradation of hcPET. Our data shows that the adhesive unit hydrophobin and degradation unit PETase are functionally displayed on the surface of yeast cells. The turnover rate of the whole-cell biocatalyst toward hcPET (crystallinity of 45%) dramatically increases approximately 328.8-fold compared with that of purified PETase at 30 °C. In addition, molecular dynamics simulations explain how the enhanced adhesion can promote the enzymatic degradation of PET. This study demonstrates engineering the whole-cell catalyst is an efficient strategy for biodegradation of PET.


Asunto(s)
Ácidos Ftálicos , Tereftalatos Polietilenos , Tereftalatos Polietilenos/metabolismo , Hidrolasas/metabolismo , Ácidos Ftálicos/metabolismo , Etilenos
16.
Biomacromolecules ; 12(3): 551-9, 2011 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-21294539

RESUMEN

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a biodegradable polyester, has been a good candidate of biomaterial employed in tissue engineering. However, the PHBV film is hydrophobic and has no recognition sites for cell attachment. In this study, PHBV films are activated by ammonia plasma treatment to produce amino groups on the surface, followed by sequential reactions with a heterobifunctional cross-linker containing a segment of poly(ethylene glycol) (PEG) and further with RGD-containing peptides. XPS analyses of modified surfaces after each reaction step reveal that the RGD-containing peptides have been covalently grafted onto PHBV films. The result of cell viability assay indicates that the RGD-modified PHBV films exhibit a distinctly improved cellular compatibility. Moreover, according to the results of serum adsorption tests by optical waveguide lightmode spectroscopy (OWLS) and fibrinogen adsorption tests by enzyme-linked immunosorbent assay (ELISA) on unmodified and modified PHBV surfaces, the introduced PEG chains can significantly decrease the nonspecific adsorption of proteins from serum and fibrinogen from plasma, thus decreasing the risk of thrombus formation and improving the blood compatibility of implanted materials.


Asunto(s)
Materiales Biocompatibles/síntesis química , Oligopéptidos/química , Poliésteres/química , Polietilenglicoles/química , Adsorción , Materiales Biocompatibles/farmacocinética , Proteínas Sanguíneas/metabolismo , Reactivos de Enlaces Cruzados , Humanos , Unión Proteica/efectos de los fármacos , Trombosis/inducido químicamente
17.
J Int Med Res ; 49(12): 3000605211065370, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34939439

RESUMEN

Plastic bronchitis (PB) is a rare and potentially fatal disease characterized by acute progressive dyspnea caused by bronchial casts in the bronchial tree. We analyzed two children with asthma and PB who presented with high fever, cough and dyspnea. Both cases showed acute onset and rapid disease progression. Laboratory examination revealed that both children were infected with influenza A virus. Emergency fiberoptic bronchoscopy was performed within 20 hours of admission. Immediately after removing the bronchial casts, their dyspnea symptoms improved significantly, and they recovered after comprehensive treatment with antiviral drugs, antibiotics and glucocorticoids. When children with asthma have acute progressive and difficult-to-relieve dyspnea after infection with influenza A virus, clinicians should be aware of the possibility of PB and perform bronchoscopy as soon as possible to facilitate early diagnosis and treatment and improve patient prognosis.


Asunto(s)
Asma , Bronquitis , Virus de la Influenza A , Gripe Humana , Asma/complicaciones , Asma/tratamiento farmacológico , Bronquitis/complicaciones , Bronquitis/diagnóstico , Bronquitis/tratamiento farmacológico , Broncoscopía , Niño , Humanos , Gripe Humana/complicaciones , Gripe Humana/diagnóstico , Gripe Humana/tratamiento farmacológico , Plásticos
18.
Sci Total Environ ; 753: 142064, 2021 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-32911172

RESUMEN

The cotransport behaviors of colloidal polystyrene microplastic particles (PSMPs) and tetracycline (TC) (20 mg/L) were investigated in saturated porous media in KCl and CaCl2 solutions of various ionic strengths (1, 10, 50, 100 mM). Furthermore, the effects of TC concentration (0, 1, 5, 10, 20 mg/L) on the cotransport behaviors of PSMPs and TC in 100 mM KCl solution were assessed. The cotransport behaviors were analyzed by comparing the individual transport behaviors of PSMPs or TC. When cotransported, the presence of TC (20 mg/L) slightly inhibited PSMPs mobility in K+ solutions (the C/C0 decreased in the range of 0-5.9%), but facilitated it in Ca2+ solutions (the C/C0 increased in the range of 6.7-42.6%). In KCl solutions, although the presence of TC (PSMPs) did not significantly affect the transport behaviors of PSMPs (TC), the attachment efficiencies of both PSMPs and TC showed a non-linear and non-monotonic change with increase in ionic strength. However, in CaCl2 solutions, the effects of TC (PSMPs) on the transport behaviors of PSMPs (TC) were remarkable and a non-linear non-monotonic change was observed. The adsorption of TC on PSMPs might play a critical role during the cotransport. Thus, the balance between the transport-inhibiting (e.g., the reduction in electrostatic repulsive force) and transport-facilitating effects (e.g., the effects on hydrophilicity/hydrophobicity of PSMPs due to TC adsorption) may be responsible for the observed changes. Overall, the results demonstrated that the cotransport behaviors of PSMPs and TC were more complicated than their individual transport behaviors in porous media, which might vary considerably with environmental conditions. This work could greatly improve our understanding of complex cotransport behaviors and environmental risk of PSMPs.


Asunto(s)
Microplásticos , Poliestirenos , Concentración Osmolar , Plásticos , Porosidad
19.
Langmuir ; 26(12): 10025-30, 2010 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-20491465

RESUMEN

An assay triggered by recognition-induced charge switching is developed for protein detection and quantification. Aptamer-functionalized silica nanoparticles (NPs) have been synthesized to capture lysozyme, resulting in an alternation of the surface charge from negative to partially positive. The binding event is then translated and monitored by the fluorescence signal of a highly fluorescent anionic poly(fluorene-alt-vinylene) (PFVSO(3)), which "stains" on protein/aptamer-NP complexes via electrostatic interaction. Blue-greenish fluorescence of PFVSO(3) is observed in the presence of lysozyme by the naked eye, while no fluorescence is obtained for NPs upon treatment with a mixture of foreign proteins. A linear relationship between NP fluorescence and lysozyme is observed in the concentration range of 0-22.5 microg/mL, which gives a limit of detection as approximately 0.36 microg/mL. This work demonstrates a convenient label-free conjugated polyelectrolyte (CPE)-based protein detection with high specificity and sensitivity, which has potential applications in medical diagnosis.


Asunto(s)
Aptámeros de Péptidos , Muramidasa/análisis , Nanopartículas/química , Polímeros/química , Proteínas , Sensibilidad y Especificidad , Dióxido de Silicio
20.
Sci Total Environ ; 709: 136138, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-31887523

RESUMEN

Polyethylene terephthalate (PET) is one of the most widely used plastics in the world. Accumulation of the discarded PET in the environment is creating a global environmental problem. Recently, a bacterial enzyme named PETase was found to have the novel ability to degrade the highly crystallized PET. However, the enzymatic activity of native PETase is still low limiting its possible use in recycling of PET. In this study, we developed a whole-cell biocatalyst by displaying PETase on the surface of yeast (Pichia pastoris) cell to improve its degradation efficiency. Our data shows that PETase could be functionally displayed on the yeast cell with enhanced pH and thermal stability. The turnover rate of the PETase-displaying yeast whole-cell biocatalyst towards highly crystallized PET dramatically increased about 36-fold compared with that of purified PETase. Furthermore, the whole-cell biocatalyst showed stable turnover rate after seven repeated use and under some chemical/solvent conditions, and its ability to degrade different commercial highly crystallized PET bottles. Our results reveal that PETase-displaying whole-cell biocatalyst affords a promising route for efficient biological recycling of PET.


Asunto(s)
Tereftalatos Polietilenos/química , Bacterias , Biodegradación Ambiental , Hidrolasas , Plásticos
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