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1.
Environ Res ; 239(Pt 1): 117345, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37821065

RESUMEN

Owing to accelerated urbanization and industrialization, many plastic products have been manufactured and discharged into the environment, causing environmental and public health problems. Plastics in environmental media are further degraded by prolonged exposure to light, heat, mechanical friction, and other factors to form new pollutants called microplastics (MPs). Medical plastics have become a crucial source of plastics in environmental media. However, the release profiles of MPs from medical plastics and their potential ecological and health risks remain unclear. We used optical photothermal infrared spectroscopy to explore the release profiles of eight typical disposable medical devices under high-temperature steam disinfection (HSD). We also evaluated the toxicity of disposable medical devices-derived MPs in Caenorhabditis elegans (C. elegans). Our results showed that the changes in the surface morphology and modification of the disposable medical devices were mainly associated with the material. Polypropylene (PP) and polystyrene (PS) materials exhibited high aging phenomena (e.g., bumps, depressions, bulges and cracks), and HSD broke their oxygen-containing functional groups and carbon chains. By contrast, minor changes in the chemical and physical properties were observed in the polyvinyl chloride (PVC)-prepared disposable medical devices under the same conditions. Further physicochemical characterization indicated that the amount of MPs released from PP-prepared disposable medical devices (P4: 1.27 ± 0.34 × 106) was greater than that from PVC-prepared disposable medical devices (P7: 1.08 ± 0.14 × 105). The particle size of the released MPs was the opposite, PVC-prepared disposable medical devices (P7: 11.45 ± 1.79 µm) > PP-prepared disposable medical devices (P4: 7.18 ± 0.52 µm). Toxicity assessment revealed that disposable medical devices-released MPs significantly increased germ cell apoptosisin C. elegans. Moreover, MPs from PP-prepared disposable medical devices disrupted the intestinal barrier of worms, decreasing their lifespan. Our findings provided novel information regarding the profiles and mechanisms of MP release from disposable medical devices and revealed their potential risks to ecological environment.


Asunto(s)
Microplásticos , Plásticos , Animales , Microplásticos/toxicidad , Caenorhabditis elegans , Polipropilenos , Carbono
2.
Int J Mol Sci ; 24(24)2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38139049

RESUMEN

Microplastics (MPs) are emerging pollutants and pose a significant threat to marine ecosystems. Although previous studies have documented the mechanisms and toxic effects of aging MPs in various environments, the impact of the marine environment on MPs remains unclear. In the present study, the aging process of polystyrene (PS) in seawater was simulated and the changes in its physicochemical properties were investigated. Our results showed that the surface of the PS eroded in the seawater, which was accompanied by the release of aged MPs with a smaller size. In situ optical photothermal infrared microspectroscopy revealed that the mechanism of PS aging was related to the opening of the carbonyl group and breaking of the bond between carbon and benzene removal. To verify the toxic effects of aged PS, Caenorhabditis elegans was exposed to PS. Aged PS resulted in a greater reduction in locomotion, vitality, and reproduction than virgin PS. Mechanistically, aged PS led to oxidative stress, high glutathione s-transferase activity, and high total glutathione in worms. Together, our findings provided novel information regarding the accelerated aging of PS in seawater and the increased toxicity of aged PS, which could improve our understanding of MPs' ecotoxicity in the marine environment.


Asunto(s)
Poliestirenos , Contaminantes Químicos del Agua , Animales , Poliestirenos/toxicidad , Poliestirenos/química , Plásticos , Caenorhabditis elegans , Ecosistema , Microplásticos/química , Envejecimiento , Agua de Mar/química
3.
Bioconjug Chem ; 31(5): 1474-1485, 2020 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-32286806

RESUMEN

Exploring a combined phototherapeutic strategy to overcome the limitations of a single mode therapy and inducing high anticancer efficiency is highly promising for precision cancer nanomedicine. However, a single-wavelength laser activates dual photothermal/photodynamic therapy (PTT/PDT) treatment is still a formidable challenge. Herein, we strategically design and fabricate a multifunctional theranostic nanosystem based on chlorin e6-functionalized polydopamine (PDA) coated prussian blue/manganese dioxide nanoparticles (PB-MnO2@PDA-Ce6 NPs). Interestingly, the obtained PB-MnO2@PDA NPs not only offer an effective delivery system for Ce6 but also provide strong optical absorption in the near-infrared range, endowing high antitumor efficacy of PTT. More importantly, the as-prepared PB-MnO2@PDA-Ce6 nanoagents exhibit an effective oxygen generation, superior reactive oxygen species (ROS), and outstanding photothermal conversion ability to greatly improve PTT and PDT treatments. As a result, both in vitro and in vivo treatments guided by MR imaging on liver cancer cells reveal the complete cell/tumor eradication under a single wavelength of 660 nm laser irradiation, implying the simultaneous synergistic PDT/PTT effects triggered by PB-MnO2@PDA-Ce6 nanoplatform, which are much higher than individual treatment. Taken together, our phototherapeutic nanoagents exhibit an excellent therapeutic performance, which may act as a nanoplatform to find safe and clinically translatable routes to accelerate cancer therapeutics.


Asunto(s)
Ferrocianuros/química , Indoles/química , Rayos Infrarrojos , Compuestos de Manganeso/química , Nanopartículas/química , Óxidos/química , Oxígeno/metabolismo , Fotoquimioterapia/métodos , Polímeros/química , Línea Celular Tumoral , Diseño de Fármacos , Humanos , Indoles/farmacología , Rayos Láser , Polímeros/farmacología
4.
J Environ Sci (China) ; 69: 217-226, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29941257

RESUMEN

As well-known persistent organic pollutants (POPs), organofluorine pollutants such as perfluorooctane sulfonate (PFOS) have been proven to be bioaccumulated and harmful to health. However, toxicological assessment of organofluorinated nanoparticles, which have emerged as a novel tool for biomedical and industrial applications, is lacking, to the best of our knowledge. To assess the biological effects and health risk of fluorinated nanoparticles, trifluoroethyl aryl ether-based fluorinated poly(methyl methacrylate) nanoparticles (PTFE-PMMA NPs) were synthesized with various fluorine contents (PTFE-PMMA-1 NPs 12.0wt.%, PTFE-PMMA-2 NPs 6.1wt.% and PTFE-PMMA-3 NPs 5.0wt.%), and their cytotoxicity was investigated in this study. The in vitro experimental results indicated that the cytotoxicity of PTFE-PMMA NPs was mild, and was closely related to their fluorine (F) contents and F-containing side chains. Specifically, the cytotoxicity of PTFE-PMMA NPs decreased with increasing F content and F-containing side chains. After exposure to PTFE-PMMA NPs at a sublethal dose (50µg/mL) for 24hr, the phospholipid bilayer was damaged, accompanied by increasing permeability of the cell membrane. Meanwhile, the intracellular accumulation of reactive oxygen species (ROS) occurred, resulting in the increase of DNA damage, cell cycle arrest and cell death. Overall, the PTFE-PMMA NPs were found to be relatively safe compared with typical engineered nanomaterials (ENMs), such as silver nanoparticles and graphene oxide, for biomedical and industrial applications.


Asunto(s)
Polímeros de Fluorocarbono/toxicidad , Nanopartículas del Metal/toxicidad , Nanopartículas/toxicidad , Pruebas de Toxicidad , Ácidos Alcanesulfónicos/toxicidad , Muerte Celular , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Fluorocarburos/toxicidad , Nanopartículas del Metal/química , Polimetil Metacrilato/toxicidad , Especies Reactivas de Oxígeno
5.
Environ Pollut ; 341: 123012, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38008254

RESUMEN

Microplastics (MPs) refer to plastic particles with a size less than 5 mm, which attracted widespread attention as an emerging pollutant. The monitoring of atmospheric microplastics (AMPs) in a megacity was carried out to study the characteristics and spatiotemporal distribution of AMPs, explore the sources and estimate the deposition flux. The results showed that the annual average abundance of AMPs in Wuhan was 82.85 ± 57.66 n·m-2·day-1. The spatiotemporal distribution characteristics of AMPs show that spring was the highest season, followed by autumn, winter, and summer; the city center was higher than the suburbs. Fiber was the main type of AMPs in Wuhan, followed by fragment, film and pellet. The proportion of AMPs were mainly small (<0.5 mm) and medium (0.5-1.0 mm). Transparent and white were the main colors of AMPs, followed by red, brown. A total of 10 types polymers were detected, polyethylene terephthalate (PET) was dominant. There are positive correlations between AMPs and SO2, NO2 in the atmosphere, indicating that they might be influenced by intense human activity. The polycyclic aromatic hydrocarbons (PAHs) and AMPs in spring showed an extremely significant positive correlation (p < 0.05). AMPs might mainly originate from the wear and tear shedding of textiles, the aging of agricultural films and plastic waste based on their polymer types and main uses. The potential geographical sources of AMPs were mainly the surrounding cities. The annual deposition flux of AMPs was about 308 tons if there were no remove processes, which highlighted the importance of atmospheric transport and deposition of MPs. The analysis of the abundance, morphological characteristics and sources of AMPs can provide data support and reference for mega-cities with high global population activities, or cities in global mid-latitude regions.


Asunto(s)
Contaminantes Atmosféricos , Contaminantes Químicos del Agua , Humanos , Microplásticos/análisis , Plásticos , Ciudades , Monitoreo del Ambiente/métodos , Contaminantes Atmosféricos/análisis , Contaminantes Químicos del Agua/análisis
6.
Chemosphere ; 316: 137864, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36642129

RESUMEN

The pollution of microplastics (MPs) and polycyclic aromatic hydrocarbons (PAHs) in the environment is a global problem, which has attracted extensive attention of many researchers. In present study, MPs and PAHs are investigated to study the impact of human activities and their possible relationship in China's second largest urban lake, East Lake. The abundance of MPs are 3329.19 ± 2059.26 particles/m3 and 2207.56 ± 1194.04 particles/kg in water and sediment, respectively. MPs are predominantly characterized by fibers, polypropylene (PP) and polyethylene (PE), colorlessness in water and sediment. The abundance of MPs in water with frequent human activities is higher, which is reversed in sediments, indicating that disturbance is not conducive to the enrichment of MPs in sediments. The concentration of 16 PAHs are 36.95 ± 13.76 ng/L and 897.08 ± 232.34 ng/g in water and sediment, respectively. PAHs in water are mainly 2-3-ring, while there are 4-ring PAHs in sediments. The good corresponding relationship between MPs and PAHs indicates that human activities have an important impact on the distribution of pollutants compared to the interaction of pollutants. In addition, the significant positive correlation between lakeshore length and water MPs abundance indicates that surface runoff may be an important source of water MPs. The pollution load index shows that MPs in sediment has reached moderate to severe pollution level, while the water is slightly polluted level. The potential ecological risk assessment results show that more than half of the sediment sites are at dangerous to very dangerous ecological risk level.


Asunto(s)
Contaminantes Ambientales , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Humanos , Microplásticos , Plásticos , Monitoreo del Ambiente/métodos , Hidrocarburos Policíclicos Aromáticos/análisis , Lagos , Contaminantes Químicos del Agua/análisis , Sedimentos Geológicos , China , Agua , Medición de Riesgo
7.
Environ Sci Pollut Res Int ; 29(11): 16324-16331, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34651267

RESUMEN

Silver nanoparticles (AgNPs) and heavy metals are considered to coexist in the environment. Increasing evidence shows that AgNPs can interact with heavy metals; however, the impact of distinct exposure conditions on their combined toxicity is still largely unknown. Here, we investigated the co-effects of AgNPs and heavy metals, including arsenic (As), cadmium (Cd), and nickel (Ni), in target cell lines. The results demonstrated that pretreated with polyvinylpyrrolidone-coated (PVP-coated) AgNPs at noncytotoxic concentrations significantly inhibited the cytotoxicity of As and Cd in human-hamster hybrid AL cells, but had slight effect on the toxicity of Ni. The antagonistic effects have also been observed in other non-cancerous cell lines, such as Chinese hamster ovary (CHO) cells, mouse embryonic fibroblasts (MEFs), and human normal liver (LO2) cells. In addition, the co-effects between AgNPs and heavy metals are independent of surface coatings of AgNPs. Our data revealed that the combined biological effects of AgNPs and heavy metals are closely related to the physicochemical properties of heavy metals themselves and the tested cell lines.


Asunto(s)
Nanopartículas del Metal , Metales Pesados , Animales , Células CHO , Cricetinae , Cricetulus , Fibroblastos , Nanopartículas del Metal/toxicidad , Ratones , Povidona , Plata
8.
Environ Pollut ; 307: 119500, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35667519

RESUMEN

Microplastics (MPs) pollution in Tangxun Lake, the largest urban lake in China, was investigated. The average MPs pollution in sediment (1.81 ± 1.75 × 104 items kg-1) is at a high level, while the MPs in lakeshore water (917.77 ± 742.17 items m-3) is in the middle to low level compared with existing studies, which is related to the government's protection. Fragments and fibers are the most common shapes in sediment and water, respectively. MPs size <1 mm dominates in the sediment, while the MPs in water has a larger size. The distribution of MPs in the inner lake shows that pellets tend to "hidden" in sediments. Suspected MPs are randomly selected for polymer detection by Micro-Raman microscopy. Polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET) are the most common polymer types in water, sediment and atmospheric deposition MPs samples. The input of wastewater, fishery and surrounding human activities are the main sources of MPs in sediment. Atmospheric deposition has a great impact on the distribution of MPs, while the contribution of surface runoff to lake MPs is not remarkable. In addition, MPs in sediments have exceeded the environmental carrying capacity. More attention should be focused on the sediment, where huge amounts of MPs are "hidden".


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Lagos/análisis , Plásticos , Aguas Residuales , Agua , Contaminantes Químicos del Agua/análisis
9.
J Mater Chem B ; 10(9): 1453-1462, 2022 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-35188170

RESUMEN

Exploration of versatile nanoplatforms within one single nanostructure for multidisciplinary treatment modalities, especially achieving a synergistic therapeutic efficacy of combinational gene/photothermal cancer therapy is still a great challenge in biomedicine and nanotechnology. In this study, a unique photothermal nanocarrier has successfully been designed and developed for a combination of gene therapy (GT) and photothermal therapy (PTT) of cancer cells. Surface-engineered iron oxides (α-Fe2O3) nanoparticles (NPs) with poly(3,4-ethylenedioxythiophene) (PEDOT) polymer coatings are synthesized using a one-pot in situ oxidative polymerization method. The results show that the as-prepared α-Fe2O3@PEDOT core-shell NPs with a uniform particle size exhibit positively charged surfaces, facilitating efficient siRNA Bcl-2 (B-cell lymphoma-2) uptake for delivery to breast cancer cells. More importantly, α-Fe2O3@PEDOT core-shell NPs not only display good biocompatibility and water dispersibility but also strong optical absorption enhancement in the Vis-NIR region as compared to α-Fe2O3 NPs. The obtained α-Fe2O3@PEDOT core-shell NPs show an efficient photothermal conversion efficacy (η = 54.3%) and photostability under NIR laser irradiation. As a result, both in vitro and in vivo biological studies on two types of breast cancer cells/tumors treated with α-Fe2O3@PEDOT-siRNA nanocomplexes demonstrate high cancer cell apoptosis and tumor inhibition induced by synergistic GT/PTT therapy under mild conditions compared to an individual GT or PTT alone. Taken together, this is the first example of the use of an α-Fe2O3@PEDOT core-shell nanoagent as a siRNA delivery nanocarrier for highly effective gene/photothermal combination anticancer therapy.


Asunto(s)
Neoplasias de la Mama , Compuestos Férricos/química , Fototerapia , Neoplasias de la Mama/terapia , Compuestos Bicíclicos Heterocíclicos con Puentes , Línea Celular Tumoral , Femenino , Humanos , Nanoestructuras , Fototerapia/métodos , Polímeros , ARN Interferente Pequeño/farmacología
10.
Environ Pollut ; 303: 119173, 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35306093

RESUMEN

The global pollution of microplastics (MPs) has attracted widespread attention, and the atmosphere was an indispensable media for the global transmission of MPs. With the growing awareness of MPs, atmospheric microplastics (AMPs) have been proposed as a new topic in recent years. Compared with the extensive studies on MPs in Marine and terrestrial environments, the studies of AMPs remain limited. In this study, sampling and analysis methods, occurrence, source analysis and health risk of AMPs were summarized and discussed. According to the different sampling methods, AMPs can be divided into suspension microplastics (SAMPs) and deposition microplastics (DAMPs). Previous studies have shown that SAMPs and DAMPs differ in composition and abundance, with SAMPs generally having a higher fraction of fragments. The mechanism of the migration of AMPs between different media was not clear yet. We further collated global data on the composition characteristics of MPs in soil and fresh water, which showed that the fragment MPs in soil and fresh water was higher than that in the atmosphere. Polymers in soil and fresh water were mainly PP and PE, while AMPs in the atmosphere were mainly PET. The shape composition of the MPs in both atmospheric and freshwater systems suggests that there may be the same dominant factor. The transport of AMPs and source apportionment were the important issues of current research, but both of them were at the initial stage. Therefore, AMPs needs to be further studied, especially for the source and fate, which would be conducive to understand the global distribution of AMPs. Furthermore, a standardized manual on sampling and processing of AMPs was also necessary to facilitate the comparative analysis of data between different studies and the construction of global models.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Medios de Cultivo , Monitoreo del Ambiente , Plásticos , Suelo , Contaminantes Químicos del Agua/análisis
11.
Langmuir ; 27(22): 13629-34, 2011 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-21961996

RESUMEN

Gold nanoparticles conjugated with DNA represent an attractive and alternative platform for broad applications in biosensors, medical diagnostic, and biological analysis. However, current methods to conjugate DNA to gold nanoparticles are time-consuming. In this study, we report a novel approach to rapidly conjugate DNA to gold nanoparticles (AuNPs) to form functional DNA/AuNPs in 2-3 h using Tween 80 as protective agent. With a fluorescence-based technique, we determine that the DNA density on the surface of AuNPs achieves about ∼60 strands per particles, which is comparable to the loading density in the current methods. Moreover, the DNA/AuNPs synthesized by our approach exhibit an excellent stability as a function of temperature, pH, and freeze-thaw cycle, and the functionality of DNA/AuNPs conjugates is also verified. The work presented here has important implications to develop the fast and reproducible synthesis of stable DNA-functionalized gold nanoparticles.


Asunto(s)
ADN/química , Oro/química , Nanopartículas del Metal , Polisorbatos/química , Tensoactivos/química , Fluorescencia , Concentración de Iones de Hidrógeno , Temperatura
12.
Huan Jing Ke Xue ; 42(10): 4593-4601, 2021 Oct 08.
Artículo en Zh | MEDLINE | ID: mdl-34581101

RESUMEN

To explore the pollution characteristics and potential health risks of heavy metals in PM2.5 on haze days in Central China, PM2.5 samples were collected from the Huanggang monitoring station, a regional observation point in Central China, between January 13 and 24, 2018. The contents of Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sn, and Pb in PM2.5 were analyzed by inductively coupled plasma mass spectrometry(ICP-MS), and the enrichment factor method was used to determine the potential risk based on the exposure model recommended by the Environmental Protection Administration(EPA). The results showed that during the observation period, the concentrations of Zn in PM2.5 were highest, and the concentrations of the carcinogens As and Cd were higher than the secondary standard limits of China's ambient air quality standard(GB 3095-2012), with 70% of these elemental concentrations accounting for the largest proportion in the middle haze period. The enrichment factor analysis showed that Cd, Sn, Co, Pb, and Zn were the most abundant elements, especially during the middle haze period, and were mostly derived from transportation and coal combustion. The results of the human health risk assessment showed that exposure via hand-mouth feeding was the main non-carcinogenic risk, and the exposure and non-carcinogenic risks of children were significantly higher than those of adults. Pb poses a non-carcinogenic risk to children, while heavy metals in PM2.5 pose no non-carcinogenic risks to adults and carcinogenic heavy metals pose no carcinogenic risks.


Asunto(s)
Metales Pesados , Material Particulado , Adulto , Niño , China , Monitoreo del Ambiente , Humanos , Metales Pesados/análisis , Material Particulado/análisis , Medición de Riesgo
13.
ACS Nano ; 14(11): 14731-14739, 2020 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-33146012

RESUMEN

Graphene oxide (GO) has recently been highlighted as a promising multipurpose two-dimensional material. However, free-standing graphene oxide films suffer from poor strength and flexibility, which limits scaling-up of production and lifetime structural robustness in applications. Inspired by the relationship between the organic and inorganic components of the hierarchical structure of nacre found in mollusk shells, we have fabricated self-assembled, layered graphene-based composite films. The organic phase of our composite is produced via environmentally friendly and economical methods based on bacterial production of γ-poly(glutamic acid) (PGA). Composite films made of GO, PGA, and divalent cations (Ca2+) were prepared through a slow solvent evaporation method at ambient temperature, resulting in a nacre-like layered structure. These biobased nanocomposite films showed impressive mechanical properties, which resulted from a synergistic combination of hydrogen bonding with the bacterially produced PGA and ionic bonding with calcium ions (Ca2+). The GO/PGA/Ca2+ composite films possessed a high strength of 150 ± 51.9 MPa and a high Young's modulus of 21.4 ± 8.7 GPa, which represents an increase of 120% and over 70% with respect to pure GO films. We provide rational design strategies for the production of graphene-based films with improved mechanical performance, which can be applied in filtration purification of wastewater in the paper, food, beverage, pigment, and pharmaceuticals industries, as well as for manufacturing of functional membranes and surface coatings.


Asunto(s)
Grafito , Nácar , Nanocompuestos , Polímeros
14.
J Biomed Mater Res B Appl Biomater ; 108(1): 272-281, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31013400

RESUMEN

Modifications of sintering temperature and treatment time of bovine-derived bone grafts affect their physicochemical properties and further influence biological activity. Three different temperature sintered bovine-derived bone grafts: group I (300 °C 3 h), group II (300 °C 3 h plus 530 °C 6 h), and group III (300 °C 3 h plus 1000 °C 2 h) and Bio-Oss® were characterized and then compared in vitro for their effects on bone marrow stromal cells (BMSCs) migration, proliferation, and differentiation as estimated by cell migration assay, Alkaline phosphatase (ALP) activity assay, and Alizarin red staining. Further, the four bone grafts were implanted into the calvarial defects of rabbits to evaluate bone regeneration and graft degradation. The four deproteinized bovine-derived bone grafts displayed different surface topography. Group II displayed the highest potential of attracting cells. Both groups I and II markedly promote BMSCs differentiation. After 6 and 12 weeks, defects grafted with groups I and II displayed a significant higher bone fraction than defects grafted with group III and Bio-Oss®. Bone graft remnants remained in all four groups. Taken together, sintering at 300 °C for 3 h and sintering at 300 °C for 3 h with an addition of 530 °C for 6 h of bovine-dervied bone grafts displayed potential use in bone regeneration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:272-281, 2020.


Asunto(s)
Regeneración Ósea/efectos de los fármacos , Sustitutos de Huesos/farmacología , Diferenciación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Minerales/farmacología , Cráneo , Animales , Bovinos , Masculino , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/patología , Conejos , Ratas , Ratas Sprague-Dawley , Cráneo/lesiones , Cráneo/patología , Cráneo/fisiología
15.
Chem Commun (Camb) ; (9): 1106-8, 2009 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-19225651

RESUMEN

A facile biomimetic method is reported for the synthesis of novel BaCO(3) nanofibres with double-stranded and cylindrical helical morphologies via a phosphonated block co-polymer-controlled mineralization process.


Asunto(s)
Bario/química , Materiales Biomiméticos/química , Carbonatos/química , Nanopartículas del Metal/ultraestructura , Microscopía Electrónica de Rastreo , Polímeros/química , Difracción de Rayos X
16.
Acta Pharmacol Sin ; 29(11): 1370-5, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18954532

RESUMEN

AIM: Investigation into pharmacokinetic-pharmacodynamic properties of interferon- alpha (IFN-alpha)2b-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres (MS) in rhesus monkey primates. METHOD: IFN-alpha2b was loaded with biodegradable PLGA with 3 inherent viscosities using a double emulsion and solvent evaporation method. The particle size, surface morphology, and in vitro release profiles were investigated. Two groups of rhesus monkeys (n=3) were injected intramuscularly with either 3 MIU/kg commercial IFN-alpha2b lyophilized powder or IFN-alpha2b-loaded PLGA microspheres (inherent viscosity of 0.89 dL/g). In vitro release was determined by Lowry protein assay. The serum IFN and neopterin levels were determined by the enzyme-linked immunosorbent assay (ELISA) method to evaluate biological activity of the microspheres in rhesus monkeys. RESULTS: The IFN-alpha2b microspheres with 3 inherent viscosities (0.39, 0.89, and 1.13 dL/g) were entirely spherical and had a smooth surface. The average diameter of each type was 45.55, 81.23, and 110.25 microm, respectively. The in vitro release was 30 d. The pharmacokinetic-pharmacodynamic properties between the IFN-alpha2b microspheres and IFN-alpha2b lyophilized powder were significantly different (P<0.05). CONCLUSION: The drug residence time for the IFN-alpha2b of the PLGA microsphere with an inherent viscosity of 0.89 dL/g in plasma significantly increased and had a longer time of biological effects in rhesus monkeys following intramuscular administration.


Asunto(s)
Antineoplásicos/farmacología , Antineoplásicos/farmacocinética , Interferón-alfa/farmacología , Interferón-alfa/farmacocinética , Animales , Antineoplásicos/administración & dosificación , Área Bajo la Curva , Preparaciones de Acción Retardada , Excipientes , Inyecciones Intramusculares , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Ácido Láctico , Macaca mulatta , Masculino , Microscopía Electrónica de Rastreo , Microesferas , Tamaño de la Partícula , Ácido Poliglicólico , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Proteínas Recombinantes
17.
Biomater Sci ; 6(7): 1946-1961, 2018 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-29850672

RESUMEN

Recruitment of endogenous bone marrow-derived mesenchymal stem cells (BMSCs) has been widely discussed as an alternative strategy for bone regeneration. Strontium (Sr) is known to direct the BMSCs' commitment to the bone lineage and encourage bone formation; however, the underlying mechanisms remain elusive. In this study, an Sr-incorporated micro/nano rough titanium surface (MNT-Sr) was fabricated by hydrothermal treatment in an attempt to facilitate BMSCs' recruitment and their osteogenic differentiation to enhance rapid osseointegration. Micro rough titanium (MT) was set as the control biomaterial. In vitro, MNT-Sr and its extracts promoted the migration and osteogenic differentiation of BMSCs. In animal studies, green fluorescent protein (GFP)-labeled BMSCs were intravenously injected into wild-type rats for tracing before tibial implantation surgery. The GFP+BMSC recruitment to the implantation site was successfully triggered by MNT-Sr implantation. A trend for increased bone area (BA%), bone-implant contact (BIC%) and removal torque values (RTVs) was observed for the MNT-Sr implant compared to that observed for MT at 2 weeks. Advanced mechanism analysis indicated that Sr2+ enhanced the SDF-1α/CXCR4 signaling pathway both in vitro and in vivo. Taken together, these findings suggest that MNT-Sr has promising therapeutic potential for future use in dental implants by homing endogenous stem cells to stimulate bone regeneration.


Asunto(s)
Materiales Biocompatibles/farmacología , Oseointegración/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Estroncio/farmacología , Titanio/farmacología , Animales , Materiales Biocompatibles/química , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Interfase Hueso-Implante , Diferenciación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Regulación de la Expresión Génica , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Masculino , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Oseointegración/genética , Osteogénesis/genética , Ratas , Ratas Sprague-Dawley , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Transducción de Señal , Estroncio/química , Tibia/efectos de los fármacos , Tibia/cirugía , Titanio/química
18.
J Phys Chem B ; 110(13): 6432-6, 2006 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-16570935

RESUMEN

A novel way for directed solution growth of hollow superstructures of CaCO3 has been successfully developed on the basis of controlled self-assembly and polymer concentration gradients using a double-hydrophilic block copolymer with a hydrophobic modification as a directing agent. A formation mechanism of such rings is proposed on the basis of the formation of CaCO3 nanoparticles in unstructured block copolymer assemblies with subsequent aggregation of these primary nanoparticles. This leads to the formation of a polymer concentration gradient from the inside to the outside of the particle. As the polymer contains multiple chelating units, this leads to a selective dissolution of the center of the particle.


Asunto(s)
Carbonato de Calcio/química , Polímeros/química , Micelas , Microscopía Electrónica de Rastreo
19.
Sci Rep ; 6: 20920, 2016 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-26865116

RESUMEN

For the increasing attention focused on saving endangered environments, there is a growing need for developing membrane materials able to perform complex functions such as removing radioactive pollutants and oil spills from water. A major challenge is the scalable fabrication of membranes with good mechanical and thermal stability, superior resistance to radiation, and excellent recyclability. In this study, we constructed a multifunctional flexible free-standing sodium titanate nanobelt (Na-TNB) membrane that was assembled as advanced radiation-tainted water treatment and oil uptake. We compared the adsorption behavior of (137)Cs(+) and (90)Sr(2+) on Na-TNB membranes under various environmental conditions. The maximum adsorption coefficient value (Kd) for Sr(2+) reaches 10(7) mL g(-1). The structural collapse of the exchange materials were confirmed by XRD, FTIR and XPS spectroscopy as well as Raman analysis. The adsorption mechanism of Na-TNB membrane is clarified by forming a stable solid with the radioactive cations permanently trapped inside. Besides, the engineered multilayer membrane is exceptionally capable in selectively and rapidly adsorbing oils up to 23 times the adsorbent weight when coated with a thin layer of hydrophobic molecules. This multifunctional membrane has exceptional potential as a suitable material for next generation water treatment and separation technologies.


Asunto(s)
Radioisótopos de Cesio/aislamiento & purificación , Óxidos/química , Petróleo/análisis , Radioisótopos de Estroncio/aislamiento & purificación , Titanio/química , Contaminantes Químicos del Agua/aislamiento & purificación , Contaminantes Radiactivos del Agua/aislamiento & purificación , Adsorción , Equipo Reutilizado , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Ensayo de Materiales , Membranas Artificiales , Nanoestructuras/química , Contaminación por Petróleo , Liberación de Radiactividad Peligrosa , Agua de Mar/química , Purificación del Agua/instrumentación , Purificación del Agua/métodos
20.
Chem Asian J ; 11(16): 2240-5, 2016 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-27411946

RESUMEN

A biocompatible probe for specific glucose recognition is based on photoinitiated boronate affinity-molecular imprinted polymers (BA-MIPs). The unique pre-self-assembly between glucose and boronic acids creates glucose-specific memory cavities in the BA-MIPs coating. As a result, the binding constant toward glucose was enhanced by three orders of magnitude. The BA-MIPs probe was applied to glucose determination in serum and urine and implanted into plant tissues for low-destructive and long-term in vivo continuous glucose monitoring.


Asunto(s)
Materiales Biocompatibles/química , Ácidos Borónicos/química , Glucosa/análisis , Impresión Molecular , Sondas Moleculares/química , Estructura Molecular , Tamaño de la Partícula , Polímeros/química , Propiedades de Superficie
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