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1.
Biofabrication ; 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31918413

RESUMO

The regeneration of damaged or loss of tissue is considered one critical step toward realizing full organ regeneration in modern medicine. Although surgical techniques continue to advance, the treatment of missing tissues in irregular wounds remains particularly difficult. With the increasing interests in the application of additive manufacturing toward tissue engineering, the fabrication of customized scaffolds for the regeneration of missing tissue via 3D-printing has become especially promising. Amongst the work on the regeneration of many important organs, liver regeneration is of particular high interest as it is the highest cause of death for many countries around the world, resulting in increasing need for liver transplant. The generation of hexagonal scaffolds for the regeneration of liver lobule is of high demand, but the three-dimensional structure has been proven difficult via traditional fabrication methods. In this work, various hexagonal scaffolds are developed for liver lobule regeneration via 3D printing using a novel biodegradable polymeric material, poly(glycerol sebacate) acrylate (PGSA). Through fine-tuning of printing parameters, a series of hexagonal scaffolds were designed and printed in mimicry of liver lobule units. The scaffolds were printed with pore sizes ranging between 100 and 900 µm in diameter together with varying surface area and three-dimensional structure to enhance cell seeding density and culture medium diffusivity. Through analyses of cell metabolic activities, the efficacy of the designs was proven through cell cultures to observe potential differences in cell proliferation rate. The combination of the high flexibility in 3D printing with the biodegradable, photocurable PGSA has made the regeneration of 3D liver lobule very promising.

2.
ACS Appl Mater Interfaces ; 11(12): 11144-11156, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30883079

RESUMO

Boron neutron capture therapy (BNCT) is a promising radiotherapy for treating glioblastoma multiforme (GBM). However, the penetration of drugs (e.g., sodium borocaptate and BSH) for BNCT into brain tumors is limited by cerebral vesicular protective structures, the blood-brain barrier, and the blood-brain tumor barrier (BTB). Although BSH has been reported to be selectively taken up by tumors, it is rapidly excreted from the body and cannot achieve a high tumor-to-normal brain ratio (T/N ratio) and tumor-to-blood ratio (T/B ratio). Despite the development of large-molecular weight boron compounds, such as polymers and nanoparticles, to enhance the permeation and retention effect, their effects remain insufficient for clinical use. To improve the efficiency of boron delivery to the tumor site, we propose combinations of self-assembled boron-containing polyanion [polyethylene glycol- b-poly(( closo-dodecaboranyl)thiomethylstyrene) (PEG- b-PMBSH)] nanoparticles (295 ± 2.3 nm in aqueous media) coupled with cationic microbubble (B-MB)-assisted focused ultrasound (FUS) treatment. Upon FUS sonication (frequency = 1 MHz, pressure = 0.3-0.7 MPa, duty cycle = 0.5%, sonication = 1 min), B-MBs can simultaneously achieve safe BTB opening and boron drug delivery into tumor tissue. Compared with the MBs of the PEG- b-PMBSH mixture group (B + MBs), B-MBs showed 3- and 2.3-fold improvements in the T/N (4.4 ± 1.4 vs 1.3 ± 0.1) and T/B ratios (1.4 ± 0.6 vs 0.1 ± 0.1), respectively, after 4 min of FUS sonication. The spatial distribution of PEG- b-PMBSH was also improved by the complex of PEG- b-PMBSH with MBs. The findings presented herein, in combination with the expanding clinical application of FUS, may improve BNCT and treatment of GBM.


Assuntos
Terapia por Captura de Nêutron de Boro , Boro/química , Microbolhas , Polímeros/química , Animais , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Glioma/patologia , Glioma/radioterapia , Humanos , Bicamadas Lipídicas/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Sonicação , Distribuição Tecidual
3.
Polymers (Basel) ; 10(11)2018 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-30961188

RESUMO

As acrylated polymers become more widely used in additive manufacturing, their potential applications toward biomedicine also raise the demand for biodegradable, photocurable polymeric materials. Polycaprolactone diacrylate (PCLDA) and poly(ethylene glycol) diacrylate (PEGDA) are two popular choices of materials for stereolithography (SLA) and digital light processing additive manufacturing (DLP-AM), and have been applied to many biomedical related research. However, both materials are known to degrade at a relatively low rate in vivo, limiting their applications in biomedical engineering. In this work, biodegradable, photocurable copolymers are introduced by copolymerizing PCLDA and/or PEGDA with poly(glycerol sebacate) acrylate (PGSA) to form a network polymer. Two main factors are discussed: the effect of degree of acrylation in PGSA and the weight ratio between the prepolymers toward the mechanical and degradation properties. It is found that by blending prepolymers with various degree of acrylation and at various weight ratios, the viscosity of the prepolymers remains stable, and are even more 3D printable than pure substances. The formation of various copolymers yielded a database with selectable Young's moduli between 0.67⁻10.54 MPa, and the overall degradation rate was significantly higher than pure substance. In addition, it is shown that copolymers fabricated by DLP-AM fabrication presents higher mechanical strength than those fabricated via direct UV exposure. With the tunable mechanical and degradation properties, the photocurable, biodegradable copolymers are expected to enable a wider application of additive manufacturing toward tissue engineering.

4.
Environ Toxicol ; 32(6): 1742-1753, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28181394

RESUMO

Silver nanoparticles (AgNPs) are commonly used nanomaterials in consumer products. Previous studies focused on its effects on neurons; however, little is known about their effects and uptake mechanisms on glial cells under normal or activated states. Here, ALT astrocyte-like, BV-2 microglia and differentiated N2a neuroblastoma cells were directly or indirectly exposed to 10 nm AgNPs using mono- and co-culture system. A lipopolysaccharide (LPS) was pretreated to activate glial cells before AgNP treatment for mimicking NP exposure under brain inflammation. From mono-culture, ALT took up the most AgNPs and had the lowest cell viability within three cells. Moreover, AgNPs induced H2 O2 and NO from ALT/activated ALT and BV-2, respectively. However, AgNPs did not induce cytokines release (IL-6, TNF-α, MCP-1). LPS-activated BV-2 took up more AgNPs than normal BV-2, while the induction of ROS and cytokines from activated cells were diminished. Ca2+ -regulated clathrin- and caveolae-independent endocytosis and phagocytosis were involved in the AgNP uptake in ALT, which caused more rapid NP translocation to lysosome than in macropinocytosis and clathrin-dependent endocytosis-involved BV-2. AgNPs directly caused apoptosis and necrosis in N2a cells, while by indirect NP exposure to bottom chamber ALT or BV-2 in Transwell, more apoptotic upper chamber N2a cells were observed. Cell viability of BV-2 also decreased in an ALT-BV-2 co-culturing study. The damaged cells correlated to NP-mediated H2 O2 release from ALT or NO from BV-2, which indicates that toxic response of AgNPs to neurons is not direct, but indirectly arises from AgNP-induced soluble factors from other glial cells.


Assuntos
Astrócitos/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Lisossomos/metabolismo , Nanopartículas Metálicas/toxicidade , Microglia/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Prata/toxicidade , Animais , Apoptose/efeitos dos fármacos , Astrócitos/imunologia , Astrócitos/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Interleucina-6/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Microglia/imunologia , Microglia/metabolismo , Necrose , Neurônios/imunologia , Neurônios/metabolismo , Fagocitose/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
5.
Biofabrication ; 9(1): 015024, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28169834

RESUMO

In these years, the artificial nerve guidance conduit (NGC) has been developed as an alternative way to repair peripheral nerve injury. Unlike autologous nerve graft, the artificial NGC without proper stimulating factors and guidance cues still cannot obtain satisfactory prognosis for clinical patients. In this study, a biodegradable polymer-based implantable device has been developed and characterized. By incorporating three stimulating factors: (1) micro-patterned surface that can directionally guide the axon as physical cue; (2) neurotrophic gradient membrane that can continually attract axon outgrowth from the proximal to distal stump as chemical cue; (3) Schwann cells (SCs) that can support the growth of neurite and form myelin sheath around axon as biological cue, we expect that this construct can be used as a promising NGC for peripheral nerve regeneration. The results showed that the micro-patterned surface with specific dimension of channels and chambers can be precisely fabricated by laser ablation. Attachment and directional extension of differentiated neural stem cells (NSCs) were observed in micro-channels. The gradient distribution of nerve growth factor 7S on gelatin membrane was successfully achieved. Significant improvement in neurite length and increase in neuronal gene expressions were also noticed in higher concentration region. When co-culturing with SCs, NSCs can differentiate toward neuronal cells with strong expression of mature neuronal markers: ßIII tubulin and microtubule-associated protein-2 (Map 2). Meanwhile, myelin basic protein was also observed, suggesting that SCs can provide biological support to neuronal cells in vitro. In the future, this advanced artificial NGC may be used as implantable prosthesis for the treatment of peripheral nerve injury with better functional recovery.


Assuntos
Materiais Biocompatíveis/química , Engenharia Tecidual , Animais , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Decanoatos/química , Glicerol/análogos & derivados , Glicerol/química , Microscopia Eletrônica de Varredura , Proteínas Associadas aos Microtúbulos/metabolismo , Proteína Básica da Mielina/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neuritos/fisiologia , Polímeros/química , Ratos , Ratos Sprague-Dawley , Células de Schwann/citologia , Células de Schwann/metabolismo , Propriedades de Superfície , Tecidos Suporte/química , Tubulina (Proteína)/metabolismo
6.
Polymers (Basel) ; 9(7)2017 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-30970919

RESUMO

Laser patterning on polymeric materials is considered a green and rapid manufacturing process with low material selection barrier and high adjustability. Unlike microelectromechanical systems (MEMS), it is a highly flexible processing method, especially useful for prototyping. This study focuses on the development of polymer surface modification method using a 193 nm excimer laser system for the design and fabrication of a microfluidic system similar to that of natural vasculatures. Besides from poly(dimethyl siloxane) (PDMS), laser ablation on biodegradable polymeric material, poly(glycerol sebacate) (PGS) and poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate) (APS) are investigated. Parameters of laser ablation and fabrication techniques to create microchannels are discussed. The results show that nano/micro-sized fractures and cracks are generally observed across PDMS surface after laser ablation, but not on PGS and APS surfaces. The widths of channels are more precise on PGS and APS than those on PDMS. Laser beam size and channel depth are high correlation with a linear relationship. Repeated laser ablations on the same position of scaffolds reveal that the ablation efficiencies and edge quality on PGS and APS are higher than on PDMS, suggesting the high applicability of direct laser machining to PGS and APS. To ensure stable ablation efficiency, effects of defocus distance into polymer surfaces toward laser ablation stability are investigated. The depth of channel is related to the ratio of firing frequency and ablation progression speed. The hydrodynamic simulation of channels suggests that natural blood vessel is similar to the laser patterned U-shaped channels, and the resulting micro-patterns are highly applicable in the field of micro-fabrication and biomedical engineering.

7.
Phys Chem Chem Phys ; 18(42): 29300-29307, 2016 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-27731868

RESUMO

Passivation of surface states is known to reduce the onset photocurrent potential by removing the Fermi level pinning effect at the Helmholtz layer and enhance the photocurrent plateau by suppressing recombination loss in the space charge region. We report for the first time that metal ions can effectively passivate surface states in situ that improves the photoelectrochemical (PEC) performance of hematite electrodes. Among metal ions studied, Cr(iii), Mn(ii), Fe(ii), Co(ii), Cu(ii) and Zn(ii) were found to enhance the photocurrent by 30-300%; whereas photocurrent density significantly dropped by 90% in Ni(ii) solution after 90 min of illumination. We further hypothesized that the surface states might be the high affinity adsorption sites on hematite surfaces. Once the surface states are occupied by metal ions, along with the Schottky barrier effect at the hematite/electrolyte interface formed by adsorbed metal ions, the PEC performance is enhanced. Our results also enable the design of a potential PEC based water treatment method to extract additional energy, for example, in the brines (containing concentrated metal ions and electrolyte) of membrane processed wastewater.

8.
Chem Biol Interact ; 254: 34-44, 2016 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-27216632

RESUMO

Although, titanium dioxide nanoparticles (TiO2NPs) are nanomaterials commonly used in consumer products, little is known about their hazardous effects, especially on central nervous systems. To examine this issue, ALT astrocyte-like, BV-2 microglia and differentiated N2a neuroblastoma cells were exposed to 6 nm of 100% anatase TiO2NPs. A lipopolysaccharide (LPS) was pre-treated to activate glial cells before NP treatment for mimicking NP exposure under brain injury. We found that ALT and BV-2 cells took up more NPs than N2a cells and caused lower cell viability. TiO2NPs induced IL-1ß in the three cell lines and IL-6 in N2a. LPS-activated BV-2 took up more TiO2NPs than normal BV-2 and released more intra/extracellular reactive oxygen species (ROS), IL-1ß, IL-6 and MCP-1 than did activated BV-2. Involvement of clathrin- and caveolae-dependent endocytosis in ALT and clathrin-dependent endocytosis and phagocytosis in BV-2 both had a slow NP translocation rate to lysosome, which may cause slow ROS production (after 24 h). Although TiO2NPs did not directly cause N2a viability loss, by indirect NP exposure to the bottom chamber of LPS-activated BV-2 in the Transwell system, they caused late apoptosis and loss of cell viability in the upper N2a chamber due to H2O2 and/or TNF-α release from BV-2. However, none of the adverse effects in N2a or BV-2 cells was observed when TiO2NPs were exposed to ALT-N2a or ALT-BV-2 co-culture. These results demonstrate that neuron damage can result from TiO2NP-mediated ROS and/or cytokines release from microglia, but not from astrocytes.


Assuntos
Apoptose/efeitos dos fármacos , Comunicação Celular/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Titânio/química , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Endocitose/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Lipopolissacarídeos/toxicidade , Lisossomos/metabolismo , Nanopartículas Metálicas/química , Camundongos , Microglia/citologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Óxido Nítrico/metabolismo , Fagocitose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
Environ Monit Assess ; 188(3): 180, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26899028

RESUMO

The elemental content of fish scales is known to be a reliable biogeochemical tag for tracing the origin of fishes. In this study, this correlation is further confirmed to exist on the surface of fish scales using a novel environmental analytical method, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), which bypasses several complicated sample preparation procedures such as acid digestion and pre-concentration. The results suggest that the elemental ratios of Sr/Ca, Ba/Ca, and Mn/Ca on the surface of fish scales are strongly correlated with the geochemical environment of their original habitat. This correlation is further demonstrated to be sensitive to variation of water in the habitat due to the adsorbed inorganic ions. In this sense, the limitation of fish scales as a biogeochemical tag is the sensitivity of LA-ICP-MS toward the studied elements. Graphical abstract Illustration of the connection between element distribution pattern over the surface of fish scales and biogeochemical environment of its habitat.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Peixes/metabolismo , Oligoelementos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Meio Ambiente , Espectrometria de Massas , Oligoelementos/análise , Poluentes Químicos da Água/análise
10.
J Colloid Interface Sci ; 466: 28-35, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26704473

RESUMO

The consideration of water energy nexus inspires the environmental engineering community to pursue a more sustainable strategy in the wastewater treatment. One potential response would be to enhance the performance of the low-pressure driven filtration system. To reach this objective, it is essential to have a better understanding regarding the surface interaction between the target substance and the surface of membrane. In this study, the hollow fiber ceramic membranes were coated with a goethite layer in order to enhance the Co(2+) rejection. Experimental results indicate that higher Co(2+) rejections are always accompanied with the significant reduction in the permeability. Based on the consideration of electroviscous effect, the surface interactions including the induced changes in viscosity, pore radius and Donnan effect in the goethite layer are likely responsible for the pH dependent behaviors in the rejection and permeability. These results could be valuable references to develop the filtration system with high rejection along with acceptable degree of permeability in the future.

11.
Environ Sci Technol ; 49(6): 3813-21, 2015 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-25692749

RESUMO

The so-called "Trojan-horse" mechanism, in which nanoparticles are internalized within cells and then release high levels of toxic ions, has been proposed as a behavior in the cellular uptake of Ag nanoparticles (AgNPs). While several reports claim to have proved this mechanism by measuring AgNPs and Ag ions (I) in cells, it cannot be fully proven without examining those two components in both intra- and extracellular media. In our study, we found that even though cells take up AgNPs similarly to (microglia (BV-2)) or more rapidly than (astrocyte (ALT)) Ag (I), the ratio of AgNPs to total Ag (AgNPs+Ag (I)) in both cells was lower than that in outside media. It could be explained that H2O2, a major intracellular reactive oxygen species (ROS), reacts with AgNPs to form more Ag (I). Moreover, the major speciation of Ag (I) in cells was Ag(cysteine) and Ag(cysteine)2, indicating the possible binding of monomer cysteine or vital thiol proteins/peptides to Ag ions. Evidence we found indicates that the Trojan-horse mechanism really exists.


Assuntos
Endocitose , Espaço Extracelular/química , Espaço Intracelular/química , Nanopartículas Metálicas/química , Prata/metabolismo , Animais , Ácido Ascórbico/química , Morte Celular/efeitos dos fármacos , Linhagem Celular , Meios de Cultura , Endocitose/efeitos dos fármacos , Peróxido de Hidrogênio/química , Íons , Lipopolissacarídeos/química , Camundongos , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Prata/toxicidade
12.
J Hazard Mater ; 270: 92-101, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24553353

RESUMO

In this paper, we demonstrate a means of simultaneously solving two serious environmental issues by reutilization of calcinated mixture of pulverized waste oyster shells blending with poly(methyl methacrylate) (PMMA) nanospheres to prepare CaO-based sorbents for CO2 capture. After 10 cycles of isothermal carbonation/calcination at 750°C, the greatest CO2 uptake (0.19 g CO2/g sorbent) was that for the sorbent featuring 70 wt% of PMMA, which was almost three times higher than that (0.07 g CO2/g sorbent) of untreated waste oyster shell. The greater CO2 uptake was likely a result of particle size reduction and afterwards surface basicity enhancement and an increase in the volume of mesopores and macropores. Following simplified life cycle assessment, whose all input values were collected from our experimental results, suggested that a significant CO2 emission reduction along with lesser human health and ecosystems impacts would be achieved immediately once waste is reutilized. Most importantly, the CO2 uptake efficiency must be greater than 20% or sorbents prepared from limestone mining would eventually produce a net positive CO2 emission.


Assuntos
Poluentes Atmosféricos/química , Exoesqueleto , Compostos de Cálcio/química , Dióxido de Carbono/química , Nanosferas/química , Óxidos/química , Polimetil Metacrilato/química , Adsorção , Animais , Sequestro de Carbono , Ostreidae , Tamanho da Partícula , Reciclagem , Propriedades de Superfície , Gerenciamento de Resíduos/métodos , Resíduos
13.
ACS Appl Mater Interfaces ; 5(16): 7937-49, 2013 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-23865744

RESUMO

It has been suggested that a high concentration of Fe(3+) in solution, a low pH, and noncomplexing ions of high ionic strength are all essential for developing a high-quality hematite array. Our curiosity was piqued regarding the role of the electrolyte ions in the hydrothermal synthesis of hematite photoanodes. In this study, we prepared hematite photoanodes hydrothermally from precursor solutions of 0.1 M FeCl3 at pH 1.55 with a background electrolyte of 1.0 M sodium halide (NaF, NaCl, NaBr, or NaI). We compared the structures and properties of the as-obtained hematite photoanodes with those of the material prepared in 1.0 M NaNO3, the most widely adopted electrolyte in previous studies. Among our studied systems, we found that the hematite photoanode prepared in NaCl solution was the only one possessing properties similar to those of the sample obtained from the NaNO3 solution-most importantly in terms of photoelectrochemical performance (ca. 0.2 mA/cm(2) with +0.4 V vs SCE). The hematites obtained from the NaF, NaBr, and NaI solutions exhibited much lower (by approximately 2 orders of magnitude) photocurrent densities under the same conditions, possibly because of their relatively less ordered crystallinity and the absence of rodlike morphologies. Because the synthetic protocol was identical in each case, we believe that these two distinct features reflect the environments in which these hematite photoanodes were formed. Consistent with the latest studies reported in the literature of the X-ray photoelectron spectra of fast-frozen hematite colloids in aqueous solutions, it appears that the degree of surface ion loading at the electrolyte-hematite interface (Stern layer) is critical during the development of hematite photoanodes. We suspect that a lower ion surface loading benefits the hematite developing relatively higher-order and a rodlike texture, thereby improving the photoelectrochemical activity.


Assuntos
Eletrodos , Compostos Férricos/química , Brometos/química , Catálise , Compostos Férricos/síntese química , Cloreto de Sódio/química , Compostos de Sódio/química , Fluoreto de Sódio/química , Iodeto de Sódio/química
14.
J Agric Food Chem ; 61(21): 5009-15, 2013 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-23646931

RESUMO

In this study, the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was adopted to determine the distribution of inorganic elements, including Ca, Cu, Fe, Mg, Mn, S, P, Pb, and Zn, in honeybees (Apis melifera L.). Two features are particularly noteworthy. First, it was found there is a significant amount of Fe located at the fringe of the abdomen in worker bees; ultrasonic imaging, scanning electron microscopy, and magnetic resonance imaging revealed that it arose from magnetic Fe-bearing nanoparticles (NPs) having an average diameter of approximately 40 nm. Interestingly, only worker bees contained these magnetic Fe-bearing NPs; no similar features appeared in larvae, pupae, wasps, or drones. Second, a detectable amount of Pb accumulated particularly in the alimentary canals of worker bees. Again, no detectable amounts of Pb in larvae, pupae, drones, or wasps, yet a level of 0.24 ± 0.05 mg/kg of Pb in pollen; therefore, the diet appears to be the primary pathway for environmental pollutants entering the honeybees' food chain.


Assuntos
Abelhas/química , Abelhas/fisiologia , Poluentes Ambientais/análise , Comportamento Alimentar , Metais/análise , Animais , Poluentes Ambientais/metabolismo , Terapia a Laser , Espectrometria de Massas , Metais/metabolismo
15.
Anal Bioanal Chem ; 404(10): 3025-36, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23052863

RESUMO

Understanding the cytotoxicity of quantum dots strongly relies upon the development of new analytical techniques to gather information about various aspects of the system. In this study, we demonstrate the in vivo biodistribution and fate of CdSe quantum dots in the murine model by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). By comparing the hot zones of each element acquired from LA-ICP-MS with those in fluorescence images, together with hematoxylin and eosin-stained images, we are able to perceive the fate and in vivo interactions between quantum dots and rat tissues. One hour after intravenous injection, we found that all of the quantum dots had been concentrated inside the spleen, liver and kidneys, while no quantum dots were found in other tissues (i.e., muscle, brain, lung, etc.). In the spleen, cadmium-114 signals always appeared in conjunction with iron signals, indicating that the quantum dots had been filtered from main vessels and then accumulated inside splenic red pulp. In the liver, the overlapped hot zones of quantum dots and those of phosphorus, copper, and zinc showed that these quantum dots have been retained inside hepatic cells. Importantly, it was noted that in the kidneys, quantum dots went into the cortical areas of adrenal glands. At the same time, hot zones of copper appeared in proximal tubules of the cortex. This could be a sign that the uptake of quantum dots initiates certain immune responses. Interestingly, the intensity of the selenium signals was not proportional to that of cadmium in all tissues. This could be the result of the decomposition of the quantum dots or matrix interference. In conclusion, the advantage in spatial resolution of LA-ICP-MS is one of the most powerful tools to probe the fate, interactions and biodistribution of quantum dots in vivo.


Assuntos
Compostos de Cádmio/farmacocinética , Terapia a Laser , Espectrometria de Massas , Pontos Quânticos , Compostos de Selênio/farmacocinética , Animais , Rim/ultraestrutura , Terapia a Laser/métodos , Fígado/ultraestrutura , Espectrometria de Massas/métodos , Camundongos , Microscopia de Fluorescência , Baço/ultraestrutura , Distribuição Tecidual
16.
Anal Chim Acta ; 699(1): 6-10, 2011 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-21704751

RESUMO

This paper describes a simple procedure for the direct analysis and determination of multiple elements in dried blood samples on a filter membrane using laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS). With this technique, we simultaneously quantified 13 elements in whole blood: Be, Mn, Co, Ni, Tl, Bi, Sb, Pb, Cu, Zn, Ba, Mg, and Cd. The measured accuracies was in agreement with the Seronorm CRM certified values, except for Mn, Zn, Ba and Cd, which presented absolute differences higher than the expanded uncertainty for these elements. The within-run precision was less than 5.7% (relative standard deviation, RSD), except for the analyses of Be, and Mn (8.6% and 11.1%, respectively). The reproducibility (between-run precision) was calculated in terms of the RSD obtained for 12 analyses (i.e., four replicates of each sample in three analytical runs). Apart from Be, Mn, and Zn, the reproducibilities of all the elements listed above ranged between 4.0% and 8.5%. In contrast, for Cd, the concentration obtained was significantly different from the certified value; analyses of this element exhibited low reproducibility. Applying the matrix-matched calibration method, the accuracy for Cd measured was in agreement with both SRM966 and BCR 635; thus, matrix-matched calibration is a practical means of overcoming matrix-enhancement effects for the quantification of Cd. Sample throughput (ca. 5 min per sample) made it possible to rapidly screen a larger number of samples relative to other techniques that require time-consuming sample preparation steps (e.g., removal of a portion of the solid sample or digestion).


Assuntos
Espectrometria de Massas/métodos , Oligoelementos/sangue , Coleta de Amostras Sanguíneas , Humanos , Lasers , Espectrometria de Massas/instrumentação
17.
Anal Bioanal Chem ; 401(3): 909-15, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21667060

RESUMO

In this study, we employed laser ablation/inductively coupled plasma mass spectrometry (LA-ICP-MS) to map the spatial distribution of Gd-doped iron oxide nanoparticles (IONPs) in one tumor slice that had been subjected to magnetic fluid hyperthermia (MFH). The mapping results revealed the high resolution of the elemental analysis, with the distribution of Gd atoms highly correlated with that of the Fe atoms. The spatial distributions of C, P, S, and Zn atoms revealed that the effect of MFH treatment was significantly dependent on the diffusion of the magnetic fluid in the tissue. An observed enrichment of Cu atoms after MFH treatment was probably due to inflammation in the tumor. The abnormal distribution of Ni atoms suggests a probable biochemical reaction in the tumor. Therefore, this LA-ICP-MS mapping technique can provide novel information regarding the spatial distribution of elements in tumors after cancer therapy.


Assuntos
Elementos , Terapia a Laser , Espectrometria de Massas , Metais Pesados/química , Neoplasias/química , Neoplasias da Próstata/química , Animais , Linhagem Celular Tumoral , Compostos Férricos/química , Gadolínio/química , Temperatura Alta , Humanos , Masculino , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/diagnóstico por imagem , Neoplasias/ultraestrutura , Neoplasias da Próstata/diagnóstico por imagem , Radiografia , Coloração e Rotulagem
18.
Talanta ; 79(2): 183-8, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19559862

RESUMO

This work describes a simple procedure for blood lead level determination. The proposed method requires little sample pretreatment and subsequent direct analysis of a dried blood spot on a filter membrane using laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS). In general, LA-ICP-MS studies are somewhat limited by the lack of matrix-matched standards for calibration purposes. Here we describe aqueous standard calibration and matrix-matched calibration methods. This method was validated by analysis of the reference materials. With the matrix-matched calibration method, the recovery ranged from 97.8% to 112.8%, while the aqueous standard calibration method ranged 90.4% to 122.4%. The lower detection limit was estimated as 0.1 ng mL(-1). The determination precision, expressed as the relative standard deviation (RSD), was not worse than 10% for all results. A sample throughput of approximately 5 min per sample made it possible to rapidly screen a large number of samples.


Assuntos
Chumbo/sangue , Espectrometria de Massas/métodos , Animais , Calibragem , Humanos , Lasers , Métodos , Padrões de Referência
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