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1.
Nat Commun ; 12(1): 5008, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34429436

RESUMO

Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces can help to guide care strategies that minimize the potential for pressure injuries in hospitalized patients or in individuals confined to the bed. This paper introduces a soft, skin-mountable class of sensor system for this purpose. The design includes a pressure-responsive element based on membrane deflection and a battery-free, wireless mode of operation capable of multi-site measurements at strategic locations across the body. Such devices yield continuous, simultaneous readings of pressure and temperature in a sequential readout scheme from a pair of primary antennas mounted under the bedding and connected to a wireless reader and a multiplexer located at the bedside. Experimental evaluation of the sensor and the complete system includes benchtop measurements and numerical simulations of the key features. Clinical trials involving two hemiplegic patients and a tetraplegic patient demonstrate the feasibility, functionality and long-term stability of this technology in operating hospital settings.


Assuntos
Técnicas Biossensoriais/métodos , Fontes de Energia Elétrica , Pressão , Temperatura , Tecnologia sem Fio , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Pele , Termografia/instrumentação , Termografia/métodos
2.
Toxicology ; 458: 152841, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34216699

RESUMO

The cardiotoxicity of various anticancer therapies, including radiotherapy, can lead to cardiovascular complications. These complications can range from damaging cardiac tissues within the irradiation field to increasing the long-term risks of developing heart failure, coronary artery disease, and myocardial infarction. We analyzed radiation-induced metabolites capable of mediating critical biological processes, such as inflammation, senescence, and apoptosis. Previously, by applying QTOF-MASS analysis to irradiated human fibroblasts, we identified that metabolite sets of lysophosphatidylcholine (LPC) were increased in these cells. In this study, radiation-induced LPC accumulation in human aortic endothelial cells (HAECs) increased reactive oxygen species (ROS) production and senescence-associated-beta-galactosidase staining, in addition to decreasing their tube-forming ability. Knockdown of lipoprotein-associated phospholipase A2 (Lp-PLA2) with small interfering RNA (siRNA) inhibited the increased LPC production induced by radiation, and reduced the radiation-induced cell damage produced by ROS and oxidized low-density lipoprotein (LDL). Lp-PLA2 depletion abolished the induction of proinflammatory factors, such as interleukin 1ß, tumor necrosis factor-alpha, matrix metalloproteinase 2, and matrix metalloproteinase 9, as well as adhesion molecules, such as intercellular adhesion molecule 1 (ICAM-1) and E-selection. Likewise, we showed that Lp-PLA2 expression was upregulated in the vasculature of irradiated rat, resulting in increased LPC production and LDL oxidation. Our data demonstrate that radiation-induced LPC production is a potential risk factor for cardiotoxicity that is mediated by Lp-PLA2 activity, suggesting that LPC and Lp-PLA2 offer potential diagnostic and therapeutic approaches to cardiovascular damage during radiotherapy.


Assuntos
1-Alquil-2-acetilglicerofosfocolina Esterase/metabolismo , 1-Alquil-2-acetilglicerofosfocolina Esterase/efeitos da radiação , Células Endoteliais/patologia , Células Endoteliais/efeitos da radiação , Lisofosfatidilcolinas/metabolismo , Fosfolipases A2/metabolismo , Fosfolipases A2/efeitos da radiação , Animais , Aorta/patologia , Aorta/efeitos da radiação , Citocinas/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Humanos , Inflamação/metabolismo , Microtúbulos/efeitos dos fármacos , Microtúbulos/efeitos da radiação , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/efeitos da radiação , Radiação Ionizante , Ratos , Ratos Endogâmicos F344 , Espécies Reativas de Oxigênio/metabolismo
3.
Exp Mol Med ; 52(10): 1730-1743, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33046822

RESUMO

Peroxisome proliferator-activated receptor gamma (PPARÉ£) agonists exert powerful anticancer effects by suppressing tumor growth. In this study, we developed PPZ023 (1-(2-(ethylthio)benzyl)-4-(2-methoxyphenyl)piperazine), a novel PPAR ligand candidate, and investigated the underlying signaling pathways in both non-small-cell lung cancer (NSCLC) and radio-resistant NSCLC cells. To identify whether PPZ023 has anticancer effects in NSCLC and radioresistant NSCLC cells, we performed WST-1, LDH, Western blot, and caspase-3 and -9 activity assays. Furthermore, we isolated exosomes from PPZ023-treated NSCLC cells and studied cell death signaling. PPZ023 reduces cell viability and increases LDH cytotoxicity and caspase-3 activity in NSCLC cells. PPZ023 induces cell death by generating reactive oxygen species (ROS) and triggering mitochondrial cytochrome c release. PPZ023 treatment causes cell death via the PERK-eIF2α-CHOP axis in both NSCLC cell lysates and exosomes, and PERK and CHOP knockdown significantly blocks ER stress-mediated apoptosis by reducing cleaved caspase-3. Interestingly, diphenyleneiodonium (DPI, a Nox inhibitor) inhibits PPZ023-induced cell death via ER stress, and PPARÉ£ knockdown inhibits PPZ023-induced ROS, ER stress, and cell death. Moreover, PPZ023, in combination with radiation, causes synergic cell death via exosomal ER stress in radioresistant NSCLC cells, indicating that PPZ023/radiation overcomes radioresistance. Taken together, our results suggest that PPZ023 is a powerful anticancer reagent for overcoming radioresistance.

4.
Nanoscale ; 11(48): 23139-23148, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31560000

RESUMO

In this study, we proposed a strategy to fabricate vertically stacked subpixel (VSS) micro-light-emitting diodes (µ-LEDs) for future ultrahigh-resolution microdisplays. At first, to vertically stack the LED with different colors, we successfully adopted a bonding-interface-engineered monolithic integration method using SiO2/SiNx distributed Bragg reflectors (DBRs). It was found that an intermediate DBR structure could be used as the bonding layer and color filter, which could reflect and transmit desired wavelengths through the bonding interface. Furthermore, the optically pumped µ-LED array with a pitch of 0.4 µm corresponding to the ultrahigh-resolution of 63 500 PPI could be successfully fabricated using a typical semiconductor process, including electron-beam lithography. Compared with the pick-and-place strategy (limited by machine alignment accuracy), the proposed strategy leads to the fabrication of significantly improved high-density µ-LEDs. Finally, we systematically investigated the effects of surface traps using time-resolved photoluminescence (TRPL) and two-dimensional simulations. The obtained results clearly demonstrated that performance improvements could be possible by employing optimal passivation techniques by diminishing the pixel size for fabricating low-power and highly efficient microdisplays.

5.
Cell Death Dis ; 9(12): 1138, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30442941

RESUMO

Procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD3), a membrane-bound homodimeric enzyme, hydroxylates lysyl residues in collagen-like peptides; however, its role in lung cancer is unknown. This study aimed to investigate the role of PLOD3 as a pro-metastatic factor and to elucidate the underlying mechanism. First, we experimentally confirmed the release of PLOD3 in circulation in animal models, rendering it a potential serum biomarker for lung cancer in humans. Thereafter, we investigated the effects of PLOD3 overexpression and downregulation on cancer cell invasion and migration in vitro and in vivo, using human lung cancer cell lines and a mouse tumor xenograft model, respectively. Further, PLOD3 levels were determined in lung tissue samples from lung cancer patients. Functional analyses revealed that PLOD3 interacts with STAT3, thereby expressing matrix metalloproteinases (MMP-2 and MMP-9) and with urokinase plasminogen activator (uPA) to enhance tumor metastasis. PLOD3 and the STAT3 pathway were significantly correlated in the metastatic foci of lung cancer patients; PLOD3-STAT3 levels were highly correlated with a poor prognosis. These results indicate that PLOD3 promotes lung cancer metastasis in a RAS-MAP kinase pathway-independent manner. Therefore, secreted PLOD3 serves as a potent inducer of lung cancer metastasis and a potential therapeutic target to enhance survival in lung cancer.


Assuntos
Proliferação de Células/genética , Neoplasias Pulmonares/genética , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/genética , Fator de Transcrição STAT3/genética , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/patologia , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Camundongos , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Metástase Neoplásica , Ligação Proteica/genética , Ativador de Plasminogênio Tipo Uroquinase/genética
6.
Mol Ther ; 26(3): 845-859, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29398486

RESUMO

Human embryonic stem cell-derived mesenchymal stem cells (hE-MSCs) have greater proliferative capacity than other human mesenchymal stem cells (hMSCs), suggesting that they may have wider applications in regenerative cellular therapy. In this study, to uncover the anti-senescence mechanism in hE-MSCs, we compared hE-MSCs with adult bone marrow (hBM-MSCs) and found that hepatocyte growth factor (HGF) was more abundantly expressed in hE-MSCs than in hBM-MSCs and that it induced the transcription of RAD51 and facilitated its SUMOylation at K70. RAD51 induction/modification by HGF not only increased telomere length but also increased mtDNA replication, leading to increased ATP generation. Moreover, HGF-treated hBM-MSCs showed significantly better therapeutic efficacy than naive hBM-MSCs. Together, the data suggest that the RAD51-mediated effects of HGF prevent hMSC senescence by promoting telomere lengthening and inducing mtDNA replication and function, which opens the prospect of developing novel therapies for liver disease.


Assuntos
Fator de Crescimento de Hepatócito/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Rad51 Recombinase/metabolismo , Animais , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Dano ao DNA , DNA Mitocondrial , Modelos Animais de Doenças , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica , Fator de Crescimento de Hepatócito/farmacologia , Humanos , Fator de Transcrição Ikaros/metabolismo , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Cirrose Hepática/terapia , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Ligação Proteica , Rad51 Recombinase/genética , Sumoilação , Telômero/efeitos dos fármacos , Telômero/genética , Telômero/metabolismo , Homeostase do Telômero/efeitos dos fármacos , Transcrição Genética
7.
J Tissue Eng Regen Med ; 12(4): 890-896, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28478656

RESUMO

Clinical irradiation therapy for cancer could increase the risk of localized wound complications. This study was conducted to evaluate the potential use of a chitosan microparticle-pluronic F127 (CSMP-PF) hydrogel complex containing bioactive molecules, substance P and transforming growth factor-ß1, to regeneratively repair skin damaged by local ionizing radiation (IR). The BALB/c/bkl mice were locally irradiated to their limbs with a single 40 Gy dose of Co-60 γ rays to induce a skin injury. The morphological characteristics of the chitosan microparticles were analysed by scanning electron microscopy. The amounts of bioactive molecules taken up and released by the CSMP-PF hydrogel complex were measured. Haematoxylin and eosin staining of IR-damaged skin showed acanthosis and hyperkeratosis in the epidermis; and damage to hair follicles/skin appendages and adipose tissue, as well as panniculus carnosus, in the dermis. Injection of the CSMP-PF hydrogel complex into IR-damaged skin resulted in skin repair, suggesting that the complex has potential for use in the regenerative repair of IR-damaged skin.


Assuntos
Quitosana , Raios gama/efeitos adversos , Hidrogéis , Lesões Experimentais por Radiação , Substância P , Fator de Crescimento Transformador beta , Cicatrização/efeitos dos fármacos , Animais , Quitosana/química , Quitosana/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Lesões Experimentais por Radiação/tratamento farmacológico , Lesões Experimentais por Radiação/patologia , Pele/lesões , Pele/metabolismo , Pele/patologia , Substância P/química , Substância P/farmacologia , Fator de Crescimento Transformador beta/química , Fator de Crescimento Transformador beta/farmacologia
8.
Sci Rep ; 7(1): 10333, 2017 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-28871141

RESUMO

In general, to realize full color, inorganic light-emitting diodes (LEDs) are diced from respective red-green-blue (RGB) wafers consisting of inorganic crystalline semiconductors. Although this conventional method can realize full color, it is limited when applied to microdisplays requiring high resolution. Designing a structure emitting various colors by integrating both AlGaInP-based and InGaN-based LEDs onto one substrate could be a solution to achieve full color with high resolution. Herein, we introduce adhesive bonding and a chemical wet etching process to monolithically integrate two materials with different bandgap energies for green and red light emission. We successfully transferred AlGaInP-based red LED film onto InGaN-based green LEDs without any cracks or void areas and then separated the green and red subpixel LEDs in a lateral direction; the dual color LEDs integrated by the bonding technique were tunable from the green to red color regions (530-630 nm) as intended. In addition, we studied vertically stacked subpixel LEDs by deeply analyzing their light absorption and the interaction between the top and bottom pixels to achieve ultra-high resolution.

9.
Tissue Eng Regen Med ; 14(4): 421-432, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30603498

RESUMO

Mesenchymal stem cells (MSCs), which are multipotent and have self-renewal ability, support the regeneration of damaged normal tissue. A number of external stimuli promote migration of MSCs into peripheral blood and support their participation in wound healing. In an attempt to harness the potential beneficial effects of such external stimuli, we exposed human MSCs (hMSCs) to one such stimulus-low-dose ionizing radiation (LDIR)-and examined their biological properties. To this end, we evaluated differences in proliferation, cell cycle, DNA damage, expression of surface markers (CD29, CD34, CD90, and CD105), and differentiation potential of hMSCs before and after irradiation with γ-rays generated using a 137CS irradiator. At doses less than 50 mGy, LDIR had no significant effect on the viability or apoptosis of hMSCs. Interestingly, 10 mGy of LDIR increased hMSC viability by 8% (p < 0.001) compared with non-irradiated hMSCs. At doses less than 50 mGy, LDIR did not induce DNA damage, including DNA strand breaks, or cause cellular senescence or cell-cycle arrest. Surface marker expression and in vitro differentiation potential of hMSCs were maintained after two exposures to LDIR at 10 mGy per dose. In conclusion, a two-dose exposure to LDIR at 10 mGy per dose not only facilitates proliferation of hMSCs, it also maintains the stem cell characteristics of hMSCs without affecting their viability. These results provide evidence for the potential of LDIR as an external stimulus for in vitro expansion of hMSCs and application in tissue engineering and regenerative medicine.

10.
Opt Express ; 25(3): 2489-2495, 2017 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-29519094

RESUMO

We report a color tunable display consisting of two passive-matrix micro-LED array chips. The device has combined vertically stacked blue and green passive-matrix LED array chips sandwiched by a transparent bonding material. We demonstrate that vertically stacked blue and green micro-pixels are independently controllable with operation of four color modes. Moreover, the color of each pixel is tunable in the entire wavelength from the blue to green region (450 nm - 540 nm) by applying pulse-width-modulation bias voltage. This study is meaningful in that a dual color micro-LED array with a vertically stacked subpixel structure is realized.

11.
Opt Express ; 24(6): A667-73, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-27136884

RESUMO

In this study, we have fabricated a blue-green color-tunable monolithic InGaN/GaN LED having a multi-junction structure with three terminals. The device has an n-p-n structure consisting of a green and a blue active region, i.e., an n-GaN / blue-MQW / p-GaN / green-MQW / n-GaN / Al2O3 structure with three terminals for independently controlling the two active regions. To realize this LED structure, a typical LED consisting of layers of n-GaN, blue MQW, and p-GaN is regrown on a conventional green LED by using a metal organic chemical vapor deposition (MOCVD) method. We explain detailed mechanisms of three operation modes which are the green, blue, and cyan mode. Moreover, we discuss optical properties of the device.

12.
Biomater Res ; 20: 12, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27114828

RESUMO

The 3-dimensional (3D) printing technologies, referred to as additive manufacturing (AM) or rapid prototyping (RP), have acquired reputation over the past few years for art, architectural modeling, lightweight machines, and tissue engineering applications. Among these applications, tissue engineering field using 3D printing has attracted the attention from many researchers. 3D bioprinting has an advantage in the manufacture of a scaffold for tissue engineering applications, because of rapid-fabrication, high-precision, and customized-production, etc. In this review, we will introduce the principles and the current state of the 3D bioprinting methods. Focusing on some of studies that are being current application for biomedical and tissue engineering fields using printed 3D scaffolds.

13.
NMR Biomed ; 29(4): 507-18, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26871685

RESUMO

Excess exposure to ionizing radiation generates reactive oxygen species and increases the cellular inflammatory response by modifying various metabolic pathways. However, an investigation of metabolic perturbations and organ-specific responses based on the amount of radiation during the acute phase has not been conducted. In this study, high-resolution magic-angle-spinning (HR-MAS) NMR and solution NMR-based metabolic profiling were used to investigate dose-dependent metabolic changes in multiple organs and tissues--including the jejunum, spleen, liver, and plasma--of rats exposed to X-ray radiation. The organs, tissues, and blood samples were obtained 24, 48, and 72 h after exposure to low-dose (2 Gy) and high-dose (6 Gy) X-ray radiation and subjected to metabolite profiling and multivariate analyses. The results showed the time course of the metabolic responses, and many significant changes were detected in the high-dose compared with the low-dose group. Metabolites with antioxidant properties showed acute responses in the jejunum and spleen after radiation exposure. The levels of metabolites related to lipid and protein metabolism were decreased in the jejunum. In addition, amino acid levels increased consistently at all post-irradiation time points as a consequence of activated protein breakdown. Consistent with these changes, plasma levels of tricarboxylic acid cycle intermediate metabolites decreased. The liver did not appear to undergo remarkable metabolic changes after radiation exposure. These results may provide insight into the major metabolic perturbations and mechanisms of the biological systems in response to pathophysiological damage caused by X-ray radiation.


Assuntos
Especificidade de Órgãos/efeitos da radiação , Plasma/metabolismo , Espectroscopia de Prótons por Ressonância Magnética/métodos , Amilases/sangue , Animais , Peso Corporal/efeitos da radiação , Análise Discriminante , Jejuno/metabolismo , Jejuno/efeitos da radiação , Análise dos Mínimos Quadrados , Redes e Vias Metabólicas/efeitos da radiação , Análise Multivariada , Tamanho do Órgão/efeitos da radiação , Ratos Endogâmicos F344 , Baço/metabolismo , Baço/efeitos da radiação , Fatores de Tempo , Raios X
14.
Genome Integr ; 7: 11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28217287

RESUMO

Three in vitro dose calibration curves for biodosimetry such as dicentric chromosome assay, fluorescence in situ hybridization (FISH) assay for translocation, and micronuclei (MNs) in binucleated cell assay were established after exposure to ionizing radiation. Peripheral blood lymphocyte samples obtained from healthy donors were irradiated with 60Co source at a dose rate of 0.5 Gy/min to doses of 0.1-6 Gy. The results from three in vitro dose calibration curves for biodosimetry were analyzed to understand the relationship among biodosimetry assay techniques. Our comparison demonstrates that there is a very strong positive correlation among the dicentric assay, FISH, and MNs analysis, and these three biodosimetry assays strongly support the in vitro dose reconstruction and the emergency preparedness of public or occupational radiation overexposure.

15.
Chem Biodivers ; 12(11): 1696-705, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26567947

RESUMO

We employed the primary cell model system as a first step toward establishing a method to assess the influence of ionizing radiation by using a combination of common and abundant metabolites. We applied X-ray irradiation amounts of 0, 1, and 5 Gy to the cells that were harvested 24, 48, or 72 h later, and profiled metabolites by 2D-NMR spectroscopy to sort out candidate molecules that could be used to distinguish the samples under different irradiation conditions. We traced metabolites stemming from the input ¹³C-glucose, identified twelve of them from the cell extracts, and applied statistical analysis to find out that all the metabolites, including glycine, alanine, and gluatamic acid, increased upon irradiation. The combinatorial use of the selected metabolites showed promising results where the product of signal intensities of alanine and lactate could differentiate samples according to the dose of X-ray irradiation. We hope that this work can form a base for treating radiation-poisoned patients in the future.


Assuntos
Espectroscopia de Ressonância Magnética , Cultura Primária de Células , Alanina/metabolismo , Relação Dose-Resposta à Radiação , Ácido Glutâmico/metabolismo , Glicina/metabolismo , Humanos , Raios X
16.
Biomaterials ; 59: 102-15, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25956855

RESUMO

Previously, we found that the delivery of mouse ES (mES) cell-derived proteins to adult fibroblasts enables the full reprogramming of these cells, converting them to mouse pluripotent stem cells (protein-iPS cells) without transduction of defined factors. During reprogramming, global gene expression and epigenetic status such as DNA methylation and histone modifications convert from somatic to ES-equivalent status. mES cell extract-derived iPS cells are biologically and functionally indistinguishable from mES cells in its potential in differentiation both in vitro and in vivo. Furthermore, these cells show complete developmental potency. However, the efficiency of generating iPS by treatment with extract from mES cells is still low. In this report, we demonstrated that protein extracts of mouse iPS cells that were previously generated by mES cell extract treatment were able to reprogram somatic cells to become ES-like cells (secondary protein-iPS cells). We confirmed that fetal animals (E12.5) could be derived from these cells. Surprisingly, the efficiency of forming Oct4-positive colonies was remarkably improved by treatment of somatic cells with mouse iPS cell extract in comparison to treatment with mES cell extract. By screening the genes differentially expressed between mouse iPS and mES cells, Zscan4, which is known to enhance telomere elongation and stabilize genomic DNA, was identified as a strong candidate to promote efficiency of reprogramming. Interestingly, treatment with protein extracted from mES cells overexpressing Zscan4 enhanced formation of Oct4-positive colonies. Our results provide an efficient and safe strategy for reprogramming somatic cells by using mouse iPS cell extract. Zscan4 might be a key molecule involved in the demonstrated improvement of reprogramming efficiency.


Assuntos
Células-Tronco Embrionárias/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Fatores de Transcrição/fisiologia , Animais , Diferenciação Celular , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
17.
PLoS One ; 9(11): e113573, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25419661

RESUMO

Radiation exposure is a threat to public health because it causes many diseases, such as cancers and birth defects, due to genetic modification of cells. Compared with the past, a greater number of people are more frequently exposed to higher levels of radioactivity today, not least due to the increased use of diagnostic and therapeutic radiation-emitting devices. In this study, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS)-based metabolic profiling was used to investigate radiation- induced metabolic changes in human fibroblasts. After exposure to 1 and 5 Gy of γ-radiation, the irradiated fibroblasts were harvested at 24, 48, and 72 h and subjected to global metabolite profiling analysis. Mass spectral peaks of cell extracts were analyzed by pattern recognition using principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The results showed that the cells irradiated with 1 Gy returned to control levels at 72 h post radiation, whereas cells irradiated with 5 Gy were quite unlike the controls; therefore, cells irradiated with 1 Gy had recovered, whereas those irradiated with 5 Gy had not. Lipid and amino acid levels increased after the higher-level radiation, indicating degradation of membranes and proteins. These results suggest that MS-based metabolite profiling of γ-radiation-exposed human cells provides insight into the global metabolic alterations in these cells.


Assuntos
Fibroblastos/efeitos da radiação , Raios gama , Metaboloma/efeitos da radiação , Metabolômica , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Derme/citologia , Análise Discriminante , Relação Dose-Resposta à Radiação , Fibroblastos/metabolismo , Humanos , Análise dos Mínimos Quadrados , Espectrometria de Massas/métodos , Análise Multivariada , Análise de Componente Principal , Fatores de Tempo
18.
J Nanosci Nanotechnol ; 14(10): 7621-6, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25942837

RESUMO

Natural and synthetic polymers, in particular those that are conductive, are of great interest in the field of tissue engineering and the pursuit of biomimetic extracellular matrix (ECM) structures for adhesion, proliferation, and differentiation of cells. In the present study, natural chitin and conductive polyaniline (PANi) blended solutions were electrospun to produce biodegradable and conductive biomimetic nanostructured scaffolds. The chitin/PANi (Chi-PANi) nanofibrous materials were characterized using field emission scanning electron microscopy, Fourier transform-infrared spectroscopy, wettability analysis, mechanical testing, and electrical conductivity measurements using a 4-point probe method. The calculated electrical conductivities of the PANi-containing nanofiber scaffolds significantly increased as the amount of PANi increased, reaching 5.21 ± 0.28 x 10(-3) S/cm for 0.3 wt% content of the conducting polymer. In addition, the viability of human mesenchymal stem cells (hMSCs) cultured on the Chi-PANi nanofiber scaffolds in vitro was found to be excellent. These results suggest that the Chi-PANi nanofiber scaffolds have great potential for use in tissue engineering applications that involve electrical stimulation.


Assuntos
Compostos de Anilina/química , Materiais Biocompatíveis/química , Condutividade Elétrica , Nanofibras/química , Nanotecnologia/métodos , Engenharia Tecidual , Tecidos Suporte/química , Materiais Biocompatíveis/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quitina/química , Humanos , Fenômenos Mecânicos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Neuritos/efeitos dos fármacos , Neuritos/metabolismo
19.
Opt Express ; 21(19): 22320-6, 2013 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-24104122

RESUMO

In this study, we produce InGaN/GaN microcolumn LED (MC-LED) arrays having nonpolar metal sidewall contacts using a top-down method, where the metal contacts only with the sidewall of the columnar LEDs with an open top for transparency. The trapezoidal profile of the as-etched columns was altered to a rectangular profile through KOH treatment, exposing the nonpolar sidewalls. While the MC-LED with no treatment emitted no light because of the etch-damaged region, the MC-LEDs with KOH treatment exhibited much improved the electrical properties with the much higher shunt resistance due to the removal of the etch-damaged region. The optical output power was strongest for the MC-LED with a 5-min treatment indicating an almost complete removal of the damaged region.

20.
Carbohydr Polym ; 97(1): 65-73, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23769518

RESUMO

Electrospinning of pure chitosan was employed to obtain a nanofibrous hemostatic material. Owing to the water-solubility of the resulting acidic chitosan nanofibers, the optimum neutralization conditions were identified by testing various alkaline solutions, so that an insoluble material could be achieved. The pore size and thickness of the neutralized chitosan nanofibers mat could be controlled using ultra-sonication. The porosity of the chitosan mat was increased from 79.9% to 97.2% with ultra-sonication treatment for 1 min, and the water absorption time decreased from 110s to 9s. The blood clotting efficiency measured for the sonicated chitosan nanofiber mat was 1.35- and 3.41-fold better than the efficiencies of the Surgicel(®) and chitosan sponge, respectively. In addition, the proliferation of normal human dermal fibroblasts on the sonicated nanofiber mat was found to be 1.4-fold higher than that on the non-sonicated material after 7 days of culture.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Nanofibras/química , Absorção , Materiais Biocompatíveis/farmacologia , Plaquetas/química , Plaquetas/fisiologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Nanofibras/ultraestrutura , Porosidade , Sonicação , Engenharia Tecidual
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