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1.
Talanta ; 246: 123530, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35561531

RESUMO

An electrochemical immunosensor for the accurate detection of cat neutrophil gelatinase-associated lipocalin (NGAL) in urine samples based on an electrode with a monolayer of gold nanoparticles (AuNPs) was proposed in this study. To fabricate the sensing electrode, a nickel mold with concave micron hemisphere array was prepared and then used to transfer the micron hemispherical structure onto a polyethylene terephthalate (PET) film using the hot embossing technique. A gold thin film was sputtered onto the micron hemispherical structure array, after which 1,6-hexanedithol and AuNPs were uniformly deposited on the PET membrane to form a sensing electrode. The NGAL concentrations were measured by electrochemical impedance spectroscopy after attaching the anti-NGAL. Results revealed that the proposed sensing scheme exhibited a wide dynamic detection range from 1 to 100 ng/mL, which is far enough to distinguish the healthy (NGAL concentration <10 ng/mL) from the damaged kidney. A low limit of detection and high sensitivity of 0.47 ng/mL and 10261.8 Ω ng-1mL, respectively, were also measured. After performing real sample detection using urine samples from cats collected at a veterinary hospital, the results confirmed that the proposed NGAL detection approach in this research could accurately detect the concentration of NGAL in cat urine samples.

2.
Biosensors (Basel) ; 12(4)2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35448267

RESUMO

In this study, we proposed a genosensor that can qualitatively and quantitatively detect genetically modified soybeans using a simple electrode with evenly distributed single layer gold nanoparticles. The DNA sensing electrode is made by sputtering a gold film on the substrate, and then sequentially depositing 1,6-hexanedithiol and gold nanoparticles with sulfur groups on the substrate. Then, the complementary to the CaMV 35S promoter (P35S) was used as the capture probe. The target DNA directly extracted from the genetically modified soybeans rather than the synthesized DNA segments was used to construct the detection standard curve. The experimental results showed that our genosensor could directly detect genetically modified genes extracted from soybeans. We obtained two percentage calibration curves. The calibration curve corresponding to the lower percentage range (1-6%) exhibits a sensitivity of 2.36 Ω/% with R2 = 0.9983, while the calibration curve corresponding to the higher percentage range (6-40%) possesses a sensitivity of 0.1 Ω/% with R2 = 0.9928. The limit of detection would be 1%. The recovery rates for the 4% and 5.7% GMS DNA were measured to be 104.1% and 102.49% with RSD at 6.24% and 2.54%. The gold nanoparticle sensing electrode developed in this research is suitable for qualitative and quantitative detection of genetically modified soybeans and can be further applied to the detection of other genetically modified crops in the future.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Nanopartículas , Técnicas Biossensoriais/métodos , Produtos Agrícolas , DNA , Técnicas Eletroquímicas/métodos , Eletrodos , Ouro , Plantas Geneticamente Modificadas/genética , Soja
3.
Front Bioeng Biotechnol ; 10: 853947, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35372290

RESUMO

Amyloid-ß(1-42) [Aß(1-42)] oligomer accumulations are associated with physiologic alterations in the brains of individuals with Alzheimer's disease. In this study, we demonstrate that a nanostructured gold electrode with deposited gold nanoparticles, induced via electrochemical impedance spectroscopy (EIS), may be used as an Aß(1-42) conformation biosensor for the detection of Alzheimer's disease. Monoclonal antibodies (12F4) were immobilized on self-assembled monolayers of the electrochemical sandwich immunoassay biosensor to capture Aß(1-42) monomers and oligomers. Western blot and fluorescence microscopy analyses were performed to confirm the presence of Aß(1-42) monomers and oligomers. EIS analysis with an equivalent circuit model was used to determine the concentrations of different Aß(1-42) conformations in this study. We identified conformations of Aß(1-42) monomers and Aß(1-42) oligomers using probe antibodies (12F4) by employing EIS. RAß(1-42) indicates the sum resistance of impedance measured during Aß(1-42) immobilization. ΔR12F4 refers to the concentration of probe antibody (12F4) binding with Aß(1-42). The concentration of Aß(1-42) oligomer was defined as the percentage of Aß(1-42) aggregation R12F4/RAß(1-42) . The experimental results show that the biosensor has high selectivity to differentiate Aß(1-40) and Aß(1-42) monomers and Aß(1-42) oligomers and that it can detect Aß(1-42) oligomer accurately. The linear detection range for Aß(1-42) oligomers was between 10 pg/ml and 100 ng/ml. The limit of detection was estimated to be 113 fg/ml.

4.
Int J Nanomedicine ; 16: 5551-5563, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34429599

RESUMO

BACKGROUND: Type I diabetes occurs when the pancreas can only make limited or minimal insulin. Patients with type 1 diabetes need effective approaches to manage diabetes and maintain their blood-glucose concentration. Recently, continuous glucose monitoring (CGM) has been used to help control blood-glucose levels in patients with type 1 diabetes. Patients with type 2 diabetes may also benefit from CGM on multiple insulin injections, basal insulin, or sulfonylureas. Enzyme-free glucose detection in a neutral environment is the recent development trend of CGM. MATERIALS AND METHODS: Pt/Au alloy electrodes for enzyme-free glucose detection in a neutral environment were formed by electrochemically depositing Pt/Au alloy on a thin polycarbonate (PC) membrane surface with a uniformly distributed micro-hemisphere array. The PC membranes were fabricated using semiconductor microelectromechanical manufacturing processes, precision micro-molding, and hot embossing. Amperometry was used to measure the glucose concentration in PBS (pH 7.4) and artificial human serum. RESULTS: The Pt/Au nanoalloy electrode had excellent specificity for glucose detection, according to the experimental results. The device had a sensitivity of 2.82 µA mM-1 cm-2, a linear range of 1.39-13.9 mM, and a detection limit of 0.482 mM. Even though the complex interfering species in human blood can degrade the sensing signal, further experiments conducted in artificial serum confirmed the feasibility of the proposed Pt/Au nanoalloy electrode in clinical applications. CONCLUSION: The proposed Pt/Au nanoalloy electrode can catalyze glucose reactions in neutral solutions with enhancing sensing performance by the synergistic effect of bimetallic materials and increasing detection surface area. This novel glucose biosensor has advantages, such as technology foresight, good detection performance, and high mass production feasibility. Thus, the proposed neutral nonenzymatic glucose sensor can be further used in CGMs.


Assuntos
Técnicas Biossensoriais , Diabetes Mellitus Tipo 2 , Glicemia , Automonitorização da Glicemia , Eletrodos , Glucose , Ouro , Humanos , Nanoestruturas , Platina
5.
Biosensors (Basel) ; 11(4)2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33917075

RESUMO

This study aimed to develop simple electrochemical electrodes for the fast detection of chloride, sodium and potassium ions in human serum. A flat thin-film gold electrode was used as the detection electrode for chloride ions; a single-piece type membrane based solid-state ion-selective electrode (ISE), which was formed by covering a flat thin-film gold electrode with a mixture of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and ion-selective membrane (ISM), was developed for sodium and potassium ions detection. Through cyclic voltammetry (CV) and square-wave voltammetry (SWV), the detection data can be obtained within two minutes. The linear detection ranges in the standard samples of chloride, sodium, and potassium ions were 25-200 mM, 50-200 mM, and 2-10 mM, with the average relative standard deviation (RSD) of 0.79%, 1.65%, and 0.47% and the average recovery rates of 101%, 100% and 96%, respectively. Interference experiments with Na+, K+, Cl-, Ca2+, and Mg2+ ions demonstrated that the proposed detection electrodes have good selectivity. Moreover, the proposed detection electrodes have characteristics such as the ability to be prepared under relatively simple process conditions, excellent detection sensitivity, and low RSD, and the detection linear range is suitable for the Cl-, Na+ and K+ concentrations in human serum.


Assuntos
Técnicas Eletroquímicas , Eletrólitos/análise , Eletrodos , Ouro , Humanos , Eletrodos Íon-Seletivos , Íons , Potássio
6.
Sci Technol Adv Mater ; 21(1): 562-572, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32939180

RESUMO

This study proposes to develop a dual-acting antibacterial film of porous chitosan (Cs) embedded with small molecular compound, which possesses photosensitive characteristics with bactericidal efficacy, to promote the accelerated recovery of infectious wounds. The Cs/small molecular compound (Cs-cpd.2) dressing was prepared using the freeze-drying method. Characterization of the synthesized Cs-cpd.2 indicated that it has high porosity and moisture absorption effect, hence enhancing the absorption of wound exudate. Experimental results showed that Cs-cpd.2 dressing has good bactericidal and bacteriostatic effects on Staphylococcus aureus under visible-light irradiation and has antibacterial effect in the dark. It was also found that the small molecular compound does not have cytotoxicity at a dose of 0-5 µM. Furthermore, Cs-cpd.2 that contained small molecular compound with a concentration of 0.3-1 µM has positive effect on both the cell viability rate and cell proliferation rate of human fibroblast CG1639. Cs-cpd.2 can significantly promote cell proliferation when the small molecular compound and the basic fibroblast growth factor bFGF were added together. Therefore, the proposed Cs-cpd.2 dressing is feasible for photodynamic therapy (PDT) and clinical wound dressing applications.

7.
Med Eng Phys ; 75: 5-12, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31780301

RESUMO

During metastasis, cancer cells migrate away from the primary tumor-site, encountering different microenvironment topographies that may facilitate or inhibit cancer cell adherence and growth; those relate to sites of invasion and seeding. To evaluate topography effects, poly-lactic-poly-glycolic (PLGA) gels are generated as flat substrates, porous, or with rectangular microchannels of varying widths (5-100 µm) and depths (10/20 µm). The topography effect on time-dependent adherence, proliferation, morphology, alignment and long-term structural development of metastatic breast-cancer and benign cells are evaluated; adherence at short time-scales (3 h) is compared to developed morphologies and multicellular structures (>2 days) indicating function. At short time-scales, both cell types exhibit rounded morphologies, however, while the benign cells tend to cluster the cancer cells preferentially adhered as single cells at high-curvature substrate-sites (e.g. convex pore-edges or channel-edges). At long times, the benign cells develop extensive, tissue-like multicellular sheets spanning across several 10 µm deep channels or filling in single-file 20 µm-deep narrow channels (5-15 µm). Contrastingly, cancer cells mainly attach as single cells to high-curvature channel bottoms, in alignment with narrow channels. Thus, cell responses to topography, specifically their localization and growth in narrow microchannels, may provide a way to distinguish cancer from benign cells, by demonstrating their inherent function.


Assuntos
Neoplasias da Mama/patologia , Mama/citologia , Mama/patologia , Microtecnologia/métodos , Contagem de Células , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Humanos
8.
Lab Chip ; 19(22): 3862-3869, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31625549

RESUMO

In this research, we propose a novel centrifugal device for the massive extraction of healthy mitochondria with a centrifuge used in general laboratories within 30 minutes. The device mainly consists of two key components. One component is a microfluidic device, which is fabricated by photolithography, nickel electroforming, and polydimethylsiloxane casting, for the efficient disruption of the cell membrane. The other component is a stainless steel container, which is manufactured by computer numerical control machining, for the storage of the cell suspension. After assembly, the appropriate number of cells is pushed through the microfluidic device for cell membrane disruption by centrifugal force generated by a general laboratory centrifuge. The solution which contains cell debris and mitochondria are collected to purify the crude mitochondria via differential centrifugation. Compared with the quantity and efficiency of mitochondria isolated from the same number of cells using a conventional kit, device-extracted mitochondria show a more complete mitochondrial electron transport chain complex and a similar number of mitochondria verified by Western blot analysis of mitochondrial complexes I-V and mitochondrial outer membrane protein Tom20, respectively, as well as a normal mitochondrial structure revealed by transmission electron microscopy. Moreover, the mitochondrial membrane potential of device-extracted mitochondria stained with tetramethylrhodamine ethyl ester is higher than that of kit-extracted mitochondria. Furthermore, the coculture of device-extracted mitochondria with fibroblasts revealed that fibroblasts could uptake foreign mitochondria through endocytosis without drug treatment. These results show that the proposed microfluidic device preserves mitochondrial protein structure, membrane integrity, and membrane potential within 30 minutes of extraction and is a useful tool for therapeutic mitochondrial transplantation and regenerative medicine.


Assuntos
Técnicas Analíticas Microfluídicas , Mitocôndrias/química , Centrifugação , Desenho de Equipamento , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Células Tumorais Cultivadas
9.
J Mater Chem B ; 7(39): 5947-5955, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31517375

RESUMO

A detection and degradation platform was developed to optically quantify the 6-enolate, 8-keto-dG, an important tautomer of mitochondrial mutated DNA 8-oxo-dG. We first found that 6-enolate, 8-keto-dG offers particular fluorescence emission under the conditions between pH ∼ 7 and ∼11. Thus, a mitochondria-targeting photosensitizer NV-12P was prepared to offer simultaneously photoinduced electron transfer and fluorescence resonance energy transfer (FRET) with 6-enolate, 8-keto-dG. Furthermore, NV-12P can also generate a reactive oxygen species to degrade 6-enolate, 8-keto-dG under irradiation conditions. This is the first publication about optical characterization, concentration detection and photodegradation of 6-enolate, 8-keto-dG, either in biological or in vitro applications.


Assuntos
8-Hidroxi-2'-Desoxiguanosina/análise , 8-Hidroxi-2'-Desoxiguanosina/química , DNA Mitocondrial/genética , Mutação , Fotólise , DNA Mitocondrial/química , Eletroquímica , Transferência Ressonante de Energia de Fluorescência , Células HeLa , Humanos , Modelos Moleculares , Conformação de Ácido Nucleico
10.
Anal Sci ; 35(9): 1037-1043, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31155546

RESUMO

The characteristics of an electrochemical biosensor based on a Prussian-blue screen-printed electrode containing glucose oxidase incorporated into polyelectrolyte microcapsules (PMC) are considered. PMC with the embedded enzyme were formed using sodium polystyrene sulfonate and poly(allylamine hydrochloride). The characteristics were compared with those of the enzyme immobilized in chitosan gel. We assessed the dependences of biosensor signals on the composition of the buffer solution, on the glucose concentration; the operational and long-term stabilities. The enzyme immobilized in PMC proved to be more sensitive to buffer molarity at a maximum within 35 - 40 mM. The apparent Michaelis constants were 1.5 and 4.1 mM at the immobilization in, respectively, chitosan and PMC. The developed biosensors were used to assay commercial juices. The biosensors' data on the glucose contents were shown to have a high correlation with the standard spectrophotometric assay (0.92 - 0.95%), which implies a possible application of the fabricated biosensors in foodstuff analysis.


Assuntos
Técnicas Biossensoriais/métodos , Quitosana/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Polieletrólitos/química , Técnicas Biossensoriais/instrumentação , Tampões (Química) , Calibragem , Cápsulas , Eletroquímica , Eletrodos , Ferrocianetos/química , Géis , Glucose/análise , Poliaminas/química , Poliestirenos/química
11.
Membranes (Basel) ; 9(4)2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-31013718

RESUMO

This work investigated changes in the biochemical parameters of multilayer membrane structures, emerging at their modification with multiwalled carbon nanotubes (MWCNTs). The structures were represented by polyelectrolyte microcapsules (PMCs) containing glucose oxidase (GOx). PMCs were made using sodium polystyrene sulfonate (polyanion) and poly(allylamine hydrochloride) (polycation). Three compositions were considered: with MWCNTs incorporated between polyelectrolyte layers; with MWCNTs inserted into the hollow of the microcapsule; and with MWCNTs incorporated simultaneously into the hollow and between polyelectrolyte layers. The impedance spectra showed modifications using MWCNTs to cause a significant decrease in the PMC active resistance from 2560 to 25 kOhm. The cyclic current-voltage curves featured a current rise at modifications of multilayer MWCNT structures. A PMC-based composition was the basis of a receptor element of an amperometric biosensor. The sensitivity of glucose detection by the biosensor was 0.30 and 0.05 µA/mM for PMCs/MWCNTs/GOx and PMCs/GOx compositions, respectively. The biosensor was insensitive to the presence of ethanol or citric acid in the sample. Polyelectrolyte microcapsules based on a multilayer membrane incorporating the enzyme and MWCNTs can be efficient in developing biosensors and microbial fuel cells.

12.
ACS Appl Mater Interfaces ; 10(11): 9858-9864, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29493214

RESUMO

In this study, a nanoimprinting method was introduced to fabricate polycarbonate films with transparent and flexible photonic crystal (FPC) structures. The fabricated flexible polymer films display a full-color grating because of the nanohemispherical structures on the surface. Through the Bragg diffraction formula, it was confirmed that the FPC polymer films transfer a part of the light energy to the second-order diffraction spectrum. Furthermore, the full-color grating properties can be modulated through geometric deformation because of the film's elasticity. Additionally, anticounterfeiting features were also successfully achieved when the polymer films were either engraved with drawings and bent or patterned with fluorophores, which can be revealed under ultraviolet light. The most important aspect of this research is that the preparation of this FPC-structured polymer film is inexpensive and convenient, enabling the mass production of a new generation of smart materials.

13.
Sci Technol Adv Mater ; 18(1): 987-996, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29230255

RESUMO

The aim of this study was to develop a porous chitosan scaffold with long-acting drug release as an artificial dressing to promote skin wound healing. The dressing was fabricated by pre-freezing at different temperatures (-20 and -80 °C) for different periods of time, followed by freeze-drying to form porous chitosan scaffolds with different pore sizes. The chitosan scaffolds were then used to investigate the effect of the controlled release of fibroblast growth factor-basic (bFGF) and transforming growth factor-ß1 (TGFß1) on mouse fibroblast cells (L929) and bovine carotid endothelial cells (BEC). The biocompatibility of the prepared chitosan scaffold was confirmed with WST-1 proliferation and viability assay, which demonstrated that the material is suitable for cell growth. The results of this study show that the pore sizes of the porous scaffolds prepared by freeze-drying can change depending on the pre-freezing temperature and time via the formation of ice crystals. In this study, the scaffolds with the largest pore size were found to be 153 ± 32 µm and scaffolds with the smallest pores to be 34 ± 9 µm. Through cell culture analysis, it was found that the concentration that increased proliferation of L929 cells for bFGF was 0.005 to 0.1 ng/mL, and the concentration for TGFß1 was 0.005 to 1 ng/mL. The cell culture of the chitosan scaffold and growth factors shows that 3.75 ng of bFGF in scaffolds with pore sizes of 153 ± 32 µm can promote L929 cell proliferation, while 400 pg of TGFß1 in scaffolds with pore size of 34 ± 9 µm can enhance the proliferation of L929 cells, but also inhibit BEC proliferation. It is proposed that the prepared chitosan scaffolds can form a multi-drug (bFGF and TGFß1) release dressing that has the ability to control wound healing via regulating the proliferation of different cell types.

14.
Sci Technol Adv Mater ; 18(1): 163-171, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28458740

RESUMO

The microvascular network is a simple but critical system that is responsible for a range of important biological mechanisms in the bodies of all animals. The ability to generate a functional microvessel not only makes it possible to engineer vital tissue of considerable size but also serves as a platform for biomedical studies. However, most of the current methods for generating microvessel networks in vitro use rectangular channels which cannot represent real vessels in vivo and have dead zones at their corners, hence hindering the circulation of culture medium. We propose a scaffold-wrapping method which enables fabrication of a customized microvascular network in vitro in a more biomimetic way. By integrating microelectromechanical techniques with thermal reflow, we designed and fabricated a microscale hemi-cylindrical photoresist template. A replica mold of polydimethylsiloxane, produced by casting, was then used to generate cylindrical scaffolds with biodegradable poly(lactide-co-glycolide) (PLGA). Human umbilical vein endothelial cells were seeded on both sides of the PLGA scaffold and cultured using a traditional approach. The expression of endothelial cell marker CD31 and intercellular junction vascular endothelial cadherin on the cultured cell demonstrated the potential of generating a microvascular network with a degradable cylindrical scaffold. Our method allows cells to be cultured on a scaffold using a conventional culture approach and monitors cell conditions continuously. We hope our cell-covered scaffold can serve as a framework for building large tissues or can be used as the core of a vascular chip for in vitro circulation studies.

15.
Int J Nanomedicine ; 12: 421-432, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28138239

RESUMO

Nerve repair in tissue engineering involves the precise construction of a scaffold to guide nerve cell regeneration in the desired direction. However, improvements are needed to facilitate the cell migration/growth rate of nerves in the center of a nerve conduit. In this paper, we propose a nerve guidance conduit with a hybrid structure comprising a microfibrous poly(lactic-co-glycolic acid) (PLGA) bundle wrapped in a micro/nanostructured PLGA membrane. We applied sequential fabrication processes, including photolithography, nano-electroforming, and polydimethylsiloxane casting to manufacture master molds for the repeated production of the PLGA subelements. After demolding it from the master molds, we rolled the microfibrous membrane into a bundle and then wrapped it in the micro/nanostructured membrane to form a nerve-guiding conduit. We used KT98/F1B-GFP cells to estimate the migration rate and guidance ability of the fabricated nerve conduit and found that both elements increased the migration rate 1.6-fold compared with a flat PLGA membrane. We also found that 90% of the cells in the hybrid nano/microstructured membrane grew in the direction of the designed patterns. After 3 days of culturing, the interior of the nerve conduit was filled with cells, and the microfiber bundle was also surrounded by cells. Our conduit cell culture results also demonstrate that the proposed micro/nanohybrid and microfibrous structures can retain their shapes. The proposed hybrid-structured conduit demonstrates a high capability for guiding nerve cells and promoting cell migration, and, as such, is feasible for use in clinical applications.


Assuntos
Regeneração Tecidual Guiada/métodos , Ácido Láctico/química , Membranas Artificiais , Nanoestruturas/química , Ácido Poliglicólico/química , Animais , Movimento Celular , Proliferação de Células , Células Cultivadas , Camundongos , Regeneração Nervosa/fisiologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Tecidos Suporte
16.
Int Wound J ; 14(1): 125-129, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26833759

RESUMO

Over the last decade, lymph node flap (LNF) transfer has turned out to be an effective method in the management of lymphoedema of extremities. Most of the time, the pockets created for LNF cannot be closed primarily and need to be resurfaced with split thickness skin grafts. Partial graft loss was frequently noted in these cases. The need to prevent graft loss on these iatrogenic wounds made us explore the possibility of attempting delayed skin grafting. We have herein reported our experience with delayed grafting with autologous banked split skin grafts in cases of LNF transfer for lymphoedema of the extremities. Ten patients with International Society of Lymphology stage II-III lymphoedema of upper or lower extremity were included in this study over an 8-month period. All patients were thoroughly evaluated and subjected to lymph node flap transfer. The split skin graft was harvested and banked at the donor site, avoiding immediate resurfacing over the flap. The same was carried out in an aseptic manner as a bedside procedure after confirming flap viability and allowing flap swelling to subside. Patients were followed up to evaluate long-term outcomes. Flap survival was 100%. Successful delayed skin grafting was done between the 4th and 6th post-operative day as a bedside procedure under local anaesthesia. The split thickness skin grafts (STSG) takes more than 97%. One patient needed additional medications during the bedside procedure. All patients had minimal post-operative pain and skin graft requirement. The patients were also reported to be satisfied with the final aesthetic results. There were no complications related to either the skin grafts or donor sites during the entire period of follow-up. Delayed split skin grafting is a reliable method of resurfacing lymph node flaps and has been shown to reduce the possibility of flap complications as well as the operative time and costs.


Assuntos
Linfonodos/transplante , Transplante de Pele/métodos , Retalhos Cirúrgicos/transplante , Bancos de Tecidos , Extremidade Superior/cirurgia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
17.
Biomed Mater ; 11(2): 025015, 2016 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-27068738

RESUMO

In this study, we have developed a microporous poly(lactic-co-glycolic acid) (PLGA) scaffold that combines a continuous release property and a three-dimensional (3D) scaffolding technique for the precise and efficient formation of endothelial cell lineage from embryonic stem cells (ESCs). Eight PLGA scaffolds (14.29%, 16.67%, 20% and 25% concentrations of PLGA solutions) mixed with two crystal sizes of sodium chloride (NaCl) were fabricated by leaching. Then, vascular endothelial cell conditioned medium (ECCM) mixed with gelatin was embedded into the scaffold for culturing of mouse embryonic stem cells (mESCs). The 14.29% PLGA scaffolds fabricated using non-ground NaCl particles (NG-PLGA) and the 25% PLGA containing scaffolds fabricated using ground NaCl particles (G-PLGA) possessed minimum and maximum moisture content and bovine serum albumin (BSA) content properties, respectively. These two groups of scaffolds were used for future experiments in this study. Cell culture results demonstrated that the proposed porous scaffolds without growth factors were sufficient to induce mouse ESCs to differentiate into endothelial-like cells in the early culture stages, and combined with embedded ECCM could provide a long-term inducing system for ESC differentiation.


Assuntos
Materiais Biocompatíveis/química , Ácido Láctico/química , Células-Tronco Embrionárias Murinas/citologia , Ácido Poliglicólico/química , Tecidos Suporte/química , Animais , Bovinos , Diferenciação Celular , Células Cultivadas , Meios de Cultivo Condicionados/química , Células Endoteliais/citologia , Gelatina , Teste de Materiais , Camundongos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Porosidade , Engenharia Tecidual/métodos
19.
Biosens Bioelectron ; 77: 90-8, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26397419

RESUMO

A sensing platform, combined amino acid labeling kit and a double-generation gold nanoparticle (DG-AuNP) chip, was designed to prove the existence of weak but crucial binding between the DV (dengue virus) and its CLEC5A receptor. At first, we have designed a kit combining the novel fluorescence turn-on sensors for lysine, arginine and cysteine amino acids. Advantages of this kit are that emission on-off switching can increase the signal-to-noise ratio and the virus must be fluorescently labelled with sufficient numbers of fluorophores because the lysine, arginine and cysteine residues of viral proteins are labelled simultaneously. Consequently, this kit can be used to light-on single DV spot both in solution and in cell under fluorescence microscopy. Second, the labeling kit was used to examine the DV binding to the CLEC5A-coated DG-AuNP chip. Based on our study, the double-generation gold nanoparticle construction of chip can support more coating areas for receptor CLEC5A and then, support more binding opportunities for DV. Meanwhile, the grooves between nanohemispheres will provide the extra driving force for DV stacking. We try to give a proof that this sensing platform is very useful for detection of weak binding mechanism.


Assuntos
Vírus da Dengue/isolamento & purificação , Ouro/química , Nanopartículas Metálicas/química , Microscopia de Fluorescência/instrumentação , Espectrometria de Fluorescência/instrumentação , Carga Viral/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Corantes Fluorescentes/química , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula
20.
Biosens Bioelectron ; 77: 603-8, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26479905

RESUMO

A polymerase chain reaction (PCR)-free technique for the effective detection of genomic length hepatitis B virus (HBV) DNA is described in this study. The honeycomb-like barrier layer of an anodic aluminum oxide (AAO) film having a uniform nanohemisphere array was used as the substrate of the sensing electrode. A 30-nm gold film was sputtered onto the AAO barrier layer surface as the electrode, followed by electrochemical deposition of gold nanoparticles (GNPs) on the hemisphere surface. A specially designed single-strand 96-mer gene fragment of the target genomic DNA of HBV based on the genome sequences of HBV was immobilized on the nanostructured electrode as the capture probe. Target HBV DNA obtained from clinical samples was hybridized to the sensing probes. Detection results illustrate two dynamic linear ranges, 10(2)-10(3) and 10(3)-10(5.1) copies/mL, having R(2) values of 0.801 and 0.996 could be obtained, respectively. The detection limit of the proposed sending scheme was measured to be 111 copies/mL. The total of 45 target samples, including 20 samples with HBV concentration being lower than 10(2) copies/mL and 25 samples with HBV concentration being in the range of 10(3)-10(5.1) copies/mL, were used for real test. The concentration of these 45 HBV DNA samples was measured by the COBAS Ampliprep system. Comparing the measured results of the COBAS Ampliprep and our system, it was illustrated that the HBV DNA concentrations measured by the proposed method in this study had a high linear correlation with the COBAS Ampliprep, having R(2) values of 0.983. The proposed sensing scheme is highly feasible for future clinical applications.


Assuntos
Condutometria/instrumentação , DNA Viral/análise , DNA Viral/genética , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Análise de Sequência de DNA/instrumentação , Sequência de Bases , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Dados de Sequência Molecular , Nanotecnologia/instrumentação , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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