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1.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-997306

RESUMO

Aspergillus infection is relatively rare disease, and we present a case of orbital aspergillus infection who presented with right orbital pain and swelling. Right orbital lesion was identified on CT, MRI, and PET-CT imaging followed by confirmation of aspergillus on histopathological examination. We demonstrate that Tc-99 m ubiquicidin scan can yield positive results in aspergillosis too, enabling its differentiation from non-infective pathologies.

2.
Microbiome ; 10(1): 201, 2022 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-36434666

RESUMO

BACKGROUND: A dominance of non-iners Lactobacillus species in the vaginal microbiome is optimal and strongly associated with gynecological and obstetric health, while the presence of diverse obligate or facultative anaerobic bacteria and a paucity in Lactobacillus species, similar to communities found in bacterial vaginosis (BV), is considered non-optimal and associated with adverse health outcomes. Various therapeutic strategies are being explored to modulate the composition of the vaginal microbiome; however, there is no human model that faithfully reproduces the vaginal epithelial microenvironment for preclinical validation of potential therapeutics or testing hypotheses about vaginal epithelium-microbiome interactions. RESULTS: Here, we describe an organ-on-a-chip (organ chip) microfluidic culture model of the human vaginal mucosa (vagina chip) that is lined by hormone-sensitive, primary vaginal epithelium interfaced with underlying stromal fibroblasts, which sustains a low physiological oxygen concentration in the epithelial lumen. We show that the Vagina Chip can be used to assess colonization by optimal L. crispatus consortia as well as non-optimal Gardnerella vaginalis-containing consortia, and to measure associated host innate immune responses. Co-culture and growth of the L. crispatus consortia on-chip was accompanied by maintenance of epithelial cell viability, accumulation of D- and L-lactic acid, maintenance of a physiologically relevant low pH, and down regulation of proinflammatory cytokines. In contrast, co-culture of G. vaginalis-containing consortia in the vagina chip resulted in epithelial cell injury, a rise in pH, and upregulation of proinflammatory cytokines. CONCLUSION: This study demonstrates the potential of applying human organ chip technology to create a preclinical model of the human vaginal mucosa that can be used to better understand interactions between the vaginal microbiome and host tissues, as well as to evaluate the safety and efficacy of live biotherapeutics products. Video Abstract.


Assuntos
Microbiota , Vaginose Bacteriana , Feminino , Gravidez , Humanos , Dispositivos Lab-On-A-Chip , Vagina , Citocinas
3.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22281144

RESUMO

Coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is a highly contagious disease with several variants, continues to spread as part of the global pandemic. With the roll-out of vaccines and development of new therapeutics that may be targeted to distinct viral molecules, there is a need to screen populations for viral antigen-specific SARS-CoV-2 antibodies. Here, we describe a rapid, multiplexed, electrochemical (EC) platform with on-chip control that enables detection of SARS-CoV-2 antibodies in less than 10 min using 1.5 {micro}L of a patient sample. The EC biosensor demonstrated 100% sensitivity and specificity, and an area under the receiver operating characteristic curve of 1, when evaluated using 93 clinical samples, including plasma and dried blood spot samples from 54 SARS-CoV-2 positive and 39 negative patients. This EC biosensor platform enables simple, cost-effective, sensitive, and rapid detection of anti-SARS-CoV-2 antibodies in complex clinical samples, which is convenient for monitoring host humoral responses to vaccination or viral infection in broad population testing, including applications in low-resource settings. We also demonstrate the feasibility of using dried blood spot samples that can be collected locally and transported to distant clinical laboratories at ambient temperature for detection of anti-SARS-CoV-2 antibodies which can be used for serological surveillance and demonstrate the utility of remote sampling.

4.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-446968

RESUMO

Many patients infected with coronaviruses, such as SARS-CoV-2 and NL63 that use ACE2 receptors to infect cells, exhibit gastrointestinal symptoms and viral proteins are found in the human gastrointestinal tract, yet little is known about the inflammatory and pathological effects of coronavirus infection on the human intestine. Here, we used a human intestine-on-a-chip (Intestine Chip) microfluidic culture device lined by patient organoid-derived intestinal epithelium interfaced with human vascular endothelium to study host cellular and inflammatory responses to infection with NL63 coronavirus. These organoid-derived intestinal epithelial cells dramatically increased their ACE2 protein levels when cultured under flow in the presence of peristalsis-like mechanical deformations in the Intestine Chips compared to when cultured statically as organoids or in Transwell inserts. Infection of the intestinal epithelium with NL63 on-chip led to inflammation of the endothelium as demonstrated by loss of barrier function, increased cytokine production, and recruitment of circulating peripheral blood mononuclear cells (PMBCs). Treatment of NL63 infected chips with the approved protease inhibitor drug, nafamostat, inhibited viral entry and resulted in a reduction in both viral load and cytokine secretion, whereas remdesivir, one of the few drugs approved for COVID19 patients, was not found to be effective and it also was toxic to the endothelium. This model of intestinal infection was also used to test the effects of other drugs that have been proposed for potential repurposing against SARS-CoV-2. Taken together, these data suggest that the human Intestine Chip might be useful as a human preclinical model for studying coronavirus related pathology as well as for testing of potential anti-viral or anti-inflammatory therapeutics.

5.
Clin Transl Sci ; 14(4): 1578-1589, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33786999

RESUMO

Sepsis is a major cause of mortality among hospitalized patients worldwide. Shorter time to administration of broad-spectrum antibiotics is associated with improved outcomes, but early recognition of sepsis remains a major challenge. In a two-center cohort study with prospective sample collection from 1400 adult patients in emergency departments suspected of sepsis, we sought to determine the diagnostic and prognostic capabilities of a machine-learning algorithm based on clinical data and a set of uncommonly measured biomarkers. Specifically, we demonstrate that a machine-learning model developed using this dataset outputs a score with not only diagnostic capability but also prognostic power with respect to hospital length of stay (LOS), 30-day mortality, and 3-day inpatient re-admission both in our entire testing cohort and various subpopulations. The area under the receiver operating curve (AUROC) for diagnosis of sepsis was 0.83. Predicted risk scores for patients with septic shock were higher compared with patients with sepsis but without shock (p < 0.0001). Scores for patients with infection and organ dysfunction were higher compared with those without either condition (p < 0.0001). Stratification based on predicted scores of the patients into low, medium, and high-risk groups showed significant differences in LOS (p < 0.0001), 30-day mortality (p < 0.0001), and 30-day inpatient readmission (p < 0.0001). In conclusion, a machine-learning algorithm based on electronic medical record (EMR) data and three nonroutinely measured biomarkers demonstrated good diagnostic and prognostic capability at the time of initial blood culture.


Assuntos
Diagnóstico Precoce , Registros Eletrônicos de Saúde/estatística & dados numéricos , Aprendizado de Máquina , Sepse/diagnóstico , Idoso , Área Sob a Curva , Biomarcadores/sangue , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Readmissão do Paciente/estatística & dados numéricos , Prognóstico , Estudos Prospectivos , Curva ROC , Sepse/sangue , Sepse/microbiologia , Sepse/mortalidade
6.
Sens Actuators B Chem ; 3052020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32863588

RESUMO

Due to the lack of specific early detection methods for pancreatic cancer, it usually goes undetected until it is advanced. By employing paper-based electrodes (PPE), herein we for the first time developed a disposable low-cost paper-based immunosensor for rapid early quantitative detection of pancreatic cancer with a new biomarker, pseudopodium-enriched atypical kinase one, SGK269 (PEAK1). The immunosensor was constructed by fabricating PPEs immobilized with the versatile nanomaterial graphene oxide for the incorporation of antibodies to form an immunosensing platform, without the need of complicated surface modification. After it was confirmed that the PPEs exhibited excellent electrochemical properties, a sandwich-type electrochemical immunosensor was subsequently constructed by employing graphene oxide layers immobilized with anti-PEAK1, and the antibody conjugated with gold nanoparticles (AuNPs-tagged-Anti PEAK1). Further, spectral and surface characteristic studies confirmed the formation of the immunosensing platform. The immunosensor for PEAK1 exhibited a wide linear range between 10 pg mL-1 and 106 pg mL-1 with a low limit of detection (LOD) of 10 pg mL-1. The obtained results point towards rapid, sensitive, and specific early diagnosis of pancreatic cancer at the point of care and other low-resource settings.

7.
Microsyst Nanoeng ; 6: 28, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34567643

RESUMO

Conventional colorimetric enzyme-linked immunosorbent assay (ELISA) is a time-consuming laboratory assay that is not very sensitive and consumes a large amount of samples. Herein, the development of a reusable, cost-effective, and eco-friendly poly(methyl methacrylate) (PMMA)/paper hybrid plug-and-play (PnP) device for high-sensitivity immunoassay by analyte enrichment and efficient passing-through washing has been reported. The PMMA device has multiple slots where a pre-patterned paper substrate can be inserted. The sample flows back-and-forth through a low-cost, 3D paper substrate within the PMMA channels, thereby enhancing the amount of analyte adsorbed and dramatically increasing the sensitivity while decreasing the assay time. After the enrichment assay, the paper substrate can simply be pulled out of the device, and the results can be qualitatively viewed with the naked eye or scanned through a simple desktop scanner for quantitative analysis. The paper substrate can be replaced with a new substrate so that the device can be reused. The limits of detection (LODs) of 200 pg/mL for immunoglobulin G (IgG) and 270 pg/mL for hepatitis B surface antigen (HBsAg) were obtained. This IgG assay is at least 10 times more sensitive than commercial ELISA kits. In addition, the PnP ELISA exhibited a significant increase in the linear dynamic range from 3 orders of magnitude in a common paper-based device to a wide range of six orders of magnitude in the PnP hybrid device. This reusable PnP device has great potential for the low-cost yet high-sensitivity detection of infectious diseases, cancers, and other important biomolecules.

8.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-786497

RESUMO

Immunoglobulin G4 (IgG4)–related diseases are a spectrum of systemic inflammatory conditions of unknown etiology, which are characterized by infiltration of tissues by IgG4 plasma cells and sclerosing inflammation (Cheuk and Chan Adv Anat Pathol 17:303-32, 2010). Although this condition was initially described in relation to autoimmune pancreatitis, now it has been reported in almost every organ system of body (Zen and Nakanuma Am J Surg Pathol 34:1812-9, 2010, Masaki et al. Ann Rheuma Dis 68:1310-5, 2009). Orbital involvement by IgG4 disease can involve extraocular muscles (EOM), lacrimal glands, conjunctiva, eyelids, infraorbital nerve, orbital fat, and nasolacrimal system (McNab and McKelvie. Ophthal Plast Reconstr Surg 31:167-78, 2015, Katsura et al. Neuroradiology 54:873-82, 2012). The basis of using ⁶⁸Ga-DOTANOC PET/CT in IgG4 orbital disease is the known expression of somatostatin receptors in chronic inflammatory cells (Cuccurullo et al. Indian J Radiol Imaging 27:509-16, 2017) and also avidity shown previously in other IgG4-related diseases (Cheng et al. Clin Nucl Med 43:773-6, 2018).


Assuntos
Túnica Conjuntiva , Pálpebras , Imunoglobulina G , Imunoglobulinas , Inflamação , Aparelho Lacrimal , Músculos , Órbita , Doenças Orbitárias , Pancreatite , Plasmócitos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Receptores de Somatostatina
9.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-951221

RESUMO

Malaria remains a major tropical health burden owing to the development of resistance and decreased sensitivity to the frequently used conventional antimalarial drugs. The drug like artemisinin possesses potent antimalarial activities, but has some limitations. Therefore, new strategies are to be implemented for optimal utilization of artemisinin to improve its therapeutic effectiveness and to overcome its limitations. The present review focuses on present scenario of malaria and pharmacological as well as analytical aspects of artemisinin. Data from 2000 to 2018 were collected from NCBI for understanding the various analytical techniques used for estimation of artemisinin. This review will reveal the facts about artemisinin which can be utilized to develop novel drug delivery system either in a combination or as alone for the wellbeing of the patients suffering from malaria.

10.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-997427

RESUMO

Immunoglobulin G4 (IgG4)–related diseases are a spectrum of systemic inflammatory conditions of unknown etiology, which are characterized by infiltration of tissues by IgG4 plasma cells and sclerosing inflammation (Cheuk and Chan Adv Anat Pathol 17:303-32, 2010). Although this condition was initially described in relation to autoimmune pancreatitis, now it has been reported in almost every organ system of body (Zen and Nakanuma Am J Surg Pathol 34:1812-9, 2010, Masaki et al. Ann Rheuma Dis 68:1310-5, 2009). Orbital involvement by IgG4 disease can involve extraocular muscles (EOM), lacrimal glands, conjunctiva, eyelids, infraorbital nerve, orbital fat, and nasolacrimal system (McNab and McKelvie. Ophthal Plast Reconstr Surg 31:167-78, 2015, Katsura et al. Neuroradiology 54:873-82, 2012). The basis of using ⁶⁸Ga-DOTANOC PET/CT in IgG4 orbital disease is the known expression of somatostatin receptors in chronic inflammatory cells (Cuccurullo et al. Indian J Radiol Imaging 27:509-16, 2017) and also avidity shown previously in other IgG4-related diseases (Cheng et al. Clin Nucl Med 43:773-6, 2018).

11.
Anal Chem ; 90(16): 9888-9896, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30028601

RESUMO

A portable multiplexed bar-chart SpinChip (MB-SpinChip) integrated with nanoparticle-mediated magnetic aptasensors was developed for visual quantitative instrument-free detection of multiple pathogens. This versatile multiplexed SpinChip combines aptamer-specific recognition and nanoparticle-catalyzed pressure amplification to achieve a sample-to-answer output for sensitive point-of-care testing (POCT). This is the first report of pathogen detection using a volumetric bar-chart chip, and it is also the first bar-chart chip using a "spinning" mechanism to achieve multiplexed bar-chart detection. Additionally, the introduction of the spin unit not only enabled convenient sample introduction from one inlet to multiple separate channels in the multiplexed detection, but also elegantly solved the pressure cross-interference problem in the multiplexed volumetric bar-chart chip. This user-friendly MB-SpinChip allows visual quantitative detection of multiple pathogens simultaneously with high sensitivity but without utilizing any specialized instruments. Using this MB-SpinChip, three major foodborne pathogens including Salmonella enterica, Escherichia coli, and Listeria monocytogenes were specifically quantified in apple juice with limits of detection of about 10 CFU/mL. This MB-SpinChip with a bar-chart-based visual quantitative readout has great potential for the rapid simultaneous detection of various pathogens at the point of care and wide applications in food safety, environmental surveillance, and infectious disease diagnosis.


Assuntos
Aptâmeros de Nucleotídeos/química , Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana/métodos , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/métodos , Nanopartículas/química , Técnicas Biossensoriais/métodos , Microbiologia de Alimentos/instrumentação , Microbiologia de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Limite de Detecção , Fenômenos Magnéticos , Técnicas Analíticas Microfluídicas/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito
12.
Anal Chem ; 90(9): 5930-5937, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29641893

RESUMO

The exploration of new physical and chemical properties of materials and their innovative application in different fields are of great importance to advance analytical chemistry, material science, and other important fields. Herein, we, for the first time, discovered the photothermal effect of an iron oxide nanoparticles (NPs)-mediated TMB (3,3',5,5'-tetramethylbenzidine)-H2O2 colorimetric system, and applied it toward the development of a new NP-mediated photothermal immunoassay platform for visual quantitative biomolecule detection using a thermometer as the signal reader. Using a sandwich-type proof-of-concept immunoassay, we found that the charge transfer complex of the iron oxide NPs-mediated one-electron oxidation product of TMB (oxidized TMB) exhibited not only color changes, but also a strong near-infrared (NIR) laser-driven photothermal effect. Hence, oxidized TMB was explored as a new sensitive photothermal probe to convert the immunoassay signal into heat through the near-infrared laser-driven photothermal effect, enabling simple photothermal immunoassay using a thermometer. Based on the new iron oxide NPs-mediated TMB-H2O2 photothermal immunoassay platform, prostate-specific antigen (PSA) as a model biomarker can be detected at a concentration as low as 1.0 ng·mL-1 in normal human serum. The discovered photothermal effect of the colorimetric system and the developed new photothermal immunoassay platform open up a new horizon for affordable detection of disease biomarkers and have great potential for other important material and biomedical applications of interest.


Assuntos
Benzidinas/química , Colorimetria , Peróxido de Hidrogênio/química , Imunoensaio , Nanopartículas/química , Antígeno Prostático Específico/análise , Temperatura , Humanos , Oxirredução , Processos Fotoquímicos
13.
Adv Drug Deliv Rev ; 128: 3-28, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28919029

RESUMO

Conventional systematically-administered drugs distribute evenly throughout the body, get degraded and excreted rapidly while crossing many biological barriers, leaving minimum amounts of the drugs at pathological sites. Controlled drug delivery aims to deliver drugs to the target sites at desired rates and time, thus enhancing the drug efficacy, pharmacokinetics, and bioavailability while maintaining minimal side effects. Due to a number of unique advantages of the recent microfluidic lab-on-a-chip technology, microfluidic lab-on-a-chip has provided unprecedented opportunities for controlled drug delivery. Drugs can be efficiently delivered to the target sites at desired rates in a well-controlled manner by microfluidic platforms via integration, implantation, localization, automation, and precise control of various microdevice parameters. These features accordingly make reproducible, on-demand, and tunable drug delivery become feasible. On-demand self-tuning dynamic drug delivery systems have shown great potential for personalized drug delivery. This review presents an overview of recent advances in controlled drug delivery using microfluidic platforms. The review first briefly introduces microfabrication techniques of microfluidic platforms, followed by detailed descriptions of numerous microfluidic drug delivery systems that have significantly advanced the field of controlled drug delivery. Those microfluidic systems can be separated into four major categories, namely drug carrier-free micro-reservoir-based drug delivery systems, highly integrated carrier-free microfluidic lab-on-a-chip systems, drug carrier-integrated microfluidic systems, and microneedles. Microneedles can be further categorized into five different types, i.e. solid, porous, hollow, coated, and biodegradable microneedles, for controlled transdermal drug delivery. At the end, we discuss current limitations and future prospects of microfluidic platforms for controlled drug delivery.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Microinjeções , Agulhas , Humanos , Microinjeções/instrumentação
14.
Chem Commun (Camb) ; 53(79): 10886-10889, 2017 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-28703226

RESUMO

A paper/poly(methyl methacrylate) (PMMA) hybrid CD-like microfluidic SpinChip integrated with DNA probe-functionalized graphene oxide (GO) nanosensors was developed for multiplex quantitative LAMP detection (mqLAMP). This approach can simply and effectively address a major challenging problem of multiplexing in current LAMP methods.


Assuntos
Sondas de DNA/química , DNA Bacteriano/análise , Grafite/química , Nanoestruturas/química , Neisseria meningitidis/isolamento & purificação , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , Polimetil Metacrilato/química , Streptococcus pneumoniae/isolamento & purificação , Técnicas Biossensoriais/instrumentação , Desenho de Equipamento , Humanos , Infecções Meningocócicas/microbiologia , Óxidos/química , Papel , Infecções Pneumocócicas/microbiologia
15.
Biosens Bioelectron ; 87: 865-873, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27657849

RESUMO

Neisseria meningitidis (N. meningitidis), Streptococcus pneumoniae (S. pneumoniae), and Haemophilus influenzae type b (Hib) are three most common pathogens accounting for most bacterial meningitis, a serious global infectious disease with high fatality, especially in developing nations. Because the treatment and antibiotics differ among each type, the identification of the exact bacteria causing the disease is vital. Herein, we report a polymer/paper hybrid microfluidic biochip integrated with loop-mediated isothermal amplification (LAMP) for multiplexed instrument-free diagnosis of these three major types of bacterial meningitis, with high sensitivity and specificity. Results can be visually observed by the naked eye or imaged by a smartphone camera under a portable UV light source. Without using any specialized laboratory instrument, the limits of detection of a few DNA copies per LAMP zone for N. meningitidis, S. pneumoniae and Hib were achieved within 1h. In addition, these three types of microorganisms spiked in artificial cerebrospinal fluid (ACSF) were directly detected simultaneously, avoiding cumbersome sample preparation procedures in conventional methods. Compared with the paper-free non-hybrid microfluidic biochip over a period of three months, the hybrid microfluidic biochip was found to have a much longer shelf life. Hence, this rapid, instrument-free and highly sensitive microfluidic approach has great potential for point-of-care (POC) diagnosis of multiple infectious diseases simultaneously, especially in resource-limited settings.


Assuntos
Técnicas Biossensoriais/instrumentação , Haemophilus influenzae/isolamento & purificação , Dispositivos Lab-On-A-Chip , Meningite Meningocócica/diagnóstico , Neisseria meningitidis/isolamento & purificação , Papel , Streptococcus pneumoniae/isolamento & purificação , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Desenho de Equipamento , Infecções por Haemophilus/líquido cefalorraquidiano , Infecções por Haemophilus/diagnóstico , Infecções por Haemophilus/microbiologia , Humanos , Limite de Detecção , Meningite Meningocócica/líquido cefalorraquidiano , Meningite Meningocócica/microbiologia , Infecções Pneumocócicas/líquido cefalorraquidiano , Infecções Pneumocócicas/diagnóstico , Infecções Pneumocócicas/microbiologia , Sistemas Automatizados de Assistência Junto ao Leito , Polímeros/química
16.
Sci Rep ; 6: 30474, 2016 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-27456979

RESUMO

Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings.


Assuntos
Biomarcadores/análise , Microfluídica/métodos , Papel , Polímeros/química , Ensaio de Imunoadsorção Enzimática , Antígenos de Superfície da Hepatite B/sangue , Humanos , Imunoglobulina G/sangue , Indóis/química , Indóis/metabolismo , Nitroazul de Tetrazólio/química , Nitroazul de Tetrazólio/metabolismo , Polimetil Metacrilato/química , Fatores de Tempo
17.
Analyst ; 141(12): 3883-9, 2016 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-27140740

RESUMO

The development of new sensitive, cost-effective and user-friendly colorimetric bioassays is in increasing demand to meet the requirement of modern clinical diagnostics and field detection. Herein, a novel iron oxide-to-Prussian blue (PB) nanoparticle (NP) conversion strategy was developed and applied to sensitive colorimetric immunosensing of cancer biomarkers. In a typical sandwich-type immunosensing system, the captured spherical antibody-conjugated iron oxide NPs were transformed into cubic PB NPs, which exhibited a highly visible blue color with high molar extinction coefficients. Hence, a new colorimetric immunosensing strategy was developed as a result of this low cost and simple transformation process. Without the aid of any complex nanoparticle stabilizing ligands and signal amplification processes, prostate-specific antigen as a model analyte can be detected at a concentration as low as 1.0 ng mL(-1) by the naked eye with good reliability for detection of real human serum samples. This is the first attempt to develop and apply the iron oxide-to-PB NP colorimetric conversion strategy for immunosensing, and shows great promise for the development of new sensitive, cost-effective and user-friendly colorimetric bioassays in various bioanalytical applications, especially in low-resource settings.


Assuntos
Colorimetria , Compostos Férricos/química , Ferrocianetos/química , Imunoensaio , Nanopartículas , Ouro , Humanos , Masculino , Antígeno Prostático Específico/sangue , Reprodutibilidade dos Testes
18.
Nanoscale ; 8(10): 5422-7, 2016 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-26838516

RESUMO

A new biomolecular quantitation method, nanoparticle-mediated photothermal bioassay, using a common thermometer as the signal reader was developed. Using an immunoassay as a proof of concept, iron oxide nanoparticles (NPs) captured in the sandwich-type assay system were transformed into a near-infrared (NIR) laser-driven photothermal agent, Prussian blue (PB) NPs, which acted as a photothermal probe to convert the assay signal into heat through the photothermal effect, thus allowing sensitive biomolecular quantitation using a thermometer. This is the first report of biomolecular quantitation using a thermometer and also serves as the first attempt to introduce the nanoparticle-mediated photothermal effect for bioassays.


Assuntos
Compostos Férricos/química , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Bioensaio , Calibragem , Ferrocianetos/química , Temperatura Alta , Humanos , Imunoensaio/métodos , Masculino , Microscopia Eletrônica de Transmissão , Antígeno Prostático Específico/química , Espectroscopia de Luz Próxima ao Infravermelho , Termômetros
19.
Curr Pharm Biotechnol ; 17(9): 772-87, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26813304

RESUMO

Therapeutic drugs administered systematically are evenly distributed to the whole body through blood circulation and have to cross many biological barriers before reaching the pathological site. Conventional drug delivery may make drugs inactive or reduce their potency as they may be hydrolyzed or degraded enzymatically and are rapidly excreted through the urinary system resulting in suboptimal concentration of drugs at the desired site. Controlled drug delivery aims to localize the pharmacological activity of the drug to the desired site at desired release rates. The advances made by micro/nanofluidic technologies have provided new opportunities for better-controlled drug delivery. Various components of a drug delivery system can be integrated within a single tiny micro/nanofluidic chip. This article reviews recent advances of controlled drug delivery made by microfluidic/nanofluidic technologies. We first discuss microreservoir-based drug delivery systems. Then we highlight different kinds of microneedles used for controlled drug delivery, followed with a brief discussion about the current limitations and the future prospects of controlled drug delivery systems.


Assuntos
Sistemas de Liberação de Medicamentos , Dispositivos Lab-On-A-Chip , Animais , Sistemas de Liberação de Medicamentos/métodos , Humanos , Agulhas
20.
Talanta ; 145: 43-54, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26459442

RESUMO

Low-cost assays have broad applications ranging from human health diagnostics and food safety inspection to environmental analysis. Hence, low-cost assays are especially attractive for rural areas and developing countries, where financial resources are limited. Recently, paper-based microfluidic devices have emerged as a low-cost platform which greatly accelerates the point of care (POC) analysis in low-resource settings. This paper reviews recent advances of low-cost bioanalysis on paper-based microfluidic platforms, including fully paper-based and paper hybrid microfluidic platforms. In this review paper, we first summarized the fabrication techniques of fully paper-based microfluidic platforms, followed with their applications in human health diagnostics and food safety analysis. Then we highlighted paper hybrid microfluidic platforms and their applications, because hybrid platforms could draw benefits from multiple device substrates. Finally, we discussed the current limitations and perspective trends of paper-based microfluidic platforms for low-cost assays.


Assuntos
Técnicas de Química Analítica/economia , Técnicas de Química Analítica/métodos , Dispositivos Lab-On-A-Chip/economia , Papel , Animais , Técnicas de Química Analítica/instrumentação , Custos e Análise de Custo , Humanos , Integração de Sistemas
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