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1.
Cancer Immunol Immunother ; 67(7): 1135-1146, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29785657

RESUMEN

Lung cancer is the leading cause of cancer death worldwide. Survival is largely dependent on the stage of diagnosis: the localized disease has a 5-year survival greater than 55%, whereas, for spread tumors, this rate is only 4%. Therefore, the early detection of lung cancer is key for improving prognosis. In this study, we present an innovative, non-invasive, cancer detection approach based on measurements of the metabolic activity profiles of immune system cells. For each Liquid ImmunoBiopsy test, a 384 multi-well plate is loaded with freshly separated PBMCs, and each well contains 1 of the 16 selected stimulants in several increasing concentrations. The extracellular acidity is measured in both air-open and hermetically-sealed states, using a commercial fluorescence plate reader, for approximately 1.5 h. Both states enable the measurement of real-time accumulation of 'soluble' versus 'volatile' metabolic products, thereby differentiating between oxidative phosphorylation and aerobic glycolysis. The metabolic activity profiles are analyzed for cancer diagnosis by machine-learning tools. We present a diagnostic accuracy study, using a multivariable prediction model to differentiate between lung cancer and control blood samples. The model was developed and tested using a cohort of 200 subjects (100 lung cancer and 100 control subjects), yielding 91% sensitivity and 80% specificity in a 20-fold cross-validation. Our results clearly indicate that the proposed clinical model is suitable for non-invasive early lung cancer diagnosis, and is indifferent to lung cancer stage and histological type.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Detección Precoz del Cáncer/métodos , Neoplasias Pulmonares/diagnóstico , Metaboloma , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/cirugía , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Adulto Joven
2.
Sensors (Basel) ; 17(4)2017 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-28346363

RESUMEN

Traditional diagnostic tests for chronic diseases are expensive and require a specialized laboratory, therefore limiting their use for point-of-care (PoC) testing. To address this gap, we developed a method for rapid and low-cost C-reactive protein (CRP) detection from blood by integrating a paper-based microfluidic immunoassay with a smartphone (CRP-Chip). We chose CRP for this initial development because it is a strong biomarker of prognosis in chronic heart and kidney disease. The microfluidic immunoassay is realized by lateral flow and gold nanoparticle-based colorimetric detection of the target protein. The test image signal is acquired and analyzed using a commercial smartphone with an attached microlens and a 3D-printed chip-phone interface. The CRP-Chip was validated for detecting CRP in blood samples from chronic kidney disease patients and healthy subjects. The linear detection range of the CRP-Chip is up to 2 µg/mL and the detection limit is 54 ng/mL. The CRP-Chip test result yields high reproducibility and is consistent with the standard ELISA kit. A single CRP-Chip can perform the test in triplicate on a single chip within 15 min for less than 50 US cents of material cost. This CRP-Chip with attractive features of low-cost, fast test speed, and integrated easy operation with smartphones has the potential to enable future clinical PoC chronic disease diagnosis and risk stratification by parallel measurements of a panel of protein biomarkers.


Asunto(s)
Microfluídica , Proteína C-Reactiva , Diseño de Equipo , Oro , Humanos , Inmunoensayo , Nanopartículas del Metal , Reproducibilidad de los Resultados , Teléfono Inteligente
3.
Nano Lett ; 15(7): 4758-68, 2015 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-26086686

RESUMEN

Significant research efforts have been dedicated to the integration of biological species with electronic elements to yield smart bioelectronic devices. The integration of DNA, proteins, and whole living cells and tissues with electronic devices has been developed into numerous intriguing applications. In particular, the quantitative detection of biological species and monitoring of biological processes are both critical to numerous areas of medical and life sciences. Nevertheless, most current approaches merely focus on the "monitoring" of chemical processes taking place on the sensing surfaces, and little efforts have been invested in the conception of sensitive devices that can simultaneously "control" and "monitor" chemical and biological reactions by the application of on-surface reversible stimuli. Here, we demonstrate the light-controlled fine modulation of surface pH by the use of photoactive molecularly modified nanomaterials. Through the use of nanowire-based FET devices, we showed the capability of modulating the on-surface pH, by intensity-controlled light stimulus. This allowed us simultaneously and locally to control and monitor pH-sensitive biological reactions on the nanodevices surfaces, such as the local activation and inhibition of proteolytic enzymatic processes, as well as dissociation of antigen-antibody binding interactions. The demonstrated capability of locally modulating the on-surface effective pH, by a light stimuli, may be further applied in the local control of on-surface DNA hybridization/dehybridization processes, activation or inhibition of living cells processes, local switching of cellular function, local photoactivation of neuronal networks with single cell resolution and so forth.


Asunto(s)
Técnicas Biosensibles/instrumentación , Nanotecnología/instrumentación , Nanocables/química , Silicio/química , Transistores Electrónicos , Animales , Complejo Antígeno-Anticuerpo/análisis , Biocatálisis , Diseño de Equipo , Humanos , Concentración de Iones de Hidrógeno , Hidrólisis , Luz , Nanocables/ultraestructura
4.
J Nanobiotechnology ; 12: 7, 2014 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-24606762

RESUMEN

BACKGROUND: The detection of biological and chemical species is of key importance to numerous areas of medical and life sciences. Therefore, a great interest exists in developing new, rapid, miniature, biocompatible and highly sensitive sensors, capable to operate under physiological conditions and displaying long-term stabilities (e.g. in-body implantable sensors). Silicon nanostructures, nanowires and nanotubes, have been extensively explored as building blocks for the creation of improved electrical biosensing devices, by virtue of their remarkably high surface-to-volume ratios, and have shown exceptional sensitivity for the real time label-free detection of molecular species adsorbed on their surfaces, down to the sensitivity of single molecules.Yet, till this date, almost no rigorous studies have been performed on the temporal morphological stability of these nanostructures, and their resulting electrical devices, under physiological conditions (e.g. serum, blood), as well as on the chemical stability of the molecular recognition over-layers covering these structures. RESULTS: Here, we present systematic time-resolved results on the morphological stability of bare Si nanowire building blocks, as well on the chemical stability of siloxane-based molecular over-layers, under physiological conditions. Furthermore, in order to overcome the observed short-term morpho-chemical instabilities, we present on the chemical passivation of the Si nanostructures by thin metal oxide nanoshells, in the range of 3-10 nm. The thickness of the metal oxide layer influences on the resulting electrical sensitivity of the fabricated FETs (field effect transistors), with an optimum thickness of 3-4 nm. CONCLUSIONS: The core-shell structures display remarkable long-term morphological stability, preventing both, the chemical hydrolytic dissolution of the silicon under-structure and the concomitant loss of the siloxane-based chemical over-layers, for periods of at least several months. Electrical devices constructed from these nanostructures display excellent electrical characteristics and detection sensitivities, with exceptionally high morphological and functional stabilities. These results pave the road for the creation of long-term implantable biosensing devices in general, and nanodevices in particular.


Asunto(s)
Técnicas Biosensibles , Nanoestructuras/química , Silicio/química , Siloxanos/química , Transistores Electrónicos , Óxido de Aluminio/química , Técnicas Biosensibles/instrumentación , Metales/química , Nanoestructuras/ultraestructura , Nanocables/química , Nanocables/ultraestructura , Óxidos/química , Prótesis e Implantes
5.
Nano Lett ; 13(7): 3157-68, 2013 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-23772673

RESUMEN

Quantitative detection of biological and chemical species is critical to numerous areas of medical and life sciences. In this context, information regarding pH is of central importance in multiple areas, from chemical analysis, through biomedical basic studies and medicine, to industry. Therefore, a continuous interest exists in developing new, rapid, miniature, biocompatible and highly sensitive pH sensors for minute fluid volumes. Here, we present a new paradigm in the development of optoelectrical sensing nanodevices with built-in self-calibrating capabilities. The proposed electrical devices, modified with a photoactive switchable molecular recognition layer, can be optically switched between two chemically different states, each having different chemical binding constants and as a consequence affecting the device surface potential at different extents, thus allowing the ratiometric internal calibration of the sensing event. At each point in time, the ratio of the electrical signals measured in the ground and excited states, respectively, allows for the absolute concentration measurement of the molecular species under interest, without the need for electrical calibration of individual devices. Furthermore, we applied these devices for the real-time monitoring of cellular metabolic activity, extra- and intracellularly, as a potential future tool for the performance of basic cell biology studies and high-throughput personalized medicine-oriented research, involving single cells and tissues. This new concept can be readily expanded to the sensing of additional chemical and biological species by the use of additional photoactive switchable receptors. Moreover, this newly demonstrated coupling between surface-confined photoactive molecular species and nanosensing devices could be utilized in the near future in the development of devices of higher complexity for both the simultaneous control and monitoring of chemical and biological processes with nanoscale resolution control.


Asunto(s)
Técnicas Biosensibles/instrumentación , Conductometría/instrumentación , Concentración de Iones de Hidrógeno , Neoplasias Experimentales/química , Neoplasias Experimentales/metabolismo , Espectrometría de Fluorescencia/instrumentación , Transistores Electrónicos , Calibración , Línea Celular Tumoral , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Refractometría/instrumentación
6.
Angew Chem Int Ed Engl ; 52(43): 11298-302, 2013 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-24038755

RESUMEN

A prize for the ribbons: High-quality crystalline semiconducting nanoribbons can be prepared by "unwrapping" core-shell nanowire precursors. For example, Ge nanowires were coated with a Si shell and the top surface was carved by etching whereas the sides were protected by a thin layer of photoresist material. Finally the Ge core was removed selectively by chemical means to give fully opened and flat nanoribbon structures.

7.
Cancer Rep (Hoboken) ; 6(6): e1834, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37178052

RESUMEN

BACKGROUND: Radiation-induced sarcoma (RIS) is a late toxicity of radiation therapy (RT) usually associated with poor prognosis. Due to ongoing improvements in childhood cancer treatment and patient outcomes, RIS may become more prevalent notwithstanding evolving indications for RT. Due to limited reported studies, we sought to review our experience with RIS in survivors of pediatric cancer. METHODOLOGY: Data were collected on RIS patients following treatment for childhood cancer (initial diagnosis <18 years) identified in the CanSaRCC database. Additionally, details on the protocol guidance at time of treatment were compared with current guidelines for the same disease. RESULTS: Among 12 RIS identified, median age at initial diagnosis was 3.5 years (range 0.16-14) and the latency from RT to RIS diagnosis was 24.5 (range 5.4-46.2) years. Initial diagnoses included neuroblastoma, rhabdomyosarcoma, Ewing sarcoma, Wilms tumor, retinoblastoma and Hodgkin's Lymphoma. RIS histologies included osteosarcoma and soft tissue sarcomas. In comparison to protocols followed at time of diagnosis to current ones (2022), 7/12 (58%) patients would have required RT. RIS treatment included chemotherapy, radiation and surgery in 3/11 (27%), 10/11 (90%), and 7/11 (63%) patients, respectively. With a median follow-up time of 4.7 years from diagnosis of RIS, 8 (66%) patients were alive and 4 (33%) had died of progressive RIS. CONCLUSION: RIS is a serious late effect of radiotherapy in childhood cancer; however, radiation remains an integral component of primary tumor management and requires participation from a specialized multi-disciplinary team, aiming to mitigate RIS and other potential late effects.


Asunto(s)
Neoplasias Óseas , Neoplasias Renales , Neoplasias de la Retina , Sarcoma , Neoplasias de los Tejidos Blandos , Humanos , Niño , Lactante , Preescolar , Adolescente , Canadá/epidemiología , Sarcoma/diagnóstico , Sarcoma/etiología , Sarcoma/terapia , Neoplasias de los Tejidos Blandos/diagnóstico , Neoplasias de los Tejidos Blandos/etiología , Neoplasias de los Tejidos Blandos/terapia , Progresión de la Enfermedad
8.
Cancer Med ; 12(18): 18872-18881, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37724607

RESUMEN

OBJECTIVES: We conducted a retrospective multi-centre study to assess the real-world outcome of regorafenib (REGO) and cabozantinib (CABO) in recurrent/refractory bone tumours (BTs) including osteosarcoma (OST), Ewing sarcoma (EWS) and chondrosarcoma (CS)/extra-skeletal mesenchymal CS (ESMC). METHODS: After regulatory approval, data from patients with recurrent BT (11 institutions) were extracted from CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration) database. Patient characteristics, treatment and outcomes were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. RESULTS: From July 2018 to May 2022, 66 patients received REGO or CABO; 39 OST, 18 EWS, 4 CS and 5 ESMC. Median age was 27.8 years (range 12-76); median starting dose was 60 mg for CABO (n = 37, range 40-60) and 120 mg for REGO (n = 29, range 40-160). Twenty-eight (42.4%) patients required dose reduction: hand-foot syndrome 7 (10.6%), nausea/vomiting 1 (1.5%), diarrhoea 1 (1.5%), 2 elevated LFTs (3%), elevated bilirubin 1 (1.5%) and mucositis 1 (1.5%). The median OS for patients with OST, EWS, CS and ESMC was 8.5 months (n = 39, 95% CI 7-13.1); 13.4 months (n = 18, 95% CI 3.4-27.2), 8.1 (n = 4, 95% CI 4.1-9.3) and 18.2 (n = 5, 95% CI (10.4-na), respectively. Median PFS for OST, EWS, CS and ECMS was 3.5 (n = 39, 95% CI 2.8-5), 3.9 (n = 18, 95% CI 2.1-5.9), 5.53 (n = 4. 95% CI 2.13-NA) and 11.4 (n = 5, 95% CI 1.83-14.7), respectively. Age, line of therapy, REGO versus CABO, or time from diagnosis to initiation of TKI were not associated with PFS on univariable analysis. CONCLUSION: Our real-world data show that TKIs have meaningful activity in recurrent BT with acceptable toxicities when started at modified dosing. Inclusion of TKIs in earlier lines of treatment and/or maintenance therapy could be questions for future research.


Asunto(s)
Neoplasias Óseas , Condrosarcoma , Osteosarcoma , Sarcoma de Ewing , Sarcoma , Neoplasias de los Tejidos Blandos , Humanos , Adulto , Niño , Adolescente , Adulto Joven , Persona de Mediana Edad , Anciano , Recurrencia Local de Neoplasia/tratamiento farmacológico , Canadá , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Óseas/patología , Sarcoma/tratamiento farmacológico , Sarcoma de Ewing/tratamiento farmacológico , Sarcoma de Ewing/patología , Osteosarcoma/patología , Estudios Retrospectivos
9.
Ther Adv Med Oncol ; 15: 17588359231198943, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37781501

RESUMEN

Background: Radiation-induced sarcomas (RIS) tend to have aggressive behaviour and because of their rarity, the most appropriate management for these malignancies is uncertain. Objectives: Using the Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) database, a national sarcoma registry, we aimed to investigate prognostic factors and outcomes for RIS. Design: Retrospective study of RIS patients treated from 1996 to 2021 at three Canadian centres. Methods: RIS was defined as a sarcoma arising in a previously irradiated field following a 3+ year latency period, whose histology was distinct from the initially irradiated tumour. Clinicopathologic and treatment-related information was extracted from the CanSaRCC database. Overall survival (OS) was defined as the time from RIS diagnosis to death from any cause. Response rate (RR) to neoadjuvant chemotherapy (NACT) was based on physician assessment. Time-to-event analyses were estimated using the Kaplan-Meier method, with Cox regression for multivariate analysis. We considered a two-tailed p-value of <0.05 as statistically significant. Results: One hundred seven tumours met the criteria for RIS and were divided into three subgroups: breast angiosarcoma (BAS, n = 54), osteosarcoma (OST, n = 16), and other soft-tissue sarcomas (STS, n = 37). Patients were mostly female (n = 85, 79%), treated initially for breast carcinomas (n = 54, 50.5%), and diagnosed with high-grade tumours (n = 61/71, 86%). None had evidence of synchronous metastasis. Patients with OST were younger (median age: 48 years, p < 0.001), and BAS had the shortest latency interval (8 versus 18 years for OST/STS, p < 0.001). Most patients underwent surgery, 76% (n = 76/100) R0; 24% (n = 26) received radiation therapy, mostly (n = 15, 57.7%) neoadjuvant. Among those receiving chemotherapy, 30 (75%) underwent NACT; among patients with documented response assessment, the RR was 68% (n = 17/25), being even higher in the BAS population (89.5%, n = 13/17). Median OS was 53 months (95% CI 34-101), with a 5-year OS of 47.6%; larger tumour size, high histologic grade and older age were independent prognostic factors for worse OS. Conclusion: Surgery is standard, and NACT might be useful to downsize large lesions, especially in BAS patients. Raising RIS awareness is fundamental to promoting appropriate management and fostering research through multi-institutional collaborations.

10.
Curr Oncol ; 29(6): 4260-4266, 2022 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-35735449

RESUMEN

Sarcoma can present as locally advanced disease involving pleura for which extra-pleural pneumonectomy (EPP) may be the only surgical option to ensure adequate local control. Data were collected on patients who underwent EPP between January 2009 and August 2021 at Princess Margret Hospital and SickKids (Toronto) using the CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration). Ten patients with locally advanced sarcoma involving the pleura, aged 4 to 59 years (median 19.5 years) underwent EPP. Nine (90%) received pre-operative chemotherapy and eight (80%) achieved an R0 resection. Hemithoracic radiation was administered preoperatively (n = 6, 60%) or postoperatively (n = 4, 40%). Five (50%) patients were alive without disease at last follow-up (median 34.2 months) and time from EPP to last FU was median 29.2 months (range 2.2-87.5). Two patients (20%) had local recurrence, 4.3 and 5.8 months from EPP, and both died from progressive disease, 13.1 and 8.2 months from EPP, respectively. One patient died from brain metastasis (17 months), one died from radiation associated osteosarcoma (66 months), and one died from surgical complications (heart failure from constrictive pericarditis). EPP offers a feasible and life-prolonging surgical consideration for patients with locally advanced sarcoma involving the pleura in combination with chemotherapy and radiation. Consequently, EPP should be considered during multi-disciplinary tumor board discussions at high-volume centers.


Asunto(s)
Mesotelioma , Neoplasias Primarias Secundarias , Neoplasias Pleurales , Sarcoma , Adulto , Canadá , Niño , Terapia Combinada , Humanos , Mesotelioma/patología , Mesotelioma/secundario , Mesotelioma/cirugía , Pleura/patología , Pleura/cirugía , Neoplasias Pleurales/patología , Neoplasias Pleurales/cirugía , Neumonectomía , Sarcoma/cirugía
11.
Micromachines (Basel) ; 10(12)2019 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-31817408

RESUMEN

The importance of the bi-directional natural killer-dendritic cell crosstalk in coordinating anti-tumour and anti-microbial responses in vivo has been well established. However, physical parameters associated with natural killer-dendritic cell interactions have not been fully elucidated. We have previously used a simple "Y" shaped microfluidic device to study natural killer cell-migratory responses toward chemical gradients from a conditioned medium of dendritic cells. There are, however, limitations of the Y-shaped microfluidic devices that could not support higher throughput analyses and studies of cell-cell interactions. Here, we report two novel microfluidic devices (D3-Chip, T2-Chip) we applied in advanced studies of natural killer-cell migrations and their interactions with dendritic cells in vitro. The D3-Chip is an improved version of the previously published Y-shaped device that supports high-throughput analyses and docking of the cells of interest in the migration assay before they are exposed to a chemical gradient. The T2-Chip is created to support analyses of natural killer-dendritic cell cell-cell interactions without the requirement of promoting a natural killer cell to migrate long distances to find a loaded dendritic cell in the device. Using these two microfluidic platforms, we observe quantitative differences in the abilities of the immature and lipopolysaccharide-activated mature dendritic cells to interact with activated natural killer cells. The contact time between the activated natural killer cells and immature dendritic cells is significantly longer than that of the mature dendritic cells. There is a significantly higher frequency of an immature dendritic cell coming into contact with multiple natural killer cells and/or making multiple simultaneous contacts with multiple natural killer cells. To contrast, an activated natural killer cell has a significantly higher frequency of coming into contact with the mature dendritic cells than immature dendritic cells. Collectively, these differences in natural killer-dendritic cell interactions may underlie the differential maturation of immature dendritic cells by activated natural killer cells. Further applications of these microfluidic devices in studying natural killer-dendritic cell crosstalk under defined microenvironments shall enrich our understanding of the functional regulations of natural killer cells and dendritic cells in the natural killer-dendritic cell crosstalk.

12.
Biosens Bioelectron ; 99: 259-267, 2018 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-28772229

RESUMEN

Mobile sensing based on the integration of microfluidic device and smartphone, so-called MS2 technology, has enabled many applications over recent years, and continues to stimulate growing interest in both research communities and industries. In particular, it has been envisioned that MS2 technology can be developed for various cell functional assays to enable basic research and clinical applications. Toward this direction, in this paper, we describe the development of a MS2-based cell functional assay for testing cell migration (the Mkit). The system is constructed as an integrated test kit, which includes microfluidic chips, a smartphone-based imaging platform, the phone apps for image capturing and data analysis, and a set of reagent and accessories for performing the cell migration assay. We demonstrated that the Mkit can effectively measure purified neutrophil and cancer cell chemotaxis. Furthermore, neutrophil chemotaxis can be tested from a drop of whole blood using the Mkit with red blood cell (RBC) lysis. The effects of chemoattractant dose and gradient profile on neutrophil chemotaxis were also tested using the Mkit. In addition to research applications, we demonstrated the effective use of the Mkit for on-site test at the hospital and for testing clinical samples from chronic obstructive pulmonary disease patient. Thus, this developed Mkit provides an easy and integrated experimental platform for cell migration related research and potential medical diagnostic applications.


Asunto(s)
Técnicas Biosensibles , Ensayos de Migración Celular , Movimiento Celular/genética , Neoplasias/diagnóstico , Quimiotaxis/genética , Humanos , Técnicas Analíticas Microfluídicas , Neoplasias/genética , Neutrófilos/patología , Teléfono Inteligente
13.
Integr Biol (Camb) ; 9(11): 892-893, 2017 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-29022985

RESUMEN

Correction for 'A bioenergetic mechanism for amoeboid-like cell motility profiles tested in a microfluidic electrotaxis assay' by Hagit Peretz-Soroka et al., Integr. Biol., 2017, DOI: .

14.
Integr Biol (Camb) ; 9(11): 844-856, 2017 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-28960219

RESUMEN

The amoeboid-like cell motility is known to be driven by the acidic enzymatic hydrolysis of ATP in the actin-myosin system. However, the electro-mechano-chemical coupling, whereby the free energy of ATP hydrolysis is transformed into the power of electrically polarized cell movement, is poorly understood. Previous experimental studies showed that actin filaments motion, cytoplasmic streaming, and muscle contraction can be reconstituted under actin-activated ATP hydrolysis by soluble non-filamentous myosin fragments. Thus, biological motility was demonstrated in the absence of a continuous protein network. These results lead to an integrative conceptual model for cell motility, which advocates an active role played by intracellular proton currents and cytoplasmic streaming (iPC-CS). In this model, we propose that protons and fluid currents develop intracellular electric polarization and pressure gradients, which generate an electro-hydrodynamic mode of amoeboid motion. Such energetic proton currents and active streaming are considered to be mainly driven by stereospecific ATP hydrolysis through myosin heads along oriented actin filaments. Key predictions of this model are supported by microscopy visualization and in-depth sub-population analysis of purified human neutrophils using a microfluidic electrotaxis assay. Three distinct phases in cell motility profiles, morphology, and cytoplasmic streaming in response to physiological ranges of chemoattractant stimulation and electric field application are revealed. Our results support an intrinsic electric dipole formation linked to different patterns of cytoplasmic streaming, which can be explained by the iPC-CS model. Collectively, this alternative biophysical mechanism of cell motility provides new insights into bioenergetics with relevance to potential new biomedical applications.


Asunto(s)
Movimiento Celular , Fenómenos Electrofisiológicos , Metabolismo Energético , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/metabolismo , Citoplasma/metabolismo , Corriente Citoplasmática , Voluntarios Sanos , Humanos , Hidrólisis , Dispositivos Laboratorio en un Chip , Microfluídica , Modelos Biológicos , Contracción Muscular , Miosinas/metabolismo , Neutrófilos/metabolismo
15.
Integr Biol (Camb) ; 9(4): 303-312, 2017 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-28367571

RESUMEN

Chemotaxis is a classic mechanism for guiding cell migration and an important topic in both fundamental cell biology and health sciences. Neutrophils are a widely used model to study eukaryotic cell migration and neutrophil chemotaxis itself can lead to protective or harmful immune actions to the body. While much has been learnt from past research about how neutrophils effectively navigate through a chemoattractant gradient, many interesting questions remain unclear. For example, while it is tempting to model neutrophil chemotaxis using the well-established biased random walk theory, the experimental proof was challenged by the cell's highly persistent migrating nature. A special experimental design is required to test the key predictions from the random walk model. Another question that has interested the cell migration community for decades concerns the existence of chemotactic memory and its underlying mechanism. Although chemotactic memory has been suggested in various studies, a clear quantitative experimental demonstration will improve our understanding of the migratory memory effect. Motivated by these questions, we developed a microfluidic cell migration assay (so-called dual-docking chip or D2-Chip) that can test both the biased random walk model and the memory effect for neutrophil chemotaxis on a single chip enabled by multi-region gradient generation and dual-region cell alignment. Our results provide experimental support for the biased random walk model and chemotactic memory for neutrophil chemotaxis. Quantitative data analyses provide new insights into neutrophil chemotaxis and memory by making connections to entropic disorder, cell morphology and oscillating migratory response.


Asunto(s)
Ensayos de Migración Celular , Quimiotaxis , Neutrófilos/citología , Movimiento Celular , Factores Quimiotácticos , Simulación por Computador , Humanos , Sistema Inmunológico , Memoria Inmunológica , Técnicas Analíticas Microfluídicas , Neutrófilos/metabolismo
16.
Sci Rep ; 7(1): 3100, 2017 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-28596573

RESUMEN

Neutrophil trafficking in tissues critically regulates the body's immune response. Neutrophil migration can either play a protective role in host defense or cause health problems. Fibroblast growth factor 23 (FGF23) is a known biomarker for chronic kidney disease (CKD) and was recently shown to impair neutrophil arrest on endothelium and transendothelial migration. In the present study, we further examined the effect of FGF23 on human blood neutrophil chemotaxis using two new microfluidic devices. Our results showed that chemotaxis of FGF23 pre-treated neutrophils to a fMLP gradient, in the presence or absence of a uniform FGF23 background, is quantitatively lower compared to the control cells. This effect is accompanied with a stronger drifting of FGF23 pre-treated cells along the flow. However, without the FGF23 pre-treatment, the FGF23 background only reduces chemotaxis of transmigrated cells through the thin barrier channel to the fMLP gradient. The effect of FGF23 on neutrophil migration and the correlation between multiple cell migration parameters are further revealed by chemotactic entropy and principle component analysis. Collectively, these results revealed the effect of FGF23 on weakening neutrophil chemotaxis, which shed light on FGF23 mediated neutrophil migration with direct disease relevance such as CKD.


Asunto(s)
Quimiotaxis de Leucocito/inmunología , Factores de Crecimiento de Fibroblastos/metabolismo , Dispositivos Laboratorio en un Chip , Neutrófilos/inmunología , Neutrófilos/metabolismo , Factor-23 de Crecimiento de Fibroblastos , Humanos , Migración Transendotelial y Transepitelial/inmunología
17.
Lab Chip ; 16(6): 943-58, 2016 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-26899264

RESUMEN

Portable electronic devices and wireless communication systems enable a broad range of applications such as environmental and food safety monitoring, personalized medicine and healthcare management. Particularly, hybrid smartphone and microfluidic devices provide an integrated solution for the new generation of mobile sensing applications. Such mobile sensing based on microfluidic devices (broadly defined) and smartphones (MS(2)) offers a mobile laboratory for performing a wide range of bio-chemical detection and analysis functions such as water and food quality analysis, routine health tests and disease diagnosis. MS(2) offers significant advantages over traditional platforms in terms of test speed and control, low cost, mobility, ease-of-operation and data management. These improvements put MS(2) in a promising position in the fields of interdisciplinary basic and applied research. In particular, MS(2) enables applications to remote in-field testing, homecare, and healthcare in low-resource areas. The marriage of smartphones and microfluidic devices offers a powerful on-chip operating platform to enable various bio-chemical tests, remote sensing, data analysis and management in a mobile fashion. The implications of such integration are beyond telecommunication and microfluidic-related research and technology development. In this review, we will first provide the general background of microfluidic-based sensing, smartphone-based sensing, and their integration. Then, we will focus on several key application areas of MS(2) by systematically reviewing the important literature in each area. We will conclude by discussing our perspectives on the opportunities, issues and future directions of this emerging novel field.


Asunto(s)
Técnicas Analíticas Microfluídicas , Aplicaciones Móviles , Teléfono Inteligente , Enfermedad , Análisis de los Alimentos , Inocuidad de los Alimentos , Humanos , Técnicas Analíticas Microfluídicas/instrumentación , Teléfono Inteligente/instrumentación , Agua/análisis
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