Organic Electronic Platform for Real-Time Phenotypic Screening of Extracellular-Vesicle-Driven Breast Cancer Metastasis.

Tumor-derived extracellular vesicles (TEVs) induce the epithelial-to-mesenchymal transition (EMT) in nonmalignant cells to promote invasion and cancer metastasis, representing a novel therapeutic target in a field severely lacking in efficacious antimetastasis treatments. However, scalable technologies that allow continuous, multiparametric monitoring for identifying metastasis inhibitors are absent. Here, the development of a functional phenotypic screening platform based on organic electrochemical transistors (OECTs) for real-time, noninvasive monitoring of TEV-induced EMT and screening of antimetastatic drugs is reported. TEVs derived from the triple-negative breast cancer cell line MDA-MB-231 induce EMT in nonmalignant breast epithelial cells (MCF10A) over a nine-day period, recapitulating a model of invasive ductal carcinoma metastasis. Immunoblot analysis and immunofluorescence imaging confirm the EMT status of TEV-treated cells, while dual optical and electrical readouts of cell phenotype are obtained using OECTs. Further, heparin, a competitive inhibitor of cell surface receptors, is identified as an effective blocker of TEV-induced EMT. Together, these results demonstrate the utility of the platform for TEV-targeted drug discovery, allowing for facile modeling of the transient drug response using electrical measurements, and provide proof of concept that inhibitors of TEV function have potential as antimetastatic drug candidates.

Etiología de baja visión y ceguera en siete centros de referencia en Colombia entre los años 2012 a 2017 / Etiology of low vision and blindness in seven reference centers in Colombia between the years 2012 to 2017

Introducción: La baja visión y la ceguera tienen alta prevalencia mundial, siendo categorías de discapacidad frecuentes en Colombia. Se requieren estudios que caractericen la etiología de las deficiencias visuales permanentes. Objetivo: Identificar y caracterizar las diferentes causas de baja visión y ceguera en siete centros de referencia para la población con discapacidad visual en Colombia, atendida entre los años 2012 a 2017 en seis ciudades capitales. Materiales y métodos:Estudio retrospectivo, serie de casos, descriptivo y multicéntrico.Resultados: Se contó con una muestra de 879 registros de pacientes con discapacidad visual. El 70% (612/879) con baja visión y 30% (267/879) con ceguera. Para todos los grupos de edad es más prevalente la baja visión. La etiología más frecuente en pacientes con baja visión fue la degeneración macular asociada a la edad (DMAE) (24%, 144/612); en pacientes con ceguera fue el glaucoma (17%, 45/267). Discusión: Posiblemente en Colombia las causas de baja visión y ceguera van más allá de las cataratas, errores de refracción no corregidos y ceguera infecciosa. Discusión: Las etiologías más frecuentes encontradas son condiciones oculares crónicas y diversas, que requieren intervenciones específicas para disminuir su prevalencia y prevenir casos de baja visión y ceguera.

Introduction: Low vision and blindness have high global prevalence, with categories of disability common in Colombia. Studies that characterize the etiology of permanent visual impairments are required. Objective:To identify and characterize the different causes of low vision and blindness in seven reference centers for the visually impaired population in Colombia, attended between 2012 and 2017 in six capital cities. Materials and Methods:Retrospective, case series, descriptive and multicenter study. Results: A sample of 879 records of visually impaired patients was available. Low vision is more prevalent for all age groups. 70% (612/879) low vision and 30% (267/879) blindness. The most common etiology in patients with low vision was age-related macular degeneration (DMAE) (24%, 144/612); in patients with blindness it was glaucoma (17%, 45/267). Discussions: Possibly in Colombia the causes of low vision and blindness go beyond cataracts, un corrected refractive errors and infectious blindness. Conclusions: The most common etiologies found are chronic and diverse eye conditions, which require specific interventions to decrease their prevalence and prevent cases of low vision and blindness.

Introdução: Baixa visão e cegueira têm alta prevalência global, com categorias de incapacidade comuns na Colômbia. São necessários estudos que caracterizem a etiologia das deficiências visuais permanentes. Objetivo: Identificar e caracterizar as diferentes causas de baixa visão e cegueira em sete centros de referência para a população deficiente visual na Colômbia, atendidos entre 2012 e 2017 em seis capitais. Materiais e Métodos: Estudo retrospectivo, série de casos, descritivo e multicêntrico. Resultados: Uma amostra de 879 registros de pacientes com deficiência visual estava disponível. 54% (478/879) homens. A baixa visão é mais prevalente para todas as faixas etárias. 70% (612/879) baixa visão e 30% (267/879) cegueira. A etiologia mais comum em pacientes com baixa visão foi a degeneração macular relacionada à idade (DMAE) (24%, 144/612); em pacientes com cegueira foi glaucoma (17%, 45/267).Discussão: Possivelmente na Colômbia as causas da baixa visão e cegueira vão além da catarata, erros refrativos não corrigidos e cegueira infecciosa. Conclusões: As etiologias mais comuns encontradas são condições oculares crônicas e diversas, que requerem intervenções específicas para diminuir sua prevalência e prevenir casos de baixa visão e cegueira

Dual Mode Sensing of Binding and Blocking of Cancer Exosomes to Biomimetic Human Primary Stem Cell Surfaces.

Cancer-derived exosomes (cEXOs) facilitate transfer of information between tumor and human primary stromal cells, favoring cancer progression. Although the mechanisms used during this information exchange are still not completely understood, it is known that binding is the initial contact established between cEXOs and cells. Hence, studying binding and finding strategies to block it are of great therapeutic value. However, such studies are challenging for a variety of reasons, including the need for human primary cell culture, the difficulty in decoupling and isolating binding from internalization and cargo delivery, and the lack of techniques to detect these specific interactions. In this work, we created a supported biomimetic stem cell membrane incorporating membrane components from human primary adipose-derived stem cells (ADSCs). We formed the supported membrane on glass and on multielectrode arrays to offer the dual option of optical or electrical detection of cEXO binding to the membrane surface. Using our platform, we show that cEXOs bind to the stem cell membrane and that binding is blocked when an antibody to integrin ß1, a component of ADSC surface, is exposed to the membrane surface prior to cEXOs. To test the biological outcome of blocking this interaction, we first confirm that adding cEXOs to cultured ADSCs leads to the upregulation of vascular endothelial growth factor, a measure of proangiogenic activity. Next, when ADSCs are first blocked with anti-integrin ß1 and then exposed to cEXOs, the upregulation of proangiogenic activity and cell proliferation are significantly reduced. This biomimetic membrane platform is the first cell-free label-free in vitro platform for the recapitulation and study of cEXO binding to human primary stem cells with potential for therapeutic molecule screening as it is compatible with scale-up and multiplexing.

Caracterización de pacientes con enfermedad de ojo seco en una institución de referencia en la ciudad de Medellín, Colombia / Characterization of patients with dry eye disease from distinguished ophthalmology clinic in Medellín, Colombia

Introducción: La enfermedad de ojo seco ha sido definida como una entidad multifactorial en la cual se pierde la homeostasis de la película lagrimal. Objetivo: Caracterizar a los pacientes con enfermedad de ojo seco atendidos en la unidad de ojo seco de la Clínica de Oftalmología Sandiego. Materiales y métodos: Estudio observacional, descriptivo, de cohorte retrospectiva. Se documentaron pruebas cualitativas, cuantitativas, cuestionario OSDI y tipo de ojo seco de los pacientes que consultaron en el periodo de marzo de 2016 a diciembre de 2017 con diagnóstico confirmado de enfermedad de ojo seco. Resultados: En 107 pacientes se confirmó el diagnóstico de ojo seco, 80.4% fueron mujeres. La mediana de edad fue 53 años (38-69). El 64.5% tenía ojo seco evaporativo, 12.2% acuodeficiente y 23.4% mixto. El OSDI fue mayor a 33 en 67 pacientes. La osmolaridad lagrimal y la MMP-9 estuvieron alteradas en 78.5 y 76.6%, respectivamente. Conclusión: La realización de pruebas clínicas, laboratorio y cuestionarios de síntomas, permiten realizar el diagnóstico integral de la enfermedad ojo seco según las recomendaciones del DEWS II, apoyando la clasificación del mismo, reconocimiento de factores de riesgo y planteamiento de posibles etiologías que ayudan en el tratamiento.

ackground: Dry eye disease has been defined by DEWS II as a multifactorial entity in which tear film homeostasis is altered. Objective: To characterize patients with dry eye disease evaluated in the dry eye unit of Clínica de Oftalmología Sandiego. Materials and methods: Observational, descriptive, retrospective cohort study. Information was collected from patients who consulted the dry eye unit in the period from March 2016 to December 2017 and who were diagnosed with dry eye disease. The results of qualitative and quantitative tests, as well as the dry eye symptoms questionnaire, were documented.

Supported Membrane Platform to Assess Surface Interactions between Extracellular Vesicles and Stromal Cells.

Extracellular vesicles (EVs) are membrane-encapsulated particles secreted by eukaryotic cells that stimulate cell communication and horizontal cargo exchange. EV interactions with stromal cells can result in molecular changes in the recipient cell and, in some cases, lead to disease progression. However, mechanisms leading to these changes are poorly understood. A few model systems are available for studying the outcomes of surface interactions between EV membranes with stromal cells. Here, we created a hybrid supported bilayer incorporating EVs membrane material, called an extracellular vesicle supported bilayer, EVSB. Using EVSBs, we investigated the surface interactions between breast cancer EVs and adipose-derived stem cells (ADSCs) by culturing ADSCs on EVSBs and analyzing cell adhesion, spreading, viability, vascular endothelial growth factor (VEGF) secretion, and myofibroblast differentiation. Results show that cell viability, adhesion, spreading, and proangiogenic activity were enhanced, conditions that promote oncogenic activity, but cell differentiation was not. This model system could be used to develop therapeutic strategies to limit EV-ADSC interactions and proangiogenic conditions. Finally, this model system is not limited to the study of cancer but can be used to study surface interactions between EVs from any origin and any target cell to investigate EV mechanisms leading to cellular changes in other diseases.

Reproducible in vitro model for dystrophic calcification of cardiac valvular interstitial cells: insights into the mechanisms of calcific aortic valvular disease.

Calcific aortic valvular disease (CAVD) is the most prevalent valvular pathology in the United States. Development of a pharmacologic agent to slow, halt, or reverse calcification has proven to be unsuccessful as still much remains unknown about the mechanisms of disease initiation. Although in vitro models of some features of CAVD exist, their utility is limited by the inconsistency of the size and time course of the calcified cell aggregates. In this study, we introduce and verify a highly reproducible in vitro method for studying dystrophic calcification of cardiac valvular interstitial cells, considered to be a key mechanism of clinical CAVD. By utilizing micro-contact printing, we were able to consistently reproduce cell aggregation, myofibroblastic markers, programmed cell death, and calcium accumulation within aggregates of 50-400 µm in diameter on substrates with moduli from 9.6 to 76.8 kPa. This method is highly repeatable, with 70% of aggregates staining positive for Alizarin Red S after one week in culture. Dense mineralized calcium-positive nanoparticles were found within the valvular interstitial cell aggregates as shown by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The area of micro-contact printed aggregates staining positive for caspase 3/7 activity increased from 5.9 ± 0.9% to 12.6 ± 4.5% over one week in culture. Z-VAD-FMK reduced aggregates staining positive for Alizarin Red S by 60%. The state of cell stress is hypothesized to play a role in the disease progression; traction force microscopy indicates high substrate stresses along the aggregate periphery which can be modulated by altering the size of the aggregates and the modulus of the substrate. Micro-contact printing is advantageous over the currently used in vitro model as it allows the independent study of how cytokines, substrate modulus, and pharmacologic agents affect calcification. This controlled method for aggregate creation has the potential to be used as an in vitro assay for the screening of promising therapeutics to mitigate CAVD.