Cocoa powder and catechins as natural mediators to modify carbon-black based screen-printed electrodes. Application to free and total glutathione detection in blood.

In this work, for the first time, the direct usability of natural products, catechins (CT) and cocoa powder (CO), as electrochemical mediators able to modify a carbon black modified screen-printed electrode (SPE-CB) is proved, and, as proof of applicability, free (GSH) and total glutathione (GSH + GSSG) in blood samples is successfully determined. Noteworthy, the cocoa powder (naturally rich in catechins), dissolved in DMSO, was able to give rise to a useful highly redox-active catechol-quinone surface-confined system onto a carbon black nanoparticles modified screen-printed electrode (SPE-CB-CO - Cocoatrode), giving rise to a similar behaviour obtained with pure catechins (SPE-CB-CT). The electrodeposition process has been carefully studied, the resulting immobilized natural mediator (obtained using both CT and CO) features investigated, and the performance of the resulting sensors (SPE-CB-CT and Cocoatrode) tested and compared. Both modified electrodes (SPE-CB-CT and Cocoatrode) have a good inter-electrodes precision (RSD ip,a ≤ 4.2%, n = 3) and intra-electrodes repeatability (RSD ip,a ≤ 3.9%, n = 20), indicating a robust and stable 'fabrication' strategy. Finally, SPE-CB-CT and Cocoatrode have been employed for the detection of free (GSH) and total (GSH+GSSG) glutathione in blood samples, using differential pulse voltammetry decrease in the mediator's reduction peak (Δi %), as analytical signal. Analytical curves (R2 ≥ 0.998), for the GSH detection, have been determined both with SPE-CB-CT and Cocoatrode in the 2.5 × 10-8-6.0 × 10-5 M and 5.0 × 10-8-1.0 × 10-4 M concentration ranges, respectively. Limits of detections (LODs) were ≤2.6 × 10-8 M. GSH (free and total) determined in blood samples, by the proposed CT and CO sensors, showed a good intra-electrode repeatability (RSD ip,a ≤ 9.0%, n = 3), with good recoveries (from 88.3% to 117.7%). The values obtained were in agreement with a classical spectrophotometric method (GSH and GSSG concentration relative error between -4.7 and +9.8%). The SPE-CB-CT and the Cocoatrode platforms demonstrated high potentiality in sensing and biosensing scenario, opening new gates to the natural/food products employment as unconventional, eco-friendly and economically affordable analytical active tools.

Beta-Talasemia: Un mundo de complicaciones con nuevas alternativas de tratamiento / Beta-Thalassemia: A world of complications with new alternatives of treatment

Introducción: ß-talasemia, es causada por mutaciones en el gen de la globina HBB, que codifica la subunidad ß de la HbA. La enfermedad es conocida por ser altamente prevalente en el área que se extiende desde África subsahariana, a través de la región mediterránea y Medio Oriente. En Colombia, se han reportado varios estudios independientes de hemoglobinopatías en ciudades como Cartagena, Buenaventura, Cali, San Andrés y Providencia debido a su gran población afrodescendiente sobre la cual las Talasemias y otras hemoglobinopatías tienen incidencia directa. Objetivo: recolectar datos acerca de las características clínicas, complicaciones y clasificaciones de ß-talasemia con el fin de brindar una fuente de información que permita realizar un diagnóstico eficaz y en consecuencia un tratamiento que busque llegar a la curación completa de los pacientes que sufren esta condición, con el mínimo de complicaciones para los mismos. Conclusión: la ß-Talasemia es una hemoglobinopatía estructural que tiene un porcentaje de prevalencia e incidencia importante en el mundo. En Colombia no se tiene claro cuál es la epidemiología real para esta condición puesto que no se han realizado estudios que abarquen una muestra adecuada y significativa. Esta enfermedad genera múltiples complicaciones en diferentes órganos, que no solo están asociadas al desarrollo de la enfermedad, sino también a la terapia de trasfusión a largo plazo. Por esta razón, los nuevos tratamientos están encaminas a lograr en un futuro la curación completa, reduciendo al máximo las complicaciones..(AU)

Introduction: ß-thalassemia is caused by mutations in the HBB globin gene, which encodes the ß subunit of HbA. The disease is known to be highly prevalent in the area that stretches from sub-Saharan Africa, through the Mediterranean region and the Middle East. In Colombia, several independent studies of hemoglobinopathies have been reported in cities such as Cartagena, Buenaventura, Cali, San Andrés and Providencia due to their large Afro-descendant population on wich the thalassemias and other hemoglobinopathies.have direct incidence. Objective: to collect data about the clinical characteristics, complications and classifications of ß-thalassemia in order to provide a source of information that allows an effective diagnosis and a treatment that seeks to reach the complete cure of patients that have this condition. , with the minimum of complications for them. Conclusion: ß-thalassemia is a structural hemoglobinopathy that has a percentage of prevalence and incidence important in the world. In Colombia it is not clear what is the real epidemiology for this condition that has not been conducted studies that include an adequate and significant sample.This disease generates multiple complications in different organs, but not only in long-term transfusion therapy. For this reason, the new treatments are aimed at achieving complete healing in the future, minimizing complications at maximum..(AU)