28 research outputs found
A rapid and versatile microfluidic method for the simultaneous extraction of polar and non-polar basic pharmaceuticals from human urine
In sample preparation, simultaneous extraction of analytes of very different polarity from biological matrixes represents a challenge. In this work, verapamil hydrochloride (VRP), amitriptyline (AMP), tyramine (TYR), atenolol (ATN), metopropol (MTP) and nortriptyline (NRP) were used as basic model analytes and simultaneously extracted from urine samples by liquid-phase microextraction (LPME) in a microfluidic device. The model analytes (target compounds) were pharmaceuticals with 0.4 < log P < 5. Different organic solvents and mixtures of them were investigated as supported liquid membrane (SLM), and a mixture of 2:1 (v/v) tributyl phosphate (TBP) and dihexyl ether (DHE) was found to be highly efficient for the simultaneous extraction of the non-polar and polar model analytes. TBP reduced the intrinsic hydrophobicity of the SLM and facilitated extraction of polar analytes, while DHE served to minimize trapping of non-polar analytes. Sample and acceptor phase composition were adjusted to pH 12 and pH 1.5, respectively. Urine samples were pumped into the microfluidic system at 1 μL min-1 and the extraction was completed in 7 min. Recoveries exceeded 78% for the target analytes, and the relative standard deviation (n = 4) was below 7% in all cases. Using five microliters of SLM, the microfluidic extraction system showed good long-term stability, and the same SLM was used for more than 18 consecutive extractions.Agencia de Gestió d'Ajusts Universitaris i the Recerca 2017-SGR-329Ministerio de Ciencia e Innovación PGC2018-096608-B-C2
A microfluidic liquid phase microextraction method for drugs and parabens monitoring in human urine
Frequent consumption of pharmaceuticals and personal care products (PPCPs) have emerged as a current problem that highlights the pressing need for new multi-residue analytical methods that allow their simultaneous determination to assess their overall effect on human health. In this regard and for the first time, a versatile microfluidic based- liquid phase microextraction (LPME) method was developed for simultaneous monitoring of ten compounds from six different classes: amoxicillin, sulfadiazine, sulfamerazine, tiamphenicol, ethyl 4-hydroxybenzoate, flumequine, propyl 4-hydroxybenzoate, 5-hydroxydiclofenac, 3-hydroxydiclofenac and diclofenac. The microfluidic device was combined with a HPLC-UV system for the separation and determination of the model analytes in the sample. Optimal conditions were reached using 2-nitrophenyl octyl ether as supported liquid membrane, pH 3.5 as donor phase, pH 11.5 as acceptor phase, 0.5 µL min−1 as donor flow rate and 1 µL min−1 as acceptor flow rate. Under optimal method conditions, the extraction efficiency was between 85 and 100% for most compounds after 10 min extraction, and it was successfully applied in non-diluted human urine, with recoveries between 70 and 100% for all analytes except for sulfamerazine (52% recovery). In addition, the extraction of metabolites (3-hydroxydiclofenac and 5-hydroxydiclofenac) was also demonstrated in microfluidic systems with recoveries between 71 and 100% in human urine. The proposed method allowed consecutive extraction and only requires 5 µL of organic solvent and less than 15 µL of sample volume
A novel integrated platform enabling simultaneous microextraction and chemical analysis on-chip
Altres ajuts: acords transformatius de la UABThe nature and size of biological, pharmaceutical or environmental analytes complicates their extraction and detection outside of laboratories and near the site of interest by the current chromatographic methods because they require the combination of bulky extraction and detection methods. In order to solve this inefficient centralized control, a ground-breaking and miniaturized proof of concept platform is developed in this work. The platform integrates for the very first time an electro-membrane extraction process and an accurate analyte quantification method in the same device, by using electrochemical impedance spectroscopy (EIS) as analytical technique. The microfluidic flow cell, including the microfluidic components, is fabricated in polymeric materials by rapid prototyping techniques. It comprises a four-electrode platinum thin-film chip that enables the control of the microextraction and the full characterization of the process, i.e., extraction efficiency determination, at the same time. The microfluidic system has been simulated by using computational tools, enabling an accurate prediction of the effect of the different experimental conditions in the microextraction efficiency. The platform has been validated in the microextraction of the nonsteroidal anti-inflammatory drug ketoprofen in a range from 0.5 ppm to 6 ppm. The predicted microextraction efficiency values obtained by EIS were compared with those calculated from the high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), showing an excellent agreement. This validates the high potential of this integrated and miniaturized platform for the simultaneous extraction by electro-membrane and also the analysis within the platform, solving one of the of most important limitations of current systems
Organotypic 3D Cell-Architecture Impacts the Expression Pattern of miRNAs–mRNAs Network in Breast Cancer SKBR3 Cells
Background. Currently, most of the research on breast cancer has been carried out in conventional two-dimensional (2D) cell cultures due to its practical benefits, however, the three-dimensional (3D) cell culture is becoming the model of choice in cancer research because it allows cell–cell and cell–extracellular matrix (ECM) interactions, mimicking the native microenvironment of tumors in vivo. Methods. In this work, we evaluated the effect of 3D cell organization on the expression pattern of miRNAs (by Small-RNAseq) and mRNAs (by microarrays) in the breast cancer SKBR3 cell line and analyzed the biological processes and signaling pathways regulated by the differentially expressed protein-coding genes (DE-mRNAs) and miRNAs (DE-microRNAs) found in the organoids. Results. We obtained well-defined cell-aggregated organoids with a grape cluster-like morphology with a size up to 9.2 × 105 μm3. The transcriptomic assays showed that cell growth in organoids significantly affected (all p < 0.01) the gene expression patterns of both miRNAs, and mRNAs, finding 20 upregulated and 19 downregulated DE-microRNAs, as well as 49 upregulated and 123 downregulated DE-mRNAs. In silico analysis showed that a subset of 11 upregulated DE-microRNAs target 70 downregulated DE-mRNAs. These genes are involved in 150 gene ontology (GO) biological processes such as regulation of cell morphogenesis, regulation of cell shape, regulation of canonical Wnt signaling pathway, morphogenesis of epithelium, regulation of cytoskeleton organization, as well as in the MAPK and AGE–RAGE signaling KEGG-pathways. Interestingly, hsa-mir-122-5p (Fold Change (FC) = 15.4), hsa-mir-369-3p (FC = 11.4), and hsa-mir-10b-5p (FC = 20.1) regulated up to 81% of the 70 downregulated DE-mRNAs. Conclusion. The organotypic 3D cell-organization architecture of breast cancer SKBR3 cells impacts the expression pattern of the miRNAs–mRNAs network mainly through overexpression of hsa-mir-122-5p, hsa-mir-369-3p, and hsa-mir-10b-5p. All these findings suggest that the interaction between cell–cell and cell–ECM as well as the change in the culture architecture impacts gene expression, and, therefore, support the pertinence of migrating breast cancer research from conventional cultures to 3D models
Microextracción en fase Líquida usando membranas líquidas soportadas sobre fibras huecas (HF-LPME, Hollow Fiber Based Liquid Phase Microextraction) como procedimiento de preconcentración y limpieza para la determinación de fármacos en matrices biológicas
El objetivo de esta Tesis Doctoral es el estudio y puesta a punto de diferentes metodologías de microextracción que implican el uso de membranas líquidas soportadas (supported liquid membrane, SLM) sobre fibras huecas de polipropileno, y su aplicación a
Dispositivo microfluídico y método para multiextracción
El objeto de la presente invención es un dispositivo microfluídico, portátil y reutilizable, para multiextracción simultánea de un primer elemento contenido en una primera disolución donadora y de un segundo elemento contenido en una segunda disolución donadora, mediante el uso una misma disolución aceptora en una sola etapa.Peer reviewedConsejo Superior de Investigaciones Científicas (España)A1 Solicitud de patente con informe sobre el estado de la técnic
Microfluidic liquid-phase microextraction based on natural deep eutectic solvents immobilized in agarose membranes
A selective and efficient microfluidic method-based liquid phase microextraction for the determination of sulfonamides in urine samples
Liquid phase microextraction (LPME) into a microfluidic has undergone great advances focused on downscaled and miniaturized devices. In this work, a microfluidic device was developed for the extraction of sulfonamides in order to accelerate the mass transfer and passive diffusion of the analytes from the donor phase to the acceptor phase. The subsequent analysis was carried out by high performance liquid chromatography with UV-DAD (HPLC-DAD). Several parameters affecting the extraction efficiency of the method such as the supported liquid membrane, composition of donor and acceptor phase and flow rate were investigated and optimized. Tributyl phosphate was found to be a good supported liquid membrane which confers not only great affinity for analytes but also long-term stability, allowing more than 20 consecutive extractions without carry over effect. Under optimum conditions, extraction efficiencies were over 96 % for all sulfonamides after 10 minutes extraction and only 10 µL of sample was required. Relative standard deviation was between 3-5 % for all compounds. Method detection limits were 45, 57, 54 and 33 ng mL−1 for sulfadiazine (SDI), sulfamerazine (SMR), sulfamethazine (SMT) and sulfamethoxazole (SMX), respectively. Quantitation limits were 0.15, 0.19, 0.18 and 0.11 µg mL−1 for SDI, SMR, SMT SMX, respectively. The proposed microfluidic device was successfully applied for the determination of sulfonamides in urine samples with extraction efficiencies within the range of 86-106 %. The proposed method improves the procedures proposed to date for the determination of sulfonamides in terms of efficiency, reduction of the sample volume and extraction time