133 research outputs found
Using gold nanobeacons as a theranostic technique to recognize, detect, and inhibit specific nucleic acids
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Nanomedicine-based strategies to target and modulate the tumor microenvironment
Funding Information: The authors acknowledge financial support from Fundação para a Ciência e a Tecnologia / Ministério da Ciência, Tecnologia, e Ensino Superior in the framework of PhD grant 2020.06638.BD (to D.P.S.), and from the European Research Council grant agreement No 848325 (J.C. for the ERC Starting Grant). Funding Information: The authors acknowledge financial support from Funda??o para a Ci?ncia e a Tecnologia/ Minist?rio da Ci?ncia, Tecnologia, e Ensino Superior in the framework of PhD grant 2020.06638.BD (to D.P.S.), and from the European Research Council grant agreement No 848325 (J.C. for the ERC Starting Grant). None declared by authors. Publisher Copyright: © 2021 Elsevier Inc.The interest in nanomedicine for cancer theranostics has grown significantly over the past few decades. However, these nanomedicines need to overcome several physiological barriers intrinsic to the tumor microenvironment (TME) before reaching their target. Intrinsic tumor genetic/phenotypic variations, along with intratumor heterogeneity, provide different cues to each cancer type, making each patient with cancer unique. This brings additional challenges in translating nanotechnology-based systems into clinically reliable therapies. To develop efficient therapeutic strategies, it is important to understand the dynamic interactions between TME players and the complex mechanisms involved, because they constitute invaluable targets to dismantle tumor progression. In this review, we discuss the latest nanotechnology-based strategies for cancer diagnosis and therapy as well as the potential targets for the design of future anticancer nanomedicines.publishersversionpublishe
A novel microfluidic cell co-culture platform for the study of the molecular mechanisms of Parkinson's Disease and other synucleinopathies
Copyright © 2016 Fernandes, Chutna, Chu, Conde and Outeiro. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Although, the precise molecular mechanisms underlying Parkinson's disease (PD) are still elusive, it is now known that spreading of alpha-synuclein (aSyn) pathology and neuroinflammation are important players in disease progression. Here, we developed a novel microfluidic cell-culture platform for studying the communication between two different cell populations, a process of critical importance not only in PD but also in many biological processes. The integration of micro-valves in the device enabled us to control fluid routing, cellular microenvironments, and to simulate paracrine signaling. As proof of concept, two sets of experiments were designed to show how this platform can be used to investigate specific molecular mechanisms associated with PD. In one experiment, naïve H4 neuroglioma cells were co-cultured with cells expressing aSyn tagged with GFP (aSyn-GFP), to study the release and spreading of the protein. In our experimental set up, we induced the release of the contents of aSyn-GFP producing cells to the medium and monitored the protein's diffusion. In another experiment, H4 cells were co-cultured with N9 microglial cells to assess the interplay between two cell lines in response to environmental stimuli. Here, we observed an increase in the levels of reactive oxygen species in H4 cells cultured in the presence of activated N9 cells, confirming the cross talk between different cell populations. In summary, the platform developed in this study affords novel opportunities for the study of the molecular mechanisms involved in PD and other neurodegenerative diseases.JF was supported by FCT (SFRH/BD/73908/2010). TO is supported by the DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB). The work was also supported by FCT through the Associated Laboratory IN—Institute of Nanoscience and Nanotechnology and the research project EXCL/CTM-NAN/0441/2012.info:eu-repo/semantics/publishedVersio
Machine learning for next-generation nanotechnology in healthcare
Funding: The authors acknowledge financial support from FCT Portugal in the framework of PhD grant 2020.06638.BD (to D.P.S.), and the European Research Council grant agreement 848325 (J. Conde for the ERC Starting Grant). T.R. is an Investigador Auxiliar supported by FCT Portugal (CEECIND/ 00684/2018).Nanotechnology for healthcare is coming of age, but automating the design of composite materials poses unique challenges. Although machine learning is supporting groundbreaking discoveries in materials science, new initiatives leveraging learned patterns are required to fully realize the promise of nanodelivery systems and accelerate development pipelines.publishersversionpublishe
Lightweight Automated Feature Monitoring for Data Streams
Monitoring the behavior of automated real-time stream processing systems has
become one of the most relevant problems in real world applications. Such
systems have grown in complexity relying heavily on high dimensional input
data, and data hungry Machine Learning (ML) algorithms. We propose a flexible
system, Feature Monitoring (FM), that detects data drifts in such data sets,
with a small and constant memory footprint and a small computational cost in
streaming applications. The method is based on a multi-variate statistical test
and is data driven by design (full reference distributions are estimated from
the data). It monitors all features that are used by the system, while
providing an interpretable features ranking whenever an alarm occurs (to aid in
root cause analysis). The computational and memory lightness of the system
results from the use of Exponential Moving Histograms. In our experimental
study, we analyze the system's behavior with its parameters and, more
importantly, show examples where it detects problems that are not directly
related to a single feature. This illustrates how FM eliminates the need to add
custom signals to detect specific types of problems and that monitoring the
available space of features is often enough.Comment: 10 pages, 5 figures. AutoML, KDD22, August 14-17, 2022, Washington,
DC, U
Carotid body chemosensitivity: Early biomarker of dysmetabolism in humans
info:eu-repo/semantics/publishedVersio
Miniaturization of aqueous two-phase extraction for biological applications
Aqueous two-phase extraction (ATPE) is a biocompatible liquid-liquid (L-L) separation technique that has been under research for several decades towards the purification of biomolecules, ranging from small metabolites to large animal cells. More recently, with the emergence of rapid-prototyping techniques for fabrication of microfluidic structures with intricate designs, ATPE gained an expanded range of applications utilizing physical phenomena occurring exclusively at the microscale.
Studies of ATPSs at nanoliter-scale are further extending the range of applications of these systems by taking advantage of rapid diffusion times, increased degree of control of individual liquid streams and droplets, continuous flow and the integration of multi-dimensional separation modes. Several examples of microfluidic ATPS platforms are described.
The partition of molecules between two co-flowing liquid streams confined within a microchannel was successfully demonstrated by the on-line extraction of a fluorescein isothiocyanate (FITC) labeled immunoglobulin G (IgG) from a salt rich flow to a PEG rich flow. IgG diffusion to the PEG-rich phase was complete after 16 cm of channel using flow rates of 1 and 0.2 μL/min for the salt and PEGrich phases respectively. Besides proteins, ATPS have also been used to separate other more complex biomolecules in microfluidics such as virus-like particles.
The potential of miniaturization as a high-throughput screening tool has also been explored. The developed setup allowed the screening of a wide range of concentrations inside the microchannel by varying the flow rates of the solutions while using sub-mL volumes for each ATPS-forming system.
As a novel demonstration of the integrative potential of ATPE as a microfluidic sample preparation module, a microfluidic device comprising two modules was developed and used to perform a complex matrix clean-up in-line with an immunoassay.
References:
Silva, D. F., Azevedo, A. M., Fernandes, P., Chu, V. et al., Design of a microfluidic platform for monoclonal antibody extraction using an aqueous two-phase system. J. Chromatogr. A 2012, 1249, 1–7.
Jacinto, M. J., Soares, R. R. G., Azevedo, A. M., Chu, V. et al., Optimization and miniaturization of aqueous two phase systems for the purification of recombinant human immunodeficiency virus-like particles from a CHO cell supernatant. Sep. Purif. Technol. 2015, 154, 27–35.
Silva, D. F. C., Azevedo, A. M., Fernandes, P., Chu, V. et al., Determination of aqueous two phase system binodal curves using a microfluidic device. J. Chromatogr. A 2014, 1370, 115–120.
Soares, R. R., Novo, P., Azevedo, A. M., Fernandes, P. et al., On-chip sample preparation and analyte quantification using a microfluidic aqueous two-phase extraction coupled with an immunoassay. Lab Chip 2014, 14, 4284–429
A microfluidic platform combined with bacteriophage receptor binding proteins for multiplex detection of Escherichia coli and Pseudomonas aeruginosa in blood
Bloodstream infections (BSIs) are triggered by the existence of pathogens in blood and are considered a major health burden worldwide, especially when they result in sepsis and septic shock. Common diagnostic methods are time-consuming, present low specificity, or suffer from interference of blood components, which hampers a timely and effective treatment of BSIs. In this work, a novel microfluidic assay was developed combining a bead-based chip and bacteriophage receptor binding proteins (RBPs) as extremely specific and sensitive recognition molecules for the multiplex concentration and detection of Escherichia coli and Pseudomonas aeruginosa, which are highly prevalent bacteria in BSIs. The device comprises a microcolumn in which antibody-functionalized agarose beads were packed allowing the entrapment of the target bacterium from blood, providing its concentration and separation. For bacterial detection, two recombinant RBPs (Gp54 and Gp17) were fused with different fluorescent proteins and used for the identification of P. aeruginosa and E. coli by the measurement of the distinct fluorescent signals obtained. The developed microfluidic-based assay enabled a fast (70min) and highly specific multiplex detection of both pathogens in whole blood, achieving a detection limit of around 103 CFU, without requiring any time-consuming bacterial pre-enrichment step. Furthermore, it provided a quantitative assessment of bacterial loads present in blood. Noteworthy, this miniaturized and inexpensive device presents simple fabrication and operation, showing great potential to be fully automated, demonstrating to be ideal in point-of-care settings.The authors acknowledge the funding from the Portuguese Foundation for Science and Technology (FCT) under the scope of the project “Phages‐on‐chip” PTDC/BTM‐SAL/32442/2017 (POCI‐01-0145‐FEDER‐032442) and the strategic funding of the research units CEB (UIDB/04469/2020) and INESC MN (UID/05367/2020) through the pluriannual BASE and PROGRAMATICO financing and BioTecNorte operation (NORTE‐01-0145‐FEDER‐000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. S.P.C. and C.R.F.C. acknowledge the FCT for the grants SFRH/BD/130098/2017 and PD/BD/135274/2017, respectively.info:eu-repo/semantics/publishedVersio
Genotoxic effects of occupational exposure to lead and influence of polymorphisms in genes involved in lead toxicokinetics and in DNA repair
This work was partly supported by the Spanish Ministry of Science
and Innovation (PSI2010-15115) and Portuguese Fundação para a
Ciência e a Tecnologia (grants PDCT/SAU-OBS/59821/2004, PTDC/QUI/
67522/2006 and PTDC/SAU-OSM/105572/2008, and fellowship SFRH/
BD/22612/2005 to M. Pingarilho).publishersversionpublishe
Rapid optimization of chromatography operating conditions using a nano- liter scale column on a microfluidic chip with integrated pneumatic valves and optical sensors
Purification of monoclonal antibodies (mAbs) is traditionally achieved by chromatographic separations, which are very robust but require time-consuming optimization on a case-by-case, particularly if a non-affinity step is used. In this context, multimodal chromatography has been explored as a versatile and cost-effective alternative to the established affinity step employed for capturing mAbs. However, selective capture/polishing of a target mAb using such multimodal ligands comes with the need for extensive and time-consuming optimization, due to the multitude of interactions that can be simultaneously promoted in the ligand. In this work, we developed a novel microfluidic platform comprising multimodal chromatography beads inside micro-columns for rapid screening of operating conditions. Sequential liquid insertion in the device was achieved by using integrated pneumatic valves and the chromatographic assays were combined with a signal acquisition module for on-chip fluorescence measurements.
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