The introduction of immune checkpoint inhibitors has demonstrated significant improvements in survival for subsets of cancer patients. However, they carry significant and sometimes life-threatening ...toxicities. Prompt prediction and monitoring of immune toxicities have the potential to maximise the benefits of immune checkpoint therapy. Herein, we develop a digital nanopillar SERS platform that achieves real-time single cytokine counting and enables dynamic tracking of immune toxicities in cancer patients receiving immune checkpoint inhibitor treatment - broader applications are anticipated in other disease indications. By analysing four prospective cytokine biomarkers that initiate inflammatory responses, the digital nanopillar SERS assay achieves both highly specific and highly sensitive cytokine detection down to attomolar level. Significantly, we report the capability of the assay to longitudinally monitor 10 melanoma patients during immune inhibitor blockade treatment. Here, we show that elevated cytokine concentrations predict for higher risk of developing severe immune toxicities in our pilot cohort of patients.
A core element in clinical diagnostics is the data interpretation obtained through the analysis of patient samples. To obtain relevant and reliable information, a methodological approach of sample ...preparation, separation, and detection is required. Traditionally, these steps are performed independently and stepwise. Microchip capillary electrophoresis (MCE) can provide rapid and high-resolution separation with the capability to integrate a streamlined and complete diagnostic workflow suitable for the point-of-care setting. Whilst standard clinical diagnostics methods normally require hours to days to retrieve specific patient data, MCE can reduce the time to minutes, hastening the delivery of treatment options for the patients. This review covers the advances in MCE for disease detection from 2008 to 2017. Miniaturised diagnostic approaches that required an electrophoretic separation step prior to the detection of the biological samples are reviewed. In the two main sections, the discussion is focused on the technical set-up used to suit MCE for disease detection and on the strategies that have been applied to study various diseases. Throughout these discussions MCE is compared to other techniques to create context of the potential and challenges of MCE. A comprehensive table categorised based on the studied disease using MCE is provided. We also comment on future challenges that remain to be addressed.
Display omitted
•Clinical microchip electrophoresis (MCE) performed immunoassays, genotyping, and small molecule determination.•MCE enabled fast separation of biomarkers which was a crucial step for disease identification.•There were only a few reports that fulfilled the promise of point-of-care diagnostics.•The MCE strategies are discussed based on the targeted diseases.•Recent advancements and challenges of MCE are highlighted.
One of the most cited limitations of capillary and microchip electrophoresis is the poor sensitivity. This review continues to update this series of biannual reviews, first published in ...Electrophoresis in 2007, on developments in the field of online/in‐line concentration methods in capillaries and microchips, covering the period July 2016–June 2018. It includes developments in the field of stacking, covering all methods from field‐amplified sample stacking and large‐volume sample stacking, through to isotachophoresis, dynamic pH junction, and sweeping. Attention is also given to online or in‐line extraction methods that have been used for electrophoresis.
One of the most cited limitations of capillary (and microchip) electrophoresis is the poor sensitivity. This review continues to update this series of biennial reviews, first published in ...Electrophoresis in 2007, on developments in the field of on‐line/in‐line concentration methods in capillaries and microchips, covering the period July 2014–June 2016. It includes developments in the field of stacking, covering all methods from field amplified sample stacking and large volume sample stacking, through to isotachophoresis, dynamic pH junction, and sweeping. Attention is also given to on‐line or in‐line extraction methods that have been used for electrophoresis.
The synergistic stacking approach of field‐enhanced sample injection‐micelle‐to‐solvent stacking was used for high sensitivity CZE‐ESI‐MS of eight penicillins and sulfonamides. Sensitivity ...enhancement factors (peak height) were 1629–3328 compared to typical injection, with LODs from 0.11 to 0.55 ng/mL. The analytical figures of merit were acceptable. SPE on a fortified seawater sample resulted in 50‐fold enrichment with recoveries of 85–110%. The overall method LODs were 0.002–0.011 ng/mL.
Simultaneous electrophoretic concentration and separation (SECS) was used as a simple and environmental friendly sample preparation strategy for herbicides in beer samples. An electric field was used ...to facilitate the separation and concentration of the analytes based on their charge from a 20 mL sample of diluted beer into two separate 20 μL aliquots of an acceptor electrolyte housed inside a micropipette. The anionic organophosphonate and cationic quaternary ammonium herbicides were concentrated in the anodic and cathodic pipette, respectively. Under optimized conditions, SECS was completed in 30 min at an applied voltage of 150 V, which provided analyte concentration factors of up to 90. After sample preparation, the SECS concentrate of cationic and anionic herbicides was analyzed by stacking CE with UV detection and also by LC–MS, respectively. The method detection limit for the diluted and undiluted sample was as low as 3 and 15 ng/mL, respectively. The method was linear over two orders of concentration with repeatability and intermediate precision of better than 5.8 and 7.0%RSD, respectively. Accuracy values were between 91.0–115.1%.
Resistive pulse sensing (RPS) has become a pivotal platform for single‐molecule and nanoparticle analysis. Key to RPS is the sensing pore structure, the preparation of which is a subject of active ...research. While existing schemes produce pores with precise entrance diameters, producing pores with arbitrarily complex, 3D internal structures remains an open problem. Herein, two‐photon polymerization (TPP)‐based nanolithography is introduced for the reliable preparation of customizable RPS pores. For the first time, accurate micro‐ and nanopores with different cone angles are successfully prepared and their performance is studied experimentally and by simulation. Subsequently, accurate 3D pores are studied for selected RPS analysis: cis‐ and transconical pores for the investigation of the pore's preferential transport capability; symmetrical pores for the electrical tracking of nanoparticle position; and cylindrical pores for the surface charge analysis of chemically distinct nanoparticles of the same size. The TPP nanolithography technique enables tailored 3D pore designs with openings as small as 600 nm in diameter, providing opportunities for new RPS implementations that simultaneously investigate the physical and transport properties of translocating objects.
Two‐photon polymerization (TPP)‐based nanolithography is introduced for the reliable preparation of customizable resistive pulse sensing (RPS) pores for the first time. These tailored RPS pores are explored as versatile platforms for robust nanoparticle analysis, providing opportunities for the simultaneous investigation of physical/chemical and transporting properties of target objects.
Analytical methods for chiral compounds require a separation step prior to mass spectrometric detection. CE can separate enantiomers by the use of a chiral selector and can be hyphenated with MS. The ...chiral selector can be either embedded inside the capillary (electrochromatography) or added into the background solution (EKC). This review describes the fundamentals and highlights the recent developments (September 2009–May 2013) of chiral CEC and EKC with detection using MS. There were 20 research and more than 30 review papers during this period. The research efforts were driven by fundamental studies, such as the development of novel chiral selectors in electrochromatography and of advanced partial filling techniques in EKC in order to optimise separation. Other developments were in application studies, such as in food analytics and metabolomics.
Accurate identification of malignant lung lesions is a prerequisite for rational clinical management to reduce morbidity and mortality of lung cancer. However, classification of lung nodules into ...malignant and benign cases is difficult as they show similar features in computer tomography and sometimes positron emission tomography imaging, making invasive tissue biopsies necessary. To address the challenges in evaluating indeterminate nodules, the authors investigate the molecular profiles of small extracellular vesicles (sEVs) in differentiating malignant and benign lung nodules via a liquid biopsy‐based approach. Aiming to characterize phenotypes between malignant and benign groups, they develop a single‐molecule‐resolution‐digital‐sEV‐counting‐detection (DECODE) chip that interrogates three lung‐cancer‐associated sEV biomarkers and a generic sEV biomarker to create sEV molecular profiles. DECODE capturessEVs on a nanostructured pillar chip, confines individual sEVs, and profiles sEV biomarker expression through surface‐enhanced Raman scattering barcodes. The author utilize DECODE to generate a digitally acquired sEV molecular profiles in a cohort of 33 people, including patients with malignant and benign lung nodules, and healthy individuals. Significantly, DECODE reveals sEV‐specific molecular profiles that allow the separation of malignant from benign (area under the curve, AUC = 0.85), which is promising for non‐invasive characterisation of lung nodules found in lung cancer screening and warrants further clinincal validaiton with larger cohorts.
Digital small extracellular vesicle (sEV) counting detection (DECODE) chip—a nanostructured array integrated with surface‐enhanced Raman scattering to capture and characterize single sEVs by forming a binary unit (DECODE pixel)—detects phenotypic differences in plasma sEVs of patients with benign or malignant lung lesions. The digital analyses of liquid biopsy by DECODE are promising for noninvasive early‐stage lung cancer screening.
PDF
