Speciation of selenium-containing small molecules in urine and cell lysate by CE-ICPMS with in-capillary enrichment.

The quantitative speciation of selenium in biological systems is highly important for evaluating health status and elucidating transformations of Se species in physiological and pathological processes. Hyphenation of capillary electrophoresis with inductively coupled plasma mass spectrometry (CE-ICPMS) is promising for this purpose. However, the unfavorable or insufficient sensitivity for selenium analysis with CE-ICPMS seriously limits its practical applications in biological analysis, e.

Biofuel cell-based self-powered immunosensor for detection of 17β-estradiol by integrating the target-induced biofuel release and biogate immunoassay.

A novel biofuel cell (BFC)-based self-powered electrochemical immunosensing platform was developed by integrating the target-induced biofuel release and biogate immunoassay for ultrasensitive 17β-estradiol (E2) detection. The carbon nanocages/gold nanoparticle composite was employed in the BFCs device as the electrode material, through which bilirubin oxidase and glucose oxidase were wired to form the biocathode and bioanode, respectively. Positively charged mesoporous silica nanoparticles (PMSN) were encapsulated with glucose molecules as biofuel and subsequently coated by the negatively charged AuNPs-labelled anti-E2 antibody (AuNPs-Ab) serving as a biogate.

Multiplex Profiling of Biomarker and Drug Uptake in Single Cells Using Microfluidic Flow Cytometry and Mass Spectrometry.

To perform multiplex profiling of single cells and eliminate the risk of potential sample loss caused by centrifugation, we developed a microfluidic flow cytometry and mass spectrometry system (μCytoMS) to evaluate the drug uptake and induced protein expression at the single cell level. It involves a microfluidic chip for the alignment and purification of single cells followed by detection with laser-induced fluorescence (LIF) and inductively coupled plasma mass spectrometry (ICP-MS). Biofunctionalized nanoprobes (BioNPs), conjugating ∼3000 6-FAM-Sgc8 aptamers on a single gold nanoparticle (AuNP) ( = 0.

Two-Dimensional Multi-parameter Cytometry Platform for Single-Cell Analysis.

A 2D flow cytometry platform, known as CytoLM Plus, was developed for multi-parameter single-cell analysis. Single particles or cells after hydrodynamic alignment in a microfluidic unit undergo first-dimension fluorescence and side scattering dual-channel optical detection. They were thereafter immediately directed to ICP-MS by connecting the microfluidic unit with a high-efficiency nebulizer to facilitate the second-dimension ICP-MS detection.

Open flow cytometer with the combination of 3D hydrodynamic single cell focusing and confocal laser-induced fluorescence detection.

Flow cytometry is among the most powerful tools for single-cell analysis, while the high cost and mechanical complexity of the commercial instrumentation limit the applications in personalized single-cell analysis. For this issue, we hereby construct an open and low-cost flow cytometer. It is highly compact to integrate the functions of (1) single cell aligning by a lab-made modularized 3D hydrodynamic focusing device, and (2) fluorescence detection of the single cells by a confocal laser-induced fluorescence (LIF) detector.

[Determination of glutathione in cells by capillary electrophoresis-laser induced fluorescence].

Glutathione (GSH) is vital for oxidative stress resistance and heavy metals detoxification. It is significant to develop a sensitive and accurate quantitative GSH approach for the toxicity mechanism for studying heavy metals in cells. A high-sensitive capillary electrophoresis-laser induced fluorescence (CE-LIF) detection approach was proposed in this study to detect GSH content in cells.

Intolerance of profligacy: an aptamer concentration gradient-tailored unicellular array for high-throughput biologics-mediated phenotyping.

In aptamer-based assay schemes, aptamer probes not labeled with biomarkers have to be eliminated before testing, which may lead to a tremendous waste of precious probes. We herein propose a microfluidics system integrating an aptamer concentration gradient generator (Apt-CGG) and a dual single-cell culturing array (D-SCA), termed Mi-Apt-SCA. This facilitates the precise construction of a nanoscale-gradient microenvironment and the high-throughput profiling of single-cell growth/phenotypes with the minimal consumption of Apt-probe.

Tracking cellular transformation of As(III) in HepG2 cells by single-cell focusing/capillary electrophoresis coupled to ICP-MS.

The cellular metabolism of metals is highly critical to elucidate their potential cytotoxicity or cell protection mechanism. In this work, an asymmetric serpentine microfluidic device (ASMD) with high sampling efficiency and excellent focusing performance was developed for single-cell focusing. ASMD coupling with ICP-MS ensures single-cell assay to provide the information for trivalent arsenic (As(III)) uptake by HepG2 cells, which reveals the heterogeneity of cellular arsenic distribution, and elucidates the arsenic elimination behaviors in single HepG2 cells.

Dual-Multivalent-Aptamer-Conjugated Nanoprobes for Superefficient Discerning of Single Circulating Tumor Cells in a Microfluidic Chip with Inductively Coupled Plasma Mass Spectrometry Detection.

The efficient recognition of circulating tumor cells (CTCs) with an aptamer probe confers numerous benefits; however, the stability and binding affinity of aptamers are significantly hampered in real biological sample matrices. Inspired by the efficient preying mechanism by multiplex tubing feet and endoskeletons of sea urchins, we engineered a superefficient biomimetic single-CTC recognition platform by conjugating dual-multivalent-aptamers (DMAs) Sgc8 and SYL3C onto AuNPs to form a sea urchin-like nanoprobe (sea urchin-DMA-AuNPs). Aptamers Sgc8 and SYL3C selectively bind with the biomarker proteins PTK7 and EpCAM expressed on the surface of CTCs.

Two-Dimensional Cytometry Platform for Single-Particle/Cell Analysis with Laser-Induced Fluorescence and ICP-MS.

A two-dimensional cytometry platform (CytoLM) with high sensitivity and high temporal resolution is developed for single-particle and single-cell sampling and analysis. First, a flow-assisted vortex capillary cell sampling (VCCS) unit confines the sample stream in curved flow and drives to focus and align the particles or cells in a small probe volume. By coupling VCCS to a laser-induced fluorescence (LIF) detector with data acquisition and processing capability, a high-throughput single-particle/cell analysis system (VCCS-LIF) was established.

Intracellular silver speciation by coupling capillary electrophoresis to ICP-MS integrating a high performance spiral flow spray chamber.

The study of silver species and their distribution/transformation in cell interior is of high significance for the elucidation of toxicology of silver nanoparticles (AgNPs). The intracellular speciation of dissolved Ag(I) and AgNPs was reported. The analytical platform integrated capillary electrophoresis (CE) to inductively coupled plasma-mass spectrometry (ICP-MS) incorporating a high efficiency interface and a high performance spiral flow spray chamber (SFSC).

Identification of intracellular cadmium transformation in HepG2 and MCF-7 cells.

It is of significance to elucidate or understand the intracellular transformation & migration behaviors of heavy metals in specific cells. Herein, we report the fast and efficient separation of cadmium-metallothioneins (Cd-MTs) and Cdin cell lysate by a short column capillary electrophoresis (SC-CE), followed by coupling with inductively coupled plasma mass spectrometry (ICP-MS) to facilitate the speciation of intracellular cadmium species. The incorporation of sodium dodecyl sulfate (SDS) in running buffer significantly reduces the peak width of Cdfrom 170 s to 26 s in the electrophoretogram, causing a 5.

Inertial-Force-Assisted, High-Throughput, Droplet-Free, Single-Cell Sampling Coupled with ICP-MS for Real-Time Cell Analysis.

Single-cell analysis facilitates perception into the most essential processes in life's mysteries. While it is highly challenging to quantify them at the single-cell level, where precise single-cell sampling is the prerequisite. Herein, a real-time single-cell quantitative platform was established for high-throughput droplet-free single-cell sampling into time-resolved (TRA) ICP-MS and real-time quantification of intracellular target elements.

Structure-activity relationship investigation of coumarin-chalcone hybrids with diverse side-chains as acetylcholinesterase and butyrylcholinesterase inhibitors.

Chalcones containing tertiary amine side-chains have potent activity as acetylcholinesterase (AChE) inhibitors. However, the effects of the location of the tertiary amine groups as well as of other groups on AChE and butyrylcholinesterase (BChE) activity have not been reported. Here, we report the synthesis and testing of 36 new coumarin-chalcone hybrids (5d-7j, 9d-11f, 12k-13m) against AChE and BChE.

Discovery of potent and selective acetylcholinesterase (AChE) inhibitors: acacetin 7-O-methyl ether Mannich base derivatives synthesised from easy access natural product naringin.

Naringin, as a component universal existing in the peel of some fruits or medicinal plants, was usually selected as the material to synthesise bioactive derivates since it was easy to gain with low cost. In present investigation, eight new acacetin-7-O-methyl ether Mannich base derivatives (1-8) were synthesised from naringin. The bioactivity evaluation revealed that most of them exhibited moderate or potent acetylcholinesterase (AChE) inhibitory activity.

Enzyme digestion to isolate and culture human scalp dermal papilla cells: a more efficient method.

In this study, we show a more efficient method for isolation and cultivation of dermal papilla cells from hair follicles of human scalp skin. The dermal partments of low hair follicles were pulled out from cutaneous fat and the bulb epithelium was teased out from the fibrous sheath with attached dermal papilla by applying gentle pressure with the tip of an occal forceps. When these fibrous sheaths were entirely digested into isolated cells by collagenase D but the dermal papillae were justly to be digested, collagenase D was discarded and the dermal papillae were isolated completely out from the resuspension solution by repeated low-speed centrifugation and transferred to another dish for free-floating culture.