Unveil early-stage nanocytotoxicity by a label-free single cell pH nanoprobe

Protein secretion of cells plays a vital role in intercellular communication. The abnormality and dysfunction of cellular protein secretion are associated with various physiological disorders, such as malignant proliferation of cells, aberrant immune function, and bone marrow failure. The heterogeneity of protein secretion exists not only between varying populations of cells, but also in the same phenotype of cells. Therefore, characterization of protein secretion from single cell contributes not only to the understanding of intercellular communication in immune effector, carcinogenesis and metastasis, but also to the development and improvement of diagnosis and therapy of relative diseases. In spite of abundant highly sensitive methods that have been developed for the detection of secreted proteins, majority of them fall short in providing sufficient spatial and temporal resolution for comprehensive profiling of protein secretion from single cells. The real-time imaging techniques allow rapid acquisition and manipulation of analyte information on a 2D plane, providing high spatiotemporal resolution. Here, we summarize recent advances in real-time imaging of secretory proteins from single cell, including label-free and labelling techniques, shedding light on the development of simple yet powerful methodology for real-time imaging of single-cell protein secretion.

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Real-Time Monitoring and Detection of Single-Cell Level Cytokine Secretion Using LSPR Technology

Micromachines ◽

10.3390/mi11010107 ◽

2020 ◽

Vol 11 (1) ◽

pp. 107 ◽

Cited By ~ 3

Author(s):

Chen Zhu ◽

Xi Luo ◽

Wilfred Villariza Espulgar ◽

Shohei Koyama ◽

Atsushi Kumanogoh ◽

...

Keyword(s):

Single Cell ◽

Real Time ◽

Single Cells ◽

Clinical Diagnostics ◽

Cytokine Secretion ◽

Localized Surface Plasmon ◽

Single Cell Level ◽

Label Free ◽

Real Time Monitoring ◽

Cell Level

Cytokine secretion researches have been a main focus of studies among the scientists in the recent decades for its outstanding contribution to clinical diagnostics. Localized surface plasmon resonance (LSPR) technology is one of the conventional methods utilized to analyze these issues, as it could provide fast, label-free and real-time monitoring of biomolecule binding events. However, numerous LSPR-based biosensors in the past are usually utilized to monitor the average performance of cell groups rather than single cells. Meanwhile, the complicated sensor structures will lead to the fabrication and economic budget problems. Thus, in this paper, we report a simple synergistic integration of the cell trapping of microwell chip and gold-capped nanopillar-structured cyclo-olefin-polymer (COP) film for single cell level Interleukin 6 (IL-6) detection. Here, in-situ cytokine secreted from the trapped cell can be directly observed and analyzed through the peak red-shift in the transmittance spectrum. The fabricated device also shows the potential to conduct the real-time monitoring which would greatly help us identify the viability and biological variation of the tested single cell.

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Single-Cell Electroporation with Real-Time Impedance Assessment Using a Constriction Microchannel

Micromachines ◽

10.3390/mi11090856 ◽

2020 ◽

Vol 11 (9) ◽

pp. 856

Author(s):

Yifei Ye ◽

Xiaofeng Luan ◽

Lingqian Zhang ◽

Wenjie Zhao ◽

Jie Cheng ◽

...

Keyword(s):

Electric Field ◽

Single Cell ◽

Real Time ◽

Single Cells ◽

Intracellular Delivery ◽

Microfluidic System ◽

Label Free ◽

Precise Control ◽

Cell Electroporation ◽

Single Cell Electroporation

The electroporation system can serve as a tool for the intracellular delivery of foreign cargos. However, this technique is presently limited by the inaccurate electric field applied to the single cells and lack of a real-time electroporation metrics subsystem. Here, we reported a microfluidic system for precise and rapid single-cell electroporation and simultaneous impedance monitoring in a constriction microchannel. When single cells (A549) were continuously passing through the constriction microchannel, a localized high electric field was applied on the cell membrane, which resulted in highly efficient (up to 96.6%) electroporation. During a single cell entering the constriction channel, an abrupt impedance drop was noticed and demonstrated to be correlated with the occurrence of electroporation. Besides, while the cell was moving in the constriction channel, the stabilized impedance showed the capability to quantify the electroporation extent. The correspondence of the impedance variation and electroporation was validated by the intracellular delivery of the fluorescence indicator (propidium iodide). Based on the obtained results, this system is capable of precise control of electroporation and real-time, label-free impedance assessment, providing a potential tool for intracellular delivery and other biomedical applications.

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Label-Free and Quantitative Dry Mass Monitoring for Single Cells during In Situ Culture

Cells ◽

10.3390/cells10071635 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1635

Author(s):

Ya Su ◽

Rongxin Fu ◽

Wenli Du ◽

Han Yang ◽

Li Ma ◽

...

Keyword(s):

Cell Growth ◽

Single Cell ◽

Hela Cells ◽

Quantitative Measurement ◽

Single Cells ◽

Dry Mass ◽

Quantitative Detection ◽

Label Free ◽

Mass Sensitivity

Quantitative measurement of single cells can provide in-depth information about cell morphology and metabolism. However, current live-cell imaging techniques have a lack of quantitative detection ability. Herein, we proposed a label-free and quantitative multichannel wide-field interferometric imaging (MWII) technique with femtogram dry mass sensitivity to monitor single-cell metabolism long-term in situ culture. We demonstrated that MWII could reveal the intrinsic status of cells despite fluctuating culture conditions with 3.48 nm optical path difference sensitivity, 0.97 fg dry mass sensitivity and 2.4% average maximum relative change (maximum change/average) in dry mass. Utilizing the MWII system, different intrinsic cell growth characteristics of dry mass between HeLa cells and Human Cervical Epithelial Cells (HCerEpiC) were studied. The dry mass of HeLa cells consistently increased before the M phase, whereas that of HCerEpiC increased and then decreased. The maximum growth rate of HeLa cells was 11.7% higher than that of HCerEpiC. Furthermore, HeLa cells were treated with Gemcitabine to reveal the relationship between single-cell heterogeneity and chemotherapeutic efficacy. The results show that cells with higher nuclear dry mass and nuclear density standard deviations were more likely to survive the chemotherapy. In conclusion, MWII was presented as a technique for single-cell dry mass quantitative measurement, which had significant potential applications for cell growth dynamics research, cell subtype analysis, cell health characterization, medication guidance and adjuvant drug development.

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Quantifying single-cell secretion in real time using resonant hyperspectral imaging

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1814977115 ◽

2018 ◽

Vol 115 (52) ◽

pp. 13204-13209 ◽

Cited By ~ 11

Author(s):

José Juan-Colás ◽

Ian S. Hitchcock ◽

Mark Coles ◽

Steven Johnson ◽

Thomas F. Krauss

Keyword(s):

Single Cell ◽

Real Time ◽

Protein Secretion ◽

Cell Communication ◽

Label Free ◽

Cell Secretion ◽

Physiological Disorder ◽

Real Time Analysis ◽

Technology Heterogeneity

Cell communication is primarily regulated by secreted proteins, whose inhomogeneous secretion often indicates physiological disorder. Parallel monitoring of innate protein-secretion kinetics from individual cells is thus crucial to unravel systemic malfunctions. Here, we report a label-free, high-throughput method for parallel, in vitro, and real-time analysis of specific single-cell signaling using hyperspectral photonic crystal resonant technology. Heterogeneity in physiological thrombopoietin expression from individual HepG2 liver cells in response to platelet desialylation was quantified demonstrating how mapping real-time protein secretion can provide a simple, yet powerful approach for studying complex physiological systems regulating protein production at single-cell resolution.

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ZipSeq : Barcoding for Real-time Mapping of Single Cell Transcriptomes

10.1101/2020.02.04.932988 ◽

2020 ◽

Cited By ~ 2

Author(s):

Kenneth H. Hu ◽

John P. Eichorst ◽

Chris S. McGinnis ◽

David M. Patterson ◽

Eric D. Chow ◽

...

Keyword(s):

Gene Expression ◽

Single Cell ◽

Real Time ◽

Dimensional Space ◽

Single Cells ◽

Expression Patterns ◽

Live Cells ◽

Glass Substrates ◽

Complete Mapping

ABSTRACTSpatial transcriptomics seeks to integrate single-cell transcriptomic data within the 3-dimensional space of multicellular biology. Current methods use glass substrates pre-seeded with matrices of barcodes or fluorescence hybridization of a limited number of probes. We developed an alternative approach, called ‘ZipSeq’, that uses patterned illumination and photocaged oligonucleotides to serially print barcodes (Zipcodes) onto live cells within intact tissues, in real-time and with on-the-fly selection of patterns. Using ZipSeq, we mapped gene expression in three settings: in-vitro wound healing, live lymph node sections and in a live tumor microenvironment (TME). In all cases, we discovered new gene expression patterns associated with histological structures. In the TME, this demonstrated a trajectory of myeloid and T cell differentiation, from periphery inward. A variation of ZipSeq efficiently scales to the level of single cells, providing a pathway for complete mapping of live tissues, subsequent to real-time imaging or perturbation.

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A single-cell Raman-based platform to identify developmental stages of human pluripotent stem cell-derived neurons

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2001906117 ◽

2020 ◽

Vol 117 (31) ◽

pp. 18412-18423 ◽

Cited By ~ 2

Author(s):

Chia-Chen Hsu ◽

Jiabao Xu ◽

Bas Brinkhof ◽

Hui Wang ◽

Zhanfeng Cui ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Single Cell ◽

Raman Spectra ◽

Large Scale ◽

Developmental Stages ◽

Single Cells ◽

Classification Model ◽

Label Free ◽

Machine Learning Classification

Stem cells with the capability to self-renew and differentiate into multiple cell derivatives provide platforms for drug screening and promising treatment options for a wide variety of neural diseases. Nevertheless, clinical applications of stem cells have been hindered partly owing to a lack of standardized techniques to characterize cell molecular profiles noninvasively and comprehensively. Here, we demonstrate that a label-free and noninvasive single-cell Raman microspectroscopy (SCRM) platform was able to identify neural cell lineages derived from clinically relevant human induced pluripotent stem cells (hiPSCs). By analyzing the intrinsic biochemical profiles of single cells at a large scale (8,774 Raman spectra in total), iPSCs and iPSC-derived neural cells can be distinguished by their intrinsic phenotypic Raman spectra. We identified a Raman biomarker from glycogen to distinguish iPSCs from their neural derivatives, and the result was verified by the conventional glycogen detection assays. Further analysis with a machine learning classification model, utilizing t-distributed stochastic neighbor embedding (t-SNE)-enhanced ensemble stacking, clearly categorized hiPSCs in different developmental stages with 97.5% accuracy. The present study demonstrates the capability of the SCRM-based platform to monitor cell development using high content screening with a noninvasive and label-free approach. This platform as well as our identified biomarker could be extensible to other cell types and can potentially have a high impact on neural stem cell therapy.

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Global cDNA Amplification Combined with Real-Time RT–PCR: Accurate Quantification of Multiple Human Potassium Channel Genes at the Single Cell Level

Yeast ◽

10.1002/1097-0061(20000930)17:3<201::aid-yea30>3.0.co;2-r ◽

2000 ◽

Vol 1 (3) ◽

pp. 201-210 ◽

Cited By ~ 40

Author(s):

A. Al-Taher ◽

A. Bashein ◽

T. Nolan ◽

M. Hollingsworth ◽

Brady G.

Keyword(s):

Potassium Channel ◽

Single Cell ◽

Real Time ◽

Quantitative Pcr ◽

Single Cells ◽

Initial Step ◽

Small Samples ◽

Rt Pcr ◽

Real Time Quantitative Pcr ◽

Global Amplification

We have developed a sensitive quantitative RT–PCR procedure suitable for the analysis of small samples, including single cells, and have used it to measure levels of potassium channel mRNAs in a panel of human tissues and small numbers of cells grown in culture. The method involves an initial global amplification of cDNA derived from all added polyadenylated mRNA followed by quantitative RT–PCR of individual genes using specific primers. In order to facilitate rapid and accurate processing of samples, we have adapted the approach to allow use ofTaqMan™real-time quantitative PCR. We demonstrate that the approach represents a major improvement over existing conventional and real-time quantitative PCR approaches, since it can be applied to samples equivalent to a single cell, is able to accurately measure expression levels equivalent to less than 1/100th copy/cell (one specific cDNA molecule present amongst108total cDNA molecules). Furthermore, since the initial step involves a global amplification of all expressed genes, a permanent cDNA archive is generated from each sample, which can be regenerated indefinitely for further expression analysis.

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Gating a Single Cell: A Label-Free and Real-Time Measurement Method for Cellular Progression

Analytical Chemistry ◽

10.1021/acs.analchem.9b03136 ◽

2020 ◽

Vol 92 (2) ◽

pp. 1738-1745

Author(s):

Saw Lin Oo ◽

Shishir Venkatesh ◽

Abdul-Mojeed Ilyas ◽

Vaithinathan Karthikeyan ◽

Clement Manohar Arava ◽

...

Keyword(s):

Single Cell ◽

Real Time ◽

Measurement Method ◽

Time Measurement ◽

Label Free ◽

Real Time Measurement

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Multiplexed and single-cell detection of microRNA with plasmonic nanoparticle assemblies

Canadian Journal of Chemistry ◽

10.1139/cjc-2021-0023 ◽

2021 ◽

Author(s):

Gurbrinder Ghotra ◽

Nguyen Le ◽

Heyam Hayder ◽

Chun Peng ◽

Jennifer I. L. Chen

Keyword(s):

Nucleic Acid ◽

Single Cell ◽

Low Cost ◽

Single Cells ◽

Cell Detection ◽

Label Free ◽

Plasmonic Nanoparticle ◽

Nanoparticle Assemblies ◽

Single Cell Detection ◽

Target Binding

We present a label-free, low cost and miniatured biosensing platform based on the disassembly of core-satellite plasmonic nanoparticle assemblies. The rapid and selective detection of an exemplary nucleic acid biomarker, has-miRNA-210-3p, was achieved via the strand displacement nucleic acid reaction. Target binding leads to dehybridization of the DNA linkers and changes in the scattering properties of nanostructures as monitored by darkfield microscopy. We demonstrate the ability to detect microRNA expunged from single cells and the potential to multiplex discrete assemblies to enable diverse biological applicability. The work may help translate the applicability of microRNA as diagnostic biomarkers, quantitate their abundance in the microenvironment, and facilitate the study of their correlation or causation to other biomolecules at the single-cell level.

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