Recent advances in droplet microfluidics for single-cell analysis

Droplet Microfluidics for Current Cancer Research: From Single-Cell Analysis to 3D Cell Culture

“…Accurate single-cell analysis plays an important role in cancer diagnosis, personalized treatment, and anticancer drug discovery and is necessary to reveal the genomic, transcriptomic, and proteomic heterogeneity of cancer cells. , In this section, we present recent droplet-based platforms for the single-cell heterogeneity analysis of cancer cells. In addition, considering that CTCs are significant biomarkers in liquid biopsies for cancer diagnosis, studies on the combination of droplet microfluidics and microfluidic enrichment technologies for single-cell analysis of CTCs are also discussed (Table ).…”

“…As a powerful platform for biochemical analysis, several classic reviews on droplet microfluidics for single-cell genomic, transcriptomic, proteomic, and metabolic analyses have been documented. − Nonetheless, to the best of our knowledge, no specific review has focused on the applications of droplet microfluidics in cancer research. Herein, we first introduce the fundamental technologies of droplet microfluidics, including single/double emulsion droplet generation and active/passive droplet manipulation, aiming to help researchers easily understand the underlying mechanisms of droplet microfluidics (Figure ).…”

Integrated Microfluidics for Single‐Cell Separation and On‐Chip Analysis: Novel Applications and Recent Advances

“…• Label-free separation • High versatility and compatibility with miniaturized bioassays for enhanced separation and analysis capabilities [202] • Well-controlled cell positions allow long-term single-cell analysis • Facilitates single-cell-bead pairings and singlecell co-cultures [195,203] • Motile cells might leave the compartments [263] • Limited control in ratios and distances between cells in single-cell co-culture [202] • Potential cross-talk between wells or traps [127] • Targeted delivery challenging, as reagents are distributed throughout the array [127] • Limited dynamic range in sorting cells of different sizes or types…”

“…• Label-free, contact-free separation • Controlled confinement of single cells in welldefined microenvironments [125,127,201] • No cross-talk between droplets [125,127,201] • Minimal sample and reagent usage, therefore cost reduction [125,127] • Suitable for a variety of assays, including genomic, transcriptomic, proteomic, and metabolic studies [125] • Fast reaction times and real-time detection [127,131] • High-throughput [126,127] • Cell encapsulation into droplets nonselective and based on Poisson statistics, which might lead to a high number of empty droplets [131,132,189] • Droplet size crucial in cell viability, nutrient replenishment and waste removal in droplets are limited [136,201] • Culturing of single adherent cells challenging [136,201,264] • Potential for droplet coalescence or instability, affecting assay results [265,266] • Application of image recognition techniques for selective droplet manipulation [131] • In-droplet solution exchange for nutrient supply and waste removal [133,134] • Gentle manipulation of large droplets without breakage for improved cell viability for longer periods [135] • Cell attachment on microgels prior to droplet encapsulation to establish adherent cell cultures in droplets [140] • Precise positioning and targeted manipulation of droplets leveraging microwells, magnetophoresis, DMF or microvalves [124,[141][142][143]204] NiFe-based magnetic microtweezer to trap and extract magnetic particles from a continuous stream of droplets (see Section 2.2.4 for droplet microfluidics). [57] The platform exhibited exceptional performance i...…”

“…[124] Droplet-based microfluidic technologies and their application to single-cell workflows offer significant advantages such as high throughput, parallelization possibilities, controlled confinement of single cells, and significant reagent cost reduction. [125][126][127] Furthermore, droplets provide an ideal microenvironment for conducting a variety of biological assays, offering precise spatial and temporal resolution. For example, multiple recent publications have showcased the substantial analytical potential of DMF for single-cell genome and transcriptome analyses.…”