Understanding cellular heterogeneity is essential for deciphering the complexities of cellular subpopulations, differentiation processes, and microenvironmental influences. Single-cell proteomics plays a crucial role in explaining this complexity, but traditional techniques face significant challenges, particularly regarding sample loss and the sensitivity of analyzing small cell populations.
To address these issues, Prof. Shuailong Zhang and Prof. Hang Li from the Beijing Institute of Technology have recently published a review article titled “Droplet-Based Microfluidics with Mass Spectrometry for Microproteomics” in Engineering. This review explores the integration of droplet-based microfluidics with mass spectrometry (MS), emphasizing its potential to minimize sample loss and enhance sensitivity in single-cell proteomics studies.
The review starts by introducing droplet microfluidics and its applications in single-cell analysis. Technologies such as SODA, nanoPOTS, and digital microfluidics (DMF) platforms enable precise manipulation of microdroplets on a chip. This capability facilitates complex tasks, including cell culture, single-cell isolation, cell manipulation, sample preparation, and analytes enrichment, leading to a deeper understanding of cellular behavior and interactions.
The authors highlight recent advances in combining droplet microfluidics with MS for single-cell proteomics. Technologies like nanoPOTS, SODA, and OAD chip allow multistep sample preparation on a single chip, significantly improving analytical efficiency. DMF platforms such as DMF-SP3 and DISCO provide highly sensitive proteomics analyses, especially for small cell populations. The review underscores how versatile droplet microfluidics can seamlessly integrate with MS systems, such as the integrated DMF and DMF-µSH-MS, offering researchers rapid and sensitive tools for in-depth proteomic analysis.
The article presents various applications of microproteomics in biological research, including studies on cellular heterogeneity, spatial proteomics, and biomarker discovery. These insights not only enhance our molecular understanding of cellular diversity but also lay the groundwork for more precise and practical approaches in precision medicine.
Droplet-based microfluidics holds tremendous potential in microproteomics, enabling miniaturized and integrated workflows that effectively reduce sample loss. Recent advancements in droplet microfluidic devices and high-resolution MS have made automated parallel processing and deep quantitative analysis of single cells a reality, facilitating biological and clinical applications. This technology has been instrumental in characterizing cellular heterogeneity and discovering new biomarkers.
Looking ahead, further developments in microfluidics and MS are expected to push single-cell proteomics to new frontiers. Optimizing workflows and instrumentation will improve analytical sensitivity, revealing low-abundance proteins and their post-translational modifications. Advanced MS techniques combined with machine learning tools will enhance data analysis capabilities, simplifying the interpretation of complex proteomic data. Despite challenges such as efficient sample transfer and ionization interface design, researchers are actively exploring innovative separation techniques to improve high-throughput capabilities. The continued evolution of droplet-based microfluidics and MS is set to revolutionize our understanding of cellular systems, leading to groundbreaking advancements in both basic research and clinical applications.
DOI: 10.1016/j.eng.2024.08.018