Inertial and Deterministic Lateral Displacement Integrated Microfluidic Chips for Epithelial-Mesenchymal Transition...

Area of Science:

• Biomedical Engineering
• Oncology
• Microfluidics

Background:

• Circulating tumor cells (CTCs) are crucial biomarkers for cancer diagnosis and monitoring.
• Existing CTC isolation methods often suffer from low efficiency, purity, or cell damage.
• Minimizing damage and maximizing purity are essential for reliable CTC analysis.

Purpose of the Study:

• To develop an efficient and gentle microfluidic system for isolating rare circulating tumor cells (CTCs).
• To analyze the relationship between PD-L1 expression and the epithelial-mesenchymal transition (EMT) process in breast cancer cells.
• To establish a high-throughput platform for potential clinical liquid biopsy applications.

Main Methods:

• Construction of an inertia-assisted single-cell focusing generator (I-SCF) and a droplet-based deterministic lateral displacement (D-DLD) microfluidic system (IDIC).
• Utilized fluid dynamics (continuous fluid swing, Dean flow) and droplet-shaped DLD for cell focusing and separation based on size.
• Analyzed protein expression (EpCAM, PD-L1, N-cadherin) in breast cancer cell lines undergoing TGF-β-induced EMT.

Main Results:

• Achieved high cell separation efficiency (>95%) and purity (>84.01%) with a single-cell survival rate exceeding 98.6%.
• Successfully detected downstream epithelial-mesenchymal transition (EMT) and analyzed protein levels, establishing a link between PD-L1 and EMT.
• Demonstrated high throughput capacity (5 mL of diluted whole blood in ~2.8 hours).

Conclusions:

• The IDIC microfluidic system offers superior CTC isolation efficiency, purity, and cell viability compared to traditional methods.
• The platform enables the study of CTC heterogeneity and its relationship with cancer progression markers like PD-L1 and EMT.
• This technology holds significant promise for advancing clinical liquid biopsy for early cancer detection and treatment monitoring.