中文版本

Opportunity

Current cell encapsulation technologies, particularly those based on droplet microfluidics, face significant challenges in achieving high encapsulation efficiency and deterministic single-cell encapsulation. Traditional methods rely on Poisson distribution, which necessitates diluting cell suspensions to avoid empty droplets, thereby reducing overall efficiency. Alternative approaches, such as post-encapsulation droplet sorting or pre-encapsulation cell alignment, require complex external force fields (e.g., magnetic, dielectric, or electrokinetic forces) or fluorescent labeling. These methods not only demand sophisticated instrumentation but also risk altering cell behavior due to external stressors, leading to inaccurate downstream analyses. There is a pressing need for a simpler, label-free, and high-efficiency method to encapsulate cells deterministically while preserving their native biological properties.

Technology

The patent introduces an innovative hydrogel-based cell encapsulation method that leverages cell metabolism to achieve deterministic encapsulation without external force fields or labeling. The process involves:

1. Preparing a cell suspension (aqueous phase) with alginate and culture medium.
2. Forming an emulsion via droplet microfluidics, where droplets encapsulate cells.
3. Incubating the emulsion to allow metabolic byproducts (e.g., lactate, CO₂) to acidify the droplets, reducing pH to ≤6.5.
4. Introducing a pH-sensitive crosslinker (e.g., calcium sulfate nanoparticles) that dissolves at low pH, triggering alginate gelation selectively in cell-containing droplets.
5. Separating hydrogel particles (containing cells) from empty droplets via phase difference.

Key innovations include:

• Metabolic-Driven Encapsulation: Cell-containing droplets are identified by pH changes caused by metabolic activity, eliminating the need for labels.
• Nanoparticle Crosslinkers: Calcium sulfate nanoparticles enable pH-dependent gelation, ensuring high specificity.
• Batch Sorting: Cells with different metabolic rates (e.g., cancer vs. normal cells) can be sorted sequentially.

Advantages  

• High Efficiency: Achieves >90% cell encapsulation and >80% single-cell encapsulation rates.
• Label-Free: Avoids fluorescent markers or external forces, preserving native cell behavior. Simplified Workflow: No complex instruments or post-encapsulation sorting required.
• Versatility: Applicable to diverse cell types (e.g., cancer cells, stem cells, immune cells).
• Downstream Compatibility: Encapsulated cells maintain viability (>96%) and proliferative capacity.

Applications  

• Single-Cell Analysis: Transcriptomics, metabolomics, and proteomics studies.
• Cell Sorting: Isolation of live/dead cells or rare cell populations (e.g., circulating tumor cells).
• Tissue Engineering: Production of uniform cell-laden hydrogels for 3D culture.
• Liquid Biopsy: Metabolic profiling of cancer cells for precision medicine.
• Reagent Kits: Commercial kits for standardized cell encapsulation.