Self-Pumping Spheroid Membrane Enabling Long-Term Spheroid Culture and Label-Free Immune Cytotoxicity Screening.

Area of Science:

• Biomaterials Engineering
• Cancer Research
• Immunology

Background:

• Paper-based hanging-drop platforms offer low-cost, scaffold-free tumor spheroid culture for drug screening.
• Conventional designs hinder immune cell infiltration and dead cell clearance, limiting immunotherapy evaluation.
• Existing platforms require manual intervention for medium exchange and cell management.

Purpose of the Study:

• To develop an advanced spheroid culture platform that overcomes limitations of conventional designs.
• To enable efficient immune cell transport and dead cell removal within tumor spheroids.
• To provide a robust system for evaluating drug and cell-based cancer therapies.

Main Methods:

• Fabrication of a self-pumping spheroid membrane (SPSM) using parylene C deposition and O2 plasma treatment.
• Incorporation of a precisely tuned pore structure and vertical wettability gradient for size-selective transport.
• Validation through long-term spheroid culture (>14 days) and cytotoxicity assays with doxorubicin and CAR T cells.

Main Results:

• The SPSM platform supported long-term spheroid culture with high cell viability (>95%) and minimal handling.
• Demonstrated size-selective cell transport and passive dead cell separation.
• Label-free efficacy assessment based on spheroid size correlated with standard fluorescence staining methods.

Conclusions:

• The developed SPSM is a robust and quantitative platform for evaluating drug and immune cell therapies.
• This technology facilitates broader immuno-oncology investigations by improving immunotherapy assessment.
• The platform offers a simplified, scaffold-free approach for advanced tumor spheroid culture.