A Pillar-Free Diffusion Device for Studying Chemotaxis on Supported Lipid Bilayers

Area of Science:

• Biomedical Engineering
• Cell Biology
• Microfluidics

Background:

• Chemotactic cell migration is vital in health and disease.
• Cells migrate through extracellular matrix and along stromal cell surfaces.
• Existing models lack the ability to replicate membrane-bound chemotaxis.

Purpose of the Study:

• To engineer a novel microfluidic device for studying chemotactic migration via membrane-bound interactions.
• To mimic stromal cell membranes using supported lipid bilayers (SLBs) tethered with membrane-bound factors.
• To precisely control chemokine gradients for observing cell behavior.

Main Methods:

• Micro-milling was used to create a multichannel diffusion device.
• Supported lipid bilayers (SLBs) were tethered with membrane-bound factors.
• Hydrogel barriers were formed using a liquid pinning process in pillar-free channels.
• Jurkat T cell migration was observed under a CXCL12 chemokine gradient on ICAM-1 tethered SLBs.

Main Results:

• The device precisely controls the timing and profile of chemokine gradients.
• The engineered SLB system successfully mimicked stromal cell membranes.
• Cells exhibited distinct migratory behaviors on mobile versus immobilized ICAM-1.
• The platform demonstrated proof-of-concept for studying membrane-bound chemotaxis.

Conclusions:

• The developed microfluidic platform enables precise investigation of membrane-bound chemotaxis.
• This technology can be applied to study various biological processes involving cell migration, including cancer, immunity, and stem cell research.