Biointerfaces with ultrathin patterns for directional control of cell migration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Cell Biology

Background:

• Precise control of cell migration is critical for wound healing and tissue regeneration.
• Existing methods often rely on tall sidewall constraints, limiting design flexibility.
• Need for advanced biointerfaces that can guide cell movement directionally.

Purpose of the Study:

• To design and fabricate novel polydimethylsiloxane (PDMS) platforms with ultrathin patterned titanium oxide (TiO_x) arrowheads.
• To investigate the ability of these patterns to achieve unidirectional cell migration without physical sidewall constraints.
• To explore the integration of microelectrodes for dynamic monitoring of cell migration.

Main Methods:

• Fabrication of PDMS platforms with 10 nm thick TiO_x arrowhead patterns of varying arm lengths (10, 20, 35 μm).
• Seeding of MC3T3-E1 cells on the patterned surfaces.
• High-resolution fluorescence imaging to analyze cell adhesion and focal adhesions.
• Integration of microelectrodes for impedance-based monitoring of cell migration.

Main Results:

• MC3T3-E1 cells exhibited unidirectional migration along the tips of the TiO_x arrowheads, guided by asymmetrical contact areas.
• Ultrathin arrowhead patterns successfully directed cell migration without the need for tall sidewall constraints.
• Asymmetrical focal adhesion distribution and protrusion formation were observed, correlating with the arrowhead geometry and promoting directed migration.
• Integrated microelectrodes enabled dynamic impedance measurements to characterize individual cell migration.

Conclusions:

• Ultrathin TiO_x arrowhead patterns on PDMS provide an effective strategy for unidirectional cell migration guidance.
• This approach offers a novel method for designing biointerfaces with precise control over cell movement.
• The integrated microfluidic device has significant potential for developing advanced biosensors for single-cell monitoring in regenerative medicine.