Substrate elasticity controls fibroblast motility on non-oxidized PDMS under weak adhesion
Arata Nagai1, Kyotaro Kanazashi1, Hiromu Kuwabara1
1College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258, Japan.
Biophysics and Physicobiology
|June 29, 2026
Summary
Substrate stiffness and surface properties significantly impact cardiac fibroblast behavior. Non-oxidized, less-adhesive surfaces promote rounded cell morphology, potentially maintaining fibroblasts in a less engaged state.
Area of Science:
- Biomaterials Science
- Cell Biology
- Mechanobiology
Background:
- Cardiac fibroblasts are crucial for heart tissue dynamics, responding to microenvironmental cues.
- Substrate mechanics and surface properties influence cell behavior, including motility and morphology.
- Polydimethylsiloxane (PDMS) is a common biomaterial for in vitro studies, but its surface properties can be altered by treatment.
Purpose of the Study:
- To investigate the effects of substrate stiffness and surface condition on chicken embryonic cardiac fibroblast motility and morphology.
- To understand how non-oxidized PDMS surfaces influence cell adhesion and behavior compared to oxidized surfaces.
- To explore the implications for mechanobiology and in vitro model design.
Main Methods:
- Culturing cardiac fibroblasts on collagen-coated PDMS substrates with varying elastic moduli (~10 kPa soft, ~400 kPa stiff).
- Utilizing non-plasma/UV/ozone treated PDMS to maintain native hydrophobic character and weak adhesion.
- Employing time-lapse phase-contrast microscopy for observing cell motility, spreading, and morphology.
- Quantitative analysis of motility cycles, static phase duration, and cell elongation.
Main Results:
- Non-oxidized PDMS surfaces led to weak cell-substrate adhesion, delayed spreading, and frequent partial detachment.
- Fibroblast motility cycles were irregular, characterized by contraction-driven retraction and partial detachment.
- Soft substrates resulted in longer motility cycles and trailing edges, while stiff substrates promoted rounded, less polarized cells.
- Adhesion instability significantly influenced cell elongation and static phase duration, independent of stiffness alone.
Conclusions:
- Substrate stiffness and surface adhesion instability critically regulate cardiac fibroblast motility and morphology.
- Non-oxidized PDMS surfaces preserve a rounded, less-spread fibroblast morphology, potentially maintaining cells in a less differentiated state.
- Understanding these interactions is vital for designing biomaterials that accurately mimic in vivo conditions for mechanobiology research.
