Cell Morphology on Poly(methyl methacrylate) Microstructures as Function of Surface Energy.

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Chemistry

Background:

• Substrate topography is known to regulate cell function.
• A systematic analysis of the underlying principles is lacking.
• Surface energy's role in substrate-mediated cell phenotype modulation requires investigation.

Purpose of the Study:

• To evaluate the hypothesis that surface energy is a decisive factor in substrate-mediated cell phenotype modulation.
• To assess cell behavior on synthetic microstructures with varying surface energies.
• To establish a common physicochemical cause for cell adhesion and geometry on microstructures.

Main Methods:

• Fabrication of synthetic microstructures (cubes and walls) from poly(methyl methacrylate) using variotherm injection molding.
• Characterization of surface energy using static contact angle measurements.
• Evaluation of cell morphology and adhesion of NT2/D1 and MC3T3-E1 cells on microstructured surfaces via light scanning microscopy.

Main Results:

• Cell behavior demonstrated a profound dependence on surface energy.
• Microstructured 'walls' promoted significant cell elongation.
• A lack of cell adhesion was observed on 'cubes' with the lowest periodicity.
• A critical water contact angle of ≤ 80° was identified as necessary for adequate cell adhesion.

Conclusions:

• Surface energy acts as a switch for cell adhesion and growth by adjusting the periodicity of hydrophobic structures.
• Cell elongation on walls and critical surface energy levels for adhesion were achieved for specific cell types.
• A water-drop model provides a physicochemical explanation for observed cell/droplet geometries and cell adhesion.