Stabilizing light-responsive azobenzene films in an aqueous environment with thin polymer coatings

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Chemistry

Background:

• Mimicking dynamic cell-extracellular matrix (ECM) interactions is crucial for biomaterial development.
• Light-responsive materials offer potential for dynamic ECM mimicry, but their stability in cell culture is understudied.
• Azobenzene-based films enable photopatterning for dynamic surface control.

Purpose of the Study:

• To evaluate the impact of poly(dimethylsiloxane) (PDMS) and parylene C coatings on azobenzene-based photopatternable films.
• To assess the stability and biocompatibility of these coated films in dry and aqueous environments.
• To determine the suitability of these materials for cell culture applications requiring dynamic ECM mimicry.

Main Methods:

• Fabrication of azobenzene-based films.
• Application of thin poly(dimethylsiloxane) (PDMS) and parylene C coatings.
• Photopatterning using laser interference irradiation to form surface relief gratings (SRGs).
• Evaluation of SRG formation, erasure, and reconfiguration in dry and aqueous conditions.
• Assessment of material stability and biocompatibility, including cell adhesion studies.

Main Results:

• Parylene C coatings significantly improved the stability of azobenzene films compared to PDMS coatings.
• Parylene C demonstrated superior biocompatibility and promoted better cell adhesion.
• The coated films retained photopatterning capabilities (formation, erasure, reconfiguration) in aqueous environments.
• PDMS coatings showed limitations in long-term stability and biocompatibility.

Conclusions:

• Parylene C coatings are advantageous for enhancing the performance of azobenzene-based photopatternable materials.
• These findings open new avenues for developing cell-culture-compatible biomaterials that dynamically mimic the ECM.
• The improved stability and biocompatibility of parylene C-coated films are critical for advanced biomedical applications.