Layer-by-layer films made from extracellular matrix macromolecules on silicone substrates

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Chemistry

Background:

• Layer-by-layer (LbL) nanofilms are crucial for biomedical applications.
• Extracellular matrix (ECM) macromolecules are ideal for LbL film preparation.
• Polydimethylsiloxane (PDMS) is a versatile substrate for biomaterial development.

Purpose of the Study:

• To assess the build-up and stability of type I collagen (Col1)/chondroitin sulfate (CS) or Col1/Heparin (HN) LbL films on PDMS.
• To evaluate integrin-mediated cell adhesion on these ECM-based films.
• To explore the potential of these films in mechanobiology and microfluidics.

Main Methods:

• Layer-by-layer (LbL) assembly of Col1/CS and Col1/HN films on PDMS.
• Quartz crystal microbalance with dissipation (QCM-D) for film build-up analysis.
• Atomic force microscopy (AFM) for structural and thickness characterization.
• Cell adhesion and cytoskeletal organization studies using primary chondrocytes.

Main Results:

• Consistent film build-up observed, with greater adsorption for Col1/HN films.
• Col1/CS films demonstrated stability in media, while Col1/HN films showed instability.
• AFM revealed fibrillar structures (20–30 nm thick) for both film types.
• Films promoted cell adhesion compared to tissue culture plastic.
• Cell adhesion was mediated by beta1 integrin interaction with collagen fibrils.

Conclusions:

• Stable ECM-based nanofilms can be constructed on PDMS substrates.
• These films support integrin-mediated cell adhesion, primarily through collagen interactions.
• The developed films hold significant potential for mechanobiology, microfluidics, and other biomedical applications.