Cellular Responses Modulated by FGF-2 Adsorbed on Albumin/Heparin Layer-by-Layer Assemblies

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Chemistry

Background:

• Growth factors are crucial for cell culture but require constant medium supplementation.
• Immobilizing growth factors on surfaces offers a sustained signaling reservoir.
• Albumin/heparin (Alb/Hep) assemblies present a novel approach for growth factor immobilization.

Purpose of the Study:

• To fabricate and characterize Alb/Hep assemblies for controlled binding of basic fibroblast growth factor (FGF-2).
• To assess the bioactivity of immobilized FGF-2 on cell proliferation and differentiation.
• To optimize FGF-2 surface concentration for enhanced cellular response.

Main Methods:

• Layer-by-layer adsorption of albumin and heparin, followed by glutaraldehyde crosslinking.
• Surface morphology analysis using atomic force microscopy (AFM).
• Characterization of Alb/Hep assembly formation and FGF-2 adsorption using SPR, FTIR MIRS, and UV/VIS spectroscopy.
• In vitro assessment of cell attachment, proliferation, and differentiation using calf pulmonary arterial endothelial cells (CPAE).

Main Results:

• Two Alb/Hep bilayers were sufficient to cover the substrate surface.
• FGF-2 binding to Alb/Hep assemblies was dose- and time-dependent, reaching up to 120 ng/cm(2).
• Immobilized FGF-2 retained bioactivity, stimulating CPAE cell proliferation and differentiation.
• Optimal cell response was observed at a lower FGF-2 surface concentration (30 ng/cm(2)).

Conclusions:

• Alb/Hep assemblies provide a stable and effective platform for immobilizing FGF-2.
• The immobilized FGF-2 supports cell attachment, proliferation, and differentiation.
• Controlled surface concentration of FGF-2 is crucial for maximizing cellular responses.