Genipin-cross-linked layer-by-layer assemblies: biocompatible microenvironments to direct bone cell fate

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Biochemistry

Background:

• Improving osseointegration of bone biomaterials is crucial for bone repair.
• Layer-by-layer (LbL) films using natural components are promising for biomimetic coatings.
• Chondroitin sulfate A (CSA), a glycosaminoglycan (GAG), promotes osteoblast maturation but native LbL films lack stiffness.

Purpose of the Study:

• To develop stiffened CSA-based LbL films using a natural cross-linking agent.
• To investigate the effect of genipin (GnP) cross-linking on film properties and cellular response.
• To explore a novel FRET couple (FITC/GnP) for characterizing GnP-cross-linked systems.

Main Methods:

• Fabrication of CSA-based LbL films.
• Cross-linking of films using genipin (GnP).
• Characterization of film structure, topography, and mechanical properties, including FRET analysis.
• Assessment of preosteoblast adhesion, proliferation, and differentiation on the developed films.

Main Results:

• Genipin (GnP) cross-linking significantly stiffened the CSA-based LbL films.
• The GnP-cross-linked films exhibited unique microscale topography and tunable mechanical properties.
• A novel FITC/GnP FRET couple was successfully used for structural characterization.
• GnP-cross-linked films demonstrated significantly enhanced preosteoblast adhesion, proliferation, and differentiation.

Conclusions:

• Genipin (GnP) is an effective and less cytotoxic natural cross-linker for GAG-based LbL films.
• The developed GnP-cross-linked CSA films possess desirable properties for bone tissue engineering.
• These biomimetic coatings show significant potential for improving bone repair and osseointegration.