Living biointerfaces based on non-pathogenic bacteria to direct cell differentiation.

Area of Science:

• Biomaterials Science
• Cell Biology
• Microbiology

Background:

• Mammalian cell adhesion to synthetic materials is crucial for biomedical applications.
• Current methods for surface functionalization often lack dynamic and adaptable properties.
• Fibronectin fragments, like FNIII(7-10), are known to mediate cell-material interactions.

Purpose of the Study:

• To develop a novel living biointerface for improved mammalian cell attachment and differentiation on synthetic materials.
• To utilize genetically modified bacteria to present specific cell-binding motifs on material surfaces.
• To establish a tunable and stable bacterial biofilm system for biomaterial functionalization.

Main Methods:

• Genetically modified Lactococcus lactis were engineered to express the FNIII(7-10) fibronectin fragment on their surface.
• L. lactis strains were used to form stable biofilms on material surfaces.
• Murine C2C12 myoblasts were cultured on these bacterial biofilms to assess cell adhesion, alignment, and differentiation.

Main Results:

• The engineered L. lactis successfully formed stable, tunable biofilms presenting the FNIII(7-10) fragment.
• The FNIII(7-10) fragment, containing RGD and PHSRN sequences, effectively bound to α5β1 integrins on C2C12 myoblasts.
• C2C12 myoblasts seeded on the biofilms exhibited bipolar alignment and differentiated into myotubes, indicating successful cell signaling and adhesion.

Conclusions:

• Living bacterial biofilms expressing fibronectin fragments offer a versatile and effective biointerface for biomaterial functionalization.
• This approach facilitates mammalian cell adhesion, spreading, and differentiation, paving the way for new biomedical applications.
• The bacterial biointerface can be engineered to present diverse biochemical signals, offering a new paradigm in surface modification for regenerative medicine and tissue engineering.