Anti-Fibronectin Aptamer Modifies Blood Clot Pattern and Stimulates Osteogenesis: An Ex Vivo Study

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Scaffold (SCA) functionalization with aptamers (APT) enables specific bioactive molecule adsorption onto biomaterial surfaces.
• Anti-fibronectin aptamers were utilized to functionalize scaffolds for enhanced biological interactions.

Purpose of the Study:

• To investigate if scaffolds enriched with anti-fibronectin aptamers promote coagulum (PhC) and osteoblast (OSB) differentiation.
• To evaluate the impact of aptamer functionalization on cellular and molecular responses in a bone defect model.

Main Methods:

• Scaffolds were functionalized with 20 μg of aptamers via simple adsorption.
• Functionalized scaffolds were implanted in rat calvaria defects for coagulum formation.
• Osteoblasts were seeded onto the formed coagulum and scaffolds, with and without aptamer functionalization, for analysis.

Main Results:

• Aptamer functionalization led to increased alkaline phosphatase and bone sialoprotein immunolabeling in osteoblasts.
• Enhanced presence of mesenchymal stem cells, leukocytes, and lymphocytes was observed in aptamer-functionalized scaffolds.
• Aptamer-modified scaffolds promoted a denser fibrin network and increased osteoblast and white blood cell populations in the coagulum.

Conclusions:

• Scaffold functionalization with fibronectin aptamers significantly alters blood clot formation morphology and function.
• Aptamer-modified scaffolds facilitate selective protein expression crucial for osteogenic differentiation.
• Increased transforming growth factor beta 1 (TGF-b1) gene expression indicates potential for enhanced regenerative therapies.