Biometric surfactant polymers designed for shear-stable endothelialization on biomaterials

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Chemistry

Background:

• Vascular biomaterials often require surface modifications to improve endothelial cell (EC) integration.
• Current methods can be complex, necessitating simpler, effective surface functionalization strategies.

Purpose of the Study:

• To develop and evaluate novel extracellular matrix (ECM)-like biomimetic surfactant polymers for enhanced EC adhesion and growth.
• To investigate the effect of varying peptide (RGD) and carbohydrate (maltose) ratios on polymer surfaces under shear stress.

Main Methods:

• Synthesized poly(vinyl amine) (PVAm) backbone polymers with tunable RGD:maltose ratios.
• Modified glass surfaces with these polymers and fibronectin (FN) as a control.
• Exposed confluent human pulmonary artery endothelial cells (HPAECs) to shear stresses (0-40.6 dyn/cm²) for 2 and 6 hours.
• Quantified EC coverage and analyzed cytoskeletal organization.

Main Results:

• EC retention after 6h shear stress followed the order: 100% RGD > FN > 75% RGD > 50% RGD.
• The 100% RGD surface maintained >50% EC monolayer at low-moderate shear, significantly outperforming other surfaces.
• Increased peptide density correlated with enhanced EC shear stability and improved cytoskeletal organization.

Conclusions:

• Surface peptide density is a key factor in controlling EC shear stability on vascular biomaterials.
• Biomimetic polymers with high RGD density offer superior EC retention and stability.
• Enhanced EC stability is linked to the cells' ability to reorganize their cytoskeleton in response to surface cues.