Reliable Surface Modification of ePTFE Using a Photoreactive Hemocompatible Peptide to Promote Endothelial Affinity...

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Cardiovascular Engineering

Background:

• Expanded polytetrafluoroethylene (ePTFE) is a common biomaterial for cardiovascular devices due to its stability.
• ePTFE's chemical inertness presents challenges for surface modification.
• Developing methods to improve ePTFE hemocompatibility is crucial for medical applications.

Purpose of the Study:

• To modify the ePTFE surface with a hemocompatible peptide (HCP) using a photoreaction technique.
• To evaluate the hemocompatibility of the modified ePTFE in vitro and in vivo.
• To enhance endothelial cell affinity and reduce platelet adhesion on ePTFE.

Main Methods:

• Synthesized a photoreactive HCP (histidine-glycine-glycine-valine-arginine-leucine-tyrosine) by conjugating a phenylazide group.
• Immobilized the photoreactive HCP onto ePTFE surfaces via UV exposure after argon plasma treatment.
• Assessed surface modification using fluorescent labeling and evaluated hemocompatibility through in vitro cell culture and in situ porcine blood contact tests.

Main Results:

• Photoreactive HCP successfully modified the ePTFE surface, including within its pores.
• In vitro tests showed a 5-fold increase in endothelial affinity and significant reduction in platelet adhesion and aggregation.
• In vivo porcine model demonstrated increased recruitment of monocytes/macrophages and endothelial cells, with reduced platelet adhesion compared to unmodified ePTFE.

Conclusions:

• Photoreactive HCP immobilization is an effective strategy for modifying ePTFE surfaces.
• The modified ePTFE exhibits enhanced hemocompatibility, characterized by improved endothelialization and anti-thrombotic properties.
• This approach offers a promising method for developing advanced cardiovascular medical devices.