Evolution of Phage Display Approaches to Select Highly Specific Hemocompatible Peptides

Area of Science:

• Biomaterials Science
• Cell Biology
• Biotechnology

Background:

• Synthetic biomaterials for blood contact face a conflict between promoting endothelial cell lining and preventing platelet adhesion.
• Developing surfaces that achieve both is crucial for improving hemocompatibility.
• Peptide modification offers a promising strategy to reconcile these conflicting requirements.

Purpose of the Study:

• To discover and validate peptides that can simultaneously promote endothelial progenitor cell (EPC) adhesion and inhibit platelet adhesion on biomaterial surfaces.
• To overcome challenges in selecting peptides that bind to intact cell surfaces using an improved phage display method.

Main Methods:

• Utilized phage display technology for peptide discovery against endothelial progenitor cells (EPCs).
• Incorporated a negative selection step against platelets to eliminate cross-reactive peptides.
• Introduced a phage binding index for quantitative assessment of target affinity.
• Modified expanded polytetrafluoroethylene (ePTFE) surfaces with selected peptide candidates.

Main Results:

• Successfully identified peptide candidates with high affinity for EPCs.
• Demonstrated that one modified ePTFE surface exhibited enhanced EPC affinity.
• Showcased a significant reduction in thrombus formation on the modified ePTFE surface.

Conclusions:

• The developed "smart" peptides effectively address the conflicting requirements of blood-contacting biomaterials.
• The improved phage display method is effective for selecting peptides targeting complex cell surfaces.
• Peptide-modified ePTFE surfaces show potential for enhanced hemocompatibility and reduced thrombogenicity.