Click-coated, heparinized, decellularized vascular grafts

Area of Science:

• Biomaterials Science
• Vascular Engineering
• Surface Chemistry

Background:

• Decellularized aortas are promising scaffolds for vascular tissue engineering.
• Achieving a blood-compatible surface remains a challenge for these scaffolds.
• Heparin immobilization is crucial for preventing thrombosis.

Purpose of the Study:

• To develop a novel method for creating a dense, oriented heparin layer on decellularized aortas.
• To enhance the in vivo blood compatibility of decellularized aortic scaffolds.
• To mimic the native endothelial cell surface heparan sulfate presentation.

Main Methods:

• Modification of aortic amino groups to azido groups using 3-azidobenzoic acid.
• Attachment of azide-clickable dendrons via alkyne-azide click chemistry.
• Decoration of dendron end groups with end-on modified heparin chains.
• Characterization using X-ray photoelectron spectroscopy, NMR, MS, and FTIR.
• Verification of coating continuity via fluorescent microscopy and histology.
• Assessment of anti-thrombogenicity using Factor Xa assay and platelet adhesion studies.

Main Results:

• A tenfold amplification of adhesion sites was achieved through dendron attachment.
• Heparin chains were successfully immobilized in an oriented, end-on fashion.
• Characterization confirmed the successful synthesis and continuity of the heparin layer.
• Anti-thrombogenic assays and platelet adhesion studies demonstrated improved blood compatibility.

Conclusions:

• The developed method enables the engineering of oriented heparin coatings on decellularized aortas.
• This approach significantly enhances the blood compatibility of vascular scaffolds.
• Oriented heparin immobilization holds potential for improving the in vivo performance of vascular grafts.