# Combined Pharmacological Conditioning of Endothelial Cells for Improved Vascular Graft Endothelialization

## TL;DR

A new drug combination improves endothelial cell coverage on small vascular grafts, reducing thrombosis risk and enhancing functionality.

## Contribution

A synergistic pharmacological cocktail enhances endothelialization and antithrombogenic properties on vascular grafts.

## Key findings

- The four-agent cocktail increased cell area and reduced cells needed for surface coverage in HUVECs.
- Enhanced tight junction formation and nitric oxide production preserved endothelial functionality.
- The treatment significantly reduced thrombus formation via inhibition of platelet activation and thrombin binding.

## Abstract

The development of functional endothelial monolayers on synthetic vascular grafts remains challenging, particularly for small-diameter vessels (<6 mm) prone to thrombosis. Here, we present a pharmacological strategy combining 8-(4-chlorophenylthio) adenosine 3′,5′-cyclic monophosphate sodium salt (pCPT-cAMP, a tight junction promoter) with nitric oxide/cGMP pathway agonists 3-morpholinosydnonimine (SIN-1), captopril, and sildenafil) to enhance endothelialization. In human umbilical vein endothelial cells (HUVECs), this four-agent cocktail induced a flat, extended phenotype with a 3-fold increased cell area and 57.5% fewer cells required for surface coverage compared to controls. Immunofluorescence analysis revealed enhanced ZO-1 expression and continuous tight junction formation, while sustained nitric oxide (NO) production (3.9-fold increase) and restored prostacyclin (PGI2) secretion demonstrated preserved endothelial functionality. Anticoagulation assays confirmed a significant reduction in thrombus formation (p < 0.01) via dual inhibition of platelet activation and thrombin binding. These findings establish a synergistic drug combination that promotes rapid endothelialization while maintaining antithrombogenic activity, offering a promising solution for small-diameter vascular grafts. Further studies should validate long-term stability and translational potential in preclinical models.