endothelialization

Endothelialization is the process by which endothelial cells form a continuous monolayer lining the luminal surface of blood vessels and other intravascular or prosthetic materials. It is crucial for vascular homeostasis, providing a non-thrombogenic, anti-adhesive surface that regulates permeability, coagulation, inflammation, and vasomotor tone.

Endothelial cells can cover damaged areas by the migration and proliferation of resident endothelial cells and by recruitment of circulating endothelial progenitor cells from the bone marrow, a process often called reendothelialization after injury. Shear stress from blood flow promotes alignment and maturation of endothelial cells and supports their barrier function.

In the clinical and biomedical context, rapid and complete endothelialization of vascular grafts, stents, and tissue-engineered vessels reduces thrombosis and neointimal hyperplasia and improves long-term patency. Strategies to promote endothelialization include surface modification of implants with bioactive coatings, immobilized adhesion peptides, nitric oxide donors, or heparin; seeding with endothelial cells or progenitor cells; and controlled growth factor delivery.

Assessment can involve histology, immunostaining for endothelial markers (eg, CD31, VE-cadherin), functional tests of nitric oxide production, and imaging of luminal lining.