Please consider supporting DiscoverMedNews

Article

A vascular graft from a combination of tropoelastin and polyglycerol sebacate mimics the structure of living blood vessels

Apr 12, 2023 | Other Medical Disciplines

In this study, a consortium of researchers led by the University of Sydney reported that they developed a novel vascular graft from a combination of tropoelastin (TE) and polyglycerol sebacate (PGS) that mimics the structure of living blood vessels. The results of this study have shown that this vascular graft facilitates de novo formation of a structurally appropriate elastin-containing intima-media region following implantation in mice.

Native arteries contain a distinctive intima-media composed of organized elastin and an adventitia containing mature collagen fibrils. Elastin-containing structures in the intima-media region are crucial for normal arterial function.

A vascular graft is used to repair the damaged artery. Autologous vascular grafts from the patient’s saphenous veins, radial arteries, and internal mammary arteries are considered gold-standard grafts. Commercially available synthetic grafts are made from expanded polytetrafluoroethylene and polyethylene terephthalate. Due to thrombosis and restenosis, they show markedly decreased patency over time when small-diameter (1–6 mm) are used. Furthermore, their non-degradable nature does not support the complete regeneration of arteries.

About the study

The researchers fabricated a non-porous biodegradable vascular graft from a combination of TE and PGS, a highly elastic and degradable biomaterial. Mixing TE with PGS in ratios of 30:70, 50:50, 70:30, and 100:0 resulted in the formation of electrospun scaffolds, which were named TE30, TE50, TE70, and TE100, respectively. The results showed that TE50 and TE70 each supported the proliferation of endothelial cells of the human umbilical vein and smooth muscle cells of the human coronary artery, as well as the expression of functional artery-related proteins.

This paper describes TE-PGS scaffold fabrication, characterization, selection, implantation into the abdominal aorta in mice, and remodeling into a neoartery. TE50 was selected for implantation into the abdominal aorta of the mouse because it was less prone to thrombosis.

The non-porous TE50 acted as a framework for stimulating distinctive regeneration profiles in the intima-media and the adventitia. After implantation in the abdominal aorta of the mouse, the graft developed distinct cellular and extracellular matrix profiles that approximated the native adventitia and intima-media by eight weeks. By eight months, the graft degraded completely, forming a neoartery. Adventitia was found to contain mature collagen. An internal elastic lamina, similar to that of mouse abdominal aorta, was also formed after eight months.

The authors concluded that their results demonstrated the potential of TE50 as a functional vascular graft capable of achieving complete arterial regeneration.

The study was published in Advanced Materials.

Journal Reference

Wang Z et al. Rapid Regeneration of a Neoartery with Elastic Lamellae. Advanced Materials 2022; 34: 2205614 (Open Access)  https://onlinelibrary.wiley.com/doi/10.1002/adma.202205614

Learn How to Go Paperless on PDFelement Wondershare EdrawMind