Surface modification of decellularized bovine carotid arteries with human vascular cells significantly reduces their thrombogenicity

Eriselda Keshi,Anja Reutzel-Selke,Johann Pratschke,Marie Weinhart,Nicolai Seiffert,Brigitta Globke,Simon Moosburner,Ulrich Kertzscher,Hannah Everwien,Peter Tang,Michael Lommel,Karl Herbert Hillebrandt,Benjamin Strücker,Nils Haep,Igor Maximillian Sauer

doi:10.1186/s13036-021-00277-2

Abstract

BackgroundSince autologous veins are unavailable when needed in more than 20% of cases in vascular surgery, the production of personalized biological vascular grafts for implantation has become crucial. Surface modification of decellularized xenogeneic grafts with vascular cells to achieve physiological luminal coverage and eventually thromboresistance is an important prerequisite for implantation. However, ex vivo thrombogenicity testing remains a neglected area in the field of tissue engineering of vascular grafts due to a multifold of reasons.MethodsAfter seeding decellularized bovine carotid arteries with human endothelial progenitor cells and umbilical cord-derived mesenchymal stem cells, luminal endothelial cell coverage (LECC) was correlated with glucose and lactate levels on the cell supernatant. Then a closed loop whole blood perfusion system was designed. Recellularized grafts with a LECC > 50% and decellularized vascular grafts were perfused with human whole blood for 2 h. Hemolysis and complete blood count evaluation was performed on an hourly basis, followed by histological and immunohistochemical analysis.ResultsWhile whole blood perfusion of decellularized grafts significantly reduced platelet counts, platelet depletion from blood resulting from binding to re-endothelialized grafts was insignificant (p = 0.7284). Moreover, macroscopic evaluation revealed thrombus formation only in the lumen of unseeded grafts and histological characterization revealed lack of CD41 positive platelets in recellularized grafts, thus confirming their thromboresistance.ConclusionIn the present study we were able to demonstrate the effect of surface modification of vascular grafts in their thromboresistance in an ex vivo whole blood perfusion system. To our knowledge, this is the first study to expose engineered vascular grafts to human whole blood, recirculating at high flow rates, immediately after seeding.

Highlights

Cardiovascular disease (CVD) affects the majority of the adult population over the age of 60, with an estimated annual mortality of 17.3 million deaths worldwide [1, 2]
In the present study we were able to demonstrate the effect of surface modification of vascular grafts in their thromboresistance in an ex vivo whole blood perfusion system
Studies have demonstrated the crucial role of a functional luminal endothelium: it prevents thrombus formation within tissue engineered vascular grafts (TEVG), and prevents intimal hyperplasia through nitric oxide released by these cells [11]

Summary

Introduction

Cardiovascular disease (CVD) affects the majority of the adult population over the age of 60, with an estimated annual mortality of 17.3 million deaths worldwide [1, 2]. Prosthetic grafts have been widely implemented after DeBakey established the clinical usefulness of grafts made of Dacron (a fiber made of polyester polyethylene terephthalate) in 1950 and ePTFE (expanded polytetrafluorethylene) grafts two decades later [6] Complications such as intimal hyperplasia, calcification, thrombotic occlusion, high infection rates and biomechanical mismatch have hampered their success, especially when substituting small-diameter blood vessels [7,8,9]. 3) It requires a balance between the surface area of the tissue engineered construct seeded with endothelial cells and the thrombogenic surface area of the connecting tubes, which is especially difficult to achieve in an ex vivo whole blood perfusion setup [18]. Ex vivo thrombogenicity testing remains a neglected area in the field of tissue engineering of vascular grafts due to a multifold of reasons

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