|
Author
Molins Colomer, Maite
|
Abstract
Coronary artery disease is one of the most common cardiovascular diseases, affecting more than 40,000 adults in Spain every year. Of these, between 10 and 20% undergo a surgical procedure called coronary artery bypass grafting (CABG) in which autologous arteries or veins are used as grafts to bypass totally or partially occluded coronary arteries. This means that any patient must undergo two operations, one to harvest the autologous vessel and another one to bypass the coronary arteries, increasing the risk of the procedures and the time to recover.
The internal mammary artery, the radial artery and the saphenous vein are the most used autologous vessels in coronary artery bypass procedures, being the saphenous vein the preferred graft for all non-lateral artery disease due to its availability and versatility. However, its extraction from the leg is associated with high morbidity, and its patency is limited in the long term, with 50% of the grafts failing in the first 10 years. This work proposes a different alternative to overcome these problems: the use of cadaveric human re-endothelialized saphenous veins. These veins, obtained from donors, are decellularized to remove cells and genetic material and then re-endothelialized to prevent thrombosis of the grafts after implantation and maintain patency.
Decellularized saphenous veins from cadaveric donors were used as scaffolds and several attempts were carried out to recellularize them. The method used in this work to seed cells in veins was based on a method to grow cells in 3D silicone tubes, which was adapted first to seed flat vein fragments, and then to the cell-seeding of tubular veins through the design of a rotating 3D printed bioreactor. Different coatings to promote cell adhesion to the walls of the vein were studied, proving that the surface of the vein on its own (without any coatings) was suitable for cell adhesion on flat vein fragments, where cells attached and grew successfully for five days. Although no cell adhesion was achieved in the lumen of the tubular veins placed in the 3D printed bioreactors, a new silicone bioreactor was manufactured with increased oxygen permeability and lower volume. The rotating speed was evaluated as one of the causes which might be behind the limited cell adhesion. Isolated cell colonies could be observed using the new setup, indicating improvements compared to the first bioreactor, but complete recellularization has not been yet achieved.
|
|
