|
Author
del Pozo Fàbregas, Blanca
|
Abstract
Coronary artery bypass grafting (CABG) is a procedure in which autologous arteries or veins are used as grafts to bypass totally or partially occluded coronary arteries. The saphenous vein is the most used bypass conduit, but its harvesting involves a large incision in the leg. This work proposes a different alternative to overcome these problems: the use of cadaveric vascular vessels. Decellularization techniques applied in these vessels could end up with the biological scaffold that the patient may require for CABG. On the other hand, recellularization techniques into the biological scaffold may regenerate the endothelial layer, which is necessary to maintain patency and prevent thrombosis of vascular grafts.
In this work, femoral arteries and saphenous veins from donors were used to study their potential application to CABG through decellularization techniques. Different decellularization protocols using hypo- and hypertonic solutions and enzymes have been considered. Quantitative assays were carried out to assure that structural biomolecules were maintained and that DNA was reduced after decellularization. Qualitative assays were also carried out to analize the ECM structure and orientation. Biomechanical properties were also studied. Finally, as the decellularized vessels were preserved in glycerol, a cleaning protocol was defined to obtain a free-glycerol final scaffold, which was analysed for potential cytotoxicity. Recellularization experiments using Human Umbilical Vein Endothelial Cells (HUVECs) were carried out once the non-cytotoxicty of the decellularized vessels was confirmed.
The same decellularization protocol could be defined for femoral arteries and saphenous veins, although minor differences were reported among the tissues. The quantity of structural biomolecules and also its structure were maintained after the decellularization protocol. Morever, biomechanical properties remained also constant after the decellularization protocol. On the other hand, results from the cleaning protocol confirmed that at least five washes with NaCl 0.9% were required to obtain glycerol-free tissues. Cytotoxicity analysis confirmed the non-cytotoxic activity of the vascular vessels. Finally, the first attempt to recellularize the obtained vessels demonstrate that HUVECs can be seeded on these vessels, but the protocol needs to be improved to obtain a completely recellularized vessel.
|
|
