Evaluation of an in vitro endothelialized vascular graft under pulsatile shear stress with a novel radiolabeling procedure.
OBJECTIVE
To improve the hemocompatibility of vascular grafts, endothelial cell (EC) seeding of biomaterials prior to implantation is critical. The current in vitro study was designed to investigate such a feasibility on a collagen-coated heparin-bonded graft and to evaluate cell detachment upon pulsatile shear stress.


METHODS
Endothelial cells (EA-hy-926) were seeded onto grafts. The endothelialization of the grafts was evaluated by the [3H]-thymidine incorporation, scanning electron microscopy (SEM) and histological examinations. After in situ EC radiolabeling with a novel 99mTc technique, the prostheses were exposed to pulsatile shear stress (0.27 N/m2), mimicking the shear rate occurring in a superficial femoral artery, for 3 h in a flow circuit and EC loss quantified by gamma camera detection.


RESULTS
Complete EC coverage was achieved after 5 days. Three hours of artificial perfusion resulted in a low EC loss (12.9+/-0.8%, n = 7). SEM shows EC withstanding shear stress in valleys of prosthesis circumvolutions.


CONCLUSIONS
These satisfactory results could be explained by the high affinity of EC for heparinized surfaces in addition to cell surface receptors involved in adhesion to collagen.
Laboratoire de Biophysique, Université Victor Ségalen Bordeaux 2, France. u443@bordeaux.inserm.fr
P
P
Fernandez
R
R
Bareille
V
V
Conrad
D
D
Midy
L
L
Bordenave
D001345:Autoradiography; D001672:Biocompatible Materials; D001807:Blood Vessel Prosthesis; D002455:Cell Division; D002460:Cell Line; D003094:Collagen; D004730:Endothelium, Vascular / Q000166:cytology*; D006493:Heparin; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D015609:Organotechnetium Compounds; D010091:Oximes; D011673:Pulsatile Flow; D013314:Stress, Mechanical; D019690:Technetium Tc 99m Exametazime
D001672:Biocompatible Materials; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D006493:Heparin; D003094:Collagen