Smooth muscle cells improve endothelial cell retention on polytetrafluoroethylene grafts in vivo.
OBJECTIVE
We investigated the influence of smooth muscle cells (SMC) on endothelial cell (EC) retention on polytetrafluoroethylene (PTFE) grafts and the effect of SMC seeding on intimal hyperplasia in vivo in a rabbit model.


METHODS
Fibronectin-coated PTFE grafts (4 mm diameter) were seeded with either EC alone, SMC alone, or SMC followed 24 hours later by EC. The grafts were connected to an extracorporal aortic shunt for 1 hour or were individually implanted for 1, 30, and 100 days into the infrarenal aorta as an end-to-side bypass graft. The number of retained cells was compared at 1 hour and at 1 day after implantation. Neointimal thickness was measured 30 and 100 days after implantation.


RESULTS
After 1-hour exposure to blood flow, EC retention rate was greater (P <.005) if seeded on top of SMC (98% +/- 2%; n = 8) versus being seeded alone (65 +/- 11%; n = 8). SMC retention rate was 95 +/- 5% (n = 8) when seeded alone. Similar cell retention was obtained 1 day after implantation. After 30-day implantation the neointima was thicker in grafts seeded with EC and SMC (282 +/- 136 microm; n = 3) than with EC only (52 +/- 45 microm; n = 3; P <.001). However, the neointimal thickness for dual-cell-seeded grafts (126 +/- 60 microm; n = 3) was not significantly different (P =.09) from EC-seeded grafts (79 +/- 48 microm; n = 3) after 100-day implantation.


CONCLUSIONS
EC retention on PTFE grafts in vivo is improved if seeded over a layer of SMC. Further studies are needed to determine whether overlying EC modulate proliferation of underlying SMC.
Yu
Hong
H
Department of Surgery, University of Miami School of Medicine, Miami, FL 33101, USA. hyu@med.miami.edu
Dai
Wangde
W
Yang
Zhe
Z
Kirkman
Paul
P
Weaver
Fred A
FA
Eton
Darwin
D
Rowe
Vincent L
VL
D000818:Animals; D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D004730:Endothelium, Vascular / Q000378:metabolism / Q000502:physiology*; D006083:Graft Occlusion, Vascular / Q000473:pathology / Q000517:prevention & control*; D007150:Immunohistochemistry; D023421:Models, Animal; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000637:transplantation*; D011138:Polytetrafluoroethylene / Q000494:pharmacology*; D011336:Probability; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011817:Rabbits; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D017539:Tunica Intima / Q000473:pathology; D014654:Vascular Patency / Q000502:physiology
D011138:Polytetrafluoroethylene