This paper is only available as a PDF. To read, Please Download here.
Background. Prosthetic vascular grafts with adherent endothelial cell monolayers may prove useful for small-caliber vessel bypass. However, endothelial cells adhere poorly to prosthetic graft material, and they are stripped when exposed to in vivo shear stress. This study sought to determine whether in vitro shear stress conditioning improves endothelial cell adhesion and decreases thrombogenicity of endothelial cell-seeded grafts.
Methods. The lumens of 1.5 mm (inside diameter) spun polyurethane polymer vascular grafts were seeded with bovine aortic endothelial cells and cultured in vitro for 6 days with or without continuous laminar shear stress, first at 1 to 2 dynes/cm2 for 3 days, then at approximately 25 dynes/cm2 for 3 days. Grafts preconditioned by shear stress and the static control grafts were then exposed to arterial shear stress at 25 dynes/cm2 for 25 seconds. The number of dislodged cells was counted, and the grafts were examined by light and scanning electron microscopy. Whole blood clotting time in the grafts was also determined.
Results. Exposure of grafts to acute shear stress dislodged 1.35×106±0.44×106 cells from static grafts compared with 1.05×104±0.16×104 cells from grafts preconditioned by shear stress. By light and electron microscopy an intact endothelial monolayer was observed to cover the lumen of shear stress-conditioned grafts, whereas few cells remained on the luminal surface of grafts not previously exposed to shear stress. The clotting time in shear stress-conditioned grafts was significantly prolonged in relation to grafts not exposed to shear stress.
Conclusions. These findings show that endothelial cell adhesion and retention on vascular grafts in vitro is markedly enhanced by preconditioning the seeded endothelial cell monolayer with long-term shear stress. Consequently, vascular grafts containing shear stress-conditioned endothelial monolayers are less thrombogenic in vitro than small-caliber vascular grafts without intact endothelial cell monolayers.
References
- A single-stage technique for seeding vascular grafts with autogenous endothelium.Surgery. 1978; 84: 498-504
- Endothelial cell seeding.J Vasc Surg. 1991; 13: 731-732
- Improved patency of collagen-impregnated grafts after in vitro autogenous endothelial cell seeding.J Vasc Surg. 1987; 6: 325-332
- The role of an endothelial cell lining in limiting distal anastomotic hyperplasia of 4-mm-I.D. Dacron grafts in a canine model.J Biomed Mater Res. 1991; 25: 525-533
- Comparison of immediate seeding of endothelial cells with culture lining of small diameter ePTFE carotid interposition grafts.J Surg Res. 1991; 51: 33-39
- Early normalization of platelet survival by endothelial seeding of Dacron arterial prostheses in dogs.Surgery. 1982; 92: 385-393
Ott MJ, Olson JL, Ballermann BJ. Chronic in vitro flow promotes ultrastructural differentiation of endothelial cells. Endothelium (in press).
- Regulation of bovine glomerular endothelial cell growth in vitro.Am J Phys Cell. 1989; 25: C182-C189
- Surface thrombogenicity of arterial prostheses.Surg Gynecol Obstet. 1973; 136: 12-16
- Rheological aspects of thrombosis and haemostasis: basic principles and applications.Thromb Haemost. 1986; 55: 415-425
- In vitro adherence and kinetics studies of adult human endothelial cell seeded polytetrafluoroethylene and gelatin impregnated Dacron grafts.Eur J Vasc Surg. 1991; 5: 93-103
- Kinetics of endothelial cell seeding.J Vasc Surg. 1985; 2: 778-784
- Use of fibrin glue as a substrate for in vitro endothelialization of PTFE vascular grafts.Surgery. 1989; 105: 512-522
- Endothelial cell seeding of small diameter vascular grafts.Artif Organs. 1990; 14: 355-360
- Interactions at the blood/material interface.Ann Vasc Surg. 1990; 4: 98-103
- Quantification of gas denucleation and thrombogenicity of vascular grafts.J Biomed Mater Res. 1991; 25: 373-386
Article info
Publication history
Accepted:
July 21,
1994
Footnotes
*Supported by National Institutes of Health grant DK47023 and National Institutes of Health institutional training grant T32CA09635 (M.J.O.). This work was done during the tenure of an Established Investigator Award from the American Heart Association (B.J.B.).
Identification
Copyright
© 1995 Mosby-Year Book, Inc. Published by Elsevier Inc.
User license
Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0) | How you can reuse 
Elsevier's open access license policy
Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0)
Permitted
For non-commercial purposes:
- Read, print & download
- Redistribute or republish the final article
- Text & data mine
- Translate the article (private use only, not for distribution)
- Reuse portions or extracts from the article in other works
Not Permitted
- Sell or re-use for commercial purposes
- Distribute translations or adaptations of the article
Elsevier's open access license policy
