CHARACTERISTICS OF VASCULAR WALL CELLS SUBJECTED TO DYNAMIC CYCLIC STRAIN AND FLUID SHEAR CONDITIONS IN-VITRO

We recently developed an in vitro silicone rubber tubular apparatus, t he vascular simulating device (VSD), which simulates pressure, flow, a nd strain characteristics of peripheral arteries (Benbrahim et al., 19 94, J. Vasc. Surg. 20, 184-194). In this report, we tested the ability of silicone rubber surfaces to support the growth and differentiation of endothelial cells (EC) and smooth muscle cells (SMC) and studied t he effects of arterial levels of pressure, how, and strain on these pr operties. Human umbilical and saphenous vein EC and bovine aortic EC a nd SMC were cultured on coated and uncoated silicone rubber in flat an d tubular configurations (6 mm inner diameter) and on tissue culture p lastic (TCP). Attachment, growth, and differentiation were compared on these surfaces. In addition, the effects of arterial pressure, flow, and strain conditions on adhesion and subsequent growth and differenti ation were studied in the tubular configuration. Attachment and growth of vascular wall cells on fibronectin-coated silicone rubber was simi lar to that obtained on TCP. Application of arterial levels of pressur e, flow, and strain did not alter adhesion of the cells to the tubes. Subsequent passage of these cells demonstrated that attachment, growth , and differentiation (uptake of LDL and expression of factor VIII-rel ated antigen by EC and expression of muscle-specific actin by SMC) wer e similar in cells derived from experimental and control tubes which w ere not subjected to arterial conditions. Finally, mRNA expression of specific ''housekeeping'' genes was similar in cells isolated from exp erimental and control tubes. We conclude that the VSD supports the cul ture of viable and differentiated EC and SMC. These experiments demons trate that it is possible to evaluate the effects of arterial strain a nd fluid shear on vascular wall cells in vitro, in a configuration sim ilar to the blood vessel wall. (C) 1996 academic Press, Inc.