Nano-scale clustering of integrin-binding ligands regulates endothelial cell adhesion, migration, and endothelialization rate: novel materials for small diameter vascular graft applications

This article presents a novel, clinically relevant electrostatic endothelial cell transplantation (seeding/sodding) device (U.S. & Foreign Patent Protections Pending) for small-diameter (<6 mm) vascular prostheses. The prototype apparatus was designed and built to tissue engineer 4.0 mm, I.D. GORE-TEX® (W.L. Gore & Associates, Inc.) standard wall graft segments varying in length from 4 to 12 cm. The prototype electrostatic endothelial cell transplantation apparatus is composed of an external and internal conductor, aluminum base, end supports, pillow blocks, filling apparatus, electric motor drive system, and a voltage source. The cylindrical capacitor arrangement of the device along with an electrical potential applied across the internal and external conductors creates the unique feature of this endothelial cell transplantation technique, an electric field within the cylindrical capacitor (within the graft lumen) which in turn induces a temporary positive surface charge on the graft (dielectric material) luminal surface. Multiple studies have shown that a positively charged substrate is more conducive to endothelial cell adhesion and morphological maturation (flattening) (1,2, 7,8,10,13-15). This induced positive surface charge dissipates immediately upon removal from the electrostatic endothelial cell transplantation device. Thus, after endothelial cell adhesion the graft luminal surface reverts back to its natural (nonthrombogenic) negative surface charge.

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Electrostatic Endothelial Cell Seeding Technique for Small-Diameter (<6 MM) Vascular Prostheses: Feasibility Testing

Cell Transplantation ◽

10.1177/096368979700600613 ◽

1997 ◽

Vol 6 (6) ◽

pp. 623-629 ◽

Cited By ~ 1

Author(s):

Gary L. Bowlin ◽

Stanley E. Rittgers

Keyword(s):

Endothelial Cells ◽

Cell Adhesion ◽

Endothelial Cell ◽

Surface Charge ◽

Feasibility Study ◽

Small Diameter ◽

Cell Seeding ◽

Vascular Prostheses ◽

Endothelial Cell Seeding ◽

Endothelial Cell Adhesion

Multiple studies have indicated the importance of surface charge in the adhesion of multiple cardiovascular cell lines including platelets and endothelial cells on the substrate materials (1,4,7-10,12-15). It is the purpose of this article to report a feasibility study conducted using an electrostatic endothelial cell seeding technique. The feasibility study was conducted using human umbilical vein endothelial cells (HUVEC), a static pool apparatus, a voltage source, and a parallel plate capacitor. The HUVEC concentration and seeding times were constant at 560,000 HUVEC/ml and 30 min, respectively. Scanning electron microscopy examination of the endothelial cell adhesion indicated that an induced temporary positive surface charge on e-PTFE graft material enhances the number and the maturation (flattening) of HUVECs adhered. The results indicated that the total number of endothelial cells adhered (70.9 mm2) was increased from 9198 ± 1194 HUVECs on the control (no induced surface charge) e-PTFE to 22,482 ± 4814 HUVECs (2.4 × control) on the maximum induced positive surface charge. The total number of cells in the flattened phase of adhesion increased from 837 ± 275 to 6785 ± 1012 HUVECs (8.1 ×) under identical conditions. Thus, the results of the feasibility study support the premise that electrostatic interaction is an important factor in both the endothelial cell adhesion and spreading processes and suggest that the electrostatic seeding technique may lead to an increased patency of small diameter (<6 mm) vascular prostheses.

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