Biodegradable polymer nanofiber mesh to maintain functions of endothelial cells

Maintaining functions of endothelial cells in vitro is a prerequisite for effective endothelialization of biomaterials as an approach to prevent intimal hyperplasia of small- diameter vascular grafts. The aim of this study was to design suitable nanofiber meshes (NFMs) that further maintain the phenotype and functions of human coronary artery endothelial cells (HCAECs). Collagen- coated random and aligned poly(L-lactic acid)-co-poly(epsilon-caprolactone) (P( LLA- CL)) NFMs were fabricated using electrospinning. Mechanical testing showed that tensile modulus and strength were greater for the aligned P(LLA-CL) NFM than for the random NFM. Spatial distribution of the collagen in the NFMs was visualized by labeling with fluorescent dye. HCAECs grew along the direction of nanofiber alignment and showed elongated morphology that simulated endothelial cells in vivo under blood flow. Both random and aligned P(LLA-CL) NFMs preserved phenotype (expression of platelet endothelial cell adhesion molecule-1, fibronectin, and collagen type IV in protein level) and functions (complementary DNA microarray analysis of 112 genes relevant to endothelial cell functions) of HCAECs. The P(LLA-CL) NFMs are potential materials for tissue- engineered vascular grafts that may enable effective endothelialization.