Abstract 17236: Regulating Optimal Angiogenesis and Leukocyte Adhesion of Human Endothelial Cells by Gradient Nanopore Substrate

Abstract

Introduction: Understanding signals in the microenvironment that regulate endothelial cell behavior are important in tissue engineering. Hypothesis: Although many studies have examined the cellular effects of nanotopography, no study has investigated the functional regulation of human endothelial cells grown on nano-sized gradient pore substrate. Methods: We examined the cellular response of human umbilical vein endothelial cells (HUVECs) by using a gradient nanopore substrate (GPS) with three different types of hole nanopore patterns (HP): which diameters were described in HP1, 120-200 nm; HP2, 200-280 nm; HP3, 280-360 nm. Results: Our study revealed that: (1) HUVECs showed highest proliferation and attachment capacity on HP2 (200-280 nm) GPS, (2) HP2 GPS was determined to be the optimal diameter for extending greater angiogenic potential to HUVECs and (3) both HP2 and HP3 GPS significantly decrease leukocyte adhesion compared to Flat. Moreover, expressions of VCL, TLN1, PXN, ITGA2, ITGA6, ITGAV, ITGB3 and ROCK1 in HUVECs cultured on HP2 GPS were significantly greater than that of Flat. Conversely, TLN1, PXN, ROCK 1 and ROCK2 mRNA levels decreased on HP3 GPS compared to those of Flat. Mature tube structures at 24 hours were found in HUVECs stimulated by HP2 GPS. Expressions of angiogenesis related markers (ANGPT1, TIE2 and CXCR4) and endothelial-related marker (vWF) were significantly increased in HUVECs grown on HP2 GPS. The adhesion of peripheral blood mononuclear cells (PBMNCs) to HUVECs stimulated by HP2 and HP3 GPS was significantly reduced compared to those of Flat at 3, 6 and 24 hours after PBMNC seeding. Conclusions: Optimal functional regulations of HUVECs were achieved by nanopore substrate with 200-280 nm-sized pores. Our results provide the possibility of applying nanopore interface-based implant devices in the field of cardiovascular regenerative therapy.