Migration of co-cultured endothelial and smooth muscle cells on material surfaces

Surface endothelialization of a medical device after implantation into the cardiovascular system depends upon competitive migration between endothelial cells (ECs) and smooth muscle cells (SMCs). While both cell types have been extensively studied, the relative migration under mixed co-culture conditions remains elusive. Herein, we investigate the migration of ECs and SMCs on tissue culture plates under different culture modes. Compared with monocultures, mixed co-culture slows down the migration of both cell types. Our analyses suggest that this reduced migration likely involves intensified intercellular interactions and expanded cell coverage during the mixing of two entities with different sizes. We find that the mixed co-culture may alter the relative migration between ECs and SMCs. We further examine the relative migration of the two cell types on arginine-glycine-aspartate (RGD) nanoarrays prepared using block copolymer micelle nanolithography and show that nanopatterns with varied RGD nanospacings (29-121 nm) can significantly tune the relative migration rate, effectively reversing the migratory dominance of one cell type over the other. This study sheds new insights on the behavior of co-cultured cells on biomaterials with modified surfaces.