Construction of cell-compatible layer and culture of human umbilical vascular endothelial cells on porous polystyrene membranes

Porous polystyrene (PS) membranes with pore sizes ranged from nanometer scale to several decades' micrometers were fabricated by the thermally induced phase-separation technique, and were characterized by scanning electron microscopy (SEM). Oxidation of PS membranes by concentrated sulfuric acid induced a decrease of the carbon amount on the membrane surfaces accompanying with an increase of the oxygen amount. The hydrophilic surfaces thus constructed proved quite effective to promote endothelial cell adhesion and growth. After culturing for 4 days, a confluent endothelial cells (ECs) layer was observed on nonporous PS membrane treated previously with sulfuric acid for 15 min at 28.5°C. The observation under SEM showed that ECs on the PS membrane surfaces at the fourth day were inversely proportional to the pore size: the smaller the pore size, the larger the amount of ECs on the membrane surfaces. It is supposed that the existence of pores on the membrane surface might generate some disadvantageous resistance to the spreading of cells.