Enhanced adhesion of endothelial cells onto a polypropylene hollow-fiber membrane by plasma discharge treatment and high inoculum cell density

Abstract

The effect of plasma discharge treatment of a microporous polypropylene hollow-fiber membrane commonly used for gas exchange in a conventional artificial lung on the adhesion of endothelial cells was investigated with the aim of constructing a hybrid artificial lung bearing endothelial cells on the membrane. The initial adhesion density and growth rate of the cells on the membrane were markedly increased following plasma discharge treatment (13.56 MHz, 30W) of the membrane for 5 to 20 min in the presence of 0.05 mmHg of various gases, such as ammonia, oxygen, and water vapor. Treatment of the membrane with ammonia for 5 min resulted in the highest increase in the cell adhesion density on 5 days from 1.4×102 to 2.0×103 cells/cm2, and the cell density reached 5.0×103 cells/cm2 after cultivation for 14 days. Increasing the inoculum cell concentration from 3.3×105 to 3.2×106 cells/ml resulted in an initial cell adhesion of 0.9×105 cells/cm2, even after 1 day. It was observed under a microscope that the cells were distributed uniformly to cover almost all of the surface area of the membrane. After the plasma discharge treatment, the permeability of the membrane to water increased to 9% of that of a polyethylene hollow fiber having pore diameters larger than 0.4 μm.