Hydrodynamically stable adhesion of endothelial cells onto a polypropylene hollow fiber membrane by modification with adhesive protein

The effect on the adhesion of endothelial cells of immobilization of adhesion proteins onto a microporous polypropylene hollow fiber membrane for a conventional artificial lung was investigated with the aim of constructing a hybrid artificial lung bearing endothelial cells on the modified membrane. The membrane was modified by adsorption or covalent bonding of adhesion proteins of fibronectin, gelatin, or Pronectin. The density of adherent cells on the membrane modified by adsorption of or covalent bonding with fibronectin reached 1 × 10⁵ cells/cm² after 1 day of incubation, which corresponds to the confluent cell density in a conventional culture dish, while the cell densities on the membranes modifieds with gelatin and Pronectin were 1–5 × 10⁴ cells/cm² and 0.5–1 × 10⁴ cells/cm², respectively. The loading of hydrodynamic shear force (0.23N/m²) for 30min to the membranes bearing endothelial cells had little effect on the density of adhered cells. The membrane covalently bonded with fibronectin could well maintain a high cell density even after the loading of a higher shear force of 1.15N/m² for 180min, however, at this level of shear force 49% of adhered cells on the fibronectin-adsorbed membrane were lost after 30min. A partial cardiopulmonary bypass in rats employing the hybrid artificial lung model composed of a polypropylene hollow fiber membrane covalently bonded with fibronectin and endothelial cell adhesion showed the inhibition of tumor necrosis factor- release and an increase in IL-10 concentration in the circulating blood compared with that employing an artificial lung without cells. Long-term partial cardiopulmonary bypass employing the hybrid artificial lung model should be studied further.