Enhanced albumin binding to polypropylene beads via anhydrous ammonia gaseous plasma.

Plasma surface modification technique was used to add amino groups onto the surfaces of polypropylene beads by exposing them to anhydrous ammonia plasma. Through these amino groups, albumin was attached to the polypropylene beads. Attached albumin was further stabilized by crosslinking with glutaraldehyde. The effect of washing albuminated polypropylene beads with saline and human plasma was investigated. It was found that after initial rapid removal of albumin, the concentration of attached albumin tended to reach a steady-state. After 52 h of washing, the amount of albumin retained on the beads varied between 125 and 171 micrograms/cm2.