Development of an anaphylatoxin scavenging device. Principle, surface molecular design, and selective adsorption

The anaphylatoxins (C3a and C5a) generated upon extracorporeal circulation often cause adverse reactions at local and systemic levels. In this paper, the principle surface molecular design and highly selective adsorptional behaviors of anaphyatoxin-scavenging materials were demonstrated. Both C3a and C5a are highly basic proteins, whereas most plasma proteins are negatively charged in blood. This indicates that negatively charged surfaces could preferentially adsorb these basic proteins from plasma. Based on the above working hypothesis, surface molecular designs aiming at incorporation of negatively charged groups such as carboxylate and sulfonate groups on surfaces were attempted. The control of surface density at the outermost layer was assessed by x-ray photoelectron spectroscopy. The designed surfaces preferentially adsorbed C3a and C5a from activated serum. This provides a rational basis for the extracorporeal anaphylatoxin-scavenging device under development.