The complement (C) system is a major contributor to innate immunity and is composed of more than 30 proteins. Three cascades (classical, lectin and alternative) may be activated by differing triggers resulting in the generation of complement component 3 (C3). In turn, particularly in the alternative pathway, C3 may further generate C3a and C3b. C3a acts as an anaphylotoxin that promotes inflammatory processes where C3b can be further cleaved to generate inactive C3b (iC3b) which has opsonic properties. Nanoparticles, and nanoparticulate surfaces, are known to activate the C system. Determination of C activation, ex vivo, by nanoparticles may provide information as to their biocompatibility and possible CARPAgenicity. This test method describe a protocol for the determination of C activation, in human plasma, by Enzyme Linked Immunosorbent Assay (ELISA) measurement of iC3b concentrations.
The title and scope are in draft form and are under development within this ASTM Committee.