IMMUNOCHEMICAL CHARACTERIZATION OF ANTIBODY-COATED NANOPARTICLES

A new method using surface plasmon resonance (SPR) through the BIAcore was used to demonstrate the specific interaction between an anti-CD4 monoclonal antibody (IOT4a), adsorbed on poly(methylidene malonate 2.1 .2) (PMM 2.1.2) nanoparticles, and the CD4 molecule. The results obtai ned were compared with the interaction of the same immunonanoparticles with rabbit anti-mouse Fc antibodies. The molar ratio (Fc)/(Fab) was 1, suggesting that the same number of epitopes on the Fc and the Fab f ragments were accessible after IOT4a adsorption onto nanoparticles. Co mparing the observed association rates of free antibody and antibody a dsorbed on nanoparticles, the number of molecules of IOT4a antibody on PMM 2.1.2 nanoparticles was estimated as between 2.6 and 3 per nanopa rticle. The properties of the antibody-coated nanoparticles are compat ible with their use as antibody-targeted pharmacophores.