STABILITY OF OROSOMUCOID-COATED POLYISOBUTYLCYANOACRYLATE NANOPARTICLES IN THE PRESENCE OF SERUM

Orosomucoid-coated polyisobutylcyanoacrylate nanoparticles are propose d as a biomimetic drug carrier. The stability of the orosomucoid layer adsorbed on the nanoparticle surface was evaluated in vitro in the pr esence of serum. Orosomucoid was determined by micellar electrokinetic capillary chromatography. Results showed that, in the presence of a c oncentrated fetal calf serum solution, the orosomucoid layer started t o desorb after 5 min and that, after 30 min, only 25% of the initial a dsorbed orosomucoid layer remained onto the nanoparticle surface. Usin g turbidimetry and photon correlation spectrometry, it was demonstrate d that nanoparticle degradation was mainly responsible for the desorpt ion of orosomucoid. With diluted human serum, orosomucoid desorption w as reduced, which allowed the study of the effect of the orosomucoid l ayer on serum protein adsorption. By comparing the electropherograms o f the proteins desorbed from orosomucoid-coated and uncoated nanoparti cles, it was observed that orosomucoid could dramatically reduce the a dsorption of serum protein onto the nanoparticles. An attempt to ident ify the main serum proteins adsorbed was also performed: haptoglobin a nd opsonins (immunoglobulin and C3 protein of complement) adsorbed ont o uncoated nanoparticles, whereas only opsonins adsorbed to a lower ex tent onto orosomucoid-coated nanoparticles. Other unidentified protein s were also adsorbed.