Stability of orosomucoid-coated polyisobutylcyanoacrylate nanoparticles in the presence of serum

Orosomucoid-coated polyisobutylcyanoacrylate nanoparticles are proposed as a biomimetic drug carrier. The stability of the orosomucoid layer adsorbed on the nanoparticle surface was evaluated in vitro in the presence of serum. Orosomucoid was determined by micellar electrokinetic capillary chromatography. Results showed that, in the presence of a concentrated fetal calf serum solution, the orosomucoid layer started to desorb after 5 min and that, after 30 min, only 25% of the initial adsorbed orosomucoid layer remained onto the nanoparticle surface. Using turbidimetry and photon correlation spectrometry, it was demonstrated that nanoparticle degradation was mainly responsible for the desorption of orosomucoid. With diluted human serum, orosomucoid desorption was reduced, which allowed the study of the effect of the orosomucoid layer on serum protein adsorption. By comparing the electropherograms of the proteins desorbed from orosomucoid-coated and uncoated nanoparticles, it was observed that orosomucoid could dramatically reduce the adsorption of serum protein onto the nanoparticles. An attempt to identify the main serum proteins adsorbed was also performed: haptoglobin and opsonins (immunoglobulin and C3 protein of complement) adsorbed onto uncoated nanoparticles, whereas only opsonins adsorbed to a lower extent onto orosomucoid-coated nanoparticles. Other unidentified proteins were also adsorbed.