Competition of opsonins and dysopsonins on the nanoparticle surface

The biological behavior and fate of nanoparticles are dependent on their retention time in the blood circulation system. The protein corona components, especially opsonins, and dysopsonins, adsorbed on the nanoparticle surface determine their blood circulation time. The protein corona formation is a dynamic process that involves the competition between different proteins to be adsorbed on the nanoparticles. Therefore, studying how proteins compete and are oriented on the nanoparticle surface is essential. We hypothesized that the presence of opsonins (immunoglobulin (IgG)) might affect the adsorption of dysopsonins (human serum albumin (HSA)) and vice versa. Using the molecular dynamics simulations, we showed that the adsorption of HSA on the GO surface after the IgG adsorption is more probable than the opposite order of adsorption. It was also observed that the higher lateral diffusion of the HSA compared to the IgG helped the system reach a more stable configuration while the initial adsorption of the HSA limits the lateral diffusion of IgG. Therefore, replacing IgG adsorbed on the GO surface with HSA is plausible while the reverse process is less likely to occur. This study revealed that albumin might extend the blood circulation time of GO by replacing opsonins (IgG).