Are zinc oxide nanoparticles safe? A structural study on human serum albumin using in vitro and in silico methods.

With due attention to adsorption of proteins on the nanoparticles surface and the formation of nanoparticle-protein corona, investigation of nanoparticles toxicity on the structure of proteins is important. Therefore, this work was done to evaluate toxicity of Zinc oxide nanoparticles (ZnO NPs) on the structure of human serum albumin (HSA) through in vitro and in silico studies. First, ZnO NPs were synthesized using hydrothermal method and their size and morphology were determined by SEM and TEM methods and then to study its toxicity on the HSA structure were used UV-Vis and fluorescence spectroscopy. Also, in order to investigate interaction mechanism of ZnO NP with HSA at the atomistic level was used molecular dynamics (MD) simulation. The obtained images from SEM and TEM showed that ZnO NPs were nanosheet with size of less than 40 nm. The results of spectroscopic studies showed ZnO NPs lead to significant conformational changes in the protein's absorption and emission spectra. Moreover, MD results indicated the minor structure changes in HSA due to interaction with ZnO NP during the 100 ns simulation, and the formation of nanoparticle-protein corona complex is mainly because of electrostatic interactions between charge groups of HSA and ZnO NP.Communicated by Ramaswamy H. Sarma.