The investigation of protein corona of zinc oxide nanoparticles and zinc ions release impact on CHO cell

Abstract

The past decade has witnessed an exponential growth in nanotechnology of engineered nanomaterials (ENs) on the large scale for both industrial and household purposes. ZnO NPs are amongst the most common ENs. The potential for their release into the environment and human health have raised considerable concern. The NPs are coated by different proteins when entering organism and surface modifications may have considerable influence to NPs fate. In this study ZnO NPs coating with protein, known as protein corona, was formed from model protein bovine serum albumin (BSA). The aim of this study was to evaluate the effect of ZnO NPs coating with albumin (ZnO-BSA NPs) on Chinese hamster ovary (CHO) cells. We demonstrated that in the concentration range 0.1-10 μg/ml ZnO-BSA and Zn+2 ions had stimulating effect on cell viability, while ZnO NPs had no stimulation. At higher concentrations (25-200 μg/ml) cell viability decreased in a concentration-dependent manner. ZnO NPs effect on proliferation followed the same trend except that it was decreased by 86% at 25 μg/ml after 24 h incubation. Plasma membrane (PM) permeability induction may play an important role in NPs-induced cell death. We applied lactate dehydrogenase (LDH) leakage and propidium iodide (PI) test for PM permeability evaluation. LDH activity increased linearly increasing NPs concentration and reached 2.5-fold higher level for ZnO-BSA NPs as compared to control. PI results followed the same trend that PM had been 12 % more permeable when exposed to ZnO-BSA NPs. NPs ability to increase PM permeability may have similar effect to the membranes of intracellular organelles. The increased permeability of mitochondrial inner membrane may result in depletion of mitochondrial membrane potential (MP). We evaluated the impact of NPs on MP using JC-1 dye. [...]