Titanium dioxide (TiO2) has been considered as non-toxic mineral particles widely used in the fields like cosmetics, food and drug. When the scale come to nanometer, TiO2 nanoparticles (nano-TiO2) exhibits multiple specific characteristics coupled with unknown risks on health. The purpose of this study was to systematically research the influence of nano-TiO2 on erythrocyte. The results indicated that the erythrocytes treated with nano-TiO2 underwent abnormal sedimentation, hemagglutination and dose dependent hemolysis, totally differing from those treated with micro-TiO2. The ghost cells were firstly investigated by using ultra-thin cell section in the case under nano-TiO2. The mechanism of such adverse effects is (1) the attachment around erythrocyte change the surface native properties and ultimately lead to hemoagglutination; (2) the content leak to the outside of erythrocyte through the breakage induced by both the nano-TiO2 trans-membrane and the oxidative stress under nano-TiO2. Our findings imply that nano-TiO2 may have potential toxicity to human being health.

Abstract A fused benzimidazole–imidazole scaffold was designed and synthesized using a facile procedure involving deprotection and cyclization reactions. The acidic conditions and high yields for the benzimidazole ring closure allow potential application of this efficient methodology for the design and synthesis of a range of bioactive compounds. Graphical abstract

Four series of heterocyclic compounds were obtained using Ugi-type multicomponent reactions (MCRs) with methyl 2-formylbenzoate as one of the starting materials. A facile and efficient one-pot procedure was suitable for all the MCRs under acidic conditions. This process provided access to four series of complex and potentially biologically active scaffolds.