Health risk assessments of lithium titanate nanoparticles in rat liver cell model for its safe applications in nanopharmacology and nanomedicine

Due to their high chemical stability, lithium titanate (Li2TiO3) nanoparticles (LTT NPs) now are projected to be transferred into different nanotechnology areas like nano pharmacology and nano medicine. With the increased applications of LTT NPs for numerous purposes, the concerns about their potential human toxicity effects and their environmental impact are also increased. However, toxicity data for LTT NPs related to human health are very limited. Therefore we aimed to investigate toxicity potentials of various concentrations (0-1,000 ppm) of LTT NPs (<100 nm) in cultured primary rat hepatocytes. Cell viability was detected by [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. DNA damage was analyzed by scoring liver micronuclei rates and by determining 8-oxo-2-deoxyguanosine (8-OH-dG) levels. The results of MTT and LDH assays showed that higher concentrations of dispersed LTT NPs (500 and 1,000 ppm) decreased cell viability. Also, LTT NPs increased TOS (300, 500 and 1,000 ppm) levels and decreased TAC (300, 500 and 1,000 ppm) levels in cultured hepatocytes. The results of genotoxicity tests revealed that LTT NPs did not cause significant increases of micronucleated hepatocytes and 8-OH-dG as compared to control culture. In conclusion, the obtained results showed for the first time that LTT NPs had dose dependent effects on oxidative damage and cytotoxicity but not genotoxicity in cultured primary rat hepatocytes for the first time.