Ecotoxicity and in vitro safety profile of the eco-friendly silver and titanium dioxide nanoparticles

This study investigated the ecotoxicity and in vitro safety profile of novel metallic nanoparticles (silver and titanium dioxide) prepared from Aloe vera extract by biosynthesis method, evaluating the acute toxicity and bioaccumulation in soil. Samples were analyzed for phytotoxicity against Lactuca sativa, Cucumis sativus and Brassica oleracea, soil toxicity (ranging from 12.5 to 100 mg mL-1) and biocompatibility by MTT (in VERO and L929 cells ranging from 12.5 to 100 mu g mL-1). Phytotoxicity assays showed that for Lactuca sativa seeds, all nanoparticles showed toxicity for all tested concentrations (12.5-100 mg mL-1), while for Cucumis sativus seeds TiO2-NPs in concentrations of 12.5, 50 and 100 mg mL-1 and AgNPs in concentrations of 25 and 100 mg mL-1. For Brassica oleracea, the TiO2-NPs (100 mg mL-1), Ag/TiNPs (12.5 and 100 mg mL-1) and AgNPs (12.5 and 100 mg mL-1) demonstrated toxicity. For cytotoxicity assays, AgNPs and Ag/TiNPs showed a decrease in the cell viability for the two strains tested (99-50.7 % for VERO and 99-45.3 % for L929). Therefore, the results will contribute to understanding the main parameters of phytotoxicity, bioavailability and biocompatibility of separate metallic nanoparticles (TiO2-NPs and AgNPs) and combined (Ag/TiNPs).