RESEARCH PAPER Oral intake of zirconia nanoparticle alters neuronal development and behaviour of Drosophila melanogaster Monalisa Mishra & Debabrat Sabat & Basanti Ekka & Swetapadma Sahu & Unnikannan P & Priyabrat Dash Received: 3 April 2017 /Accepted: 13 July 2017 # Springer Science+Business Media B.V. 2017 Abstract Zirconia nanoparticles (ZrO 2 NPs) have been extensively used in teeth and bone implants and thus get a chance to interact with the physiological system. The current study investigated the oral administration of various concentrations of ZrO 2 NPs synthesized by the hydrothermal method (0.25 to 5.0 mg L -1 ) on Drosoph- ila physiology and behaviour. The size of the currently studied nanoparticle varies from 10 to 12 nm. ZrO 2 NPs accumulated within the gut in a concentration- dependent manner and generate reactive oxygen spe- cies (ROS) only at 2.5 and 5.0 mg L -1 concentra- tions. ROS was detected by nitroblue tetrazolium (NBT) assay and 2′,7′-dichlorofluorescein (H2DCF) staining. The ROS toxicity alters the larval gut structure as revealed by DAPI staining. The NP stress of larvae affects the Drosophila development by distressing pupa count and varying the phenotypic changes in sensory organs (eye, thorax bristle, wings). Besides phenotypic changes, flawed climbing behaviour against gravity was seen in ZrO 2 NP-treated flies. All together, for the first time, we have reported that a ROS-mediated ZrO 2 NP toxicity alters neuronal development and functioning using Drosophila as a model organism. Keywords Zirconia nanoparticles . Drosophila melanogaster . Toxicity . Behaviour . Sensory organs . Neurotechnology . Nanomedicine Introduction Zirconia (ZrO 2 ) is widely used in the biomedical indus- try because of its inertness. Recently, zirconia nanopar- ticles (ZrO 2 NPs) are used in labelling, targeting, and drug loading (Nagy et al. 2016). Mesoporous zirconia has a greater surface area and thus is used for loading and targeted release of drug to cancer cells (Tang et al. 2010). Fluorescent-labelled zirconia is used for drug adsorption studies (Nagy et al. 2015). The functional- ized ZrO 2 NPs (pagination, targeting, or labelling) are biocompatible and thus used for the treatment of oral, colon, or hepatocellular carcinoma (Al-Fahdawi et al. 2015; Sponchia et al. 2015). Amalgamation of ZrO 2 NPs like silica-zirconia-malic acid composite is used as a nanocarrier to deliver medicine into targeted tumour site (Nagy et al. 2016). Besides drug delivery, zirconia nanocomposites are used in implants due to their least side effects (Sotoudeh et al. 2013). ZrO 2 NPs provide high flexure strength with minimal ion release paralleled to other metallic implants (Kosmač et al. 1999; Lacefield 1999; Manicone et al. 2007). Zirconia has its J Nanopart Res (2017) 19:282 DOI 10.1007/s11051-017-3971-y M. Mishra (*) : D. Sabat : S. Sahu Neural Developmental Biology Laboratory, Department of Life Science, National Institute of Technology, Rourkela, Odisha 769008, India e-mail: mishramo@nitrkl.ac.in B. Ekka : P. Dash Department of Chemistry, National Institute of Technology, Rourkela, Odisha 769008, India U. P School of Biology, IISER Thiruvananthapuram, Trivandrum, Kerala 695016, India