Genotoxicity of gold nanoparticles functionalized with indolicidin towards Saccharomyces cerevisiae Elisabetta de Alteriis 1 , Annarita Falanga 2 , Stefania Galdiero 2 , Marco Guida 1 , Valeria Maselli 1 , Emilia Galdiero 1, ⁎ 1. Department of Biology, University of Naples “Federico II”, 80100 Naples, Italy 2. Department of Pharmacy, University of Naples “Federico II”, 80134 Naples, Italy ARTICLE INFO ABSTRACT Article history: Received 22 September 2016 Revised 23 January 2017 Accepted 26 April 2017 Available online 10 May 2017 The toxic effects of gold nanoparticles surface-functionalized with the antimicrobial peptide indolicidin (AuNPs-indolicidin) towards the yeast Saccharomyces cerevisiae, one of the major eukaryotic model organisms, have been evaluated. Growth and survival, genotoxicity, as measured by comet assay, and expression of the YCA1, an apoptosis indicating gene, following 72 hr exposure of yeast to AuNPs-indolicidin, and to AuNPs and indolicidin alone have been examined. The gold nanoparticles exerted toxicity with DNA damage, accompanied by reactive oxygen species production (ROS), but they do not inhibit yeast growth and viability. Genotoxicity was less pronounced for surface-functionalized nanoparticles, showing that S. cerevisiae is quite resistant to the complex AuNPs-indolicidin. A progressive reduction of the genotoxic effect was observed along 72 hr exposure, presumably due to the activation of DNA repair mechanisms. These findings suggest the occurrence of a physiological protective response of S. cerevisiae towards nanoparticles, thereby providing useful information to the assessment of the environmental impact of metal nanoparticles. © 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. Keywords: Ecotoxicity Antimicrobial peptide Comet assay Yeast Nanoparticles Oxidative stress Introduction The increased use of engineered nanoparticles (NPs) in com- mercial products (cosmetics, electronics, paints, medical devices, food, packaging, catalysts, antimicrobial fabrics, water treatment membranes) (Aitken et al., 2006; Handy et al., 2008; Karnik et al., 2005; Roco, 2003; Savolainen et al., 2010) unavoidably leads to their significant accumulation in the earth with great concerns regarding the possible adverse effects on environment as well as on human health. There- fore, assessment of NP toxicity is needed before any applica- tion and it is strictly necessary when NPs are used in the biomedical field as drug or gene delivery systems or for other therapeutic purposes. In particular, gold nanoparticles (AuNPs) have received significant attention because of their unique physico-chemical properties that make them well suited for biomedical applications (Levy et al., 2010; Ma et al., 2011). A number of studies have evaluated the toxicity of a variety of AuNPs with different sizes and coatings (Alkilany and Murphy, 2010; Murphy et al., 2008), showing that AuNPs are mainly inert, though some authors report about their cytotox- icity (Pan et al., 2014; Tiedemann et al., 2014). Toxicity tests were mainly performed on freshwater algae (Renault et al., 2008), daphnias (Galdiero et al., 2015; Li et al., 2010), zebrafish embryos (Browning et al., 2009) and adult zebrafish (Geffroy et al., 2012). JOURNAL OF ENVIRONMENTAL SCIENCES 66 (2018) 138 – 145 ⁎ Corresponding author. E-mail: egaldier@unina.it (Emilia Galdiero). http://dx.doi.org/10.1016/j.jes.2017.04.034 1001-0742/© 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. Available online at www.sciencedirect.com ScienceDirect www.elsevier.com/locate/jes