title: Ecotoxicity of halloysite nanotube-supported palladium nanoparticles in Raphanus sativus L.
abstract: Halloysite nanotubes (HNTs) are natural nanomaterials that are biocompatible and available in large amounts at low prices. They are emerging nanomaterials with appealing properties for applications like support for metal nanoparticles (NPs). The potential environmental impacts of NPs can be understood in terms of phytotoxicity. Current research has been focusing on HNT applications in cell or animal models, while their use in plants is limited so their ecotoxicological impact is poorly documented. To date there are no studies on the phytotoxic effects of functionalized halloysites (functionalized-HNTs). To develop a quantitative risk assessment model for predicting the potential impact of HNT-supported palladium nanoparticles (HNT-PdNPs) on plant life, an investigation was undertaken to explore their effects on seed germination, seedling development, and mitotic division in root tip cells of 2 lots of Raphanus sativus L. with different vigor. The results showed that exposure to 1500 mg/L of HNTs, functionalized-HNTs, and HNT-PdNPs had no significant influence on germination, seedling development, xylem differentiation, or mitotic index in both lots. Cytogenetic analyses revealed that treatments with functionalized-HNT significantly increased the number of aberrations in low-vigor seeds. These results suggest that low-vigor seeds represent a model for a stress test that would be useful to monitor the effects of NPs. Moreover the present study offers scientific evidence for the use of halloysite for environmental purposes, supporting the biological safety of HNT-PdNPs. Environ Toxicol Chem 2016;35:2503-2510. © 2016 SETAC.
authors.affiliation: Dipartimento di Scienze della Vita, Università degli Studi di Siena, Siena, Italy.|Istituto di Biolo, gia e Biotecnologia Agraria "CNR", Pisa, Italy.
authors.forename: Lorenza
authors.initials: L
authors.lastname: Bellani
authors.affiliation: Istituto di Biolo, gia e Biotecnologia Agraria "CNR", Pisa, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Giorgetti
authors.affiliation: Dipartimento STEBICEF, Sez. Chimica, Università degli Studi di Palermo, Palermo, Italy. serena.riela@unipa.it.
authors.forename: Serena
authors.initials: S
authors.lastname: Riela
authors.affiliation: Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Palermo, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lazzara
authors.affiliation: Dipartimento STEBICEF, Sez. Botanica ed Ecologia vegetale, Università degli Studi di Palermo, Palermo, Italy. anna.scialabba@unipa.it.
authors.forename: Anna
authors.initials: A
authors.lastname: Scialabba
authors.affiliation: Dipartimento STEBICEF, Sez. Chimica, Università degli Studi di Palermo, Palermo, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Massaro
mesh_terms: D000538:Aluminum Silicates / Q000633:toxicity*; D000818:Animals; D000077215:Clay; D018525:Germination / Q000187:drug effects; D053768:Metal Nanoparticles / Q000633:toxicity*; D043942:Nanotubes / Q000633:toxicity*; D010165:Palladium / Q000633:toxicity*; D031224:Raphanus / Q000187:drug effects* / Q000254:growth & development; D018570:Risk Assessment; D012639:Seeds / Q000187:drug effects
chemical_list: D000538:Aluminum Silicates; D010165:Palladium; D000077215:Clay
keywords: Cytological analysis; Halloysite nanotubes; Palladium nanoparticles; Raphanus sativus L; Seed germination