Fitotoksični učinci nanočestica srebra stabiliziranih s različitim omotačima na duhan (Nicotiana tabacum L.)

master's thesis

• Title (english): Phytotoxic effects of differently coated silver nanoparticles on tobacco (Nicotiana tabacum L.)
• Author: Dajana Matić
• Mentor: Biljana Balen (mentor)
• Mentor: Petra Cvjetko (pomoć pri izradi, neposredni voditelj)
• Committee member: Biljana Balen (član povjerenstva)
• Committee member: Tatjana Bakran-Petricioli (član povjerenstva)
• Committee member: Sunčica Bosak (član povjerenstva)
• Committee member: Jasna Hrenović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2018-03-21, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Zbog jedinstvenih i korisnih svojstava nanočestica srebra (AgNP) povećava se njihova upotreba u različitim industrijskim i znanstvenim područjima te komercijalnim proizvodima, što neizbježno dovodi do njihovog otpuštanja u okoliš s nepoznatim posljedicama za žive organizme. Iako mehanizmi toksičnosti AgNP nisu posve razjašnjeni, jasno je da fizikalno-kemijska svojstva AgNP utječu na njihove biološke učinke. U ovom radu istraženi su učinci AgNP stabiliziranih s tri različita omotača (citrat, PVP ili CTAB), samih omotača te ionskog srebra (AgNO3) na isklijavanje i rast klijanaca duhana (Nicotiana tabacum L.) te na pojavu oksidacijskog stresa. Najizraženiji negativan učinak na rast klijanaca duhana je zabilježen nakon tretmana s AgNP-CTAB te omotačem CTAB, dok tretmani s AgNO3 nisu značajno utjecali na isklijavanje i rast klijanaca. Promjene u parametrima oksidacijskog stresa i aktivnosti antioksidacijskih enzima pokazale su da i AgNP i AgNO3 izazivaju pojavu oksidacijskog stresa, ali djelovanjem različitih mehanizama. Dobiveni rezultati upućuju na zaključak da omotači koji se koriste za stabilizaciju AgNP uvelike utječu na njihovu toksičnost te da toksičnost AgNP nije posljedica otpuštanja iona Ag+, već djelovanja samih nanočestica.

Abstract (english)

Due to their unique and beneficial properties, silver nanoparticles (AgNP) have been increasingly used in various industrial and scientific fields and commercial products. That makes environmental exposure to nanoparticles inevitable with unknown consequences on living organisms. Although the mechanisms of AgNP toxicity have not been fully elucidated, it is evident that physicochemical properties of AgNP affect their biological impacts. In this work, the effects of AgNP with three different coatings (citrate, PVP or CTAB), pure coatings and ionic silver (AgNO3) on germination and growth of tobacco (Nicotiana tabacum L.) seedlings as well as on the appearance of oxidative stress were investigated. The most prominent negative effect on tobacco seedling growth was detected in plants treated with AgNP-CTAB and CTAB coating, whereas AgNO3 treatments had no significant impact on the germination and seedling growth. Observed changes in the parameters of oxidative stress and activity of antioxidant enzymes demonstrated that both AgNP and AgNO3 induce oxidative stress, although by different mechanisms. The obtained results indicate that the toxicity of AgNP is greatly influenced by coatings used for their stabilization and that nanoparticles themselves account for their toxicity rather than released Ag+ ions.

• Keywords: nanočestice srebra; omotači; ionsko srebro; klijanci duhana; oksidacijski stres; antioksidacijski enzimi
• Keywords (english): silver nanoparticles; coatings; ionic silver; tobacco seedlings; oxidative stress; antioxidant enzymes
• Language: croatian
• URN:NBN: urn:nbn:hr:217:602621
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2020-03-21
• Created on: 2018-05-03 08:51:04