title: The effect of nanoparticle degradation on amphiphilic polymer-coated quantum dot toxicity: the importance of particle functionality assessment in toxicology [corrected].
abstract: Colloidal semiconductor nanoparticles (quantum dots) have attracted a lot of interest in technological and biomedical research, given their potent fluorescent properties. However, the use of heavy-metal-containing nanoparticles remains an issue of debate. The possible toxic effects of quantum dots remain a hot research topic and several questions such as possible intracellular degradation of quantum dots and the effect thereof on both cell viability and particle functionality remain unresolved. In the present work, amphiphilic polymer [corrected] coated CdSe/ZnS quantum dots were synthesized and characterized, after which their effects on cultured cells were evaluated using a multiparametric setup. The data reveal that the quantum dots are taken up through endocytosis and when exposed to the low pH of the endosomal structures, they partially degrade and release cadmium ions, which lowers their fluorescence intensity and augments particle toxicity. Using the multiparametric method, the quantum dots were evaluated at non-toxic doses in terms of their ability to visualize labeled cells for longer time periods. The data revealed that comparing different particles in terms of their applied dose is challenging, likely due to difficulties in obtaining accurate nanoparticle concentrations, but evaluating particle toxicity in terms of their biological functionality enables an easy and straightforward comparison.
authors.affiliation: Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium; Center of Nano- and Biophotonics, Ghent University, Ghent, Belgium.
authors.forename: Stefaan J
authors.initials: SJ
authors.lastname: Soenen
authors.affiliation: Department of Physics, Philipps University of Marburg, Marburg, Germany.
authors.forename: José-Maria
authors.initials: JM
authors.lastname: Montenegro
authors.affiliation: Department of Physics, Philipps University of Marburg, Marburg, Germany.
authors.forename: Abuelmagd M
authors.initials: AM
authors.lastname: Abdelmonem
authors.affiliation: DNA Damage Group, Swansea University, Swansea, UK.
authors.forename: Bella B
authors.initials: BB
authors.lastname: Manshian
authors.affiliation: DNA Damage Group, Swansea University, Swansea, UK.
authors.forename: Shareen H
authors.initials: SH
authors.lastname: Doak
authors.affiliation: Department of Physics, Philipps University of Marburg, Marburg, Germany; CIC biomaGUNE, San Sebastián, Spain.
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Parak
authors.affiliation: Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium. Electronic address: Stefaan.Desmedt@ugent.be.
authors.forename: Stefaan C
authors.initials: SC
authors.lastname: De Smedt
authors.affiliation: Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium; Center of Nano- and Biophotonics, Ghent University, Ghent, Belgium.
authors.forename: Kevin
authors.initials: K
authors.lastname: Braeckmans
mesh_terms: D000818:Animals; D002104:Cadmium / Q000737:chemistry; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects; D005453:Fluorescence; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D018384:Oxidative Stress / Q000187:drug effects; D016716:PC12 Cells; D011109:Polymethacrylic Acids / Q000737:chemistry*; D045663:Quantum Dots / Q000633:toxicity*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D018675:Toxicity Tests
chemical_list: D011109:Polymethacrylic Acids; D017382:Reactive Oxygen Species; D002104:Cadmium; C030613:polymethacrylic acid
keywords: Cadmium; Degradation; Particle functionality; Quantum dot; Toxicity