title: Controlling the cytotoxicity of CdSe magic-sized quantum dots as a function of surface defect density.
abstract: Quantum dots are potentially very useful as fluorescent probes in biological systems. However, they are inherently cytotoxic because of their constituents. We controlled the cytotoxicity of CdSe magic-sized quantum dots (MSQDs) as a function of surface defect density by altering selenium (Se) concentration during synthesis. Higher Se concentrations reduced the cytotoxicity of the CdSe MSQDs and diminished mRNA expression of methallothionein because of the low cadmium ions (Cd(2+)) concentration adsorbed on the surface of the MSQDs. These results agree with luminescence spectra, which show that higher Se concentrations decrease the density of surface defects. Therefore, our results describe for the first time a simple way of controlling the cytotoxicity of CdSe MSQDs and making them safer to use as fluorescence probes in biological systems.
authors.affiliation: Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia , Uberlândia, Brazil.
authors.forename: Anielle Christine Almeida
authors.initials: AC
authors.lastname: Silva
authors.forename: Marcelo José Barbosa
authors.initials: MJ
authors.lastname: Silva
authors.forename: Felipe Andrés Cordero
authors.initials: FA
authors.lastname: da Luz
authors.forename: Danielle Pereira
authors.initials: DP
authors.lastname: Silva
authors.forename: Samantha Luara Vieira
authors.initials: SL
authors.lastname: de Deus
authors.forename: Noelio Oliveira
authors.initials: NO
authors.lastname: Dantas
mesh_terms: D000199:Actins / Q000737:chemistry; D002104:Cadmium / Q000737:chemistry; D019187:Cadmium Compounds / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D007477:Ions; D049449:Luminescence; D008668:Metallothionein / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D018384:Oxidative Stress; D045663:Quantum Dots; D017382:Reactive Oxygen Species; D012643:Selenium / Q000737:chemistry; D018036:Selenium Compounds / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D000199:Actins; D019187:Cadmium Compounds; D007477:Ions; C491053:MT2A protein, human; D017382:Reactive Oxygen Species; D018036:Selenium Compounds; D002104:Cadmium; D008668:Metallothionein; C058667:cadmium selenide; D012643:Selenium
keywords: CdSe MSQDs; Cytotoxicity; HeLa cells; methallothionein; surface defect levels