title: Synthesis and characterization of quantum dots designed for biomedical use.
abstract: Semiconductor quantum dots (QDs) have become promising nanoparticles for a wide variety of biomedical applications. However, the major drawback of QDs is their potential toxicity. Here, we determined possible cytotoxic effects of a set of QDs by systematic photophysical evaluation in vitro as well as in vivo. QDs were synthesized by the hydrothermal aqueous route with sizes in the range of 2.0-3.5 nm. Cytotoxic effects of QDs were studied in the human pancreatic carcinoid cell line BON. Cadmium telluride QDs with or without zinc sulfide shell and coated with 3-mercaptopropionic acid (MPA) were highly cytotoxic even at nanomolar concentrations. Capping with l-glutathione (GSH) or thioglycolic acid (TGA) reduced the cytotoxicity of cadmium telluride QDs and cadmium selenide QDs. Determination of the toxicity of QDs revealed IC50 values in the micromolar range. In vivo studies showed good tolerability of CdSe QDs with ZnS shell and GSH capping. We could demonstrate that QDs with ZnS shell and GSH capping exhibit low toxicity and good tolerability in cell models and living organisms. These QDs appear to be promising candidates for biomedical applications such as drug delivery for enhanced chemotherapy or targeted delivery of light sensitive substances for photodynamic therapy.
authors.affiliation: Institute of Physiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Berlin 10117, Germany. Electronic address: weronika.kuzyniak@charite.de.
authors.forename: Weronika
authors.initials: W
authors.lastname: Kuzyniak
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa. Electronic address: sesan006@yahoo.com.
authors.forename: Oluwasesan
authors.initials: O
authors.lastname: Adegoke
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa. Electronic address: kes@mailbox.co.za.
authors.forename: Kutloano
authors.initials: K
authors.lastname: Sekhosana
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa. Electronic address: sarah.ds@mailbox.co.za.
authors.forename: Sarah
authors.initials: S
authors.lastname: D'Souza
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa. Electronic address: g09t1043@campus.ru.ac.za.
authors.forename: Sesethu Charmaine
authors.initials: SC
authors.lastname: Tshangana
authors.affiliation: Institute of Physiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Berlin 10117, Germany. Electronic address: bjoern.hoffmann@charite.de.
authors.forename: Björn
authors.initials: B
authors.lastname: Hoffmann
authors.affiliation: Institute of Physiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Berlin 10117, Germany. Electronic address: eugeny.ermilov@charite.de.
authors.forename: Eugeny A
authors.initials: EA
authors.lastname: Ermilov
authors.affiliation: Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa. Electronic address: t.nyokong@ru.ac.za.
authors.forename: Tebello
authors.initials: T
authors.lastname: Nyokong
authors.affiliation: Institute of Physiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Berlin 10117, Germany. Electronic address: michael.hoepfner@charite.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Höpfner
mesh_terms: D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002642:Chick Embryo; D049033:Chorioallantoic Membrane / Q000378:metabolism; D016503:Drug Delivery Systems; D005978:Glutathione / Q000737:chemistry*; D006801:Humans; D045663:Quantum Dots / Q000737:chemistry* / Q000633:toxicity*; D018036:Selenium Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; D005978:Glutathione; C031238:zinc sulfide
keywords: Biocompatibility; Cytotoxicity; Nanoparticles; Quantum dots