title: Effects of long-term exposure of gelatinated and non-gelatinated cadmium telluride quantum dots on differentiated PC12 cells.
abstract: BACKGROUND
  The inherent toxicity of unmodified Quantum Dots (QDs) is a major hindrance to their use in biological applications. To make them more potent as neuroprosthetic and neurotherapeutic agents, thioglycolic acid (TGA) capped CdTe QDs, were coated with a gelatine layer and investigated in this study with differentiated pheochromocytoma 12 (PC12) cells. The QD--cell interactions were investigated after incubation periods of up to 17 days by MTT and APOTOX-Glo Triplex assays along with using confocal microscopy.
  
  
  RESULTS
  Long term exposure (up to 17 days) to gelatinated TGA-capped CdTe QDs of PC12 cells in the course of differentiation and after neurites were grown resulted in dramatically reduced cytotoxicity compared to non-gelatinated TGA-capped CdTe QDs.
  
  
  CONCLUSIONS
  The toxicity mechanism of QDs was identified as caspase-mediated apoptosis as a result of cadmium leaking from the core of QDs. It was therefore concluded that the gelatine capping on the surface of QDs acts as a barrier towards the leaking of toxic ions from the core QDs in the long term (up to 17 days).
authors.affiliation: National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland.
authors.forename: Babu R
authors.initials: BR
authors.lastname: Prasad
authors.forename: Gillian
authors.initials: G
authors.lastname: Mullins
authors.forename: Natalia
authors.initials: N
authors.lastname: Nikolskaya
authors.forename: David
authors.initials: D
authors.lastname: Connolly
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Smith
authors.forename: Valérie A
authors.initials: VA
authors.lastname: Gérard
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Byrne
authors.forename: Gemma-Louise
authors.initials: GL
authors.lastname: Davies
authors.forename: Yurii K
authors.initials: YK
authors.lastname: Gun'ko
authors.forename: Yury
authors.initials: Y
authors.lastname: Rochev
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D019187:Cadmium Compounds / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D002454:Cell Differentiation / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D005780:Gelatin / Q000737:chemistry / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects; D016716:PC12 Cells; D045663:Quantum Dots; D051381:Rats; D013691:Tellurium / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D013864:Thioglycolates / Q000737:chemistry; D036401:Toxicity Tests, Chronic
chemical_list: D019187:Cadmium Compounds; D013864:Thioglycolates; C017487:2-mercaptoacetate; D005780:Gelatin; D013691:Tellurium; C028337:cadmium telluride