The effect of CdSe–ZnS quantum dots on calcium currents and catecholamine secretion in mouse chromaffin cells

Abstract Semiconductor nanocrystal quantum dots (QDs) possess an enormous potential of applications in nanomedicine, drug delivery and bioimaging which derives from their unique photoemission and photostability characteristics. In spite of this, however, their interactions with biological systems an...

Full description

Saved in:
Bibliographic Details
Published in:Biomaterials 2011-12, Vol.32 (34), p.9040-9050
Main Authors: Gosso, Sara, Gavello, Daniela, Giachello, Carlo N.G, Franchino, Claudio, Carbone, Emilio, Carabelli, Valentina
Format: Article
Language:English
Subjects:
Adrenal chromaffin cells
Advanced Basic Science
Amperometry
Animals
Cadmium Compounds - metabolism
Calcium - metabolism
Calcium Channels - metabolism
Catecholamines - metabolism
Cell Survival
Cells, Cultured
Chromaffin Cells - cytology
Chromaffin Cells - metabolism
Dentistry
Exocytosis
Male
Membrane capacitance changes
Mice
Mice, Inbred C57BL
Quantum Dots
Selenium Compounds - metabolism
Semiconductor nanocrystals
Sulfides - metabolism
Voltage-gated Ca 2+ channels
Zinc Compounds - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Semiconductor nanocrystal quantum dots (QDs) possess an enormous potential of applications in nanomedicine, drug delivery and bioimaging which derives from their unique photoemission and photostability characteristics. In spite of this, however, their interactions with biological systems and impact on human health are still largely unknown. Here we used neurosecretory mouse chromaffin cells of the adrenal gland for testing the effects of CdSe–ZnS core–shell quantum dots (5–36 nM) on Ca2+ channels functionality and Ca2+ -dependent neurosecretion. Prolonged exposure (24 h) to commonly used concentrations of CdSe–ZnS QDs (≥16 nM) showed that the semiconductor nanocrystal is effectively internalized into the cells without affecting cell integrity (no changes of membrane resistance and cell capacitance). QDs reduced the size of Ca2+ currents by ∼28% in a voltage-independent manner without affecting channel gating. Correspondingly, depolarization-evoked exocytosis, measured at +10 mV, where Ca2+ currents are maximal, was reduced by 29%. CdSe–ZnS QDs reduced the size of the readily releasable pool (RRP) of secretory vesicles by 32%, the frequency of release by 33% and the overall quantity of released catecholamines by 61%, as measured by carbon fibers amperometry. In addition, the Ca2+ -dependence of exocytosis was reduced, whereas the catecholamine content of single granules, as well as the kinetics of release, remained unaltered. These data suggest that exposure to CdSe–ZnS QDs impairs Ca2+ influx and severely interferes with the functionality of the exocytotic machinery, compromising the overall catecholamine supply from chromaffin cells.
ISSN:0142-9612
1878-5905
DOI:10.1016/j.biomaterials.2011.08.031