Document Detail

Proton-Resistant Quantum Dots: Stability in Gastrointestinal Fluids and Implications for Oral Delivery of Nanoparticle Agents.
MedLine Citation:
PMID:  20379372     Owner:  NLM     Status:  Publisher    
Semiconductor quantum dots (QDs) have shown great promise as fluorescent probes for molecular, cellular and in-vivo imaging. However, the fluorescence of traditional polymer-encapsulated QDs is often quenched by proton-induced etching in acidic environments. This is a major problem for QD applications in the gastrointestinal tract because the gastric (stomach) environment is strongly acidic (pH 1-2). Here we report the use of proton-resistant surface coatings to stabilize QD fluorescence under acidic conditions. Using both hyperbranched polyethylenimine (PEI) and its polyethylene glycol derivative (PEG grafted PEI), we show that the fluorescence of core-shell CdSe/CdS/ZnS QDs is effectively protected from quenching in simulated gastric fluids. In comparison, amphiphilic lipid or polymer coatings provide no protection under similarly acidic conditions. The proton-resistant QDs are found to cause moderate membrane damage to cultured epithelial cells, but PEGylation (PEG grafting) can be used to reduce cellular toxicity and to improved nanoparticle stability.
Aaron M Mohs; Hongwei Duan; Brad A Kairdolf; Andrew M Smith; Shuming Nie
Publication Detail:
Journal Detail:
Title:  Nano research     Volume:  2     ISSN:  1998-0000     ISO Abbreviation:  -     Publication Date:  2009 Jun 
Date Detail:
Created Date:  2010-7-13     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101518856     Medline TA:  Nano Res     Country:  -    
Other Details:
Languages:  ENG     Pagination:  500-508     Citation Subset:  -    
Departments of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology, 101 Woodruff Circle NE, Suite 2001, Atlanta, Georgia 30322, USA.
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Grant Support
P20 GM072069-01//NIGMS NIH HHS; R01 CA108468-01//NCI NIH HHS; U01 HL080711-01//NHLBI NIH HHS; U54 CA119338-01//NCI NIH HHS

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