Mohs, Aaron M. and Duan, Hongwei and Kairdolf, Brad A. and Smith, Andrew M. and Nie, Shuming (2009) Proton-resistant quantum dots: Stability in gastrointestinal fluids and implications for oral delivery of nanoparticle agents. Nano Research, 2 (6). pp. 500-508.
Official URL: http://www.springerlink.com/content/m267k866655004...
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 applications of QDs 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 improve nanoparticle stability.
|Subjects:||Physical Science > Nano objects|
Physical Science > Quantum phenomena
Material Science > Nanochemistry
|Deposited On:||29 Jun 2009 16:57|
|Last Modified:||29 Jun 2009 16:57|
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