Proton-resistant quantum dots: Stability in gastrointestinal fluids and implications for oral delivery of nanoparticle agents

Aaron M. Mohs, Hongwei Duan, Brad A. Kairdolf, Andrew M. Smith, Shuming Nie

Research output: Contribution to journalArticlepeer-review

41 Scopus citations

Abstract

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. [Figure not available: see fulltext.]

Original languageEnglish (US)
Pages (from-to)500-508
Number of pages9
JournalNano Research
Volume2
Issue number6
DOIs
StatePublished - Jun 2009

Keywords

  • Nanoparticle
  • gastrointestinal
  • oral delivery
  • polyethylene glycol (PEG)
  • polyethylenimine (PEI)
  • quantum dot

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • General Materials Science
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Proton-resistant quantum dots: Stability in gastrointestinal fluids and implications for oral delivery of nanoparticle agents'. Together they form a unique fingerprint.

Cite this