An engineered coiled-coil polypeptide assembled onto quantum dots for targeted cell imaging

Nanotechnology. 2015 Dec 11;26(49):495102. doi: 10.1088/0957-4484/26/49/495102. Epub 2015 Nov 16.

Abstract

Quantum dot (QD)-polypeptide probes have been developed through the specific metal-affinity interaction between polypeptides appended with N-terminal polyhistidine sequences and CdSe/ZnS core-shell QDs. The size and charge of a QD-polypeptide can be tuned by using different coiled-coil polypeptides. Compared to glutathione-capped QDs (QD-GSH), QD-polypeptide probes showed an approximately two- to three-fold luminescence increase, and the luminescence increase was not obviously related to the charge of the polypeptide. QD-polypeptide probes with different charge have a great effect on nonspecific cellular uptake. QD-polypeptide probes with negative charge exhibited lower nonspecific cellular uptake in comparison to the QD-GSH, while positively charged QD-polypeptide probes presented higher cellular uptake than the QD-GSH. A targeted QD-ARGD probe can obviously increase targeted cellular uptake in α v β 3 overexpressing HeLa cells compared to QD-A. In addition, QD-polypeptide probes showed lower in vitro cytotoxicity compared to the original QDs. These results demonstrate that these QD-polypeptide probes with high specific cellular uptake, high fluorescence intensity and low background noise are expected to have great potential applications in targeted cell imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytological Techniques / methods*
  • HeLa Cells
  • Humans
  • MCF-7 Cells
  • Optical Imaging / methods*
  • Peptides / chemistry*
  • Quantum Dots / chemistry*

Substances

  • Peptides