Highly Efficient Supramolecular Aggregation-Induced Emission-Active Pseudorotaxane Luminogen for Functional Bioimaging

Biomacromolecules. 2017 Mar 13;18(3):886-897. doi: 10.1021/acs.biomac.6b01777. Epub 2017 Feb 20.

Abstract

The direct tracking of cells using fluorescent dyes is a constant challenge in cell therapy due to aggregation-induced quenching (ACQ) effect and biocompatibility issues. Here, we demonstrate the development of a biocompatible and highly efficient aggregation-induced emission (AIE)-active pseudorotaxane luminogen based on tetraphenylethene conjugated poly(ethylene glycol) (TPE-PEG2) (guest) and α-cyclodextrin (α-CD) (host). It is capable of showing significant fluorescent emission enhancement at the 400-600 nm range when excited at 388 nm, without increasing the concentration of AIE compound. The fluorescent intensity of TPE-PEG2 solution was effectively enhanced by 4-12 times with gradual addition of 1-4 mM of α-CD. 2D NOSEY 1H NMR revealed clear correlation spots between the characteristic peaks of α-CD and PEG, indicating the interaction between protons of ethylene glycol and cyclodextrin, and the structures are mainly based on threaded α-CD. The host-guest complex exhibits boosted fluorescent emission because the PEG side chains are confined in "nano-cavities" (host), thus, applying additional restriction on intermolecular rotation of TPE segments. In vitro cell experiments demonstrated the potential of AIE-active pseudorotaxane polymer as a biocompatible bioimaging probe.

MeSH terms

  • A549 Cells
  • Biocompatible Materials / chemistry
  • Cell Survival / drug effects
  • Epithelial Cells / cytology
  • Fluorescent Dyes / chemistry*
  • Hep G2 Cells
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Spectroscopy
  • Micelles
  • Optical Imaging*
  • Polyethylene Glycols / chemistry
  • Polymers
  • Rotaxanes / chemistry*
  • alpha-Cyclodextrins / chemistry

Substances

  • Biocompatible Materials
  • Fluorescent Dyes
  • Micelles
  • Polymers
  • Rotaxanes
  • alpha-Cyclodextrins
  • Polyethylene Glycols
  • alpha-cyclodextrin