q&more
My watch list
my.chemie.de  
Login  

News

Water-Soluble Warped Nanographene

Synthesis of a water-soluble warped nanographene and its application for photo-induced cell death

© Wiley-VCH

13-Feb-2018: Graphene and its nano-sized little sibling, nanographene, are well known for their remarkable photoelectronic properties. However, biomedical applications are hampered by the insolubility of the materials, especially in water. A Japanese team of scientists has now introduced substituted “warped nanographene,” which is soluble in a broad range of solvents while maintaining its photophysical properties. In their publication the authors also emphasize its photodynamic potential to selectively kill cells upon irradiation.

Nanographene has the hexagonal carbon lattice of graphene but consists of only a few carbon rings with tunable electronic properties. One of its big issues hampering widespread application in optoelectronic devices or biomedicine is its insolubility. Therefore, to suppress stacking and aggregation, a new type of nanographene with a bended structure has been synthesized, the so-called warped nanographene. Kenichiro Itami at Nagoya University, Japan, and his colleagues have now found a way to furnish the warped nanographene even further to obtain a fully soluble, amphiphilic product. The new structure was biocompatible, but upon irradiation it killed its host cell. This effective photosensitization behavior could inspire future research in photodynamic cancer therapy, the authors believe.

The poor solubility of graphene-like materials has been regarded problematic since the discovery of graphene as an intriguing one-layer carbon modification in 2004. To improve solubility, Itami and his colleagues have developed warped nanographene molecules with chemical substituents at the outer rim of the aromatic structure. The substituents were introduced by the relatively simple and powerful strategy of borylation. Once the molecule is borylated, the boron substituent can be replaced by other substituents, in this case, by an aromatic molecule bearing highly soluble tetra(ethylene glycol) chains (TEG). Applying this substitution–replacement strategy twice, the scientists accomplished the synthesis of a warped, i.e., bended, nanographene molecule that was stable in a broad range of solvents including water. Excited with a laser, it exhibited green fluorescence.

This fluorescence points to applications in biology, for example, as a dye in bioimaging. A further application came rather unexpected, the scientists reported. Upon excitation, the molecule, which was otherwise not harmful to the cells, killed the cell population of the human HeLa cell line to almost 100 percent. The authors proposed: “Although the mechanism is unclear, the relatively high efficiency of the singlet oxygen generation of [the soluble warped nanographene] may contribute to its HeLa cell death.” Thus, a mechanism similar to dye sensitization and production of reactive oxygen species can be assumed.

These second-generation nanographenes combine the remarkable optoelectronic properties of graphene with biocompatibility. They may well play a future role in bioimaging, photodynamic therapy, and similar applications.

Original publication:
Lin, H.-A., Sato, Y., Segawa, Y., Nishihara, T., Sugimoto, N., Scott, L. T., Higashiyama, T. and Itami, K.; "A Water-Soluble Warped Nanographene: Synthesis and Applications for Photoinduced Cell Death"; Angew. Chem.; 2018

Facts, background information, dossiers

  • photodynamic therapy
  • nanographenes
  • cancer therapy
  • tetraethylene glycol

More about Nagoya University

  • News

    2-D tin (stanene) without buckling

    Nagoya University-led researchers produce 2D sheets of tin atoms predicted to have exotic uses in electronics. Nagoya, Japan - Sometimes it pays to be two-dimensional. The merits of graphene, a 2D sheet of carbon atoms, are well established. In its wake have followed a host of "post-graphen ... more

    Breaking down plastic waste

    What to do proteins and Kevlar have in common? Both feature long chain molecules that are strung together by amide bonds. These strong chemical bonds are also common to many other naturally occurring molecules as well as man-made pharmaceuticals and plastics. Although amide bonds can give g ... more

    Rapid synthesis towards optically active alpha-aminocarbonyl therapeutics

    A team of organic chemists at ITbM, Nagoya University, has developed a new reaction to directly install amines into carbonyl compounds using their unique phase-transfer catalyst. This unprecedented method leads to the rapid formation of optically active (chiral) α-aminocarbonyls, which are ... more

More about Angewandte Chemie

  • News

    A New Way to Atomically Thin Materials

    Metallic conductivity and hydrophilicity of MXenes have established them as electrodes in rechargeable batteries and supercapacitors, as well as other applications, including photothermal cancer therapy, electromagnetic shielding, water purification and gas sensing. In the journal Angewandt ... more

    The Making of Biorelevant Nanomaterials

    The interactions of biological macromolecules such as nucleic acids, proteins, and polysaccharide–protein conjugates can be mimicked by artificial polyelectrolytes. Such synthetic polyionic complexes are expected to serve as novel platforms to stabilize and deliver drugs, proteins, or nucle ... more

    How To Draw Electricity from the Bloodstream

    Men build dams and huge turbines to turn the energy of waterfalls and tides into electricity. To produce hydropower on a much smaller scale, Chinese scientists have now developed a lightweight power generator based on carbon nanotube fibers suitable to convert even the energy of flowing blo ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by:



Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE