Medicine research news Return to previous page
Article Released Fri-9th-February-2018 15:55 GMT
Contact: Administrator Account Institution: ResearchSEA
 Water-Soluble Warped Nanographene

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

Image Name
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 in Angewandte Chemie, 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.

(3186 characters)

About the Author
Dr. Kinchiro Itami is a professor at the Institute of Transformative Bio-Molecules (ITbM) at Nagoya University and head of the JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya, Japan. The main emphasis of his research is on the development of new synthetic methods, strategies, and concepts to solve challenging synthetic problems for realizing ideal chemical synthesis and for generating as-yet unexplored molecules of significant interest.

Author: Kenichiro Itami, Nagoya University (Japan), http://synth.chem.nagoya-u.ac.jp/wordpress/?lang=en (link below)

Title: A Water-Soluble Warped Nanographene: Synthesis and Applications for Photoinduced Cell Death

Angewandte Chemie International Edition
Permalink to the original article: https://doi.org/10.1002/anie.201713387 (link below) – Please use in your news piece to make sure altmetric.com picks it up and a link to your piece is shown on the journal's website.

Copy free of charge. We would appreciate a transcript of your article or a reference to it.
The original article is available from our online pressroom at http://pressroom.angewandte.org. (link below)
Contact: Editorial office: angewandte@wiley-vch.de
To be removed from this list, please e-mail us.

Angewandte Chemie is a journal of the Gesellschaft Deutscher Chemiker (German Chemical Society, GDCh) and is published by Wiley-VCH. It is one of the prime chemistry journals in the world.

Angewandte Chemie International Edition, Postfach 101161, 69451 Weinheim, Germany.

Wiley-VCH Verlag GmbH & Co. KGaA; – A company of John Wiley & Sons, Inc. Sitz der Gesellschaft: Weinheim; Vorsitzender des Aufsichtsrates: John Kritzmacher; Amtsgericht Mannheim, HRB 432833; Persönlich haftender Gesellschafter: John Wiley & Sons GmbH; Sitz: Weinheim; Amtsgericht Mannheim, HRB 432296; Geschäftsführer: Sabine Steinbach, Dr. Guido F. Herrmann

Associated links

Keywords associated to this article:
Create Account...