Nov 9, 2017
A paper by Professor Ellen Sletten, her group, and MIT researchers, including Professor Justin Caram's MIT postdoctoral work, was highlighted in the journal.
The researchers originally published “Flavylium Polymethine Fluorophores for Near- and Shortwave Infrared Imaging” in the 9 October 2017 issue of Angew. Chem. Int. Ed., and it was flagged as a “Hot Paper.”  Last week, on 1 November 2017, the paper was highlighted in the journal Nature under News & Views in an article by Martin J. Schnermann.
Professor Sletten and her coworkers have designed a new class of small-molecule organic dyes that fluoresce in the short-wave infrared (SWIR) region of the electromagnetic spectrum. Optical imaging can be used to observe biological processes in clinical settings in real time, with the SWIR region providing higher resolutions and depth penetration.  If the advantages of SWIR are to be translated to the clinic, fluorescent small molecules, or fluorophores, are needed that are non-toxic. The researchers synthesized such fluorophores by replacing conventionally used heterocycles (indolenines) with dimethylamino flavylium (Flav) heterocycles in the classic cyanine dye series to create a new class of polymethine dyes. As stated in the paper, “With these studies, we have achieved the brightest SWIR polymethine employed for imaging to date.”
Schnermann’s highlight article also noted that the improved resolution and tissue penetration resulting from these new dyes could enable surgeons to better visualize and remove tumor tissue, and that “Cosco and colleague’s study provides a key breakthrough required to move SWIR imaging towards general clinical use.”
This research was carried out by Professor Sletten and graduate students in her lab Emily D. Cosco and Rachael A. Day, who were aided by Erik P. Farr, a graduate student in the Schwartz Group.  The Sletten Group collaborated with Professor Moungi G. Bawendi of MIT with his postdocs Justin Caram, now Professor Caram at UCLA, Oliver T. Bruns, and his graduate student Daniel Franke.
Caram was a collaborator on the paper when he was a postdoctoral fellow in Moungi Bawendi’s group at Massachusetts Institute of Technology (MIT). Caram joined the UCLA faculty in June 2017.
Professor Sletten’s research can be viewed at her website.
Written by Laura Strom.