Typologie d'actualités: Group Luminescent lanthanide compounds, optical spectroscopy and bioimaging

A new luminescence for the direct follow-up of drug delivery

Liposomes are nanocapsules widely used for the in vivo transport and delivery of therapeutic or diagnostic agents, or both. The therapeutic agent will only become active upon its release, thus sparing healthy tissues. The follow up of such release process is crucial to understand and control the drug action.

The previously reported approaches are based on optical imaging, using exclusively organic fluorophores or inorganic nanoparticles, co-encapsulated with the drug in the liposome.

The use of luminescent lanthanide complexes is an alternative which offers a number of advantages, including the capacity of those complexes to emit in the near infrared (NIR) region, enabling their detection in biological media.

The CBM research teams have developed an original nanocapsule : a liposome comprising an Ytterbium complex encapsulated with doxorubicin (anticancer agent). The NIR emission of the lanthanide complex is only observed when the drug is encapsulated. This NIR luminescence signal can therefore enable the direct follow-up, and in real time, of the integrity of the liposome, and can thus be used to detect the drug release.

An in vivo proof of concept was performed and the lanthanide luminescent signal could be detected in a mouse model of breast cancer.

Références de l'article :

Doxorubicin-sensitized Luminescence of NIR-emitting Ytterbium Liposomes: Towards Direct Monitoring of Drug Release,

Sara Lacerda, Anthony Delalande, Svetlana V. Eliseeva, Agnès Pallier, Célia S. Bonnet, Frédéric Szeremeta, Sandra Même, Chantal Pichon, Stéphane Petoud, Eva Toth

Angewandte Chemie Int. Ed. 13 août 2021  https://doi.org/10.1002/anie.202109408

 

See the news on CNRS Chemistry Institute site

 

 




Pure and stable white light

Current white light sources, such as LEDs, tend to oscillate between different color variations, which distorts the perception of the human eye. This limitation can be very disabling, even dangerous, during surgery or in the work of graphic designers and artists.

Researchers from the Center for Molecular Biophysics and the University of Michigan (United States) have developed a new system, based on dysprosium atoms and metallacrowns, which gives exactly white light that does not vary with conditions wear or temperature.

This work has been published in the Journal of the American Chemical Society.

See the information on the CNRS Institute of Chemistry website.

Organometallic networks for the near-infrared emission of lanthanides

Researchers from the group "Luminescent lanthanide compounds, spectroscopy and optical bioimaging" and the University of Pittsburgh (USA) have designed a rigid three-dimensional chemical system of organometallic network type composed of lanthanides and organic molecules. A major originality of this work is based on the use of the cavity of this network to generate in situ the molecular system sensitizing the lanthanide cations. This new approach has the advantage, among other things, of allowing the excitation length to be controlled. This network is well suited to the real conditions of optical biomedical imaging on living cells.

See the news on the CNRS website

These researches have been published on Journal of American Chemical Society

Patrick F. Muldoon, Guillaume Collet, Svetlana V Eliseeva, Tian-Yi Luo, Stephane Petoud, and Nathaniel L Rosi. Ship-in-a-bottle preparation of long wavelength molecular antennae in lanthanide metal-organic frameworks for biological imaging. J. Am. Chem. Soc. (2020) 142, 8776-8781 - doi : 10.1021/jacs.0c01426