IBRBS - Faculté de médecine - Brest - UBO -France

Brest, January 18th, 2023


The ANR/BMBF funded project TARGET-THERAPY is a bilateral collaboration (coordinated by Dr. Tony Le Gall in France and Prof. Dr. Holger Schönherr in Germany), gathering research teams bringing expertise in chemistry, biology, and medicine.

This project aims to significantly improve the treatment of recalcitrant respiratory tract bacterial infections, focusing on the WHO priority-1 pathogen Pseudomonas aeruginosa as one of the most dangerous key multi-drug resistant bacteria.

The therapeutic approach is based on photodynamic therapy, which holds great promise to rescue the loss of efficiency of current antibiotics. It makes use of photosensitizers that upon light exposure, induce oxidative damages killing pathogens in the surrounding environment.

An integrated protocol is developed considering crucial parts including (i) the use of specifically designed photodynamic systems, (ii) an administration to the pulmonary airways by means of a clinically applicable method, and (iii) in situ activation by application of a localized light treatment. 

As a result, the target bacteria can be eradicated in the complex environment of the respiratory tract. The protocol is designed to ensure both efficiency and safety as well as to circumvent pre-existing bacterial resistance while limiting the emergence of new ones. 

For providing a proof-of-concept to this approach, a key is to have dedicated light setup solutions.


Whereas illumination under in vitro conditions is relatively easy to be done, it is much more challenging under in vivo conditions in a living subject. In that case, it is essential to have a device that is not only efficient but also qualified and approved, from a preclinical point of view. Ready-to-use solutions are available from specialized manufacturers, but they can be very expensive, not fully adapted to the intended use, and not easily adaptable or scalable.” Dr. Tony Le Gall said.

EVOSENS is  a leading photonics company in systems integration, which is located in Plouzané, France.

It participates with INSERM UMR 1078 (headed by DR Emmanuelle Génin, in the GTCA Team, headed by Prof Dr Tristan Montier) in TARGET-THERAPY project, providing its expertise in the development of “customized” solutions adapted to the envisioned biomedical application.

This partnership recently embodied in the “ILightIT!” project rewarded by BPGO , which specifically aims to help finding light setup solutions to demonstrate – under ex vivo condition and then in a murine animal model – the effectiveness of the photodynamic systems developed as part of the TARGET-THERAPY project. 

The specifications of an “ideal” light device are multiple, including (i) reduced size, (ii) no or little heating effect, (iii) emission at the peak of the absorption wavelength of photosensitizers, (iv) sufficient irradiance and power, and (v) possibility of upgrading (by adaptation of interchangeable modules, especially for the irradiating tip).

After several discussions, feasibility tests were conducted, taking into account various characteristics of the light tip, such as its material, diameter, flexibility, robustness and biocompatibility. In January 2023, EVOSENS provided to INSERM a first device that is now evaluated under various experimental settings.

In the longer term, an evolution of the illumination protocol can be envisaged, using non-invasive lighting system capable of activating photodynamic systems at infectious sites deep inside the body.