Chelating Polymers for Plutonium Decorporation

- C. Di Giorgio -
 
A new decontamination strategy for people irradiated by radionuclides through inhalation.
 
Actions of chelating polymers in case of actinides contamination through inhalation
Actions of chelating polymers in case of actinides contamination through inhalation Actions of chelating polymers in case of actinides contamination through inhalation

 

Academy 3 highlight

This project gathers experts in synthetic chemistry, biology, and actinide chemistry to develop a new strategy to recover from radionuclide contamination. This new approach thus contributes to lower the risks for humans associated with the use or misuse of radioactivity.

The project

Nuclear contamination of humans can occur in different contexts, such as nuclear plant accidents (such as the Chernobyl event), military conflicts, terrorism, etc. The problematic radioactive elements that may be released include the “actinides”, among which plutonium is one of the most harmful to human health. In case of accidental plutonium contamination, almost half of the contamination occurs through inhalation, and the lungs eventually retain more than 90% of the inhaled radioactivity. Currently, there is no efficient treatment to prevent and cure such contamination of the lungs. This project aims at developing a new class of compounds for treatment purposes, to help patients recover from plutonium lung contamination.

Lungs preferentially retain radioactive contamination because they have specific cells, the alveolar macrophages, which capture and retain toxic elements that enter the lungs. We have thus developed new molecules that are able to bind (i.e., chelate) the plutonium atoms trapped in the alveolar macrophages. These chelating molecules are polymers made from amino-carboxylates. We have developed several forms of polymers, each consisting of a branched polyethylenimine bearing three chelate groups per monomer.

We performed a series of dose-response tests in vitro (tests for toxicological assessment), putting together different amounts of polymers with lung macrophages. Transmission Electronic Microscopy images of the tested macrophages revealed massive phagocytosis (capture) of the polymers by the macrophages. Other tests showed that the chelating polymers successfully bound actinides in vitro, and plutonium in particular. We are now in the process of developing a more complete biological test to analyze the ability of the new chelating polymers to capture actinides inside macrophages. Overall, these tests will be crucial to determine the abilities of the new chelating polymers to (i) penetrate the lung macrophages, (ii) form complexes with actinides, and (iii) escape the lung system to be eliminated by urinary excretion.

The +

The new chelating polymers we are developing might become an efficient alternative to the poorly operating treatments currently proposed by the pharmacopée.

What’s next?

Similar strategies could be applied to target other actinide entrapment sites such as in the liver or bones. This could be achieved by using specific polymers targeting the liver or bones cells. Also, the chelating polymers could be used for localized radiotherapy purposes. For example, these polymers could be loaded with low period radionuclides and injected into a tumor to deliver their radiations directly at the very right site. This high-precision targeting could allow lowering the overall dose imposed to the patient and so decreasing the undesired side effects related to the chemotherapy. Altogether these show the versatility of the new chelating compounds that could thus find applications to other scientific fields, and possibly lead to patents.

Project information

Scientific domain
Chemistry, physico-chemistry, biology
 
Theme
Radiochemistry
Key words
Radioactivity
Contamination
Human health
Actinides
Inhalation
Targeting polymers
Total budget
141 114 € including :
  • 44 374 € from Académie 3 ;
  • 47 620 € from Direction Générale de l’Armement ;
  • 49 120 € from ICN/CEA.
Students inolved
Jeanne Fèvre
Partner laboratories
Institut de Chimie de Nice (ICN), Université Côte d’Azur
Laboratoire de Radiotoxicologie, (LRT), CEA/DRF/iRCM
Direction Générale de l’Armement
Project members
Christophe Di Giorgio
Christophe Den Auwer
Anne Van der Meeren

portrait Christophe Di Giorgio
portrait Christophe Di Giorgio

Christophe Di Giorgio

Institut de Chimie de Nice (ICN), Université Côte d’Azur

Project valorization

Conference:

  • Fevre, F. Lahrouch, L. Leost, A.Van der Meeren, C. Den Auwer, C. Di Giorgio. SCF 19’ (Nice, France), Functionalized polymers and their interaction with thorium. A first step toward plutonium decontamination in case of inhalation, April 26th 2019.
logos partenaires PlutoPoly
logos partenaires PlutoPoly