Thèses

Mardi 21 Septembre 2021 à 10h00.

Multicellular Tumour Spheroid (MCTS) model for evaluation of the efficiency of nanoparticle drug delivery

''Developing a standard 3D in vitro model for screening nanotherapeutics remains challenging. Several 3D tumor culture models have been developed, multicellular tumor spheroids among them are gaining popularity due to their ability to mimic some of the characteristics of natural tumors. Spheroids can be made in a variety of ways, but traditional methods have several drawbacks. In this study, agarose-based microwells were used for generation of uniform multicellular tumor spheroids of a colorectal cancer line (HCT-116). According to the findings of this project, the penetration of AGuIX®- Cy5.5 nanoparticles within spheroids is time and concentration dependent. While nanoparticles were observed in both extracellular and intracellular space of spheroids, the dominant intracellular localization of AGuIX®- Cy5.5 nanoparticles was in lysosomes; early endosomes and mitochondria, on the other hand, showed some colocalization with AGuIX®. When the localization of AGuIX®- Cy5.5 nanoparticles in spheroids and 2D cell culture was compared, the difference in nanoparticle localization in 2D and 3D highlighted the advantages of using this 3D in vitro model for nanotherapeutics screening because of its ability to recapitulate tumor features influencing nanoparticle internalization and intracellular fate.
The developed 3D in vitro model has been shown to be beneficial in therapy assessment associated with radiotherapy, as cells in spheroids (3D) showed higher radioresistance than monolayer cells(2D), indicating that this 3D in vitro model can be used to assess therapeutic efficacy of nanotherapeutics in a more realistic set up. Growth monitoring of irradiated HCT-116 spheroids revealed their ability to grow for all doses 6 days after irradiation, in contrast to the classical clonogenic survival assay, which revealed they were unable to form colonies at higher doses greater. The best radiosensitizing effect of AGuIX® was observed at 2 Gy irradiation, according to single cell proliferation analysis in spheroids.

Directeur de thèse / thesis director:
Charlotte Rivière et François Lux

Membres du jury / members of the jury:
Mme BARBERI-HEYOB Muriel, Rapportrice
Mme WILHELM Claire, Rapportrice
M. MERTANI Hichem, Examinateur
Mme ROLS Marie-Pierre, Examinatrice

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