Rapid Evaluation of Novel Therapeutic Strategies Using a 3D Collagen-Based Tissue-Like Model

Differential effects of biocompatible peritoneal dialysis fluids on human mesothelial and endothelial cells in 2D and 3D phenotypes

INTRODUCTION

Peritoneal dialysis (PD) is a life maintaining treatment in patients with end-stage renal disease. Its chronic application leads to peritoneal mesothelial layer denudation and fibrotic transformation along with vascular activation of inflammatory pathways. The impact of different PD fluids (PDF) on mesothelial and endothelial cell function and repair mechanisms are not comprehensively described.

MATERIALS AND METHODS

Mesothelial (MeT-5A) and endothelial cells (EA.hy926) were cultured in 1:1 ratio with cell medium and different PDF (icodextrin-based, amino acid-based, and glucose-based). Cell adhesion, cell migration, and cell proliferation in 2D and spheroid formation and collagen gel contraction assays in 3D cell cultures were performed.

RESULTS

Cell proliferation and cell-mediated gel contraction were both significantly decreased in all conditions. 3D spheroid formation was significantly reduced with icodextrin and amino acid PDF, but unchanged with glucose PDF. Adhesion was significantly increased by amino acid PDF in mesothelial cells and decreased by icodextrin and amino acid PDF in endothelial cells. Migration capacity was significantly decreased in mesothelial cells by all three PDF, while endothelial cells remained unaffected.

CONCLUSIONS

In 3D phenotypes the effects of PDF are more uniform in both mesothelial and endothelial cells, mitigating spheroid formation and gel contraction. On the contrary, effects on 2D phenotypes are more uniform in the icodextrin and amino acid PDF as opposed to glucose ones and affect mesothelial cells more variably. 2D and 3D comparative assessments of PDF effects on the main peritoneal membrane cell barriers, the mesothelial and endothelial, could provide useful translational information for PD studies.

Clinical transfer of AGuIX®-based radiation treatments for locally advanced cervical cancer: MR quantification and in vitro insights in the NANOCOL clinical trial framework

Clinical trials incorporating metallic nanoparticles (NPs) have recently begun. Radiotherapy planning does not take into account NPs concentrations observed in the patients' target volumes. In the framework of the NANOCOL clinical trial including patients treated for locally advanced cervical cancers, this study proposes a complete method to evaluate the radiation-induced biological effects of NPs. For this, calibration phantom was developed and MRI sequences with variable flip angles were acquired. This process allowed the quantification of NPs in the tumor of 4 patients, which was compared to the results of mass spectrometry obtained from 3 patient biopsies. The concentration of the NPs was reproduced in 3D cell models. Based on clonogenic assays, the radio-enhancement effects were quantified for radiotherapy and brachytherapy, and the impact in terms of local control was evaluated. T₁ signal change in GTVs revealed NPs accumulation ~12.4 μmol/L, in agreement with mass spectrometry. Radio-enhancement effects of about 15 % at 2 Gy were found for both modalities, with a positive impact on local tumor control. Even if further follow-up of patients in this and subsequent clinical trials will be necessary to assess the reliability of this proof of concept, this study opens the way to the integration of a dose modulation factor to better take into account the impact of NPs in radiotherapy treatment.