Toward a microfluidic model to understand pathological renal microcalcifications

Axe 1 - Biomineralisation

Post-doctorat de Guillaume Laffite

Poste actuel : ---

Laboratoires co-porteurs

• Chimie de la Matière Condensée de Paris
  Porteur de projet : Dominique Bazin
  Co-encadrants : Laure Bonhomme, Christian Bonhomme
• Physicochimie des Electrolytes et Nanosystèmes interfaciaux (ancien PECSA)
  Co-encadrant : Ali Abou-Hassan
• Hôpital Thenon
  Co-encadrant : Emmanuel Letavernier, Michel Daudon, jean-Philippe Haymann

Présentation

Recent epidemiological studies have suggested an increased frequency of kidney stone disease in all age groups during the last decades affecting about up to 5% of the industrialized population. Microfluidic technology offers valuable potentialities to understand more deeply the pathogenesis of calcium oxalate crystals precipitation. Inside a microchannel, the conditions of mixing are representative of the biological fluids flows and exchanges inside the nephron microtubules (laminar flux).

In partnership with nephrologists from Tenon’s hospital, we have developed a microfluidic device dedicated to the synthesis of CaOx crystals. On a biochemical point of view, role of biological fluids, growth inhibitors (citrate ions), thermal effect and pH have been investigated. We will also investigate the influence of calcium-phosphate spherules present on organic matrix (collagen I) as an initiator site for calcium-oxalate crystals growth in order to mimic ectopic microcalcifications (Randall’s Plaques).

Résultats

Based on the two-laminar flow technic, the team used an elastomeric based microfluidic technology devoted to the precipitation of calcium-oxalate crystals. The device is composed of a “Y-shaped” microchannel in which both calcium and oxalate ions are injected. We demonstrate the potentialities of the method by studying the morphology (FE-SEM) and the chemistry (μATR-FTIR, μDRX) of the crystallites obtained on the microchannel surface in different concentration ratio conditions (case of hypercalciuria).

Publication

• G. Laffite, C. Leroy, C. Bonhomme, Laure Bonhomme-Coury, Letavernier Emmanuel et al.
  Calcium oxalate precipitation by diffusion using laminar microfluidics: toward a biomimetic model of pathological microcalcifications
  Lab on a Chip, Royal Society of Chemistry, 2016, 16 (7), pp.1157-1160.
  Doi : 10.1039/C6LC00197A
  Ref Hal : hal-01288757v1