226. Microfluidic platform to restore the angiogenic balance in preeclampsia

Abstract

Introduction Preeclampsia is a hypertensive disorder of pregnancy linked to placenta insufficiency. Clinical studies have shown that the severity of preeclampsia is associated with the excess or the lack of angiogenic factors such as the sFlt-1/PlGF ratio (soluble Fms-like tyrosine kinase 1 and placental growth factor). Objectives Our objective is to readjust the angiogenic balance of factors that play a causative role in preeclampsia by a competitive bioassay. A specific ligand, here VEGF (Vascular Endothelial Growth Factor), is used to both capture the protein sFlt-1 in excess and release its ligand PlGF in default. Method A microfluidic extra corporal technology of micro-fluidized bed was developed to be used as a platform to screen strategies of competitive bioassay. This fluidic configuration enhances transfer between a fluid and the surface of the beads, with low back pressure and reduced risks of clogging. By grafting specific ligands on the surface of the beads, we can use this asset to capture a target present in the sample. Results This device was able to capture sFlt-1 (up to 46% ± 1 of capture) in culture supernatant and maternal plasma. We demonstrate more importantly that compared to classical apheresis columns the nonspecific absorption is completely controlled ( Discussion Continuous flow analysis enables to reach a good capture efficiency of sFlt-1. This dynamic platform mimics an extracorporeal circulation device at high flow rate, low cost and needs small volumes of sample. This last property enables us to work with precious samples such as maternal pathologic plasma.