Figure 3.

Red blood cell adhesion to endothelial cells. (A) Microfluidic model diagram. Human umbilical endothelial cells (HUVEC) were perfused for 16-40 hours (h) with culture medium in microslides coated with fibronectin (step 1), then perfused for 4 h at 1 dyn/cm² with red blood cells (RBC) from normoxic or hypoxic bags, diluted at 25% in compatible serum (from healthy donor, HD) and with the addition (or not) of 10% hemolysate (step 2). After the conditioning step (step 2), HUVEC were washed with culture medium and perfused with whole blood from sickle cell disease (SCD) patients at 1 dyn/cm² for 10 minutes before a second wash with culture medium to assess RBC adhesion to endothelial cells. All steps (except washes) were performed at 37°C. (B and C) Adhesion of RBC from steady state SCD patients to HUVEC perfused for 4 h with normoxic or hypoxic RBC sampled on day 0, 21 and 42 of storage, diluted at 25% in HD serum and with (B) 10% hemolysate or (C) 0% hemolysate. Adherent RBC were quantified on a light microscope. Mean +/- standard error of the mean of 6 independent experiments, *storage method effect. #interaction time/storage method. •Comparison between hypoxic and normoxic storage at one time point. ns: not significant.