Nanoparticle recovery from incubation media following incubation in either PBS or 10 %vol FBS (equivalent to 2.7 mg/mL total protein content) in PBS in the absence and presence of flow, nanoparticle samples underwent three centrifugation-resuspension cycles to remove unbound proteins from the bulk incubation medium. Nanoparticle samples were centrifuged in a pre-chilled centrifuge (4 °C) at 20,000 x g for 30 minutes following each wash cycle. The supernatant was discarded, and the pellet re-suspended in PBS. The process was repeated in triplicate for all samples.