title: Drag-reducing polymers diminish near-wall concentration of platelets in microchannel blood flow.
abstract: The accumulation of platelets near the blood vessel wall or artificial surface is an important factor in the cascade of events responsible for coagulation and/or thrombosis. In small blood vessels and flow channels this phenomenon has been attributed to the blood phase separation that creates a red blood cell (RBC)-poor layer near the wall. We hypothesized that blood soluble drag-reducing polymers (DRP), which were previously shown to lessen the near-wall RBC depletion layer in small channels, may consequently reduce the near-wall platelet excess. This study investigated the effects of DRP on the lateral distribution of platelet-sized fluorescent particles (diam. = 2 μm, 2.5 × 10⁸/ml) in a glass square microchannel (width and depth = 100 μm). RBC suspensions in PBS were mixed with particles and driven through the microchannel at flow rates of 6-18 ml/h with and without added DRP (10 ppm of PEO, MW = 4500 kDa). Microscopic flow visualization revealed an elevated concentration of particles in the near-wall region for the control samples at all tested flow rates (between 2.4 ± 0.8 times at 6 ml/h and 3.3 ± 0.3 times at 18 ml/h). The addition of a minute concentration of DRP virtually eliminated the near-wall particle excess, effectively resulting in their even distribution across the channel, suggesting a potentially significant role of DRP in managing and mitigating thrombosis.
authors.affiliation: McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Zhao
authors.forename: J N
authors.initials: JN
authors.lastname: Marhefka
authors.forename: J F
authors.initials: JF
authors.lastname: Antaki
authors.forename: M V
authors.initials: MV
authors.lastname: Kameneva
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D001775:Blood Circulation / Q000187:drug effects*; D001792:Blood Platelets / Q000187:drug effects*; D002417:Cattle; D004912:Erythrocytes / Q000187:drug effects; D007091:Image Processing, Computer-Assisted; D044085:Microfluidics / Q000379:methods*; D010316:Particle Size; D011108:Polymers / Q000494:pharmacology*
chemical_list: D011108:Polymers