Affiliations: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA | Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA | McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
Note: [] Address for correspondence: James F. Antaki, PhD, Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA. Tel.: 412 802 6431; Fax: 412 802 7813; E-mail: [email protected]
Abstract: Thrombosis is a common complication following the surgical implantation of blood contacting artificial organs. Platelet transport, which is an important process of thrombosis and strongly modulated by flow dynamics, has not been investigated under the shear stress level associated with these devices, which may range from tens to several hundred Pascal. The current research investigated platelet transport within blood under supra-physiological shear stress conditions through a micro flow visualization approach. Images of platelet-sized fluorescent particles in the blood flow were recorded within microchannels (2 cm × 100 μm × 100 μm). The results successfully demonstrated the occurrence of platelet-sized particle margination under shear stresses up to 193 Pa, revealing a platelet near-wall excess up to 8.7 near the wall (within 15 μm) at the highest shear stress. The concentration of red blood cells was found to influence the stream-wise development of platelet margination which was clearly observed in the 20% Ht sample but not the 40% Ht sample. Shear stress had a less dramatic effect on the margination phenomenon than did hematocrit. The results imply that cell–cell collision is an important factor for platelet transport under supra-physiologic shear stress conditions. It is anticipated that these results will contribute to the future design and optimization of artificial organs.
