Influence of erythrocyte aggregation at pathological levels on cell-free marginal layer in a narrow circular tube

Article type: Research Article

Authors: Namgung, Bumseok^a | Sakai, Hiromi^b | Kim, Sangho^{a; *}

Affiliations: [a] Department of Biomedical Engineering and Department of Surgery, National University of Singapore, Singapore | [b] Department of Chemistry, School of Medicine, Nara Medical University, Nara, Japan

Correspondence: [*] Corresponding author: Sangho Kim, PhD, Department of Biomedical Engineering, National University of Singapore 9 Engineering Drive 1, Block EA #03-12 Singapore 117575. Tel.: +65 6516 6713; Fax: +65 6872 3069; E-mail: bieks@nus.edu.sg.

Abstract: Human red blood cells (RBCs) were perfused in a circular micro-tube (inner diameter of 25 μm) to examine the dynamic changes of cell-free marginal region at both physiological (normal) and pathophysiological (hyper) levels of RBC aggregation. The cell-free area (CFA) was measured to provide additional information on the cell-free layer (CFL) width changes in space and time domains. A prominent enhancement in the mean CFL width was found in hyper-aggregating conditions as compared to that in non-aggregating conditions (P <  0.001). The frequent contacts between RBC and the tube wall were observed and the contact frequency was greatly decreased when the aggregation level was increased from none to normal (P <  0.05) and to hyper (P <  0.001) levels. In addition, the enhanced aggregation from none to hyper levels significantly enlarged the CFA (P <  0.01). We concluded that the RBC aggregation at pathophysiological levels could promote not only the CFL width (one-dimensional parameter) but also the spatiotemporal variation of CFA (two-dimensional parameter).

Keywords: Plasma layer, red blood cell, hemodynamic, microcirculation

DOI: 10.3233/CH-141909

Journal: Clinical Hemorheology and Microcirculation, vol. 61, no. 3, pp. 445-457, 2015