Red Blood Cell Responses during a Long-Standing Load in a Microfluidic Constriction

Mitsuhiro Horade,Makoto Kaneko,Hiroaki Ito,Chia-Hung Tsai

doi:10.3390/mi8040100

Abstract

Red blood cell responses during a long-standing load were experimentally investigated. With a high-speed camera and a high-speed actuator, we were able to manipulate cells staying inside a microfluidic constriction, and each cell was compressed due to the geometric constraints. During the load inside the constriction, the color of the cells was found to gradually darken, while the cell lengths became shorter and shorter. According to the analysis results of a 5 min load, the average increase of the cell darkness was 60.9 in 8-bit color resolution, and the average shrinkage of the cell length was 15% of the initial length. The same tendency was consistently observed from cell to cell. A correlation between the changes of the color and the length were established based on the experimental results. The changes are believed partially due to the viscoelastic properties of the cells that the cells’ configurations change with time for adapting to the confined space inside the constriction.

Highlights

There are established relationships between the deformability of red blood cells (RBCs) and human diseases, such as Malaria, Spherocytosis and Cryohydrocytosis [1–5]
While many works have focused on RBC deformability through short-duration compressions, such as transit time through a constriction or micro-slit [6–11], few works have focused on RBC characteristics after long-standing loads [12,13]
This work is motivated by the idea of investigating cell responses during a long-standing load using microfluidic constriction

Summary

Introduction

There are established relationships between the deformability of red blood cells (RBCs) and human diseases, such as Malaria, Spherocytosis and Cryohydrocytosis [1–5]. While many works have focused on RBC deformability through short-duration compressions, such as transit time through a constriction or micro-slit [6–11], few works have focused on RBC characteristics after long-standing loads [12,13]. RBC responses under a long-standing load reflect how a RBC changes while being plugged in microcirculation. This work is motivated by the idea of investigating cell responses during a long-standing load using microfluidic constriction. A target RBC is positioned in front of the narrow channel for recovering from prior deformation as the “Catching” phase. The RBC is moved into the constriction channel for compression as the “Loading” phase. The RBC is maintained inside the constriction for a specified duration as the long-standing load, and a camera is set for observing the responses of the cell during the load

Methods

Results

Conclusion