Red blood cells (RBCs) are the most common type of blood cell, have a biconcave disk shape with diameter of 7-8 μm and thickness of 1-2 μm, and play the fundamental role of delivering oxygen to the body tissues via the blood flow through the circulatory system [1]. RBC deformability is an essential property in the microcirculation, where the cell change their disk-like shape into a deformed one, resembling a bullet or a parachute [1,3]. RBC deformability is mainly due to the viscoelastic properties of the cell membrane, especially shear modulus and surface viscosity [1]. In this work, we report on an in vitro systematic fluid dynamic investigation of RBC suspensions flowing either in microcapillaries or in a microcirculation-mimicking silicon device containing a network of microchannels of diameter comparable to cell size. The microfluidics device is made of PDMS and is fabricated by using soft-lithography techniques. Images of the flowing RBCs were acquired by a high speed camera operated up to 1,000 frames/s. RBC membrane rheological behavior is investigated by analyzing the transient behavior of RBC shape in confined flow and by measuring the membrane viscoelastic properties in converging/diverging microchannels [4]. The time scale of the transient process is independent on the applied pressure drop and the measured value for healthy cells (around 0.1 s) is in agreement with previous micropipette data from the literature [2]. In order to study the effect of reduced deformability of the RBC membrane, the flow behavior of glutaraldehyde (GA)-hardened RBCs has been also analyzed. Hardened RBCs exhibit a faster shape evolution at higher GA concentration, thus showing that the corresponding time scale becomes shorter at increasing cytoskeleton elasticity [5]. The main results of this work is the development of a novel methodology to estimate cell membrane viscoelastic properties. Possible applications include the analysis of RBC deformability in pathological situations, for which reliable quantitative methods are still lacking.
Microconfined Flow to measure Red Blood Cell Viscoelastic Properties / Tomaiuolo, Giovanna; L., Lanotte; Preziosi, Valentina; Caserta, Sergio; Cassinese, Antonio; C., Misbah; Guido, Stefano. - (2012). (Intervento presentato al convegno ICR 2012 – XVIth International Congress on Rheology tenutosi a Lisbon, Portugal nel August 5-10, 2012).
Microconfined Flow to measure Red Blood Cell Viscoelastic Properties
TOMAIUOLO, GIOVANNA;PREZIOSI, VALENTINA;CASERTA, Sergio;CASSINESE, ANTONIO;GUIDO, STEFANO
2012
Abstract
Red blood cells (RBCs) are the most common type of blood cell, have a biconcave disk shape with diameter of 7-8 μm and thickness of 1-2 μm, and play the fundamental role of delivering oxygen to the body tissues via the blood flow through the circulatory system [1]. RBC deformability is an essential property in the microcirculation, where the cell change their disk-like shape into a deformed one, resembling a bullet or a parachute [1,3]. RBC deformability is mainly due to the viscoelastic properties of the cell membrane, especially shear modulus and surface viscosity [1]. In this work, we report on an in vitro systematic fluid dynamic investigation of RBC suspensions flowing either in microcapillaries or in a microcirculation-mimicking silicon device containing a network of microchannels of diameter comparable to cell size. The microfluidics device is made of PDMS and is fabricated by using soft-lithography techniques. Images of the flowing RBCs were acquired by a high speed camera operated up to 1,000 frames/s. RBC membrane rheological behavior is investigated by analyzing the transient behavior of RBC shape in confined flow and by measuring the membrane viscoelastic properties in converging/diverging microchannels [4]. The time scale of the transient process is independent on the applied pressure drop and the measured value for healthy cells (around 0.1 s) is in agreement with previous micropipette data from the literature [2]. In order to study the effect of reduced deformability of the RBC membrane, the flow behavior of glutaraldehyde (GA)-hardened RBCs has been also analyzed. Hardened RBCs exhibit a faster shape evolution at higher GA concentration, thus showing that the corresponding time scale becomes shorter at increasing cytoskeleton elasticity [5]. The main results of this work is the development of a novel methodology to estimate cell membrane viscoelastic properties. Possible applications include the analysis of RBC deformability in pathological situations, for which reliable quantitative methods are still lacking.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
