Flexible PDMS microparticles to mimic RBCs in blood particulate analogue fluids

Abstract

Polydimethylsiloxane (PDMS) has a wide variety of commercial and industrial applications due to its mechanical and rheological properties in a range similar to the living tissues. In this study, we demonstrate that PDMS can be used to produce deformable microparticles to be integrated in the development of particulate blood analogue fluids. The difficulties associated with the use of in vitro blood make it necessary to perform in vitro experiments of blood flow with blood analogue fluids. However, an ideal analogue must match the rheology of blood at several points, and for that, blood analogue fluids should be a suspension of microparticles with similar properties (size, shape and flexibility) to blood cells, in particular to the red blood cells (RBCs). The microparticles used in this study were produced from a transparent PDMS with crosslinking ratios of 10:1, 8:2 and 6:4; from a black PDMS with a ratio of 1:1 and from a red-pigmented PDMS. Each PDMS microparticles sample was suspended in Dextran 40 to perform deformability assays and cell-free layer analysis in a hyperbolic-shaped microchannel and steady shear viscosity measurements in a rheometer. The proposed microparticles suspensions show a great potential to mimic the structural and rheological properties of RBC suspensions and consequently to develop blood analogue fluids with rheological properties similar to real blood.

Flexible Microfluidics: Fundamentals, Recent Developments, and Applications

“…Flexible PDMS microparticles have been designed for biomicrofluidics applications [186]. Flexible transparent PDMS microparticles were produced to mimic red blood cells to be later evaluated based on their flow behaviour [187].…”

The Effect of Oil Viscosity on Droplet Generation Rate and Droplet Size in a T-Junction Microfluidic Droplet Generator

“…In addition, the droplet-based microfluidics can provide encapsulation of a single cell within a droplet, which allows for high-throughput single cell screening and analysis capabilities [5,6]. The droplet-based microfluidic systems have been successfully utilized in a variety of applications, such as single cell analysis/screening [7][8][9], protein crystallization [10], polymer chain reaction (PCR) [11], drug discovery [12][13][14], and microorganism reactions [15,16] to name a few. For all of these applications, producing droplets with controlled sizes as well as at controlled generation rates are key factors to obtain consistent and robust results.…”

Visualization and Measurements of Blood Cells Flowing in Microfluidic Systems and Blood Rheology: A Personalized Medicine Perspective

“…Nevertheless, the use of rigid particles limits the physiological realism of these studies. To overcome this limitation, over the years, several researchers have investigated other alternatives such as, polydimethylsiloxane (PDMS) microparticles [ 93 , 94 , 95 ] and hydrogel microparticles [ 96 ]. An example of the suitability of PDMS microparticle was presented by Pinho et al, 2019 [ 95 ].…”

“…To overcome this limitation, over the years, several researchers have investigated other alternatives such as, polydimethylsiloxane (PDMS) microparticles [ 93 , 94 , 95 ] and hydrogel microparticles [ 96 ]. An example of the suitability of PDMS microparticle was presented by Pinho et al, 2019 [ 95 ]. They developed flexible PDMS microparticles to mimic RBCs in blood particulate analogue fluids and these showed a great potential to mimic the structural and rheological properties of RBCs suspensions and consequently to develop blood analogue fluids similar to real blood.…”

“… Behavior of healthy RBCs, flexible particles (PDMS) and rigid particles (PMMA) when flowing through a constriction in a microchannel. Adapted from [ 91 , 95 ]. …”