A microparticle blood analogue suspension matching blood rheology

The handling of blood in vitro is demanding because of ethical, economical and safety issues. Although several Newtonian and non-Newtonian blood analogues are found in the literature, few studies have used particles to mimic red blood cells (RBCs) and built an analogue with similar rheological properties of blood. This work reports the development of a blood analogue suspension composed of polydimethylsiloxane (PDMS) microparticles with an average diameter of B7 mm. High throughput production of PDMS particles is possible using a multi-stage membrane emulsification process; up to B6 mL of microparticles are manufactured in 3 hours. PDMS particles at a concentration of around 21% (w/w) at 20 1C present steady, oscillatory and extensional rheologies very similar to those of blood under physiological conditions (37 1C and B41% hematocrit), making them a good candidate whole blood analogue. Also, flow studies were performed in microchannels with contraction to study the cell-free layer (CFL) formation and particle deformation, achieving good qualitative results. Using the procedure developed, it is possible to obtain blood analogue fluids with a shelf life of at least 6 months.This work was funded by FEDER funds through COMPETE2020—Operational Programme for Competitiveness Factors (POCI) and National Funds (PIDDAC) through FCT (Fundação para a Ciência e a Tecnologia) under projects UID/EMS/00532/ 2020, POCI-01-0145-FEDER-016861-PTDC/QEQ-FTT/4287/2014 and grant PD/BD/114313/2016. We would like to thank Prof. Gareth McKinley and Prof. Randy Ewoldt for providing us with the MITlaos software