Developing a label-free microfluidic strategy for downstream processing of stem cell-derived red blood cells

Abstract

Stem cell-originated therapeutic products, such as in vitro manufactured red blood cells (mRBC), offer a novel route to treating disease by administration of a viable somatic cells that have been selected and manipulated outside the body. Cell-based therapeutics are different to traditional biopharmaceutical products and that presents a challenge of developing robust and economically feasible manufacturing processes, especially in sample purification. To address this challenge, I investigated label-free separation methods based on cell endogenous properties such as size and deformability as sorting parameters. In this study the mechanical properties of umbilical cord blood CD34+ cells undergoing in vitro erythropoiesis were characterised to identifying the best route for mRBC purification. For the first time it has been demonstrated how deformability-induced lift force affects and contributes to particles separation in spiral microchannels. These findings were translated and incorporated into a new route for high-throughput (processing millions of cells /min and mls of medium/ min) continuous purification strategy for separating mRBC from contaminant by-products (purity >99%). This work is anticipated to bring the benefits of mRBC to a wide range of patients by enabling their manufacture as a reliable, safe and controlled supply of red blood cells for transfusion.