Magnetophoresis in Red Blood Cell Separation: A Narrative Review of the Current Evidence

Abstract

Magnetophoresis is the study and application of magnetic forces to manipulate red blood cells (RBCs). Over the decades, magnetophoresis has evolved beyond its early experimental roots and is now recognised as a versatile platform with potential use in diagnostic, therapeutic, and research settings. Many past studies have delved into the applications of magnetophoresis, including in the context of RBCs but this information remains scattered. Many types of magnetophoresis-based devices have been designed to target varying RBCs for isolation with improvements in separation efficiency and clinical applications. This includes malaria, sickle cell disease, and even non-invasive prenatal diagnosis. Accordingly, RBCs’ magnetic susceptibility is dependent on the varying oxidative states. Furthermore, there is a shift of the magnetophoresis concept and application with optimisation of non-microfluidic devices and the rise in the use of microfluidic devices, which are more cost-effective and allow for higher throughput. Despite these advancements, many device concepts remain theoretical, and significant optimisation is still required before widespread clinical adoption can occur. Nevertheless, as physiological and clinical demands evolve, magnetophoresis is poised to become an increasingly relevant tool for RBC isolation and analysis. In this narrative review, we synthesise the physiologic, biophysical, engineering, and clinical foundations of magnetophoresis, spanning early developments to modern applications.