Optimization of continuous micromagnetic separation for the treatment of Acinetobacter baumannii bacteremia

Abstract

With the rapid emergence of antibiotic-resistant bacteria and the lack of antibiotics in the development pipeline, bacteremia and sepsis are becoming an increasing health concern. Rapid diagnosis currently suffers from the need for the amplification of the bacterial signal, which is often only accomplished by overnight blood culture. Without a proper diagnosis, effective treatment may not be administered, resulting in increased mortality. Extracorporeal bacterial separation methods remove bacteria from whole blood, making them a promising avenue for both diagnosis and treatment. Specifically, micromagnetic separation removes bacteria bound to paramagnetic beads using a strong magnetic field. A small-footprint microfluidic device for micromagnetic separation was fabricated and characterized by volumetric flow testing and computational fluid dynamics. The framework for a computational analysis of micromagnetic separation was also developed, incorporating a magnetostatic finite element analysis of the device and a physiologically-based pharmacokinetic model of bacteremia. Small-footprint microfluidic devices were shown to be able to capture bacteria, but at rates and with overall capacities inadequate as an effective treatment for bacteremia. As such, these devices could be considered as means of rapid diagnosis; the development of high-throughput extracorporeal blood-cleansing devices is required for bacteremia treatment.