Microfluidic capture of selected biomolecules with functionalized particles. Design under a numerical approach

The outstanding capabilities of S/L functionalized particulate systems synergized with microfluidics offer great opportunities to address current and significant challenges, as the selective capture of biomolecules from a liquid phase, a process highly reliant on the intimate contact between both phases. In this work, we report the numerical prediction of the selective sequestration of a target biomolecule present in an aqueous solution onto engineered solid capture agents. For this purpose, a customized Eulerian/Eulerian/Lagrangian model able to track all the phases involved in the system and account for the S/L interfacial mass transfer has been developed. The challenging capture of endotoxins (LPS), sepsis causing agents, by solid beads decorated with engineered binding proteins has been selected as motivating case study. The computational tool has been successfully validated using batch data previously reported by our research group with capture deviations inferior to 5 %. Furthermore, we advance the design of microdevices to continuously withdraw LPS from biofluids and promote those variables with influence on the rate of the interfacial mass transfer. The design procedure has rendered a coil inspired T-type microreactor that displays an exceptional performance. This device can treat 1.4 L per hour of a sample containing 1 mg·mL⁻¹ LPS, attain the fluids complete mixing in less than 5 s, a uniform particle distribution and reach the LPS capture equilibrium in less than 15 s. Thus, to the best of our knowledge, we report herein for the first time the design of advanced microdevices for toxin removal assisted by a Euler/Euler/Lagrange model.