Clearance of ESKAPE Pathogens from Blood Using Bacterially Activated Macrophage Membrane-Coated Silicon Nanowires

Extracorporeal devices to cleanse blood from infecting bacteria are based upon bacterial capture to surfaces, but the current generation of capture devices has variable and inconclusive therapeutic efficacy. Here, a microfluidic device equipped with a Si capture surface with a highly periodic nanowired structure is designed. Nanowired Si surfaces are coated with macrophage membranes to benefit from the natural blood compatibility and ligand-receptor binding of macrophages. When macrophages are activated by uptake of Staphylococcus aureus or Escherichia coli, zeta potentials of activated macrophage membrane coatings become less negative than those of nonactivated ones, stimulating nonspecific bacterial capture. In addition, Toll-like receptors in bacterially activated membrane coatings on nanowired surfaces that are absent in nonactivated membrane coatings contribute to specific bacterial capture. These two factors, together with the maintenance of fluidity in activated membrane coatings, cause broad spectrum, high capture efficiencies of all six ESKAPE member pathogens, considered most threatening to human health. Surfaces with such broad-spectrum capture efficiencies have not been previously described, but are clinically most relevant because blood cleansing should start as soon as possible after a septic patient becomes symptomatic, when the causative bacterial strain is still unknown.