Channeled fibers in separation of biologically active nanoparticles

A method for separating biologically active nanoparticles from a mixture comprising:

• flowing a mobile phase through a fluid conduit, the mobile phase including a sulfate salt at a first concentration, the sulfate salt is ammonium sulfate or sodium sulfate, the fluid conduit containing a polymeric stationary phase that defines a plurality of passages through the fluid conduit, the passages defining a cross sectional dimension of from about 1 micrometer to about 4 micrometers, the polymeric stationary phase comprises a polymer, wherein the polymer is selected from the group consisting of polyvinyl alcohol, nylon, polysulfone, polymethyl methacrylate, polyethylene terephthalate, polyepoxies, polvinylidone chloride, acrylonitrile butadiene styrene, polycarbonate, and polyvinyl chloride, and wherein the polymeric stationary phase having a critical surface tension of about 35 mJ/m2 or greater and a water contact angle of about 85° or less;
• combining a mixture with the mobile phase, the mixture comprising biologically active nanoparticles, free proteins, and other matrix species, the biologically active nanoparticles comprising an envelope that includes a lipid bilayer, wherein upon the combination and at the first concentration of the sulfate salt, the biologically active nanoparticles and the free proteins adsorb or bind to the surface of the stationary phase as the mobile phase flows though the fluid conduit;
• adding an organic modifier or a surfactant to the mobile phase following the adsorption or binding of the biologically active nanoparticles and the free proteins;
• decreasing the first concentration of the sulfate salt in the mobile phase to a second concentration of the sulfate salt following the addition of the organic modifier or surfactant, at which second concentration the free proteins elute off of the surface of the stationary phase and the biologically active nanoparticles remain adsorbed or bound to the surface of the stationary phase;
• and
• further decreasing the second concentration of the sulfate salt in the mobile phase to a third concentration of the sulfate salt, at which third concentration the biologically active nanoparticles elute off of the surface of the stationary phase.