Channeled fibers in separation of biologically active nanoparticles

A method for separating biologically active nanoparticles from a mixture wherein the biologically active nanoparticles comprise an encapsulated envelop that includes a lipid bilayer, the method comprising:

• flowing a mobile phase through a fluid conduit having a first end and second end that is disposed opposite the first end, the mobile phase including a sulfate salt at a first concentration wherein the sulfate salt is ammonium sulfate or sodium sulfate, the fluid conduit containing a solid phase, the solid phase defining 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 solid phase having a surface that is non-porous to nanoparticles and that has a critical surface tension of about 35 mJ/m2 or greater and a water contact angle of about 85° or less, the surface comprising a polyethylene terephthalate;
• combining a mixture with the mobile phase, the mixture comprising the biologically active nanoparticles, free proteins and other matrix species, and allowing the biologically active nanoparticles and the free proteins to adsorb or bind to the surface of the solid phase as the mobile phase flows through the fluid conduit;
• wherein the first sulfate salt concentration is selected such that it allows adsorbing or binding of the biologically active nanoparticles and free proteins to the surface of the solid phase;
• adding an organic modifier or a surfactant to the mobile phase following the adsorption or binding of the biologically active nanoparticles and the proteins;
• decreasing the first sulfate salt concentration in the mobile phase to a second sulfate salt concentration following the addition of the organic modifier or surfactant, at which concentration the free proteins elute off of the surface of the solid phase, but the biologically active nanoparticles remaining adsorbed or bound to the surface of the solid phase at the second sulfate salt concentration;
• and
• further decreasing the second sulfate salt concentration to a third sulfate salt concentration, at which concentration the biologically active nanoparticles elute off of the surface of the solid phase.