Nucleopore track etch membrane

Mixed small micelles were prepared by passing the assemblies formed by the above-described film hydration method through the membrane extrusion filter. Typically, 100 μL of PBD-b-PEO-b-DNA (DMSO, 4 μM) solution was mixed with 35 μL of PBD₄₆-b-PEO₃₀ solution (CHCl₃, 0.4 mg/mL) for mixed assemblies with 10 mol% DNA block copolymer content or with 38 μL of PBD₄₆-b-PEO₃₀ solution (CHCl₃, 0.04 mg/mL) for mixed assemblies with 50 mol% DNA block copolymer contents. For PS-b-PEO-b-DNA assemblies, 133 μL of PS-b-PEO-b-DNA (DMSO, 3 μM) solution was mixed with 35 μL of PS₄₈-b-PEO₄₆ solution (CHCl₃, 0.74 mg/mL) or 38 μL of PS₄₈-b-PEO₄₆ (CHCl₃, 0.074 mg/mL) solution for binary assemblies containing 10 mol% or 50% DNA block copolymers, respectively. The mixture was placed into a glass vial and the solvent was evaporated under vacuum for at least 6 h. Then, 100 μL of 0.1 M PBS buffer (100 mM NaCl, 10 mM phosphate buffer pH=7.17) was added to the polymer film in the vial. The solution was vortexed, frozen and thawed 5 times before the extrusion. Finally, the samples were extruded 38 times through Whatman Nucleopore tracketch membrane with the pore size of 400 nm.